[Elenco soci]

Leali Francesco

Professore Ordinario

Università degli Studi di Modena e Reggio Emilia

Sito istituzionale
SCOPUS ID: 12345355900
Orcid: 0000-0001-6621-5379

Pubblicazioni scientifiche

[1] Dalpadulo E., Pini F., Leali F., Directed Energy Deposition Process Simulation to Sustain Design for Additive Remanufacturing Approaches, Lecture Notes in Mechanical Engineering, 1067-1078, (2023). Abstract

Abstract: Additive Manufacturing processes based on metal deposition are continuously evolving due to the extensive application potentials. Currently, they present a widespread use in manufacturing of large parts and constructions, as well as reparation of damaged components. A promising application is the Remanufacturing of existing components to produce functional design variants. A key phase for its development is the study and control of residual stress and deformations induced by the process. In fact, thermal gradients and cooling rates are more intensive than those related to the other metal additive manufacturing processes and their effect impacts on functional and assembly product requirements. This work provides the study of a laser-based Direct Metal Deposition process, supported by numerical simulation and experimental validation. The aim is to set up a framework for reliable simulations to drive the design of high performance components, which are optimized with respect to both product and process requirements. Process planning and deposition strategies highly affect heat dissipation and thermal cycles, thus, predictive techniques can be embedded in integrated product-process design approaches to avoid flaws and contain components shrinkage and deformation. The process is developed by building specific specimens, performing thermo-mechanical simulations, and comparing 3D capturing result and computed result. The simulation phase can thus be considered as a key step to structure a Design for Additive Remanufacturing workflow. Further developments concern the application of such approaches to the design of high performance components to be produced by Directed Energy Deposition process.

Keywords: Direct metal deposition | Distortion | Finite element analysis | Metal additive manufacturing | Process simulation

[2] Tamassia E., Pini F., Grunwald T., Bergs T., Leali F., Surface Grinding of Borosilicate Crown Glass Optics via a Robotic Approach Based on Superposed Trajectories, Lecture Notes in Mechanical Engineering, 354-366, (2023). Abstract

Abstract: The production of large-sized optical components with complex shapes requires several phases, including surface finishing. Currently, mainly skilled workers can correctly perform this operation, divided into the successive steps of grinding and polishing, leading to long production times, poor reproducibility of results, and exposure to human error. For this reason, the industry is trying to move towards automation involving, for example, high-precision machine tools and machining centers. However, these solutions require high investment costs and long setup times. Using robotic cells helps to reduce these expenses, manufacture larger components, and increase the flexibility in the production chain. In this research, we present an unconventional approach to the robot-assisted grinding of optical samples made of borosilicate crown glass. The samples were guided by a six-degree-of-freedom industrial robot on a rotating grinding disc while imposing to them different trajectories with complex geometry. We avoided regular grinding patterns, which are easily recognizable by human eyes and affect the quality assessment, by superposing multiple relative movements between the machined surface and the abrasive grains. The ground surfaces of the samples were characterized based on average roughness values, profile error data, and surface topography images. Finally, we selected the best robotic grinding procedure matching the trajectory and strategy with optimal surface quality, processing time, and productivity. The suggested methodology not only shortens the manufacturing sequence by eliminating manual methods but also provides components with optical properties within the required specifications for subsequent polishing steps.

Keywords: Borosilicate crown glass | Industrial robot | Superposed trajectories | Surface grinding | Surface quality

[3] Petruccioli A., Pini F., Leali F., Interoperability Framework for a Computer-Aided Approach of Tolerance-Cost Optimization, Lecture Notes in Mechanical Engineering, 839-850, (2023). Abstract

Abstract: The tolerance-cost optimization plays a central role in the design of industrial components, due to its implications in all production stages. To reduce development times and increase product quality, the systematic application of tolerance-cost optimization from the early design phases requires a deep knowledge of the tolerance effects on both product performance and production cost. However, many factors still hamper its industrial diffusion, comprising three improvement areas: data and parameters sharing, flexibility to application complexity, and integration of simulation tools. Data and parameters sharing are a key factor since directly affect the representation and information transfer of tolerances and manufacturing processes. Both tolerances-cost relations and optimization structure must be properly represented, through a knowledge modelling framework. The present paper introduces an interoperability framework for the Computer-Aided tolerance-cost optimization. Through creating instances for tolerance and manufacturing process information, the interoperability is implemented defining a systematic sequence of steps to breakdown the multi-disciplinary optimization structure. Starting from the assembly structure, with the extraction of information from the 3D models to its transfer for parametric modelling into tolerance simulation and cost estimation environments, the interoperability framework identifies input-output relations and highlights the integration provided by multi-disciplinary optimization structure. The application of the presented framework on an archetypal case study provides an analysis of the suitability of the method, highlighting the further improvements. In this way it is possible to improve the interoperability between design and simulation virtual environments, to optimize tolerances in a concurrent a multi-disciplinary manner.

Keywords: Cost estimation | Model based definition | Multi-disciplinary optimization | Tolerance design | Tolerance-cost optimization

[4] Renzi C., Leali F., User-Centered Design for Manufacturing and Assembly: An Application in the Early Design Stages, Lecture Notes in Mechanical Engineering, 217-228, (2023). Abstract

Abstract: In product design fields where the demand for an efficient usability is critical to its final success, it is essential to integrate user requirements into the design process from the earliest design stages. Particularly in the medical context, it is essential to systematically control the design phases in order not to neglect the strict constraints related to engineering design quality, safety, and usability requirements for the end user. Hence, in this work, an integrated user-centered product design and process simulation method is proposed. This method is aimed at enriching the state of the art in integrated product design and process simulation in the early design stages, as well as providing a novel design example of a device thought for medical contexts. The case study consists in the design of an intercom, aimed at improving patient-doctor communication in the case of bedridden patients on with helmet for Continuous Positive Airway Pressure (CPAP) therapy during COVID-19 pandemic emergency. Patients undergoing helmet-assisted ventilation are often immersed in a highly noisy environment, unable to fully communicate their needs to the doctors. Intercom devices are addressed to the doctors for improving ease communication with the patient. The proposed user-centered design for manufacturing and assembly proved to be efficient in such a complex design context.

Keywords: Integrated product and process design method | Process simulation | User-centered design

[5] Caramaschi M., Onfiani D., Pini F., Biagiotti L., Leali F., Workspace Placement of Motion Trajectories by Manipulability Index for Optimal Design of Cobot Assisted Rehabilitation Solutions, Computer-Aided Design and Applications, 20(S6), 1-12, (2023). Abstract

Abstract: Nowadays the rehabilitation process involves the patient and the therapist, that must interact to recover the motion of limbs and the strength of related muscles to restore the initial functionalities. The therapy relies on the experience and sensitivity of the therapist that identifies the rehabilitation exercises which are necessary to recover the expected ability. To prevent inappropriate practices an interesting aid may come by mixing collaborative robots, namely Cobots, and additive manufacturing technologies. The proper integration of a Cobot assistant and custom-printed training objects enables a significant improvement in the effectiveness of the therapy action and the related user experience since the programmed trajectories can mimic the movements related to activities of daily living. To this aim, this work describes an integrated approach to support the design of Cobot assisted rehabilitative solutions. The object selected by the patient and therapist, the motion pattern, the clamping area, and loads on the limb represents the design requirements. The motion trajectories defining the specific training tasks are the starting point to the optimal placement within the Cobot workspace. Specifically, manipulability maps can provide an objective evaluation of the locations where the exercises are performed at the best of workspace and configuration of the Cobot. A simple upper limb rehabilitation exercise based on a demonstrative handle has been selected to prove the effectiveness of the proposed approach. The results confirm that the manipulability index can be adopted to drive the preliminary design of the Cobotic solution toward a feasible configuration.

Keywords: Assisted Rehabilitation | Cobot | Integrated Design | Manipulability Index | Occupational Therapy

[6] Caramaschi M., Onfiani D., Pini F., Biagiotti L., Leali F., Workspace Placement of Motion Trajectories by Manipulability Index for Optimal Design of Cobot Assisted Rehabilitation Solutions, Computer-Aided Design and Applications, 20(S6), 1-12, (2023). Abstract

Abstract: Nowadays the rehabilitation process involves the patient and the therapist, that must interact to recover the motion of limbs and the strength of related muscles to restore the initial functionalities. The therapy relies on the experience and sensitivity of the therapist that identifies the rehabilitation exercises which are necessary to recover the expected ability. To prevent inappropriate practices an interesting aid may come by mixing collaborative robots, namely Cobots, and additive manufacturing technologies. The proper integration of a Cobot assistant and custom-printed training objects enables a significant improvement in the effectiveness of the therapy action and the related user experience since the programmed trajectories can mimic the movements related to activities of daily living. To this aim, this work describes an integrated approach to support the design of Cobot assisted rehabilitative solutions. The object selected by the patient and therapist, the motion pattern, the clamping area, and loads on the limb represents the design requirements. The motion trajectories defining the specific training tasks are the starting point to the optimal placement within the Cobot workspace. Specifically, manipulability maps can provide an objective evaluation of the locations where the exercises are performed at the best of workspace and configuration of the Cobot. A simple upper limb rehabilitation exercise based on a demonstrative handle has been selected to prove the effectiveness of the proposed approach. The results confirm that the manipulability index can be adopted to drive the preliminary design of the Cobotic solution toward a feasible configuration.

Keywords: Assisted Rehabilitation | Cobot | Integrated Design | Manipulability Index | Occupational Therapy

[7] Petruccioli A., Gherardini F., Leali F., Correction to: Assessment of close-range photogrammetry for the low cost development of 3D models of car bodywork components (International Journal on Interactive Design and Manufacturing (IJIDeM), (2022), 16, 2, (703-713), 10.1007/s12008-022-00865-6), International Journal on Interactive Design and Manufacturing, 16(2), 715-716, (2022). Abstract

Abstract: Authorswould like to correct Figure 1 and Image credits with the updated version. The corrected version of Figure 1 and Image credits updated here. The original article has been corrected.

[8] Petruccioli A., Gherardini F., Leali F., Assessment of close-range photogrammetry for the low cost development of 3D models of car bodywork components, International Journal on Interactive Design and Manufacturing, 16(2), 703-713, (2022). Abstract

Abstract: Close-range photogrammetry (C-RP) is a widespread and efficient technology to obtain digital models of physical objects. Typical limitations as sharped geometry, shiny surface finishing and light conditions can be overcome by using high-end equipment, which results in increased costs and requires specific skills in human operators. This paper aims to investigate whether a low-cost and simplified approach to C-RP makes it suitable for the 3D acquisition of bodywork components and similar free-form artefacts, as an affordable alternative to 3D scanning in fields where a lower value of accuracy is required. Hence, two commercial C-RP software were used to 3D capture handcrafted car body panels and compare the C-RP models using a 3D scan as a reference within an inspection software. Two case studies are considered: a 1:5 scale model of the front bonnet of a Ferrari 250 Testa Rossa from 1958 and a head lamp housing of a Ferrari 275 GTB from 1962. Considering the complexity of double curvature surfaces and the reflection due to material and surface treatment, both these artefacts require some pre-processing operations and an adequate set-up to perform image acquisition. These case studies represent a relevant application for the field of classic vehicle restoration, where C-RP could be a promising technique to support panel beaters and craftsmen during rebuilt operations of masks and bodywork spare parts of high-end historic cars.

Keywords: 3D capturing | 3D digital model | car body panel | Classic vehicle restoration | Close-range photogrammetry | Geometric inspection

[9] Vergnano A., Salvati E., Magistrelli A., Brambilla E., Veronesi P., Leali F., A method for yield and cycle time improvements in Al alloy casting with enhanced conductivity steel for die construction, Manufacturing Review, 9, (2022). Abstract

Abstract: A die for Al alloy casting must be designed to achieve the expected quality levels. Moreover, the casting unit cost must be regarded as the objective function to be minimised. It can be expressed as a function of the quantity of materials and energy to be used, cycle time and equipment investment. This work compares the performance of the die with inserts manufactured using the usual 1.2343 steel with that of the innovative 1.2383. The latter is considered due to its enhanced thermal conductivity, despite being more expensive. Simulation experiments are designed to evaluate different die layouts. The quality design solutions are evaluated against the cost objective function in order to identify the optimal die choice. A case study on gravity die casting (GDC) of an AlSi7Mg0.3 engine head shows faster solidification dynamics when using 1.2383 instead of 1.2343 steel. This reduces the feeder volume, thus increasing the production yield and speeding up the cycle time with a leverage effect. The higher investment cost for the inserts is rapidly returned thanks to the reduction in variable costs. The Return On Investment (ROI) with the improved die in the new solution is short compared with the life of the die.

Keywords: Cost optimisation | Cycle time | Gravity die casting | Material selection | Process yield | Steel conductivity

[10] Renzi C., Leali F., An Integrated Modular Design and Group Decision-Making Method in Complex Design Environments, Lecture Notes in Mechanical Engineering, 581-592, (2022). Abstract

Abstract: This paper deals with the design of novel products, conceived in a complex design environment, under strict constraints and several disciplines involved in. As an application, the design of micro-bioreactors for tissue-engineering is proposed. To date, in-vitro two-dimensional (2D) culture systems have been widely used to study the mechanisms underlying cell biology. However, 3D culture systems and platforms have showed to better mimic the real tissue environment. The design of a 3D culture system of bioreactor is challenging due to several criteria derived from several disciplines, as biotechnology, engineering, and manufacturing. To this aim, a two-step integrated modular design and group multi-criteria decision-making method is proposed. In step one, a functional analysis is carried out, first, to point out the interfaces between parts and the function of each part in the assembly. Generated design alternatives have been selected by means of a group Fuzzy-TOPSIS technique, in step two. The proposed integrated design method has shown efficient in the early stages of design of novel products in complex design environments.

Keywords: Conceptual design | Fuzzy-TOPSIS | Group decision making | Micro bio reactors | Modular design

[11] Tamassia E., Hähnel S., Pini F., Grunwald T., Bergs T., Leali F., An Analytical Model for Robot-Based Grinding of Axisymmetric Mold Inserts Using a Rotary Unit, Lecture Notes in Mechanical Engineering, 605-614, (2022). Abstract

Abstract: The grinding of mold inserts used for injection molding aims to improve the surface roughness according to precise quality standards. The insert surface must also have a surface topography that facilitates the release of the plastic material at the end of the injection process. In particular, fine machining lines must be parallel to the extraction direction from the mold to avoid the sticking of plastic material and subsequent surface damages compromising the functionality of the finished product. However, this step in the production chain is most often conducted manually. This paper presents an analytical model to grind a truncated cone-shaped mold insert for the mass production of plastic cups. The automated solution consists of a flexible robotic system equipped with a rotating external axis to improve the accessibility of the tool to the surface to be machined. The tool path programming requires the development of an analytical model considering the simultaneous motion of the insert and the robot joints. The effectiveness of the developed model is evaluated in terms of final surface quality, grinding lines direction, and total process time. The automated strategy developed can be easily implemented with machine tools and applied to inserts with different axisymmetric geometries.

