Product design and engineering

Color match prediction is one of the most important aspects to be considered by industries dealing with colorants. Several generally applicable theoretical models have been proposed so far for helping the colorists in achieving an exact color match. Such approaches, often based on extensive experimental tests and provided of exhaustive results, are differentiated by a specific range of application (textiles, study, paintings, etc.). Therefore, the results are subjected to restrictions or constraints (number of colorants, reliability of the prediction, etc.). The present paper describes, into a mathematical form, three widely known techniques adopted in the scientific literature for evaluating the spectrophotometric color match prediction of a target shade: Kubelka-Munch, Steams-Noechel and Artificial Neural Networks. The proposed method starts from such wide known methodologies and by means of mathematical assessment provides some useful equations to be straightforwardly used for color matching. Moreover an Artificial Neural Network based formulation is provided. The results of the work shows that the expected color distance between the predicted the real color of a shade is less than 0.8, in terms of CTEL*a*b* distance. © 2010 Asian Network for Scientific Information.

Keywords: Absorptivity and the scattering , Color distance , Color formulation , Color matching transfer function , Reflectance

The color and the color stability of a fabric dyed with a jigger machine are highly dependent on the color of the dyes and on technological parameters, such as the process temperature, pH of the dyebath, and time of dyeing. On the basis of their skill, colorists are capable of choosing the technological parameters and the recipes for dyes in order to obtain the desired dyed fabric. However, they need to perform many tests before reaching the preferred product. As a matter of fact, a straightforward relationship between the color of dyes, process parameters, and final color and color solidity is not found in literature. The present work aims to help the colorist in predicting the color and the color stability of the fabric, without the needing to physically dye it. In detail the paper describes a tool, based on the Cascade Neural Network (CNN), that is able to receive the value of some colorimetric and technological parameters as input and to predict, as output, the color appearance and the color solidity of a fabric dyed with a jigger machine. The CNN is composed of a “color prediction module” (ANN I) and a “color solidity prediction module” (ANN II) that work in cascade. The CNN has been validated by means of a large set of experiments. The mean error between the color prediction and the real values of the dyed fabric, in terms of CIE 1976 (L*, a*, b*) color distance, is equal to 0.47 with a variance of 0.031. The maximum color solidity prediction error is 0.5. © 2010, SAGE Publications. All rights reserved.

The development of vehicles for the exploration in the lunar environment is a topic of great interest. In particular, recently, there has been a growing attention toward the lunar rovers for working missions since the building of lunar bases is a primary objective for the lunar exploration. However, these vehicles have peculiar requirements to be taken into account in the design of each component. In this paper a particular component of a worker rover, developed as a collaboration between two academic institutions, has been designed for an optimal functionality. Each leg of this rover comprises a mechanism for lifting weights and the component considered, a decoupling joint, is a part of this mechanism. The design optimization was performed by means of parametric modelling and numerical simulations.

Keywords: Decoupling joint , Design , Lunar rover

Topological optimization (TO) tools are today widely employed in several engineering fields (e.g., construction, aeronautics, aerospace, and automotive). The diffusion of these tools is due to their capacity to improve mechanical properties of products through a global optimization of the product in terms of weight, stiffness, strength, and cost. On the other hand, the adoption of TO tools still requires a sizeable organizational effort because, at present, these tools are mostly stand-alone and are not well integrated into the product development process (PDP). This paper presents an innovative methodology that supports designers and analysts in formalizing and transmitting design choices taken during project activities and in making the integration of TO tools in the PDP more efficient. The methodology clearly defines the roles, the activities, the data to exchange, and the software tools to be used in the process. Some custom computer-aided design automation tools have been implemented to improve the efficiency of the methodology. Moreover, this paper defines an original procedure to support the interpretation of the TO results. © 2010 American Society of Mechanical Engineers.

Keywords: CAD automation , knowledge management , topology optimization

This paper presents a methodology in which CAD, a multi-body simulator and a topological optimization tool are synergically employed in order to support the design of a suspension component. In particular, the methodology defines some guidelines and introduces two Knowledge Based interfaces able to facilitate the integration of topological optimization of the component within a standard design process. In order to illustrate this capability, the process is applied to the conceptual design of the Upright for a Formula SAE prototype. The results show that the integrated design approach can efficiently support the selection of the optimum conceptual design of a mechanical component with complex dynamic behaviour, in particular when very little previous experience on the system is available. © Organizing Committee of TMCE 2010 Symposium.