Keywords: Automated fine machining | CAM programming | Grinding lines | Mold insert | Robot manufacturing

[12] Dalpadulo E., Pini F., Leali F., Optimization of an Engine Piston Through CAD Platforms and Additive Manufacturing Based Systematic Product Redesign, Lecture Notes in Mechanical Engineering, 486-493, (2022). Abstract

Abstract: The present work describes an automotive component design optimization process through a systematic approach. The redesign aims to improve product performance by Powder Bed Fusion metal Additive Manufacturing. The approach allows to match Topology Optimization and Design for Additive Manufacturing by exploiting benefits provided by CAD platforms that integrate CAD, CAE and CAM tools. The Systematic Concept-Selection-Based Approach aims to make redesign simple and effective, allowing design solutions exploration while containing product design lead time. Topology Optimization is the key phase to achieve lightweight design by a double-level optimization approach. In particular, the technique is setup to produce different design variants, whose subsequently undergo a Trade-off study to perform the concept selection step. Finally, one final redesign occurs and a design refinement step is performed to achieve product optimization. The case study is a high performance internal combustion engine piston, which has been redesigned to be produced by Selective Laser Melting process with benefit of weight reduction.

Keywords: Automotive | Design for additive manufacturing | Design method | Re-design | Topology optimization

[13] Garlaschelli G., Gherardini F., Malagola S., Leali F., Investigation of Warpage and Tolerances in Injection Moulding Components Based on Simulation and Experimental Validation, Lecture Notes in Mechanical Engineering, 342-353, (2022). Abstract

Abstract: This paper presents a systematic approach to model and simulate the influence that the variation of process parameters has on the final quality of an injection moulded component. In the first phase, we define a multi-steps procedure to develop a reliable digital model of the injection moulding process by the fine-tuning of the part cavity and the mould elements (e.g. detail simplification, discretization and mesh density, elements modelling, etc.) using real data as validation. In the second phase, we investigate the correlation between selected process parameters and the final tolerances of the moulded component, based on a Design of Experiments. As a case study, we selected the body of a mass airflow sensor for an automotive high performance engines, made of polybutylene terephthalate reinforced with glass-fibre, which presents roundness issues on functional features. The effects of the injection velocity and packing pressure on the deformation of the component are investigated, identifying the best combination of their values that leads to compliance with the roundness tolerances on its functional features. The injection moulding Computer Aided Engineering (CAE) software Moldex3D (CoreTech) is used to run the simulations, and the results are finally validated by comparing the experimental data obtained from the injection moulding machine that produces the component.

Keywords: Design of Experiments | Injection moulding | Simulation-based design approach | Tolerances | Warpage

[14] Petruccioli A., Pini F., Leali F., Model-Based Approach for Optimal Allocation of GD&T, Lecture Notes in Mechanical Engineering, 277-284, (2022). Abstract

Abstract: Model-based Definition (MBD) is a known design approach that aims to an effective integration of Product Manufacturing Information (PMI) within geometrical data. By means of MBD, product requirements and specifications based on Geometric Dimensioning and Tolerancing (GD&T) can be directly associated to 3D models, improving interoperability between design and simulation virtual environments. However, especially in industrial settings, many challenges still limit MBD diffusion, such as limited knowledge and application of GD&T rules, inconsistent representation of PMI, lack of methodological and organizational approach based on PMI. As a consequence, the Dimensional Management practice based on GD&T cannot be systematically applied, and the full potential of Computer-Aided specific tools remains unexpressed. In this paper, the effective implementation of MBD for PMI during both product and process design is proved through its direct application on tolerance-cost optimization. Thanks to 3D semantic annotations, a model-based framework is suggested to validate functional requirements of a mechanical assembly and to assess production efforts, enhancing the integration between tolerance analysis and manufacturing cost tools. The interrelation of GD&T schemes enables the automated transfer of the data linked to annotations toward Computer-Aided Tolerancing (CAT) and Product Cost Management (PCM) virtual environments. Consequently, PMI guides the simulations during the multi-disciplinary optimization, proving its effectiveness in communicating engineering information and enabling the transition to digital manufacturing though MBD.

Keywords: Geometric dimensioning and tolerancing (GD&T) | Model-based definition | Product manufacturing information | Tolerance-cost optimization

[15] Dalpadulo E., Petruccioli A., Pini F., Leali F., Synergic Product and Process Design for Additive Fabrication of Lightweight Vehicles, SAE Technical Papers, (2022). Abstract

Abstract: Additive manufacturing is even more capturing the interest of vehicle manufactures. Its adoption enables design potentials such as parts customization, lightweighting or functional integration. Deep adoption of additive manufacturing and integration of topology optimization design techniques enable the calculation of light components, while additive manufacturing makes it feasible by adding subsequent layers of material. Design for additive manufacturing guidelines address these challenges by enabling the build of such complex shapes thanks to parts consolidation and features integration. Several prototypes of such lightweight design concerning chassis, body, and structures have been provided, but the lack of structured and objective approaches limits the application in normal production. This work integrates Key Performance Indexes (KPIs) into the Design for Additive Manufacturing (DfAM) approach for an effective adoption of selection of trade-off studies for the selection of best product variant and process setup. The trade-off involves KPIs related to structural product requirements and laser Powder Bed Fusion process cost estimation, to return functional components that address the best ratio between weight reduction and expected manufacturing cost. Proof of the method effectiveness and its application to lighten real components is demonstrated by applying the approach to reduce the weight of a steering support system for a Formula SAE race car. The objectivity of the trade-off promotes the extensive adoption to other vehicle components for substantial fuel efficiency improvement and emissions reduction perspectives.

Keywords: 3D printers | Cost estimating | Economic and social effects | Emission control | Integration

[16] Petruccioli A., Pini F., Leali F., Development of a Computer-Aided integrated method for the tolerance-cost multi-disciplinary optimization of an automotive engine, International Journal on Interactive Design and Manufacturing, (2022). Abstract

Abstract: Geometric and dimensional deviations are the main contributors on quality and cost of products. Specifically, the selection of tolerance types and the appropriate allowable range plays a central role for an effective development process. Nevertheless, the trade-off between expected performances and target costs requires skills and interaction of many areas of engineering design, especially in the early design phases. Despite many tolerance-cost optimization practices are proposed by the research community several limitations still hamper the industrial application: among them, data and parameters sharing, flexibility to application complexity, and integration of simulation tools are the main ones. Focusing on a systematic framework, an integrated modelling and simulation environment is required to take full advantage of the concurrent use of engineering software. The present paper contributes to this aim by suggesting a Computer-Aided framework that integrates Geometric Dimensioning and Tolerancing simulations and manufacturing cost estimations in a multi-disciplinary optimization environment. Advanced tools are the cornerstones of the suggested framework, enabling easy identification of the main operational steps and providing the automation of the optimization. To be validated and demonstrate the effective applicability, the framework has been applied for the tolerance-cost optimization of an archetypal case study of an automotive engine assembly. The simulation models have been integrated within the optimization, providing several configurations of tolerances from which identify the optimal one. The analysis of optimization results allows to assess the efficiency of the method, highlighting further improvements to extend its robustness, flexibility, and application range.

Keywords: Computer-Aided design | Cost estimation | Model-based definition | Multi-disciplinary optimization | Tolerance design

[17] Dalpadulo E., Petruccioli A., Gherardini F., Leali F., A Review of Automotive Spare-Part Reconstruction Based on Additive Manufacturing, Journal of Manufacturing and Materials Processing, 6(6), (2022). Abstract

Abstract: In the Industry 4.0 scenario, additive manufacturing (AM) technologies play a fundamental role in the automotive field, even in more traditional sectors such as the restoration of vintage cars. Car manufacturers and restorers benefit from a digital production workflow to reproduce spare parts that are no longer available on the market, starting with original components, even if they are damaged. This review focuses on this market niche that, due to its growing importance in terms of applications and related industries, can be a significant demonstrator of future trends in the automotive supply chain. Through selected case studies and industrial applications, this study analyses the implications of AM from multiple perspectives. Firstly, various types of AM processes are used, although some are predominant due to their cost-effectiveness and, therefore, their better accessibility and wide diffusion. In some applications, AM is used as an intermediate process to develop production equipment (so-called rapid tooling), with further implications in the digitalisation of conventional primary technologies and the entire production process. Secondly, the additive process allows for on-demand, one-off, or small-batch production. Finally, the ever-growing variety of spare parts introduces new problems and challenges, generating constant opportunities to improve the finish and performance of parts, as well as the types of processes and materials, sometimes directly involving AM solution providers.

Keywords: classic cars | component reproduction | Industry 4.0 | original equipment manufacturer (OEM) | rapid tooling | replacement parts | restoration | reverse engineering

[18] Dalpadulo E., Pini F., Leali F., Assessment of computer-aided design tools for topology optimization of additively manufactured automotive components, Applied Sciences (Switzerland), 11(22), (2021). Abstract

Abstract: The use of Topology Optimization techniques has seen a great development since the last decade. The principal contributor to this trend is the widespread use of Additive Manufacturing technologies to effectively build complex and performant structures over different settings. Nevertheless, the use of Topology Optimization in Design for Additive Manufacturing processes is not simple and research aims to fill the gap between theory and practice by evolving at the same time both approaches, workflows, and design software that allow their implementation. Since a strong connection between methodologies and tools exists, this work proposes a method to assess computer-aided design tools or platforms. This can be applied to sustain the key phase for selection and adoption of the computer-aided tools in industrial settings embracing Additive Manufacturing. The workflow for Topology Optimization implementation, the structure of the proposed evaluation approach, and its application, are presented to demonstrate effective usability. The automotive case study is the redesign of internal combustion engine piston to benefit of metal Additive Manufacturing based enhanced product performance. A preliminary finite element model is defined and a Topology Optimization based redesign is concurrently set up through four different commercial computer-based platforms. The method accounting for the assessment of required operations for the design optimization is applied to perform the tools selection phase.

Keywords: Automotive | Computer aided design tools | Design for additive manufacturing | Design methods | Topology optimization

[19] Tagliazucchi G., Marchi G., Gherardini F., Leali F., The multiple roles of universities in U-I collaborations: The case of Emilia–Romagna motor vehicle industry, Journal of Engineering and Technology Management - JET-M, 62, (2021). Abstract

Abstract: This paper investigates the development of collaboration modes between university and local industry, within a regional system having a diffused innovation process. As a case study, we analyse into an appreciative framework the roles of a medium-sized university as producer of knowledge, intermediary organisation and regional orchestrator over time, ultimately assuming a leading role in two specific university-industry programmes supporting the motor vehicle industry of Emilia–Romagna (IT). The paper contributes to the University-Industry stream of research by identifying the factors and mechanisms underpinning the evolution of university's role in its collaboration with local industry, by the time assuming a leading and central role in spreading innovative technology into the regional system. Our findings provide managerial and policy makers contributions, and could be extended to other similar medium-tech industry for supporting diffusion of knowledge and innovation processes.

Keywords: Academic engagement | Automotive industry | Regional innovation system | Technology transfer

[20] Petruccioli A., Pini F., Leali F., TOLERANCE SPECIFICATION MODEL FOR SYSTEMATIC APPLICATION OF GD&T IN PRODUCT DESIGN, ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE), 6, (2021). Abstract

Abstract: The Dimensional Management (DM) is well known as the reference methodology for the management of dimensional and geometric variations of industrial products. Over the years, it has assumed a central role, thanks to the development of a specific design approach, known as Design for Tolerancing (DFT). Based on the Geometric Dimensioning and Tolerancing (GD&T) symbolic language, DFT allows to check and verify functional and qualitative requirements from the early design phases. Although its strength and potential to improve design optimization, DFT industrial application is still limited. Consolidated design practices, complexity of tolerance specification process, lack of support from Computer-Aided tools still limit the tolerance specification to final validation of product design. The paper aims to define a tolerance specification model for systematic application of GD&T specification. The model formalizes the identification and translation of product requirements on the components geometry, through the definition of the main step of tolerance design. Based on the integration between the GD&T-based approach and parametric threedimensional CAD modelling, the model has been applied to validate the GD&T and the tolerance specification of two mechanical assemblies with common features. The methodology proves its general effectiveness to support engineers in tolerance design and selection of the most suitable GD&T schemes.

Keywords: Design for tolerancing (DFT) | Dimensional management (dm) | Geometric dimensioning and tolerancing (gd&t) | Product design

[21] Dalpadulo E., Pini F., Leali F., COMPONENTS RESIDUAL STRESS AND DEFORMATION REDUCTION: AN INTEGRATED PROCESS DESIGN FOR ADDITIVE MANUFACTURING, ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE), 6, (2021). Abstract

Abstract: Additive Manufacturing (AM) is a key technology in current industrial transformations thanks to the significant benefits that can bring to high-level sectors. Nevertheless, AM-based design approaches require improvements that are fundamental to exploit the potentials of the technology and reduce the lack of process consistency. This work focuses on integrated Design for Additive Manufacturing (DfAM) approaches for product-process design, to meet both functional and technological targets. The key aspects of process design and issues are summarized and the design method to perform metal AM process optimization is presented. The aim is therefore to minimize process-induced defects and flaws of AM-based manufacturing of metal products, such as residual stress and distortions. The approach consists of industrialization task improvement based on modelling optimization and build optimization sub-phases supported by numerical process simulation. Integration of CAD platforms allows embedding these steps to be performed downstream of the product design, which can be achieved through functional or multifunctional optimization techniques as well (e.g. topology optimization, latticing, graded structures/materials). The design method is finally applied to perform the industrialization phase of a high-performance automotive component. The case study is a formula SAE topology optimized brake caliper to be produced by Selective Laser Melting (SLM) process. Process simulationdriven studies on modelling and build preparation subphases (i.e. orientation definition, supports generation, model distortion compensation) are conducted to support the process design. The study demonstrates the part scale level method's suitability to industrial context to improve industrialization in the redesign of components to be produced by metal AM.

Keywords: Additive manufacturing | Automotive | Design method | Powder bed fusion | Process optimization | Process simulation

[22] Dalpadulo E., Pini F., Leali F., Design for Additive Manufacturing of a Topology Optimized Brake Caliper Through CAD-Platform-Based Systematic Approach, Lecture Notes in Mechanical Engineering, 92-97, (2021). Abstract

Abstract: To implement the CAD platform-based approach of Design for Additive Manufacturing (DfAM) and validate it in a real case, an entire design optimization process of a Formula SAE front brake caliper has been performed, to be printed by Powder Bed Fusion (PBF) process. The DfAM consists in the use of a Ti6Al4V titanium alloy to better resist at high temperatures and a topology optimized shape allowed by the technology to save weight despite the density increase. Structural and thermal behavior has been discussed. DfAM process-specific techniques have been implemented for internal geometrical features and optimized shapes. The design for additive workflow is presented and finally the exploited design approach based on a CAD platform is synthesized.

Keywords: Automotive | Brake caliper | CAD platform | DfAM | Topology optimization

[23] Petruccioli A., Gherardini F., Panari D., Leali F., Computer-Aided Tolerancing Analysis of a High-Performance Car Engine Assembly, Lecture Notes in Mechanical Engineering, 121-127, (2021). Abstract

Abstract: This paper proposes the analysis of the tolerances (values, types, datum) and their effects on a mechanical assembly, as a high-performance car engine, by means of a Computer-Aided Tolerancing software. The 3D tolerance stack-ups are investigated to assess the fulfillment of the functional requirements as well as the performance specifications of the assembly. Moreover, after identifying the tolerances that mainly affect the product variability, we finally propose some corrective actions on the tolerances and assess their functional allocation, tightening or relaxing their values, ensuring assemblability and cost reduction.

Keywords: Automotive assembly | Car engine | Computer-Aided Tolerancing | Geometric dimensioning and tolerancing (GD&T) | Tolerance analysis method

[24] Vergnano A., Bergamini U., Bianchi D., Veronesi P., Spagnolo R., Leali F., Simulation and Experimental Validation of Secondary Dendrite Arm Spacing for AlSi7Mg0.3 Chassis Parts in Low Pressure Die Casting, Lecture Notes in Mechanical Engineering, 28-33, (2021). Abstract

Abstract: The structural properties of cast aluminum parts are strongly affected by the solidification in the production process. The solidification dynamics determines the Secondary Dendrite Arm Spacing (SDAS), directly affecting the structural strength of the alloy. Simulation techniques enable the integrated design of chassis parts and their production equipment. However, in order to effectively predict the SDAS formation, the simulation models need to be investigated and calibrated. The present research investigates the SDAS formation models and identifies a robust relation to be used in Design by Simulation phases for AlSi7Mg0.3 parts.

Keywords: Integrated design | Low pressure die casting | Secondary Dendrite Arm Spacing | Simulation

[25] Renzi C., Leali F., Multicriteria Decision Making Methods in Engineering Design: An Application on Medical Devices, Lecture Notes in Mechanical Engineering, 406-411, (2021). Abstract

Abstract: The design of medical devices is challenging, due to strict geometry specifications and criteria belonging to several disciplines. The aim of this paper is to provide a design methodology which seems to lack in the literature of design of biomedical devices. In particular, the case study proposed in this paper concerns with the design of Bone-Biopsy (BB) needle devices. Following the design process of Pahl and Beitz, a functional analysis is carried out, to point out the interfaces between parts of existing BB needles. A morphology matrix is used to generate alternatives for the cannula holder, the core part of the product. Generated alternatives have been ranked and scored by means of the Pugh’s Controlled Convergence method according to the decision makers' opinions. In this work, the design peculiarities related to the BB needles which have been pointed out could be extended for guiding the design of other biomedical devices.

Keywords: Bone-Biopsy needle | Conceptual design | Design of biomedical devices | Multicriteria decision making | Pugh’s Controlled Convergence

[26] Vergnano A., Piras A., Leali F., Modular Car Seat for Monitoring the Pressure Distribution on Regions of Pan and Backrest, Advances in Intelligent Systems and Computing, 1269 AISC, 9-14, (2021). Abstract

Abstract: Car driver and occupants monitoring is important for safety and comfort. The systems using vision sensors for monitoring the line of sight can be integrated with pressure sensors embedded in the seats to identify critical Out of Position conditions. A new modular car seat is here proposed to monitor the pressure distribution on different significant regions. The solution improves the limitations of existing technologies embedded in seats. The proportional and fast measurement enables online complex evaluations, while the layout reduces the risk of errors. The experiments proved the effectiveness of the prototype.

Keywords: Car seat pressure | Driver monitoring | Driver profiling | Intelligent vehicle | Modular car seat | Occupant classification | Safety system | Seat regions | Weight scale system

[27] Bici M., Gherardini F., Campana F., Leali F., A preliminary approach on point cloud reconstruction of bronze statues through oriented photogrammetry: The “Principe Ellenistico” case, IOP Conference Series: Materials Science and Engineering, 949(1), (2020). Abstract

Abstract: Close-Range Photogrammetry is a widespread and efficient technique in the 3D acquisition of artefacts, particularly in fields like Cultural Heritage. Despite this wide usage, also due to a convenient quality/cost ratio, it shows some limitations due to light conditions as well as the artefact surface finishing. In this paper, we would like to report the assessment of a photogrammetry approach to 3D capture metal reflective surfaces, such as bronze, which is a widely used material in ancient statues. To this aim, we propose a photogrammetry workflow based on systematic steps capable of overcome some of the main issues of reflective surfaces. To validate this approach, the developed 3D model is compared to a more accurate model of the same artefact, obtained with a 3D scanner. As a case study, we selected the Principe Ellenistico, an ancient bronze statue conserved in the Museo Nazionale Romano (Rome, Italy), of which a photogrammetric model is firstly developed and then compared to the scanned one.

Keywords: 3D acquisition | Bronze statue | Close-Range Photogrammetry | Principe Ellenistico | Systematic approach

[28] Dalpadulo E., Pini F., Leali F., CAD-platform-based Process optimization Design Method by Selective Laser Melting Simulation, Proceedings of the 2020 IEEE 10th International Conference on "Nanomaterials: Applications and Properties", NAP 2020, (2020). Abstract

Abstract: Additive Manufacturing based on Powder Bed Fusion processes enables the construction of end-use functional metal components, making it feasible to design several level of geometrical complexity. Nevertheless, the printing process leads to material and shape defects, residual stress and induced distortions on final components that mainly are caused by the high thermal gradients associated to the intense and nonuniform power energy sources used to selectively melt metal powders. In this paper, techniques to reduce or prevent these effects are summarized. The more broadly Design for Additive Manufacturing approach based on the use on CAD platforms for product-process design is the backbone upon this research is based on. Specifically, the work presents a design method to predict drawbacks and improve the industrialization subphase. Laser-based Powder Bed Fusion technique is considered and the implementation and validation of the Selective Laser Melting process simulation is performed in order to support the method. Two case studies are presented. The former demonstrates the simulation implementation feasibility through a CAD platform. The latter validates the simulation results compared to experimental data for further method application.

Keywords: CAD platforms | design for additive manufacturing | industrialization | powder bed fusion | process simulation | selective laser melting

[29] Dalpadulo E., Gherardini F., Pini F., Leali F., Integration of topology optimisation and design variants selection for additive manufacturing-based systematic product redesign, Applied Sciences (Switzerland), 10(21), 1-13, (2020). Abstract

Abstract: The development of additive manufacturing allows the transformation of technological processes and the redesign of products. Among the most used methods to support additive manufacturing, the design can be optimised through the integration of topology optimisation techniques, allowing for creating complex shapes. However, there are critical issues (i.e., definition of product and process parameters, selection of redesign variants, optimised designs interpretation, file exchange and data management, etc.) in identifying the most appropriate process and set-ups, as well as in selecting the best variant on a functional and morphological level. Therefore, to fully exploit the technological potentials and overcome the drawbacks, this paper proposes a systematic redesign approach based on additive manufacturing technologies that integrate topology optimisation and a tool for selecting design variants based on the optimisation of both product and process features. The method leads to the objective selection of the best redesigned configuration in accordance with the key performance indicators (KPIs) (i.e., functional and production requirements). As a case study, the redesign of a medical assistive device is proposed, previously developed in fused filament fabrication and now optimised for being 3D printed with selective laser melting.

Keywords: Assistive device | Design for additive manufacturing | Design method | Design optimisation | Design variants selection | Redesign | Selective laser melting | Topology optimisation

[30] Pedrazzi S., Vergnano A., Allesina G., Veronesi P., Leali F., Tartarini P., Muscio A., A simple test method for measurement of the interface thermal resistance of coated and uncoated metal surfaces, Journal of Physics: Conference Series, 1599(1), (2020). Abstract

Abstract: Molds for metal casting are often internally coated in order to minimize the interaction between the steel surface of the mold and the melted metal during its pouring and solidification. However, the added coating increases the thermal interface resistance during the cooling process and it can thus affect the process itself. For example, numerical predictions and experimental results are matched only if the interface resistance is even quintupled in the presence of the usual interface coating, compared to the uncoated mold. In order to have a reasonable estimate of the interface thermal resistance, an easy to use measurement approach has been tested. This consists of contacting a cold and a hot samples of metals with known thermal properties, one at ambient temperature and the other one much hotter. The temperatures of the two samples, assumed to be uniform in each sample, are measured by thermocouples placed inside the samples through a hole, and the interface resistance is calculated from the time evolution pattern of those temperatures during the thermal transient that follows the instant in which the samples have been contacted.

[31] Dalpadulo E., Pini F., Leali F., Integrated CAD platform approach for Design for Additive Manufacturing of high performance automotive components, International Journal on Interactive Design and Manufacturing, 14(3), 899-909, (2020). Abstract

Abstract: Use of Additive Manufacturing provides great potentials to settings focused on high performance products. It allows feasibility of sundry innovative features to completely rethink geometries and shapes and it leads to embrace new design approaches. The enhanced design freedom can be exploited to optimize products, using techniques such as topology optimization. The study of methods for development of optimized components to be produced by AM becomes therefore fundamental. A framework for the methodological approach to operations to be carried out from the concept model to the printed component has been analyzed and it is clear that issues and research efforts relapse both the global level of the workflow and the local level of singular tasks to be performed. Problems related to management of Design for Additive Manufacturing workflow can be solved with holistic approach, through the use of computer aided integrated tools. The aim of this work is to test the effectiveness at local level of such tools with respect to operations for both design and industrialization optimization, working on an automotive case study. In particular, specific tools for topology optimization, product simulation, printing preparation and process simulation are taken as reference and results obtained with an integrated CAD platform are discussed.

Keywords: CAD based integrated platform | Design for Additive Manufactruing | High performance automotive components | Powder Bed Fusion

[32] Rossi F., Pini F., Carlesimo A., Dalpadulo E., Blumetti F., Gherardini F., Leali F., Effective integration of Cobots and additive manufacturing for reconfigurable assembly solutions of biomedical products, International Journal on Interactive Design and Manufacturing, 14(3), 1085-1089, (2020). Abstract

Abstract: Collaborative robotics and additive manufacturing are two enabling technologies of the Industry 4.0 manufacturing paradigm. Their synergic integration requires novel and effective design approaches, aiming to the development of new reconfigurable solutions for customised processes and products. This work presents an integrated approach that exploits the capabilities of Cobots to mimic the repetitive and exhausting operator’s movements as well as the competitive advantages offered by additive manufacturing to realize tailored equipment. In particular, the case study shows the development of a customised device for the manipulation of biomedical components by means of a Cobot, which is introduced in a workstation to replace manual operations. Moreover, the flexibility and the effectiveness of a Cobot can be improved thanks to customised devices for gripping and pick-and-place operations based on a specific application. During the development phase, we simulated the assembly process, and tested different options. The final configuration, with conformal circuits and suction cups, can pick, manipulate and assembly the biomedical components, and thanks to a Fused Filament Fabrication technology is additively manufactured. In conclusion, this developed prototypal solution proves the real capabilities offered by integrating Cobots and additive manufacturing for the lean automation of a biomedical workstation.

Keywords: Additive manufacturing | Biomedical components | Collaborative robot | Design approach | Industry 4.0

[33] Bertoldi A., Gherardini F., Leali F., Implementation of a quality framework on the launch phase of an automated assembly line for top class automotive chassis, IOP Conference Series: Materials Science and Engineering, 836(1), (2020). Abstract

Abstract: Today the assembly lines of cars chassis are highly automated by robotic operations. Even in the top class automotive sector, the production of aluminium chassis involves numerous automated operations, such as TIG and MIG welding, riveting and gluing. This practice allows, on the one hand, to reduce time and costs, improve process repeatability and quality standards. On the other hand, it requires the quality improvement of the whole process (from supplied parts approval to welding reworks minimization). The industrialization phase of a new car chassis and the launch of its automated assembly line are particularly critical, even more if the line has already been designed and only minimally modifiable. Therefore, this paper proposes the implementation of a quality framework to manage the launch of an automated assembly line of a new aluminium chassis of top class cars, selected as a case study. The framework was implemented, aiming at improving the entire process quality, and finally validated by critically comparing the results obtained with those relating to models currently in production. Due to their importance to the final quality, we focused on the welding operations, which require actions both on process parameters and supplied parts approval (e.g. tolerances on parts end cuts). The new line shows a clear improvement compared to the past, with highly significant reduction of welding non-conformances, high quality level and lack of many critical issues of the previous lines thanks to corrective actions taken in the early process stages, during the pilot phase.

[34] Vergnano A., Gherardini F., Leali F., The systematic design of industrial products through design archetypes: An application on mechanical transmissions, Applied Sciences (Switzerland), 10(7), (2020). Abstract

Abstract: Engineering design is a knowledge intensive activity for both new and mature technical systems, such as mechanical transmissions. However, design knowledge is often transferred with conservative and unstructured approaches, although knowledge management would be of the utmost importance for modern industries. In this work, we introduce a design tool, called design archetype, for collecting and managing knowledge in systematic design processes. The design archetype addresses input design requirements for different design concepts, therefore, improving awareness of the design process by interactively modifying the design solution due to different input requirements. Finally, the design archetype updates the parameters of a first embodiment computer-aided design model of the concept. A method for the development of design archetypes is presented and applied to two case studies of mechanical transmission subassemblies. The results demonstrate the effectiveness of a systematic design method based on design archetypes stored in the company database.

Keywords: CAD-based tool | Design archetype | Knowledge-based engineering | Mechanical transmissions | Systematic design method

[35] Angelo L.D., Gherardini F., Stefano P.D., Leali F., Design for visual quality enhancement of artificial infrastructure facilities: An application to electricity pylons, Applied Sciences (Switzerland), 10(3), (2020). Abstract

Abstract: (1) Background: The visual impact of artificial infrastructures on natural landscapes generates a common negative perception in public opinion. However, as in the case of electrical energy, the increasing demand for power supply and its need for capillary distribution require the installation of new lines, commonly overhead lines with tall tower-like pylons. In most countries, this situation is faced with many attempts of solutions, as participatory workshops and design contests. Nevertheless, the solutions are usually not further developed into real structures due to many limitations (e.g., regulatory, safety, lack of feasibility). (2) Methods: This paper presents a systematic method for the design of tower-like pylons (e.g., electric ones) able to improve the visual quality on the landscape areas in which they will be installed. The method identifies a design strategy that advantageously exploits the inevitable visual impact of pylons on the landscape by integrating the symbolic morphology and the topologically optimized pylon structure from the earliest design phases. (3) Results: The resulting structure is designed in three steps. First, a concept is morphologically developed by integrating symbolic references to the landscape, environment, or cultural society. Second, the concept is topologically optimized, by reducing the structural weight and its visual impact, and respecting regulatory requirements. Third, the resulting structure is engineered and embodied into an industrially feasible layout. (4) Conclusions: The method is able to develop an original, brand new tower-like pylon integrating all the types of requirements, such as regulatory, industrial feasibility, and social components' needs. The resulting electricity pylon presents an enhanced visual quality according to the citizens' feedback.