Keywords: Integrated approach , Knowledge based engineering , Multi-body , Topological optimization

This paper deals with the study, design, manufacturing & testing of a particular scientific instrument, functional to investigate hydrostatic bushing behaviour under various experimental conditions. Job was conducted in concurrence with one of the leading companies in rotary transfer machines business. Machining is performed by hydrostatic unit, in which spindle assembly is contained in a sliding tube supported by a set of hydrostatic bushings. In this paper we will detail the design of a "research & test" bench whose aim is to help in developing new hydrostatic bushing systems.

Keywords: Design , Hydrostatic , Spindle , Test bench

In this paper we study the feasibility of developing a search engine capable of retrieving images from a granite image database based on a query image that is similar to the intended targets. The main focus was on the determination of the set of colour and/or texture features which yields highest retrieval accuracy. To assess the performance of the considered image descriptors we created a granite image database, formed by images recorded at our laboratory as well as taken from the Internet. Experimental results show that colour and texture features can be successfully employed to retrieve granite images from a database. We also found that improved accuracy is achieved by combining different colour and texture feature sets through classifier fusion schemes.

Keywords: CBIR , Colour , Granite , Image retrieval systems , Texture , Visual appearance

This paper describes a framework based on a publish/subscribe paradigm for interprocess communication based on XML messages sent over a TCP/IP connection. The framework manages the exchange of data within the clients of a system and permits the definition of a specific behavior for each client using a finite-state machine approach. Whilst the server-side of the framework is able to receive and dispatch events and data, the client-side of the framework is modeled as a finite-state machine able to perform state transitions after receiving the correct message. This architecture permits the loose-coupling between producers and consumers of data and the bidirectional mapping between the design of the behavior of a system and its implementation. © 2010 IEEE.

This paper addresses issues related to the assessment of product designs that today successfully uses virtual prototyping methods and techniques. Design assessment is usually performed by engineers and designers. Current trend is involving customers in the products design assessment in order to check the level of acceptability and satisfaction before proceeding with the production. In this view, methods for design review may be used in participatory design sessions where customers can intervene for customizing products. The paper presents a tool that has been originally developed for designers for the validation and modification of aesthetic properties of digital shapes, and that has also been used by customers, in participatory design sessions, for customizing their products. Copyright © 2010 by ASME.

Most of the activities concerning the design review of new products based on Virtual Reality are conducted from a visual point of view, thus limiting the realism of the reviewing activities. Adding the sense of touch and the sense of hearing to traditional virtual prototypes, may help in making the interaction with the prototype more natural, realistic and similar to the interaction with real prototypes. Consequently, this would also contribute in making design review phases more effective, accurate and reliable. In this paper we describe an application for product design review where haptic, sound and vision channels have been used to simulate the interaction with a household appliance. © 2010 Springer-Verlag.

Keywords: Interaction Design , Multimodal Interaction , Product Design Review , Virtual Prototyping

This paper presents an innovative tool based on enactive interaction for the industrial design sector. Enactive interaction is based on the action-perception paradigm where users learn how to do things by doing. Recent progresses of the research on haptics have allowed us to build an innovative tool for the modification of the shape of a digital product that includes a haptic strip as interaction device. The tool allows designers to easily and intuitively modify digital shapes just acting on the extremities of the strip. Compared to traditional design tools based on the manipulation of mathematical surfaces through geometrical manipulators and control points, this tool has proved to better exploit designers' skills and creativity. © 2010 CAD Solutions, LLC.