Keywords: Electricity pylon | Integrated design method | Topology optimization | Visual impact improvement

[36] Magrini E., Ferraguti F., Ronga A.J., Pini F., De Luca A., Leali F., Human-robot coexistence and interaction in open industrial cells, Robotics and Computer-Integrated Manufacturing, 61, (2020). Abstract

Abstract: Recent research results on human–robot interaction and collaborative robotics are leaving behind the traditional paradigm of robots living in a separated space inside safety cages, allowing humans and robot to work together for completing an increasing number of complex industrial tasks. In this context, safety of the human operator is a main concern. In this paper, we present a framework for ensuring human safety in a robotic cell that allows human–robot coexistence and dependable interaction. The framework is based on a layered control architecture that exploits an effective algorithm for online monitoring of relative human–robot distance using depth sensors. This method allows to modify in real time the robot behavior depending on the user position, without limiting the operative robot workspace in a too conservative way. In order to guarantee redundancy and diversity at the safety level, additional certified laser scanners monitor human–robot proximity in the cell and safe communication protocols and logical units are used for the smooth integration with an industrial software for safe low-level robot control. The implemented concept includes a smart human-machine interface to support in-process collaborative activities and for a contactless interaction with gesture recognition of operator commands. Coexistence and interaction are illustrated and tested in an industrial cell, in which a robot moves a tool that measures the quality of a polished metallic part while the operator performs a close evaluation of the same workpiece.

Keywords: Collaborative robotics | Depth sensing | Human-machine interface | Industrial cell | Polishing | Safe human–robot interaction

[37] Pini F., Leali F., Computer-Aided Assessment of Safety Countermeasures for Industrial Human-Robot Collaborative Applications, Springer Proceedings in Advanced Robotics, 12, 186-198, (2020). Abstract

Abstract: Human and robot collaboration represents an interesting development direction for traditional industrial robotic solutions. Especially for those cases where the operations are difficult to automate or burdensome for manual execution, the mutual exchange of human sensitivity and robot repeatability represents an effective approach. Nevertheless, industrial robots are poorly involved for collaborative tasks since specific safety countermeasures are required to avoid all the potential hazards. Consequently, the design and assessment of safety solutions represents a fundamental phase to estimate feasibility of industrial collaborative solutions. The presented work proposes a computer-aided approach to identify, assess and optimize the safety systems that enables the collaborative usage of industrial robots. It exploits the capabilities of virtual controller-based offline programming packages to design in advance the safety countermeasures. An initial consistency test validates the response of the selected tool with respect to the safety functionalities. Subsequently, a virtual replica of a potential industrial collaborative solution has been developed. As a result, it has been possible to mimic the behaviour of such a system with respect to Speed and Separation Monitoring collaborative method.

Keywords: Computer-aided assessment | Human-robot collaboration | Indutrial robots | Safey countermeasures | Speed and separation monitoring

[38] Dalpadulo E., Pini F., Leali F., Systematic integration of topology optimization techniques in design for additive manufacturing methodologies applied to automotive settings, ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE), 6, (2020). Abstract

Abstract: Additive Manufacturing is having a great trend since its implementation possible benefits have been widely discussed and efforts in technology improvements are having impact on process reliability and industrial application. The aims of this work are to analyze the current and forthcoming scenario of methods for the specific development of parts to be produced by metal AM including topology optimization as a basic design step and to demonstrate that systematical design approaches can be introduced in order to better exploit potentials offered by AM implementation. The general framework composed by the main tasks is introduced and discussed. Key factors such as advance in different design solutions exploration, product-related and process-related design constraint implementation in the design phase and method effectiveness in product development lead time minimization are presented. Linear and iterative workflows are described, considering features, decision making points, pros and cons, possible variants and research hints. A strong connection between methods and actual means is highlighted and workflow implementation using standard and integrated commercial tools is considered. Such methods are related to several automotive case studies presented in order to demonstrate their applicability and to show actual results and possible further development..

Keywords: Automotive. | Design methods | DfAM | Topology Optimization

[39] Pini F., Dalpadulo E., Leali F., CAD-based risk assessment approach for safe scheduling of HRC operations for parts produced by laser powder bed fusion, Advances in Intelligent Systems and Computing, 1131 AISC, 789-795, (2020). Abstract

Abstract: The presented paper suggests a design method which seeks to identify the best scheduling of human robot collaborative (HRC) operations with respect to a required safety level. The human behavior along manufacturing scenarios is effectively forecasted through dedicated computer-aided tools. Consequently, this method stresses the usage of virtual environment to replicate both human postures and robot encumbrances over the manufacturing operations. Moreover, it proposes a safety index formulation for HRC systems based on the minimum distance between human and robot (H-R). As results, the approach returns the safety index for every possible combination of H-R operations. Subsequently, a scheduling algorithm suggests the operations sequence depending on the expected value of the safety index, providing an evaluation of the time needed to complete the process. The method is validated on surface control phase involved in post-processing of parts produced by laser powder bed fusion (L-PBF) Additive Manufacturing.

Keywords: Additive Manufacturing | CAD-based methods | Human Robot Collaboration | Safety index | Task scheduling

[40] Gherardini F., Petruccioli A., Dalpadulo E., Bettelli V., Mascia M.T., Leali F., A methodological approach for the design of inclusive assistive devices by integrating co-design and additive manufacturing technologies, Advances in Intelligent Systems and Computing, 1131 AISC, 816-822, (2020). Abstract

Abstract: Additive Manufacturing is a widespread technology that may enhance product customization based on specific users’ needs, as in the case of assistive devices. Many chronic physical progressively disabling diseases, but also ageing, may cause severe limitations in daily life, which can be overcome by highly customized aids. Literature shows that the active involvement of the patient in the development of assistive devices through co-design allows for their greater therapeutic effectiveness and acceptance. Therefore, this paper proposes a methodological approach for the development of inclusive assistive devices to support daily activities in persons with disabling diseases of the upper-limb. The approach integrates co-design, standardized tools, and low- and high-tech prototyping techniques and tools, which lead to significant feedbacks from patients. The patients are encouraged to interact with conceptual prototypes through direct 3D CAD modelling and touch screen devices. Assessment tests highlight the suitability of the method to achieve the expected goals.

Keywords: Additive Manufacturing | Assistive device | Co-design | Hand pathologies | Inclusive method | Occupational therapy | Parametric modelling

[41] Renzi C., Di Angelo L., Leali F., Automotive Design Engineering: Material and Processes Selection Problems, Lecture Notes in Mechanical Engineering, 373-384, (2020). Abstract

Abstract: Multicrieria Decision-making methods (MCDM) are efficiently used as a support to engineering design, even if tested procedures and experience-based approaches are often preferred in SMEs and several industrial contexts. An extended critical review investigates how decision-making methods can help solving engineering design problems in automotive design. In particular, in this work, a classification of decision-making methods related to engineering design, is proposed, in which decisional techniques are matched with the design phases, and to corresponding automotive industry design problems. In literature a large amount of paper is dedicated to the selection of materials and manufacturing processes in the detail design phase. Also, hybrid methods, namely a combination of decision-making methods with other mathematical methods will be investigated to overcome some methodological drawbacks in MCDM methods. Due to the high impact of the problem in both industrial and research field, this work could help increasing production rate by reducing redesign errors related to material/processes selection problems, and concurrently transferring the knowledge of decision-making methods within the industrial context.

Keywords: Automotive design | Detail design | Material selection | Multicriteria decision making

[42] Ruini F., Pini F., Leali F., A CAE-Based Model of Aluminium Alloys Welded T-Joints for TEP Analysis, Lecture Notes in Mechanical Engineering, 577-588, (2020). Abstract

Abstract: Continuous innovation in the field of high-end motor vehicle chassis demands optimization of the weight/stiffness ratio and to achieve high quality standards. The use of light materials, such as aluminum alloys, is therefore increasingly common in the design of the chassis, whose assembly process represents a technological challenge. Welding joining processes, and in particular robot-based welding, are widely used in automotive field despite causing distortions. To predict these deformations, finite element analyzes are performed, in particular thermo-elasto-plastic simulations, which are able to satisfactorily replicate the behavior of residual stresses and strains after cooling. However, such analyzes are computationally expensive making their application difficult to complex structures. This work would investigate an alternative solution to predict distortions that effectively returns the behavior of welded assemblies. A CAE-based model for TEP analysis of welded joints is proposed. As a case study, the T-welded junction between two aluminum alloy plates (T-Joint) was considered. The model is validated by a preliminary experimental campaign.

Keywords: CAE-based model | TEP analysis | Termo-elasto-plastic model | Welding process

[43] Hähnel S., Grunwald T., Bergs T., Pini F., Leali F., Vibration-Assisted Face Grinding of Mould Steel, Lecture Notes in Mechanical Engineering, 291-303, (2020). Abstract

Abstract: This work investigates vibration-supported, force-controlled fine machining with elastic bonded mounted points for automated fine processing of mould steel samples. The aim is to compare conventional robot- or machine-tool-based face grinding with a vibration-supported grinding process. The influence of vibration support on the surface topography is investigated primarily to minimize kinematically caused grinding traces. First, the state of the art for the production of tool moulds and vibration-supported fine machining is explained. On this basis, the potentials for the reduction of grinding marks through vibration support for an increase in the degree of automation are derived and the experimental procedure is introduced. Subsequently, robot-based grinding tests with vibration support are carried out and compared with conventional grinding tests. After the tests carried out, the results are evaluated using tactile and optical measuring methods.

Keywords: Finishing | Grinding | Moulds | Vibration-assisted

[44] Dalpadulo E., Pini F., Leali F., Assessment of Design for Additive Manufacturing Based on CAD Platforms, Lecture Notes in Mechanical Engineering, 970-981, (2020). Abstract

Abstract: The aim of this paper is to analyze some critical issues in the Design for Additive Manufacturing workflow and evaluate the introduction of CAD platforms as backbone tools to shorten product development time and raise its efficiency. It is focused on the design of components to be printed by Powder Bed Fusion metal Additive Manufacturing. Even though the use of additive technologies firmly joins a CAD mathematical model and the actually printed component, the workflow from the concept to the definitive job may result in many sequential steps which have complex and slow relationships. Currently, at the state of art for the production of components specifically designed to be produced by additive manufacturing, there are issues both with the adoption of STL as interchange files and the not reversible sequence of tasks. For example, if a problem occurs in the part re-design during component industrialization, usually one must restart the work from the beginning. Thus, an improvement of the design workflow that could shorten time to product and improve both product performances and process quality and reliability, is necessary. In particular, the use of CAD platforms that integrates CAD and CAE tools has been investigated. An automotive case study, originally made by traditional subtractive technology (CNC milling), has been re-designed with topology optimization in order to be printed by Selective Laser Melting process with benefit of weight reduction. Design and industrialization tasks have been tested with respect to the selected integrated CAD platform, and potential improvements have been evaluated.

Keywords: Automotive | CAD platform | Design for Additive Manufacturing | Topology optimization

[45] Vergnano A., Gherardini F., Petruccioli A., Bonazzi E., Leali F., Robust Parameter Analysis of Compliant Part Models for Computer Aided Tolerancing, Lecture Notes in Mechanical Engineering, 241-254, (2020). Abstract

Abstract: Sheet metal parts are widely used in automotive, aerospace, ship and consumer goods industries. The final dimensions of a sheet metal assembly result from the parts deformation, which in turn is affected by many variations in material, thickness and single parts dimensions. The tolerance analysis on sheet metal assemblies improve the knowledge about the process. Advanced simulations enable the optimization of product features, GD&T scheme and assembly process. Moreover, Variational Models of both the product and the assembly system enable to assess the sources of 3D error propagation from the different contributors. However, the simulation results are very affected by the modelling approach of critical components, such as the Fixture Systems. The present paper firstly introduces a strategy to model the Fixture System and the assembly process for compliant parts. Then, a robust analysis of the variations in the model with respect to the modelling factors is performed by a Design of Experiments. A case study on an automotive fender is discussed. The results demonstrate that the modelling strategy of the clamping operation have the main effects, while the modelling of locators scheme, spot joints and FEM meshing are less important.

Keywords: 3D tolerances | Compliant parts | Computer Aided Tolerancing | Design method | Robust analysis

[46] Angelo L.D., Di Stefano P., Renzi C., Leali F., A design methodology for an innovative racing mini motorcycle frame, Computer-Aided Design and Applications, 17(6), 1116-1129, (2020). Abstract

Abstract: Sports equipment design is a young and evolving engineering discipline focused on the best simultaneous optimization of user and product as a system. In motorsports, in particular, the final performance during a race depends on many parameters related to the vehicle, circuit, weather, and tyres and the personal feelings of every single driver. Top teams in high-tech categories can invest huge amounts of money in developing simulators, but such economic commitment is not sustainable for all those teams that operate in minor but very popular categories, such as karts or mini-motorcycles. In these fields, the most common design approach is trial and error on physical prototypes. Such an approach leads to high costs, long optimization times, poor innovation, and inefficient management of the design knowledge. The present paper proposes a driver centred methodology for the design of an innovative mini racing motorcycle frame. It consists of two main phases: the drivers’ feelings translation into engineering requirements and constraints, and the exploration of the design solution space. Expected effects of the application of the proposed methodology are an overall increase in the degree of innovation, time compression, and cost reduction during the development process, with a significant impact on the competitiveness of small racing teams in minor categories.

Keywords: Design methodology | Racing motorcycle frame design | Topological optimization

[47] Vergnano A., Muscio A., Leali F., Sensor Matrix Robustness for Monitoring the Interface Pressure Between Car Driver and Seat, Advances in Intelligent Systems and Computing, 1026, 229-235, (2020). Abstract

Abstract: An effective sensor system for monitoring the pressure distribution on a car seat would enable researches on Advanced Driver Assistance Systems (ADAS) and comfort of occupants. However, the irregularities of the seat shape or those of the occupant clothes challenge the robustness of such a sensor system. Moreover, the position identification of bodies of different percentiles by few pressure sensors is difficult. So, a higher resolution pressure pad has been developed. The number of sensors is significantly increased by means of a matrix scan strategy. Tests on the pressure pad with different occupants proves its robustness in scanning the contact area.

Keywords: Advanced Driver Assistance Systems | Car seat | Comfort | Driver monitoring | Pressure | Sensor matrix

[48] Ferraguti F., Pini F., Gale T., Messmer F., Storchi C., Leali F., Fantuzzi C., Augmented reality based approach for on-line quality assessment of polished surfaces, Robotics and Computer-Integrated Manufacturing, 59, 158-167, (2019). Abstract

Abstract: Augmented reality is considered one of the enabling technologies of the fourth industrial revolution, within the Industry 4.0 program and beyond. Indeed, augmented reality solutions can increase the working quality and the productivity and allow a better use of the human resources. This technology can help the operator in the industrial applications during the crucial phases of the processes. Since the quality assessment of the surfaces is recognized to be a key phase in the polishing process, in this paper we propose a novel method that exploits augmented reality to support the operators during this phase. The metrology data measured by a surface measurement system are directly projected on the polished component through an augmented reality headset worn by the operators and used to assess the quality of the worked surfaces. Rather than imagine how a certain parameter change can affect the result achieved, the information is directly there on the component's surface. Users can see from the data where refinements are required and make better and faster decisions, which is compelling for its potential beyond industrial polishing. The proposed method is implemented and validated on an industrial cell, where the robot automatically perform the polishing task and move the head of the surface measurement system along the surface to measure the metrology parameters. Thanks to the proposed approach, the end-user and the operator can directly see on the component if the quality reached satisfies the specifications or if some parts of the surface require further refinements through additional polishing steps.

Keywords: Augmented reality | Industrial robotic solutions | Robotic polishing

[49] Leali F., Pini F., Villani V., Guest editorial note: Special issue on human-robot collaboration in industrial applications, Mechatronics, 58, 80-81, (2019).
[50] Pini F., Leali F., Human-robot collaborative reconfigurable platform for surface finishing processes, Procedia Manufacturing, 38, 76-83, (2019). Abstract

Abstract: Surface polishing can be counted among the most challenging manufacturing operations, especially when high qualitative levels in terms of surface texture characteristics are requested, such as in the case of polishing operations for plastic injection moulds. Robot-based solutions for surface polishing and quality assessment operations have been proposed at the state of the art, but it still is required the involvement of skilled workers for process supervision and final tuning operations. The introduction of human-machine collaborative solutions opens new opportunities, as the use of symbiotic polishing approaches, where both the humans and the machines capabilities can be shared to improve process effectiveness. The current work proposes a human-robot collaborative approach for surface polishing processes that integrates state of the art robot-based polishing and surface quality assessment technologies in a human-safe shared working environment. As a proof of approach feasibility, the paper presents the prototype of a reconfigurable platform designed to implement a flexible human-robot collaborative scenario for execution of polishing and quality assessment operations. Preliminary demonstrative polishing sessions on simple and complex components validate the system effectiveness with respect to manufacturing efficiency and reconfigurability capabilities. The results obtained provide a first positive response that symbiotic approach can objectively improve the polishing processes.

Keywords: Collaborative Robotics | Computer Integrated Manufacturing | Polishing Processes | Reconfigurable Systems | Robotics

[52] Gherardini F., Santachiara M., Leali F., Enhancing heritage fruition through 3D virtual models and augmented reality: An application to Roman artefacts, Virtual Archaeology Review, 10(21), 67-79, (2019). Abstract

Abstract: The spatial characteristics of museum exhibitions may limit visitors' experience of the artefacts on display. In the case of large artefacts, limited space may affect their whole visualization, or inhibit the visualization of the details farthest from the observer. In other cases, the storage of artefacts in distant sites (museums or archaeological areas) may influence their knowledge process or the possibility for comparative analysis. Moreover, the precarious state of preservation of some artefacts, with damaged or missing parts, makes it difficult to perceive their original appearance. To overcome these limitations, we propose an integrated approach based on 3D virtual models and Augmented Reality (AR) to enhance the fruition of artefacts, improving their visualization, analysis and personal/shared knowledge, also by overcoming space and time constraints. The final AR application is an easily accessible tool for most users from a mobile device, used both inside and outside museums, opening new perspectives for fruition. The framework encourages the use of free and open source software and standard devices, to maximize their dissemination and exploit the potential of such technologies, which is far greater than current use in the cultural heritage field. Selected case studies to test and validate the integrated framework are proposed, dealing with some Roman artefacts found in the area of Modena (Italy). The first is a Roman floor mosaic, found in Savignano sul Panaro (near Modena) in 2011, of which less than half of its original 4.5 x 6.9 m surface is preserved. The others are two Roman funerary lion sculptures: the first is one of two lions flanking the main door of Modena Cathedral, and the second, well-preserved but damaged, is housed in the Museo Lapidario Estense of Modena. Finally, the application was tested by museum experts and visitors both inside and outside the museum, and positively assessed.

Keywords: Augmented reality (AR) | Image-based reconstruction | Real-time visualization | Roman archaeological objects | Virtual modelling | Virtual museum

[53] Gherardini F., Panari D., Leali F., Identification of the main contributors in the 3D tolerances assessment in mechanical transmissions, Lecture Notes in Mechanical Engineering, 152-161, (2019). Abstract

Abstract: The management of spatial dimensional variations and 3D tolerance stacks is a key issue to achieve high performance and robust solutions. The state of the art in 3D tolerance analysis addresses two main difficulties: On the one hand, the issue about the dimensioning and tolerancing methods, and the related annotation transfer from 2D drawings to 3D parts. On the other hand, the lack of integration of design methods for 3D tolerance stacks calculation in the design process and, moreover, the restricted application fields in which tolerance methods are applied, as in aerospace or automotive fields. In this scenario, we propose a Computer-Aided Tolerancing (CAT)-based approach, integrated within the embodiment design of the product development and able to support the analysis and the design of 3D tolerance stacks in mechanical assembly, by simulating the 3D effects of both the dimensional and geometrical tolerances. Focusing on a gearbox assembly, the CAT-based approach aims to identify the main contributors (sources) of variation within the tolerance stacks, by means of a statistical and sensitivity analysis. After defining the design inputs (involved parts, tolerances definition, assembly sequence, and required measurements), we follow a bottom-up approach, starting from the part tolerances as set by the designers, up to the assembly tolerances. The CAT software simulates how the tolerances vary within their ranges. Finally, we are able to identify the main contributors to variation, which may require tightening their tolerance values, in order to improve the performance of the gearbox assembly.

Keywords: 3D tolerance analysis | Computer aided tolerancing | Design method | Gearbox assembly | Geometric dimensioning and tolerancing

[54] Gherardini F., Mascia M.T., Bettelli V., Leali F., A Co-Design Method for the Additive Manufacturing of Customised Assistive Devices for Hand Pathologies, Journal of Integrated Design and Process Science, 22(1), 21-37, (2019). Abstract

Abstract: Additive Manufacturing technologies are particularly suitable for developing highly customised products, even in rehabilitation and occupational therapy fields. Nowadays it is easy and cheap to design and produce such artefacts, although they require systematic approaches and standardized tests to validate their effectiveness. Therefore, this paper proposes a methodological approach for the application of Additive Manufacturing technologies to the co-design of assistive devices, focusing on rheumatoid or scleroderma patients. These patients present hand and finger disorders that limit simple everyday tasks, and need assistive devices to protect the damaged joints. The commercial assistive devices available on the market generally lack of customisation in dimensions and morphology, or their aspect is too stigmatizing. In order to achieve a better correspondence between patients' needs and assistive devices, we propose to involve the patients in a co-design team, in order to directly transfer their desires and creativity in unconventional solutions. The assistive devices are parametrically modelled and virtually prototyped in order to assess their functionality and customisation, and then additively manufactured. Finally, their effectiveness is tested by patients by means of standardized assessment tests that generate useful feedback. The paper proposes a case study about an assistive device for daily living activities.

Keywords: Additive Manufacturing technologies | Assistive device | Co-design | Occupational therapy | Parametric modelling | Rheumatoid arthritis

[55] Vergnano A., Pegreffi F., Leali F., Correlation of driver head posture and trapezius muscle activity as comfort assessment of car seat, Advances in Intelligent Systems and Computing, 903, 241-247, (2019). Abstract

Abstract: Car design must very care comfort and driving pleasure. Nonetheless, the design choices are tested with subjective evaluations. In the present research, an objective measurement equipment for driving comfort assessment is proposed. The muscles activity of the driver in different maneuvers is considered the gauge of her/his feeling with the car. The activity of trapezius muscles of both shoulders is monitored by electromyography (EMG), through electrodes applied to her/his skin. The driver posture is monitored with a robust device for head tracking, using two 9-axis orientation sensors, including gyroscope. Real driving experiments are performed both with a luxury SUV and a high-end car. As expected, the first resulted more comfortable. The proposed equipment proved to be effective in assessing the driving comfort for different seat designs and car layouts.

Keywords: Comfort | Driveability | Electromyography | Head tracking

[56] Vergnano A., Leali F., Out of position driver monitoring from seat pressure in dynamic maneuvers, Advances in Intelligent Systems and Computing, 903, 76-81, (2019). Abstract

Abstract: An airbag system is designed to reduce the accident outcome on the car occupants. The airbags deployment against manikins is severely tested according to international regulations. The accident scenarios with Out of Position (OP) occupants are critical since they can be hardly expected during design. The airbag deployment in these scenarios can be improved by developing adaptive strategies, provided that the Airbag Control Unit must be aware of the actual occupant position. The present research investigates a sensor system to monitor the occupants in an interactive Human-Car system. The driver position is monitored by pressure sensors, while an accelerometer enables to compensate for acceleration and noise. Real driving experiments in dynamic conditions are reported. The results prove that three OP conditions are effectively identified.

Keywords: Driver monitoring | Driving experiment | Intelligent vehicle | Out of position | Safety system

[57] Vergnano A., Leali F., Monitoring Driver Posture Through Sensorized Seat, Advances in Intelligent Systems and Computing, 876, 744-749, (2019). Abstract

Abstract: Future intelligent vehicles will be capable to monitor driver distraction while autonomous driving. However, in case of system fault, the intelligent vehicle must also manage an adaptive strategy for the Airbag Control Unit, since the airbag deployment against an Out of Position occupant can be additionally harmful. Thus, the present research work investigates a possibility to monitor the driver position as a robust information to an intelligent vehicle. A seat is sensorized with a map of pressure sensors. The system layout and setup are discussed in details. Signal processing strategy and real driving experiments are reported.

Keywords: Car seat | Driving experiment | Intelligent sensor | Intelligent vehicle | Pressure sensor | Safety system

[58] Villani V., Pini F., Leali F., Secchi C., Survey on human–robot collaboration in industrial settings: Safety, intuitive interfaces and applications, Mechatronics, 55, 248-266, (2018). Abstract

Abstract: Easy-to-use collaborative robotics solutions, where human workers and robots share their skills, are entering the market, thus becoming the new frontier in industrial robotics. They allow to combine the advantages of robots, which enjoy high levels of accuracy, speed and repeatability, with the flexibility and cognitive skills of human workers. However, to achieve an efficient human–robot collaboration, several challenges need to be tackled. First, a safe interaction must be guaranteed to prevent harming humans having a direct contact with the moving robot. Additionally, to take full advantage of human skills, it is important that intuitive user interfaces are properly designed, so that human operators can easily program and interact with the robot. In this survey paper, an extensive review on human–robot collaboration in industrial environment is provided, with specific focus on issues related to physical and cognitive interaction. The commercially available solutions are also presented and the main industrial applications where collaborative robotic is advantageous are discussed, highlighting how collaborative solutions are intended to improve the efficiency of the system and which the open issue are.

Keywords: Collaborative robots | Human–robot collaboration | Industrial applications | Intuitive robot programming | Safety | User interfaces

[59] Hahnel S., Pini F., Leali F., Dambon O., Bergs T., Bletek T., Reconfigurable Robotic Solution for Effective Finishing of Complex Surfaces, IEEE International Conference on Emerging Technologies and Factory Automation, ETFA, 2018-September, 1285-1290, (2018). Abstract

Abstract: In nearly every sector of industrial manufacturing, especially the mould and die making industry, polishing techniques are used. Most often, manual polishing is the only option because the tasks are too complex to be automated in terms of surface quality demands, geometrical features and restricted tool accessibility. Therefore, the European H2020 Project SYMPLEXITY 'Symbiotic Human-Robot Solutions for Complex Surface Finishing Operations' developed a CNC-machine-based machining concept comprising a composition of different finishing technologies. The solution is complemented with an objective metrology surface qualification device, which is capable to also measure big parts holistically. The SYMPLEXITY approach combines both a collaborative, intelligence-based and a cooperative human-robot-based technological approach. The demonstrator machine concept is being introduced and first fine machining experiments, comprising polishing and measurements have been conducted to generate an initial parameter set-up. The experiments have been conducted on an empiric basis to identify the main steering parameters for a future semi-analytic, model-based finishing approach.

Keywords: Abrasive Finishing | Human-Robot Interaction | Objective Surface Qualification | Robotic polishing

[60] Renzi C., Ceruti A., Leali F., Integrated geometrical and dimensional tolerances stack-up analysis for the design of mechanical assemblies: an application on marine engineering, Computer-Aided Design and Applications, 15(5), 631-642, (2018). Abstract

Abstract: This paper presents a knowledge based engineering environment methodology to support the designer in the correct setting of geometrical and dimensional tolerances in assemblies of mechanical components. The procedure is based on the definition of the functional requirements needed to allow the proper working of the assembly; in the further, a software tool is used to do a statistical analysis of the assembly relations, providing an estimation of the components waste due to poor compliance to the tolerances. A case study given by the design of a marine power transmission is presented: the methodology leads to the change of some tolerances to improve the design by reducing the number of waste components. The strength of the methodology is represented by the fact it can help unskilled designers in the correct setting of tolerances in drawings.

Keywords: CAD | CAT | design | GD&T | power transmission

[61] Santachiara M., Gherardini F., Leali F., An Augmented Reality Application for the Visualization and the Pattern Analysis of a Roman Mosaic, IOP Conference Series: Materials Science and Engineering, 364(1), (2018). Abstract

Abstract: The visualization and analysis of mosaics and pavements are often compromised by their large sizes, which do not enable the observer to perceive their whole arrangement or to focus on details placed in farthest areas from its boundaries. Moreover, the usual precarious state of conservation of these artefacts, often with damaged or missing areas, makes it difficult to perceive their original aesthetic value. To overcome these limitations, we propose an application of augmented reality able to support the observer in two ways: first, the application completes the missing surface of the mosaic or pavement by integrating the existent surface with a virtual reconstruction; second, it enables the analysis of the geometric pattern of the mosaic/pavement by overlaying virtual lines and geometric figures in order to explicit its geometric arrangements. The result is achieved via a custom Android application able to recognize and track the mosaic figure pattern and extra marker board, obtaining in that way a coordinate system used to render in real-time the reconstruction of the mosaic. Such rendering is overlaid to the video stream of the real scene. The application runs on a standard smartphone embedded in a Google Cardboard-compatible viewer and therefore is extremely affordable. As a case study, in order to reconstruct its aspects and to analyse its geometric pattern, we chose the roman mosaic re-found in Savignano sul Panaro (near Modena, Italy) in 2011, after 115 years from its first discovery, which is preserved less than half of its original 4.5 x 6.9 m surface.

Keywords: Augmented Reality | Cultural heritage | Geometric pattern | Photogrammetry | Real-time visualization | Roman mosaic

[62] Gherardini F., Santachiara M., Leali F., 3D Virtual Reconstruction and Augmented Reality Visualization of Damaged Stone Sculptures, IOP Conference Series: Materials Science and Engineering, 364(1), (2018). Abstract

Abstract: This paper proposes the integration of photogrammetric reconstruction, 3D modelling and augmented reality application in order to achieve the complete visualization of a stone sculpture even if highly damaged or fragmentary. The first part of the research aims to the reconstruction of the original aspect of an incomplete sculpture, by using photogrammetry techniques based on standard resolution photos and free software in order to obtain a first model; then, we integrate this model with other 3D digital data (from other sculptures of the same period) or with 3D modelling based on historical sources and views from historians, aiming to achieve the original aspect of the sculpture. The second part of the research consists of the embedding of the obtained model in a custom application able to render in real-time the 3D reconstruction of the lion. Then, the rendering is overlaid to the video stream of the real scene and, as a result, a complete 3D digital model of the sculpture is achieved and could be visualized through a VR viewer. As a case study, we focus on a Roman stone sculpture of a male lion conserved in the Museo Estense of Modena (Italy), which lacks of its head and its four legs. The original aspect of the lion may be achieved by integrating the damaged sculpture with other photogrammetric reconstructions of lions sculptures of the same period and with 3D model based on historical sources. Finally, the lion is visualized through an augmented reality application which digitally overlays the reconstructed models on the original one.