Keywords: Enactive interaction , Haptics , Product design , Tools for design

Currently, the design of aesthetic products is a process that requires a set of activities where digital models and physical mockups play a key role. Typically, these are modified (and built) several times before reaching the desired design, increasing the development time and, consequently, the final product cost. In this paper, we present an innovative design environment for computer-aided design (CAD) surface analysis. Our system relies on a direct visuo-haptic display system, which enables users to visualize models using a stereoscopic view, and allows the evaluation of sectional curves using touch. Profile curves are rendered using an haptic device that deforms a plastic strip, thanks to a set of actuators, to reproduce the curvature of the shape co-located with the virtual model. By touching the strip, users are able to evaluate shape characteristics, such as curvature or discontinuities (rendered using sound), and to assess the surface quality. We believe that future computer-aided systems (CAS)/CAD systems based on our approach will contribute in improving the design process at industrial level. Moreover, these will allow companies to reduce the product development time by reducing the number of physical mockups necessary for the product design evaluation and by increasing the quality of the final product, allowing a wider exploration and comparative evaluation of alternatives in the given time. © 2009 Springer-Verlag.

Keywords: Haptic , Immersive , Stereo , Tracking

The design review process of new products is time consuming, requires the collaboration and synchronization of activities performed by various experts having different competences and roles, and is today performed using different tools and different product representations. In order to improve the performances of the overall product design process, it would be beneficial the availability of Computer Aided tools supporting both conceptual design and analysis activities within an integrated environment based on a multi-disciplinary model paradigm. The paper presents an environment named PUODARSI that allows product designers to intuitively modify the shape of a product through haptic interaction and to test in real-time the structural and fluid-dynamics impact of these changes. The research work shows that a smooth and effective integration of modeling tools based on haptic interfaces, fluid-dynamics analysis tools, and Virtual Reality visualization systems is feasible in real-time through the use of a proper data model exchange. © 2010 Springer-Verlag.

Keywords: Design review , Haptic interaction , Interactive simulation , Multi-disciplinary model , Virtual design

Some Virtual Reality applications are based on the use of haptic interfaces for a more intuitive and realistic manipulation of the virtual objects. Typically, the haptic devices have a xed position in the real space, and their working space is rather limited. As a consequence, there are locations in the virtual space that are out of the working space of the haptic device, and thus cannot be reached by users during the virtual objects manipulation. The paper describes a multimodal navigation modality based on the integrated use of various and low cost interaction devices that can be operated by a user taking into account that one of his hands is engaged for the manipulation of the haptic device. Therefore, we have decided to implement the user interface by using the Nintendo® Wii Remote™ and the BalanceBoard™, which can be operated by the user using the other hand and his feet. The navigation modality has been integrated and tested in a Virtual Reality application for the virtual manual assembly of mechanical components. A preliminary validation of the application has been performed by an expert user with the aim of identifying major usability and performance issues by using the heuristic evaluation method. © 2010 by ASME.

This paper describes a multimodal system whose aim is to replicate in a virtual reality environment some typical operations performed by professional designers with real splines laid over the surface of a physical prototype of an aesthetic product, in order to better evaluate the characteristics of the shape they are creating. The system described is able not only to haptically render a continuous contact along a curve, by means of a servo controlled haptic strip, but also to allow the user to modify the shape applying force directly on the haptic device. The haptic strip is able to bend and twist in order to better approximate the portion of the surface of the virtual object over which the strip is laying. This device is 600mm long and is controlled by 11 digital servos for the control of the shape (6 for bending and 5 for twisting) and by two MOOG-FCS HapticMaster devices and two additional digital servos for 6-DOF positioning. We have developed additional input devices, which have been integrated with the haptic strip, which consist of two force sensitive handles positioned at the extremities of the strip, and a capacitive linear touch sensor placed along the surface of the strip, and four buttons. These devices are used to interact with the system, to select menu options, and to apply deformations to the virtual object. The paper describes the interaction modalities and the developed user interface, the applied methodologies, the achieved results and the conclusions elicited from the user tests. © 2010 by ASME.

The paper presents the results of a research project aiming to develop an innovative framework for the conceptual design of products based on haptic technology. The system consists of a Computer-Aided Design (CAD) system enhanced with intuitive designer-oriented interaction tools and modalities. The system integrates innovative haptic tools with 6 Degrees of Freedom (DOF) for modelling digital shapes, with sweep operators applied to class-A surfaces and force computation models based on chip formation models. The system aims to exploit designers' skills in modelling products, improving the products' design process by reducing the necessity to build several physical models for the evaluation and testing of product designs. The system requirements have been defined after observing designers during their daily work and translating the way they model shapes using their hands and craft tools into specifications for the system. The system has been tested by designers, who have found it intuitive and effective to use. Copyright © 2010 Inderscience Enterprises Ltd.