Keywords: Augmented Reality | Cultural heritage | Photogrammetry | Real-time visualization | Virtual modeling

[63] Renzi C., Panari D., Leali F., Predicting tolerance on the welding distortion in a thin aluminum welded T-joint, International Journal of Advanced Manufacturing Technology, 96(5-8), 2479-2494, (2018). Abstract

Abstract: Welding is a widely accepted process used in the assembly of aluminum chassis structures in the automotive industry. Finite element analysis (FEA) is usually adopted to predict distortions caused in the welding process. However, only nominal distortions result from FEA simulations. Welding distortions could be more accurately predicted by introducing the prediction of tolerances due to a modification of the input parameters. The aim of this work is therefore to introduce the tolerance evaluation in the FEA model, by varying the welding input parameters (geometrical and dimensional tolerances on the parts, heat input…). To find the most suitable FEA model to investigate welding process tolerance, three FEA models are compared: one is the thermo-elastic-plastic (TEP) model, and two are based on the inherent strain method. The case study uses a thin (2 mm) aluminum T-joint, which is commonly used in automotive chassis assembly. Results deriving from FEA simulations were compared with experimental data. Among the various input parameters affecting the welding process, the authors combined the dimensional tolerance on the plate thickness with the variability of the heat input. The results provided a tolerance range value for the angular distortion of the T-joint.

Keywords: automotive design | Design methods | FEA | inherent strain | Thermo-Elastic-Plastic analysis | welding Tjoint

[64] Villani V., Pini F., Leali F., Secchi C., Fantuzzi C., Survey on Human-Robot Interaction for Robot Programming in Industrial Applications, IFAC-PapersOnLine, 51(11), 66-71, (2018). Abstract

Abstract: The recent trends in modern industry highlight an increasing use of robots for a wide range of applications, which span from established manufacturing operations to novel tasks characterized by a close collaboration with the operators. Although human-robot collaboration allows to relieve operators of exhausting works, an effective collaboration requires a straightforward interaction to foster the use of robot assistants. This paper provides a comprehensive survey on human-robot interaction approaches and related interfaces addressed to robot programming. An overview of on-line and off-line robot programming techniques is first presented. Then, novel intuitive interaction means, such as those based on multi-modal interaction, virtual and augmented reality, are considered. The paper aims at pointing out that collaborative robotics can effectively reduce operator's physical workload if easy to use interfaces for robot programming are provided.

Keywords: Design methodology for HMS | Human operator support | Intelligent interfaces | Multi-modal interaction | Robotics technology

[65] Renzi C., Leali F., Decision-making methods in engineering design: a designer-oriented approach, Direccion y Organizacion, 63, 21-49, (2017). Abstract

Abstract: The use of decisional methods for the solution of engineering design problems has to be tackled on a “human” viewpoint. Hence, fundamental is the identification of design issues and needs that become a designer oriented viewpoint. Decision-based methods are systematically classified in MCDM methods, Structured Design methods and Problem Structuring methods. The results are organised in order to provide a first reference for the designer in a preliminary selection of decision-based methods. The paper shows the heterogeneous use of decision-based methods, traditionally expected to solve only some specific design problems, which have been used also in different design contexts. Moreover, several design issues, which emerged from the review process, have been pointed out and discussed accordingly. This review provided useful results for the enlargement of the state of the art on Decision Based Design methods in engineering design contexts.

Keywords: Decision Based Design methods | Engineering design. | Multi-criteria Decision Making

[66] Gherardini F., Leali F., Reciprocal Frames in Temporary Structures: An Aesthetical and Parametric Investigation, Nexus Network Journal, 19(3), 741-762, (2017). Abstract

Abstract: This paper deals with the use of reciprocal frames in temporary gridshell structures, such as architectural pavilions in expositions and installations. These architectural examples can benefit from the use of short, easy to handle, generally joint-free, and repeatable “modules” in order to create particular self-supporting structures. The lightweight and interwoven grid obtained by connecting short elements according to the reciprocity principle is structurally efficient and, at the same time, aesthetically pleasing, mainly due to the resulting tessellation. The paper firstly investigates the connection between efficiency and aesthetics. The last part of the paper investigates some temporary architectural pavilions from both an aesthetical and parametric point of view. In order to deepen our understanding of these structures, they are re-modelled according to a bottom-up approach by means of a constraint-based parametric CAD modeller. In this way, a reciprocal frame can be explored and modified by the parametric arrangement of its generative elements, which, like a natural organism, grows in self-generating forms.

Keywords: Aesthetics | Architectural pavilions | Natural form | Parametric modelling | Reciprocal Frame | Shell structure | Tessellation

[67] Gherardini F., Renzi C., Leali F., A systematic user-centred framework for engineering product design in small- and medium-sized enterprises (SMEs), International Journal of Advanced Manufacturing Technology, 91(5-8), 1723-1746, (2017). Abstract

Abstract: The systematic integration of user needs in the product design is a key issue in industry, especially for small- and medium-sized enterprises (SMEs), which suffer a lack of engineering methods and resources. Moreover, most of the approaches described in the literature are not flexible enough to be tailored on the SMEs’ needs, involve users only in the early design phases and are not fully accessible due to the high cost in their implementation. The present paper proposes a user-centred design methodological framework specifically focused on SMEs, which supports the designer from both design and manufacturing aspects along the engineering product design process. The framework integrates engineering methods with Web-based software tools, which enable the communication and the concurrent work of the design team, and supports direct participation of users. Beside state-of-the-art methods, the framework allows the integration of specifically tailored techniques. The framework is successfully validated through an industrial case study developed in collaboration with an Italian SME. As a result, the design of an injection-moulded housing and the related interfaces of a biomedical electronic device are achieved with a reduction of uncertainty and development time, by involving users throughout the design phases and suggesting methods and tools on the basis of the designers’ know-how and SME’s specific resources.

Keywords: Decision theory | Design methodology | Product design | QFD | SMEs | User-centred design

[68] Renzi C., Leali F., Di Angelo L., A review on decision-making methods in engineering design for the automotive industry, Journal of Engineering Design, 28(2), 118-143, (2017). Abstract

Abstract: Decision-making methods have proven to be an effective support to engineering design. However, it is proved that very often designers prefer tested procedures and experience-based approaches. Many reasons have been discussed in the literature, dealing with consolidated design habits of people and companies, high cost in terms of time consumption, and lack of tools and knowledge. The paper systematically investigates, through an extended critical review, how decision-making methods can be used by automotive designers to solve the most common engineering problems involved along the design process. In particular, the paper proposes an original classification of the most widely used decision-making methods in engineering design, a match between such techniques with the typical design phases, and a mapping of their application into the automotive field. This research can be considered as a further step to transfer the state-of-the-art knowledge on decision-making methods to the industrial context, establishing a common background for practitioners and researchers.

Keywords: automotive industry | Decision-making methods | engineering design | industrial design | product development

[69] Peroni M., Vergnano A., Leali F., Brentegani A., Design archetype of gears for knowledge based engineering, Lecture Notes in Mechanical Engineering, 0, 1131-1140, (2017). Abstract

Abstract: An engineering design process consists of a sequence of creative, innovative and routine design tasks. Routine tasks address well-known procedures and add limited value to the technical improvement of a product, even if they may require a lot of work. In order to focus designers work on added value tasks, the present work aims at supporting a routine task with a Design Archetype (DA). A DA captures, stores and reuses the design knowledge with a tool embedded in a CAD software. The DA algorithms drive the designer in selecting the most effective design concept to deliver the project requirements and then embody the concept through configuring a CAD model. Finally, a case study on the definition of a DA tool for gear design demonstrates the effectiveness of the DA tool.

Keywords: Computer Aided Design | Design Archetype | Design automation | Design knowledge | Engineering design

[70] Panari D., Renzi C., Vergnano A., Bonazzi E., Leali F., Integrated design method for optimal tolerance stack evaluation for top class automotive chassis, Lecture Notes in Mechanical Engineering, 2017, (2017). Abstract

Abstract: The tolerances of welded chassis are usually defined and adjusted in very expensive trials and errors on the shop floor. Computer Aided Tolerancing (CAT) tools are capable to optimize the tolerances of given product and process. However, the optimization is limited since the manufacturing process is already mostly defined by the early choices of product design. Therefore, we propose an integrated design method that considers the assembly operations before the detail design of the chassis and the concept design of the fixture system. The method consists in four phases, namely functional analysis in the CAD environment, as-sembly sequence modelling in the CAT tool, Design Of Simulation Experiment on the stack of the tolerance ranges and finally optimization of the tolerances. A case study on a car chassis demonstrates the effectiveness of the method. The method enables to selectively assign tight tolerances only on the main contributors in the stack, while generally requiring cheaper assembly operations. Moreover, a virtual fixture system is the input for the assembly equipment design as on optimized set of specifications, thus potentially reducing the number of trials and errors on the shop floor.

Keywords: 3D tolerancing | Car chassis | Computer aided tolerancing | Design op-timization | Tolerance allocation

[71] Bonazzi E., Colombini E., Panari D., Vergnano A., Leali F., Veronesi P., Numerical Simulation and Experimental Validation of MIG Welding of T-Joints of Thin Aluminum Plates for Top Class Vehicles, Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science, 48(1), 379-388, (2017). Abstract

Abstract: The integration of experiments with numerical simulations can efficiently support a quick evaluation of the welded joint. In this work, the MIG welding operation on aluminum T-joint thin plate has been studied by the integration of both simulation and experiments. The aim of the paper is to enlarge the global database, to promote the use of thin aluminum sheets in automotive body industries and to provide new data. Since the welding of aluminum thin plates is difficult to control due to high speed of the heat source and high heat flows during heating and cooling, a simulation model could be considered an effective design tool to predict the real phenomena. This integrated approach enables new evaluation possibilities on MIG-welded thin aluminum T-joints, as correspondence between the extension of the microstructural zones and the simulation parameters, material hardness, transient 3D temperature distribution on the surface and inside the material, stresses, strains, and deformations. The results of the mechanical simulations are comparable with the experimental measurements along the welding path, especially considering the variability of the process. The results could well predict the welding-induced distortion, which together with local heating during welding must be anticipated and subsequently minimized and counterbalance.

[72] Pini F., Ansaloni M., Leali F., Evaluation of operator relief for an effective design of HRC workcells, IEEE International Conference on Emerging Technologies and Factory Automation, ETFA, 2016-November, (2016). Abstract

Abstract: In recent years, Human Robot Cooperation (HRC) has found an increasing adoption in manufacturing, especially to help humans in the execution of manual assembly tasks. An effective employment of HRC encompasses human relief from exhausting operations. Therefore, the design of cooperative solutions should be developed accordingly to ergonomic aspects. The present work proposes an approach to support the integration of ergonomic evaluation of manual operations in the design of HRC solution, based on modelling and simulation of the human body along the manufacturing tasks. The proposed modified model integrates the ergonomic metrics and returns a fatigue level along the working shift scheduling. A real manual assembly of biomedical products has been selected to validate the proposed approach. As a result, the suggested fatigue model provides an objective ergonomic evaluation of manual operations which verifies the impact of the HRC solution on the production goals.

Keywords: Biomedical | Ergonomic evaluation | Human Robot Cooperation | Simulation

[73] Di Angelo L., Leali F., Di Stefano P., Can open-source 3D mechanical CAD systems effectively support university courses?, International Journal of Engineering Education, 32(3), 1313-1324, (2016). Abstract

Abstract: Most universities have introduced 3D CAD education and training in their engineering courses in recent years so as to respond to the actual needs of the industrial world for high-skilled design engineers. It is well demonstrated that the effectiveness of such courses depends on teaching an effective design approach rather than training for the use of specific commercial CAD tools. Since open-source CAD software has emerged in many fields as a promising alternative to commercial off-the-shelf systems, the present paper investigates the possibility for universities to adopt open-source instruments to effectively support their educational goals. Open-source 3D CAD systems are quantitatively evaluated by an original Compliance Index which considers the design tools typically used to model and draw industrial products and their weights in accomplishing the design tasks. The results obtained for the evaluation of a set of open-source CAD systems are presented and critically discussed.

Keywords: 3D CAD | CAD teaching | Open source 3D CAD | Software evaluation

[74] Gherardini F., Zardin B., Leali F., A parametric CAD-based method for modelling and simulation of positive displacement machines, Journal of Mechanical Science and Technology, 30(7), 3253-3263, (2016). Abstract

Abstract: We present an efficient and user-friendly parametric CAD-based design method for the graphical description of positive displacement machines, exploiting commercial parametric CAD software and a tailored interface. An executable module simulates the motion of the machine components, analyzes the machine geometry, and automatically extrapolates the geometrical data from the 3D CAD model, generating data files that can be directly used for following fluid dynamic analyses. The graphical approach supports investigation of the machine performance and exploring optimized design variants. The method has been applied to three industrial test cases: An external gear pump, an axial piston pump, and a gerotor pump. A complete case study focused on the external gear pump is proposed, as well as the results from the other two types are summarized. We validate the CAD-based method by comparing the obtained data with the data coming from the application of state-of-the-art analytical methods.

Keywords: CAD-based method | Engineering design | Graphical approach | Positive displacement machine | Software interface

[75] Leali F., Vergnano A., Pini F., Pellicciari M., Berselli G., A workcell calibration method for enhancing accuracy in robot machining of aerospace parts, International Journal of Advanced Manufacturing Technology, 85(1-4), 47-55, (2016). Abstract

Abstract: Industrial robotics provides high flexibility and reconfigurability supported by a user-friendly programming, but still lacks in accuracy. An effective workcell calibration reduces errors in robot manufacturing and enables robot machining applications. A novel workcell calibration method is embedded in an integrated design framework for an in-depth exploitation of CAD-based simulations and offline programming. The method is composed of two steps: first calibration of the workpiece-independent equipment in the workcell layout and final automated online calibration of workpiece-dependent equipment. The method is finally applied to a changeable robotic workcell for finishing aluminium cast housings for aerospace gear transmissions characterised by complex shapes and by close dimensional and geometrical specifications. Experimental results prove the method effectiveness in enhancing accuracy in robot machining.

Keywords: Aerospace industry | Industrial robotics | Integrated design | Workcell calibration

[76] Schneider U., Drust M., Ansaloni M., Lehmann C., Pellicciari M., Leali F., Gunnink J.W., Verl A., Improving robotic machining accuracy through experimental error investigation and modular compensation, International Journal of Advanced Manufacturing Technology, 85(1-4), 3-15, (2016). Abstract

Abstract: Machining using industrial robots is currently limited to applications with low geometrical accuracies and soft materials. This paper analyzes the sources of errors in robotic machining and characterizes them in amplitude and frequency. Experiments under different conditions represent a typical set of industrial applications and allow a qualified evaluation. Based on this analysis, a modular approach is proposed to overcome these obstacles, applied both during program generation (offline) and execution (online). Predictive offline compensation of machining errors is achieved by means of an innovative programming system, based on kinematic and dynamic robot models. Real-time adaptive machining error compensation is also provided by sensing the real robot positions with an innovative tracking system and corrective feedback to both the robot and an additional high-dynamic compensation mechanism on piezo-actuator basis.

Keywords: Error compensation | Optical tracking | Robot dynamics | Robot modelling | Robotic machining

[77] Renzi C., Leali F., A Multicriteria Decision-Making Application to the Conceptual Design of Mechanical Components, Journal of Multi-Criteria Decision Analysis, 23(3-4), 87-111, (2016). Abstract

Abstract: Early design is crucial for the success of the final product. In the conceptual design phase, several constraints, criteria, objectives and disciplines have to be considered. To this aim, multidisciplinary optimization has proven effective for the solution of engineering design problems, even in the industrial every-day practice, to improve and simplify the work of designers in a successful quest of the best compromise solution. In this paper, a multicriteria decision-making (MCDM)-based design platform for early optimal design of industrial components is proposed. In a group decision-making context, the selection of the most suitable component among several possible layouts is performed by means of a group Fuzzy Technique for Order of Preference by Similarity to Ideal Solution approach. Hence, a multi-objective optimization is performed on the selected component by applying a multi-objective particle swarm optimization for finding optimal component dimensions. An industrial case study is presented for showing the efficiency of the multicriteria decision-making-based design platform, regarding an innovative and low-cost solution to increase the duration of heel tips in women’s shoes.

Keywords: conceptual design | design optimization | Fuzzy TOPSIS | group multicriteria decision-making | multi-objective particle swarm optimization

[78] Gherardini F., Leali F., A Framework for 3D Pattern Analysis and Reconstruction of Persian Architectural Elements, Nexus Network Journal, 18(1), 133-167, (2016). Abstract

Abstract: Persian architecture is characterised by shapes and patterns, which can be analysed through mathematical models. Beside 2D patterns, many of the traditional geometric ornaments are realised on 3D surfaces such as domes or vaults. Literature mainly addresses the 3D problem by means of a 2D scheme, which is an important and synthetic representation but is not exhaustive and lacks of clarity. This paper proposes a framework based on the integration of 2D drawings, as in the traditional approach, and a photogrammetric 3D model based on a sample of standard resolution images (tourist pictures). The framework is tested on a muqarnas, a characteristic Persian ornament, in order to study and analyse its modular design and hierarchy of elements. As a case study, the entrance iwan of the Shah Mosque in Isfahan, Iran, is considered. The result is a link between the 3D patterns and the geometry of architectural elements, which completes and overcomes their schematic 2D representation.

Keywords: CAD modelling | Geometric analysis | Iwan | Modules | Muqarnas | Persian ornament | Representation of architecture

[79] Pini F., Ferrari C., Libbra A., Leali F., Muscio A., Robotic implementation of the slide method for measurement of the thermal emissivity of building elements, Energy and Buildings, 114, 241-246, (2016). Abstract

Abstract: A significant interest exists in measuring the thermal emissivity of building surfaces since high values combined with high solar reflectance allow rejecting solar energy absorbed by irradiated surfaces, whereas intermediate or low values permit to limit condensation of humidity, heat loss to the sky, or heat transfer through airspaces. The most used measurement method is probably that described by the ASTM C1371 Standard, which correlates the thermal emissivity to the radiative heat flux exchanged in the infrared between the sample surface, kept at ambient temperature, and the bottom surface of a hot emissometer head. With samples showing a low thermal conductivity, the 'slide method' modification is generally used: the hot head is allowed to slide above the sample in order to prevent this from warming up. The slide movement, however, is carried out by hand and time is needed to achieve a stabilized output, therefore the measurement may be time-consuming and also affected by the operator. In order to solve both problems, an automated approach is proposed here, in which the head is moved by the arm of a robot. This manages either the slide movement or the calibration with reference samples, interacting with a computerized data acquisition system that monitors the emissometer output.

Keywords: Cool roof | Emissivity | Emissometer | Infrared emittance | Infrared radiation | Measurement | Slide method | Thermal emittance

[80] Vergnano A., Renzi C., Leali F., Redesign for environment of wooden packaging for bulk recycling and recovery, ARPN Journal of Engineering and Applied Sciences, 11(1), 528-535, (2016). Abstract

Abstract: Society increasingly demands for effective waste management policies to make industries more environmentally sustainable. Organizations are even issuing directives to drive choices about these policies. In particular, modern industries produce a lot of packaging, which soon become waste, even before product usage. Research can face the problem with improvements in recycling and recovery processes. However, even if recycling and recovery would enable waste to have still a value, most costs and benefits are determined at the design stage. Therefore, Design for Environment criteria must be adopted in the design tasks, from the early conceptual design when the main design solutions are defined. The design criteria to assess possible design choices must consider all the environmental impacts of packaging over its lifecycle. The present work focuses on Redesign for Environment of packaging solutions. Following a systematic design process, we use different criteria to evaluate the effects of design solutions on packaging, since waste can be seen just as one of the main phases of packaging life. To this purpose, we adopt the stages of the waste hierarchy set by the EU Waste Framework Directive 2008/98/EC as design evaluation criteria. The waste hierarchy sets a priority order for five life cycle stages that a packaging can go through. The stages of the hierarchy can be differently weighted according to the costs and benefits they involve. The proposed Design for Environment method based on the waste hierarchy criteria is finally applied in the redesign of an industrial case study. The packaging solution as foldable wooden crates were chosen for their capability to already comply with the first stages of the hierarchy, that is reducing waste with high customization to customer requirements and crate reuse. Hence, the case study improved the next stages with easing the wood recycle and recovery processes.

Keywords: Design for environment | Foldable wooden crates | Packaging | Recovery | Recycling | Waste hierarchy

[81] Pini F., Leali F., Ansaloni M., A systematic approach to the engineering design of a HRC workcell for bio-medical product assembly, IEEE International Conference on Emerging Technologies and Factory Automation, ETFA, 2015-October, (2015). Abstract

Abstract: Human Robot Collaboration (HRC) have proved to be effective if compared to traditional hybrid automation in assembly tasks, especially when human-like sensitivity and high quality are required. However, a rigorous engineering design is mandatory in order to successfully apply HRC to Industry. Academy and Industry are asked to jointly work for exploiting the technical opportunities given by robots and humans. Scientific literature often describes the application of HRC in manufacturing but rarely presents systematic engineering design approaches. The present paper investigates and describes the systematic design of a HRC workcell for assembling bio-medical products. Moreover, productivity and profitability of the developed solution are evaluated and discussed.

Keywords: Assembly | Biomedical products | Human-Robot Collaboration

[82] Renzi C., Leali F., Pellicciari M., Andrisano A.O., Berselli G., Selecting alternatives in the conceptual design phase: an application of Fuzzy-AHP and Pugh’s Controlled Convergence, International Journal on Interactive Design and Manufacturing, 9(1), 1-17, (2015). Abstract

Abstract: The selection of conceptual design alternatives is crucial in product development. This is due both to the fact that an iterative process is required to solve the problem and that communication among design team members should be optimized. In addition, several design constraints need to be respected. Although the literature offers several alternative selection methods, to date, only very few are currently being used in industry. A comparison of the various approaches would improve the knowledge transfer between design research and practice, helping practitioners to approach these decision support tools more effectively. This paper proposes a structured comparison of two decision support methods, namely the Fuzzy-Analytic Hierarchy Process and Pugh’s Controlled Convergence. From the literature debate regarding selection methods, four relevant criteria are identified: computational effort, suitability for the early design stages, suitability for group decision making, and ease of application. Finally a sensitivity analysis is proposed to test the robustness of each method. An industrial case study is described regarding an innovative and low-cost solution to increase the duration of heel tips in women’s shoes. The selection of conceptual design alternatives of the heel tip presents complex challenges because of the extremely difficult geometric constraints and demanding design criteria.

Keywords: Concept selection | Engineering design methods | Fuzzy-analytic hierarchy process | Pugh’s controlled convergence

[83] Pini F., Leali F., Ansaloni M., Offline workpiece calibration method for robotic reconfigurable machining platform, 19th IEEE International Conference on Emerging Technologies and Factory Automation, ETFA 2014, (2014). Abstract

Abstract: Recent trends in industrial manufacturing impose the adoption of changeable systems, based on reconfigurable and flexible equipment. In this scenario, industrial robotics platforms are central to design highly reconfigurable systems. A Robotic Reconfigurable Machining Platform (RRMP), as defined, is a modular architecture for robotic workcells, designed in order to exploit the flexibility features of robots and extend their field of application to high precision machining. RRMP calibration is a key task, which involves calibration of tools, workpieces and peripherals. However, state-of-the-art calibration methods and tools lead to hardly predictable system downtime, which impacts the reconfiguration phase. A novel method to perform the workpiece calibration is proposed for the reduction of the reconfiguration efforts in RRMPs. The method is addressed through a full integration with a virtual environment for robot simulation and programming. The method is finally applied to an industrial case study and compared to the most widely diffused online approach.

Keywords: Robot offline programming | Robotic machining | Workpiece calibration

[84] Renzi C., Leali F., Cavazzuti M., Andrisano A.O., A review on artificial intelligence applications to the optimal design of dedicated and reconfigurable manufacturing systems, International Journal of Advanced Manufacturing Technology, 72(1-4), 403-418, (2014). Abstract

Abstract: Reconfigurable manufacturing systems (RMS) are considered the future of manufacturing, being able to overcome both dedicated (DMS) and flexible manufacturing systems (FMS). In fact, they provide significant cost and time reductions in the launch of new products, and in the integration of new manufacturing processes into existing systems. The goals of RMS design are the extension of the production variety, the adaption to rapid changes in the market demand, and the minimization of the investment costs. Despite the interest of many authors, the debate on RMS is still open due to the lack of practical applications. This work is a review of the state-of-The-art on the design of cellular RMS, compared to DMS, by means of optimization. The problem addressed belongs to the NP-Hard family of combinatorial problem. The focus is on non-exact meta-heuristic and artificial intelligence methods, since these have been proven to be effective and robust in solving complex manufacturing design problems. A wide investigation on the most recurrent techniques in DMS and RMS literature is performed at first. A critical analysis over these techniques is given in the end. © 2014 Springer-Verlag London.

Keywords: Artificial intelligence | Cellular manufacturing systems | Industrial design | Meta-heuristics | Optimization | Reconfigurable manufacturing systems

[85] Halbauer M., Lehmann C., Städter J.P., Berger U., Leali F., Milling strategies optimized for industrial robots to machine hard materials, IEEE International Conference on Emerging Technologies and Factory Automation, ETFA, (2013). Abstract

Abstract: Industrial robots offer a good basis for machining from a conceptual point of view. Still they are rarely utilized for machining applications in industry compared to CNC machines due to their low stiffness and the bad achievable work piece quality. Available compensation approaches, like online compensation approaches to increase position accuracy using costly additional hardware and measurement equipment as well as offline compensation approaches using a set of empirical measurement data and models to predict deviation, try to compensate errors whether to already avoid them if possible. In this paper milling and robot strategies are proposed to increase work piece quality without additional hardware or models. Experimental validations of the results have been performed for different kinds of shapes and materials. © 2013 IEEE.

[86] Pellicciari M., Berselli G., Balugani F., Meike D., Leali F., On designing optimal trajectories for servo-actuated mechanisms through highly detailed virtual prototypes, 2013 IEEE/ASME International Conference on Advanced Intelligent Mechatronics: Mechatronics for Human Wellbeing, AIM 2013, 1780-1785, (2013). Abstract

Abstract: Servo-actuated mechanisms are increasingly sub-stituting fully mechanical drives in order to increase flexibility and reconfigurability of modern automatic machines. The overall servomechanism performance, especially in the case of high-dynamic motions, is the direct consequence of several interacting factors, namely electric motor and linkage dynamics, controller efficacy, and requested motion law. In particular, Point-To-Point (PTP) trajectories are usually designed in order to comply with technological constraints, imposed by the required interaction with the handled product, and to maximize some optimality criterion such as, for instance, energy efficiency or limited actuation torques. In this context, the present paper proposes a novel method for generating either energy-optimal or torque-optimal PTP motions described by piecewise fifth-order polynomials. The optimization cost functions are based on a virtual prototype of the system, which comprises behavioral models of power converter, controller and electric motor coupled with the mechanical system. Results are then compared with experimental data obtained on a physical prototype. The comparison quantitatively shows that better-behaved PTP trajectories can be designed by including the dynamic contribution of each sub-system component. © 2013 IEEE.

Keywords: Servo-Actuated Mechanism | Trajectory Generation | Virtual Prototyping

[87] Ansaloni M., Bonazzi E., Leali F., Pellicciari M., Berselli G., Design of fixture systems in automotive manufacturing and assembly, Advanced Materials Research, 712-715, 2913-2916, (2013). Abstract

Abstract: Fixture systems have a great importance in modern manufacturing and assembly because of the high number of scenarios in which they are used. Fixture design is a complex task since the system effectiveness depends both on position and type of locators. Several authors deal with the problem of determine the most suitable design for fixture systems but their investigation is commonly limited to the evaluation of the effects due to the locators' position. In the present work a design method is proposed to evaluate the fixture systems considering also the locators' type. Since it is possible to model the fixtures as multi-performance systems, the comparison is performed by introducing appropriate sensitivity indexes. The effectiveness of the design method is proved through the application to an automotive case study. © (2013) Trans Tech Publications, Switzerland.

Keywords: Automotive | Design for manufacturing | Fixture system | Tolerance analysis

[88] Pellicciari M., Berselli G., Ori M., Leali F., The role of co-simulation in the integrated design of high-dynamics servomechanisms: An experimental evaluation, Applied Mechanics and Materials, 278-280, 1758-1764, (2013). Abstract

Abstract: This paper reports about the design and modeling process of high performance servo-actuated mechanisms for automatic machines.Besides being a delicate and time consuming process, coupled simulations based on virtual prototyping finally offer the chance to integrate engineering methods proper of control system engineering and mechanical design. In particular, the main target of this work isto investigate how different virtual prototyping approaches, each havingincreasing level of detail, can contribute to the appropriate prediction of the expected machine performance.These results are then compared with experimental data obtained on a real servomechanism prototype. The comparison quantitatively demonstrate the improvement on torque prediction and position error reduction when detailed models of the controller and the electric motor dynamics are coupled with the mechanical system model. © (2013) Trans Tech Publications, Switzerland.