Keywords: Conceptual design , Haptic modeling , Product design , Product development , Virtual prototyping

Two decades of studies about business process re-engineering have proposed several strategies for the reorganization of a production process aimed at costs saving and waste reduction. Nevertheless, there is still a substantial lack of suitable means to measure if and how much the production phases contribute to deliver value, i.e. satisfaction, to the end user. The present paper proposes a methodology aimed at supporting business process re-engineering activities by taking into account the impact each phase of a process has on the value perceived by the customers. The methodology swivels on process value analysis, that is performed through the evaluation of both the customer perceived benefits originated from the process phases, and the resources spent in the same phases. On the basis of customer satisfaction requirements, guidelines are defined in order to identify both process evolution strategies and resource reorganization activities allowing the market competitiveness of products and/or services that the process sells to be preserved and improved. The methodology has been applied to a case study in the field of the Italian footwear industry in order to assess its efficiency.

Keywords: Business process re-engineering , Customer perceived value , Footwear sector , Kano model , Process modelling , TRIZ , Value analysis

Engine efficiency is one of the key aspects to reduce CO 2 emissions. Lamborghini S.p.A. has focused attention on the engine friction modeling, analysis and measurement to understand and control the phenomena. To reduce friction it is necessary to improve understanding of the behavior of the engine components and to pay attention to detail at every tribological contact. The valvetrain can make a significant contribution to whole engine friction especially at low engine speed and this is particularly true for a high speed sports car engine. Direct acting valvetrains are often used for this type of engine to minimise the moved mass and so enable high speed operation. However the sliding contact between the cam and tappet results in higher friction loss than the roller finger follower valvetrain used on many modern passenger car engines. In addition, the high maximum engine speed demands a large valve spring force to maintain contact between cam and tappet. The large spring force can lead to increased valvetrain friction at low engine speed when the inertia force is low. Thus the development of calculation methods to quantify friction of direct acting valvetrains and support the design of components is important. This paper describes the use of advanced mathematical models to quantify power loss at cam/tappet contact, tappet/bore contact and camshaft bearings. The mathematical models are sufficiently detailed to capture the major influencing factors while being quick enough to use to enable engine designers to make decisions in the required time frame. This paper compares calculated and measured friction data for the valvetrain of a high speed passenger car engine as tested on a motored cylinder head test rig. The system friction was measured and calculated across the operating speed range with different oil supply temperature. The effect of diamond like carbon (DLC) coatings on the tappets was quantified by measurement and analysis. Copyright © 2010 SAE International.

The cushion spring is an important component of an automotive dry clutch system. In fact, it influences strongly the clutch torque transmission from engine to driveline. Therefore a study on the cushion spring compression behaviour is crucial to improve the gearshift performance in automated manual transmission. In this paper a sensitivity analysis on the load-deflection curve of a typical passenger car cushion spring is proposed. Four geometrical parameters of the main shape of the cushion spring have been analyzed and for each one the influence on the static characteristic has been shown. © 2010 Civil-Comp Press.

Keywords: Cushion spring , Dry clutch , Sensitivity analysis

The evolution from machines to systems and from objects to products has profoundly affected the meaning of the term "design" as the "role" of designers, and the new concept of industrial design&engineering, which combines the two more traditional fields of industrial design and engineering design, has taken place. While till now the shift and the extension of the industrial designer's area of expertise has affected his typical activities usually in an unarranged manner, the research presented in this paper aims at defining the guidelines for developing an innovative framework to support the design process carried out by a new designer, based on a structured integration of knowledge and tools currently used by the two main areas of reference (industrial design and industrial engineering). The paper presents the guidelines for the innovative framework, the experimental activities to qualitatively test it and some important remarks on its use by designers, both students and professional ones.

Keywords: Design process , Design&engineering , Multidisciplinary design