Keywords: Co-simulation | Digital product design | Integrated mechatronic design | Virtual prototyping

[89] Leali F., Pini F., Ansaloni M., Integration of CAM off-line programming in robot high-accuracy machining, 2013 IEEE/SICE International Symposium on System Integration, SII 2013, 580-585, (2013). Abstract

Abstract: Actual industrial robotic systems offer performance to effectively cope with the requirements in manufacturing dealing with flexibility and quality. However, their known limits in accuracy do not allow to extend their field of application to high-accuracy machining, actually covered by state-of-the-art CNC machine tools. The European Project COMET has recently proposed an approach to develop a robotic reconfigurable workcell with enhanced accuracy for machining, through the full integration of different theoretical models, technological solutions and manufacturing strategies. The present paper presents and demonstrates the effectiveness of a demo reconfigurable machining workcell for one of its possible configurations, based on CAM off-line programming. In particular, an experimental campaign has been designed and realized in order to discuss the dimensional and geometrical quality obtained for an aluminium automotive part in comparison with quality and costs offered by a standard 5-axis CNC machine tool. © 2013 IEEE.

[90] Schneider U., Ansaloni M., Drust M., Leali F., Verl A., Experimental investigation of sources of error in Robot Machining, Communications in Computer and Information Science, 371, 14-26, (2013). Abstract

Abstract: This document is divided into two parts. First a survey is given presenting sources of error in robot machining and outlining their dependencies. Environment dependent, robot dependent and process dependent errors are addressed. The second part analyses the errors according to their source, magnitude and frequency spectrum. Experiments under different conditions represent a typical set of industrial applications and allow a qualified evaluation. This analysis enables the qualified choice of suitable compensation mechanisms in order to reduce the errors in robot machining and to increase machining accuracy. © Springer-Verlag Berlin Heidelberg 2013.

Keywords: Robot compensation | Robot dynamics | Robot precision | Robotic machining

[91] Leali F., Pellicciari M., Pini F., Vergnano A., Berselli G., A calibration method for the integrated design of finishing robotic workcells in the aerospace industry, Communications in Computer and Information Science, 371, 37-48, (2013). Abstract

Abstract: Industrial robotics provides high flexibility and reconfigurability, cost effectiveness and user friendly programming for many applications but still lacks in accuracy. An effective workcell calibration reduces the errors in robotic manufacturing and contributes to extend the use of industrial robots to perform high quality finishing of complex parts in the aerospace industry. A novel workcell calibration method is embedded in an integrated design framework for an in-depth exploitation of CAD-based simulation and offline programming. The method is composed of two steps: a first offline calibration of the workpiece-independent elements in the workcell layout and a final automated online calibration of workpiece-dependent elements. The method is finally applied to a robotic workcell for finishing aluminum housings of aerospace gear transmissions, characterized by complex and non-repetitive shapes, and by severe dimensional and geometrical accuracy demands. Experimental results demonstrate enhanced performances of the robotic workcell and improved final quality of the housings. © Springer-Verlag Berlin Heidelberg 2013.

Keywords: Aerospace industry | Industrial robotics | Integrated design | Workcell calibration

[92] Leali F., Pellicciari M., Pini F., Berselli G., Vergnano A., An offline programming method for the robotic Deburring of aerospace components, Communications in Computer and Information Science, 371, 1-13, (2013). Abstract

Abstract: Deburring of aerospace components is a complex task in case of large single pieces designed and optimized to deliver many mechanical functions. A constant high quality requires accurate 3D surface contouring operations with engineered tool compliance and cutting power. Moreover, aeronautic cast part production is characterized by small lot sizes with high variability of geometries and defects. Despite robots are conceived to provide the necessary flexibility, reconfigurability and efficiency, most robotic workcells are very limited by too long programming and setup times, especially at changeover. The paper reports a design method dealing with the integrated development of process and production system, and analyzes and compares a CAD-based and a digitizer-based offline programming strategy. The deburring of gear transmission housings for aerospace applications serves as a severe test field. The strategies are compared by the involved costs and times, learning easiness, production downtimes and machining accuracy. The results show how the reconfigurability of the system together with the exploitation of offline programming tools improves the robotic deburring process. © Springer-Verlag Berlin Heidelberg 2013.

Keywords: CAD-based tools | Digitizers | Industrial robotics | Integrated design | Offline programming

[93] Pellicciari M., Berselli G., Leali F., Vergnano A., A method for reducing the energy consumption of pick-and-place industrial robots, Mechatronics, 23(3), 326-334, (2013). Abstract

Abstract: The interest in novel methods and tools for opt imizing the energy consumption in robotic systems is cur- rently increasing. From an industrial point of view,it is desirable to develop energy saving strategies also applicable to established manufacturing systems with no need for either hardware substitu tion or further investme nts. Within this scenario,the present paper reports amethod for reducing the total energy con- sumption of pick-and-place manipulators for given TCP position profiles.Firstly,electromechanical mod- els of both serial and parallel manipulators are derive d.Then,the energy-optimal trajectories are calculated, by means of constant time scaling,starting from pre-scheduled trajectories comp atible with the actuation limits. In this manner,the robot work cycle can be energetically optimized also when the TCP position profiles have been already definedon the basis of technological constraints and/or design choices aimed at guarante eing manufacturing process efficacy/robustness.The effectiveness of the pro- posed procedure is finallyevaluated on two simulation case studies. Copyright © 2013 Published by Elsevier Ltd. All rights reserved.

Keywords: Electromechanical modeling | Energy efficiency | Robotic manufacturing | Virtual prototyping

[94] Pellicciari M., Leali F., Andrisano A.O., Pini F., Enhancing changeability of automotive Hybrid Reconfigurable Systems in digital environments, International Journal on Interactive Design and Manufacturing, 6(4), 251-263, (2012). Abstract

Abstract: Changeability accomplishes the engineering design of competitive sustainable manufacturing systems, considered as industrial products characterized by inherent life cycle. Main drivers for changeability are manufacturing system reconfigurability and hybridization. A Hybrid Reconfigurable System (H-RS) is characterized by the coexistence and cooperation of industrial robots and skilled human workers to perform complex tasks within a common reconfigurable production environment. H-RSs rise use-productivity along their total system life cycle, fostering the evaluation and implementation of feasible and innovative technologies, and increasing the utilization ratio and the multiple use-or re-use-of resources. The paper proposes an engineering method which aims at enhancing changeability in H-RSs through the application of a multi level reconfigurability approach within a digital environment. The method includes the advanced design and modeling of digital devices which embed mechanics, electronics, control logic and software code. Advanced models are exploited to analyze the system performance in the system domain of changes and to realize an effective human training. An industrial case study describes the application of the method to the design of a hybrid reconfigurable workcell for manufacturing and assembly of top class car chassis. © 2012 Springer-Verlag.

Keywords: Automotive | Changeability | Digital environment | Hybrid Reconfigurable System

[95] Vergnano A., Thorstensson C., Lennartson B., Falkman P., Pellicciari M., Leali F., Biller S., Modeling and optimization of energy consumption in cooperative multi-robot systems, IEEE Transactions on Automation Science and Engineering, 9(2), 423-428, (2012). Abstract

Abstract: Reduction of energy consumption is important for reaching a sustainable future. This paper presents a novel method for optimizing the energy consumption of robotic manufacturing systems. The method embeds detailed evaluations of robots' energy consumptions into a scheduling model of the overall system. The energy consumption for each operation is modeled and parameterized as function of the operation execution time, and the energy-optimal schedule is derived by solving a mixed-integer nonlinear programming problem. The objective function for the optimization problem is then the total energy consumption for the overall system. A case study of a sample robotic manufacturing system and an experiment on an industrial robot are presented. They show that there exists a real possibility for a significant reduction of the energy consumption in comparison to state-of-the-art scheduling approaches. © 2012 IEEE.

Keywords: Energy optimization | mathematical programming | robot cells | scheduling and coordination | system modeling and simulation

[96] Andrisano A.O., Leali F., Pellicciari M., Pini F., Vergnano A., Hybrid Reconfigurable System design and optimization through virtual prototyping and digital manufacturing tools, International Journal on Interactive Design and Manufacturing, 6(1), 17-27, (2012). Abstract

Abstract: Engineering changeability-oriented and cost-driven approaches are needed by enterprises to design and optimize manufacturing and assembly systems for the demanding production requirements of the present industrial scenario. The integrated design of Reconfigurable Systems addresses tailored flexibility through modularity, integrability of resources, product and process customization, and system convertibility and diagnosability. The cooperation of robot and humans in hybrid environments offers a good trade-off between changeability, high quality and low costs, by exploiting the human dexterity and cognitive proactivity, together with robotic accuracy and performances. Virtual prototyping methods and digital manufacturing solutions are now mature and effective enough to play a strategic role within the hybrid reconfigurable system (H-RS) design and optimization process. The present research work proposes an engineering method to design and optimize H-RSs, by using virtual prototyping and digital manufacturing as a strategic support for the analysis and synthesis of the technical solutions, especially those related to human-robot cooperation. An industrial case study on a hybrid reconfigurable assembly system of a top class car aluminum chassis is finally presented. © 2011 Springer-Verlag.

Keywords: Automotive industry | Digital manufacturing | Hybrid reconfigurable system | Virtual prototyping

[97] Pellicciari M., Berselli G., Leali F., Vergnano A., A minimal touch approach for optimizing energy efficiency in pick-and-place manipulators, IEEE 15th International Conference on Advanced Robotics: New Boundaries for Robotics, ICAR 2011, 100-105, (2011). Abstract

Abstract: The interest in novel engineering methods and tools for optimizing the energy consumption in robotic systems is currently increasing. In particular, from an industry point of view, it is desirable to develop energy saving strategies applicable also to established manufacturing systems, being liable of small possibilities for adjustments. Within this scenario, an engineering method is reported for reducing the total energy consumption of pick-and-place manipulators for given end-effector trajectory. Firstly, an electromechanical model of parallel/serial manipulators is derived. Then, an energy-optimal trajectory is calculated, by means of time scaling, starting from a pre-scheduled trajectory performed at maximum speed (i.e. compatible with actuators limitations). A simulation case study finally shows the effectiveness of the proposed procedure. © 2011 IEEE.

Keywords: energy efficiency | Pick-and-place manipulators

[98] Pellicciari M., Berselli G., Leali F., Vergnano A., Lennartson B., Object-oriented modeling of industrial manipulators with application to energy optimal trajectory scaling, Proceedings of the ASME Design Engineering Technical Conference, 5(PARTS A AND B), 997-1006, (2011). Abstract

Abstract: The development of safe, energy efficient mechatronic systems is currently changing standard paradigms in the design and control of industrial manipulators. In particular, most optimization strategies require the improvement or the substitution of different system components. On the other hand, from an industry point of view, it would be desirable to develop energy saving methods applicable also to established manufacturing systems being liable of small possibilities for adjustments. Within this scenario, an engineering method is reported for optimizing the energy consumption of serial manipulators for a given operation. An object-oriented modeling technique, based on bond graph, is used to derive the robot electromechanical dynamics. The system power flow is then highlighted and parameterized as a function of the total execution times. Finally, a case study is reported show- ing the possibility to reduce the operation energy consumption when allowed by scheduling or manufacturing constraints. Copyright © 2011 by ASME.

[99] Vergnano A., Thorstensson C., Lennartson B., Falkman P., Pellicciari M., Yuan C., Biller S., Leali F., Embedding detailed robot energy optimization into high-level scheduling, 2010 IEEE International Conference on Automation Science and Engineering, CASE 2010, 386-392, (2010). Abstract

Abstract: Reduction of energy consumption is important for reaching a sustainable future. This paper presents a novel method for optimizing the energy consumption of robotic manufacturing systems. The method embeds detailed evaluations of robots' energy consumptions into a scheduling model of the overall system. The energy consumption for each operation is modelled and parameterized as function of the operation execution time, and the energy-optimal schedule is derived by solving a mixed-integer nonlinear programming problem. The objective function for the optimization problem is then the total energy consumption for the overall system. A case study of a sample robotic manufacturing system is presented. It shows that there exists a possibility for a significant reduction of the energy consumption, in comparison to state-of-the-art scheduling approaches. © 2010 IEEE.

[100] Liverani A., Leali F., Pellicciari M., Real-time 3D features reconstruction through monocular vision, International Journal on Interactive Design and Manufacturing, 4(2), 103-112, (2010). Abstract

Abstract: A fast and interactive implementation for camera pose registration and 3D point reconstruction over a physical surface is described in this paper. The method (called SRE-Smart Reverse Engineering) extracts from a continuous image streaming, provided by a single camera moving around a real object, a point cloud and the camera's spatial trajectory. The whole per frame procedure follows three steps: camera calibration, camera registration, bundle adjustment and 3D point calculation. Camera calibration task was performed using a traditional approach based on 2-D structured pattern, while the Optical Flow approach and the Lucas-Kanade algorithm was adopted for feature detection and tracking. Camera registration problem was then solved thanks to the Essential Matrix definition. Finally a fast Bundle Adjustment was performed through the Levenberg-Marquardt algorithm to achieve the best trade-off between 3D structure and camera variations. Exploiting a PC and a commercial webcam, an experimental validation was done in order to verify precision in 3D data reconstruction and speed. Practical tests helped also to tune up several optimization parameters used to improve efficiency of most CPU time consuming algorithms, like Optical Flow and Bundle Adjustment. The method showed robust results in 3D reconstruction and very good performance in real-time applications. © 2010 Springer-Verlag.

Keywords: 3D vision | Interactive modeling | Reverse engineering | Shape reconstruction | Surface remodeling

[101] Pellicciari M., Andrisano A.O., Leali F., Vergnano A., Engineering method for adaptive manufacturing systems design, International Journal on Interactive Design and Manufacturing, 3(2), 81-91, (2009). Abstract

Abstract: Adaptive manufacturing systems achieve intelligence and adaptation capabilities through the close interaction between mechanics, electronics, control and software engineering. Mechatronic design of intelligent manufacturing behaviours is of paramount importance for the final performances of complex systems and requires deep integration between mechanical and control engineering. Virtual Commissioning environments offer engineers new opportunities for the design of complex intelligent behaviours and for the enhancement of the performance of adaptive manufacturing systems. This paper discloses a systematic design method focused on interdisciplinary behavioural simulations: Virtual Commissioning tools are used to virtually explore new solution spaces for an effective mechatronic optimization. The results, achieved by applying the method in reengineering a module of an automotive sensor manufacturing line, are finally presented. © 2009 Springer-Verlag.

Keywords: Computer aided engineering | Mechatronic design | Virtual commissioning

[102] Bassoli E., Gatto A., Iuliano L., Leali F., Design for manufacturing of AN ergonomic joystick handgrip, Image Processing, Biomedicine, Multimedia, Financial Engineering and Manufacturing - Proceedings of the Sixth Biannual World Automation Congress, 461-466, (2004). Abstract

Abstract: A Reverse Engineering- (RE) and Rapid Prototyping- (RP) based approach to (he development of a joystick handgrip with ergonomic features has been elaborated. The integration of Time Compression Techniques and Computer Aided Tools lead to a time-saving procedure for the design of a product whose ergonomic quality directly descends from users' sensations of comfort. The CAD model availability throughout the progressive steps of product development ensured all the potentialities of Concurrent Engineering, while Computer Aided Engineering (CAE) simulation on the definitive geometry allowed to close the Computer Integrated loop to the manufacturing process.

Keywords: Computer Aided Engineering | Design for Manufacturing | Ergonomics | Product Development | Reverse Engineering