Design methods for mobility

This paper introduces an improved Electronic Stability Program for cars that can deal with the sudden burst of a tyre. The Improved Electronic Stability Program (IESP) is based on a fuzzy logic algorithm. The IESP collects data from the same sensors of a standard ESP and acts on brakes/throttle with the same actuators. The IESP reads the driver steering angle and the dynamic condition of the car and selectively acts on throttle and brakes in order to put the car on the required direction even during a tyre burst.

Keywords: ABS , ESP , Fuzzy logic , Tyre road contact

The standard bicycle has a well defined form: two same-size in-line wheels with a triangular-shaped frame and an almost vertical riding position. This bike model is the "safety bicycle" 1870's model. May be it is not the most efficient form and, for sure, not the latest developed. The improvement had not been so important. There was indeed a big jump in the late 80's/early 90's, some of which could be attributed both to an increase in time trials and, may be, also to the doping practices of the time. In any case, doping of some form or another has been going on since the beginning of the Tour de France. Time trials are crucial for average speed and it may be they are entirely responsible for the improvement. In any case many other significant advantages have been made on the man-machine. Training and nutrition have been improved through the years. © 2006-2014 Asian Research Publishing Network (ARPN).

Keywords: Bicycle system , Electric facilities , Transportation

The traditional automotive design process that starts from the sketches and the 2D drawings has been superseded by the modern CAD modeling tools. The step through the clay model and the following digitalization problems can be superseded. It is now possible to construct the inside and to define the ergonomic boundaries of the vehicle in an inside out process. This approach greatly reduces the time to market of the final product by including all the parts and the components that comes from other projects or from outsourcing. However a 1:1 (true scale) physical mock up of the vehicle is, in most the cases, still necessary. In fact the evaluation of the real aesthetics of the new project should be made in a true 3D environment. The inside-out approach optimizes the standardization, the outsourcing, the multi powertrains and the unified "platform" concepts. © 2006-2014 Asian Research Publishing Network (ARPN).

Keywords: Automotive design , Methodology to design , Optimization

Turbocharged spark ignition engine for automotive racing have a long and controversial history. From the times of high torque at all cost, to the actual F1 era of maximum efficiency. However turbocharging and turbocoumpounding basic concepts have not changed. It is surprising that, through the years, the same identical errors are repeated. Turbocharger (TC) unit design is a highly optimized task, that requires good concepts, good mathematical models, lots of experimental data and a very good optimization. Performances vary completely with design choices, with big differences between even close solutions. Present software for mathematical modeling of performances are far from accurate and should be corrected with experimental data to obtain effective results. Genetic Algorithms are to be used as optimization method to evaluate the best design solution. Even minor errors in design choices result in large penalties on performance.

Keywords: Automotive racing , Turbocharger

Surprisingly, the safety of a flight is still not guaranteed to maximum steam ejection of power during take-off. Moreover, modern aircraft require significant amounts of electricity. It could also be argued that today in many respects the automotive industry appears to be a technology leader with respect to the aerospace industry that, instead, is more conservative. Ferrari has developed, and implemented, on their F1 cars, an electronic device, called KERS, which is able to produce electricity, with peaks of 60 KW for 7s, with a mass of 20 kg, including rechargeable batteries. The main goal of this paper is to explore utilization of turbo-charged aerodiesel engines and conduct feasibility study of the F1-derived KERS to assist power generation in normal and critical flight phases. The KERS' reversible brushless electric motor works as a generator for all aircraft power needs and also provides starting power. It is demonstrated here that such design philosophy improves performance and flight safety of light-to-medium airplanes and helicopter. © 2006-2014 Asian Research Publishing Network (ARPN).

Keywords: Diesel engine , Hybrid aircraft , Kinetic energy recovery system , Li-ion battery systems , Turbine engines

Normally in diesel and gasoline engines, common rail systems are employed. The key factors for correct engine power management are pressure, precision and velocity. Digital computers and PID control systems characterize current systems. Recovery strategies are used when anomalies occur and engine performance is significantly reduced. So, restoring normal conditions needs technical assistance. For safety reasons this approach cannot be used in aeronautical, naval and energy-supply applications. In some cases it is necessary to utilize all the possible energy from the power unit causing significant life-reduction of the engine. In this case a progressive reduction strategy should be used and injection law should be reduced accordingly. For this purpose injection control based on fuzzy logic is more effective. In this case, traditional PID control systems are substituted by fuzzy logic control. A reference map is introduced in the Full Authority Digital Electronic Control; this map is interpreted by the fuzzy logic control system that adapts the injection law to the current engine situation. This method has been experimented on a common-rail test bed and results are compared with traditional "binary recovery strategy" FADEC. ©2006-2014 Asian Research Publishing Network (ARPN).

Keywords: Aircraft , Diesel propulsion , Engine control , Fuzzy logic

This article presents a methodology for the treatment of uncertainty in nonlinear, interference-fit, stress analysis problems arising from manufacturing tolerances. Image decomposition is applied to the uncertain stress field to produce a small number of shape descriptors that allow for variability in the location of high-stress points when geometric parameters (dimensions) are changed within tolerance ranges. A meta-model, in this case based on the polynomial chaos expansion, is trained using a full finite element model to provide a mapping from input geometric parameters to output shape descriptors. Global sensitivity analysis using Sobol's indices provides a design tool that enables the influence of each input parameter on the observed variances of the outputs to be quantified. The methodology is illustrated by a simplified practical design problem in the manufacture of automotive wheels.

Keywords: Dimensional tolerances , Global sensitivity analysis , Interference fit , Polynomial chaos expansion , Shape descriptor

In this paper experimental investigations of interference fit effects on the dynamic behaviour of assembled wheels are provided. The performed analyses on the automotive components take into account manufacturing pre-stresses and dimensional tolerances of mating parts. Experimental modal analysis is made on a set of components with identical nominal values to prove either the component or the assembly variability. For each mode a PCE-based meta model is developed upon a small sample of experimental observations and the interference fit level is estimated by means of the stress stiffening effect. The presented technique is aimed at improving the design and development of industrial components through the combination of established methodologies. The effectiveness of modal analysis, when combined with numerical/statistical approaches is pointed out.

Keywords: Design for modal assembly , Dimensional tolerances , Experimental modal analysis , PCE meta-models , Stress stiffening effect

Purpose - Supplying remote wireless sensors is not an easy task if the site where the device is located is not easily accessible. In order to obtain direct measurements of the road-vehicle interactions, sensors must be placed inside the tyre environment thus a power supply must be available for their working there without any wire connection with the car main power. The paper aims to discuss these issues. Design/methodology/approach - An electro-mechanical energy harvester has thus been developed for supplying an automotive wireless sensor of pressure, temperature and acceleration to be placed on the inner line of a tyre. The primary energy source is the vibrations or variable accelerations imposed to the device and induced in the tyre by the wheeling. Findings - The harvester has been designed by means of a multi-physics optimisation based on an integrated electromagnetic-mechanical circuit simulator. Thus an automated optimisation of the device with respect to volume constraints, magnets dimensions, induction coils placement and size have been performed to increase the average power extracted from the device at different wheeling speeds. Originality/value - The use of the multi-physics environment together with automated optimisation technique has been tested for the first time on the electromagnetic harvester structure.

Keywords: Applied electromagnetism , Energy harvesting , Multiphysics , Optimal design

Objective: To set up a prescreening tool for vehicle front-end design, allowing numerically forecasting of the results of EC directive tests, with reference to pedestrian lower leg impact. Methods: A numerical legform model has been developed and certified according to EC directive. The frontal end of the vehicle has been simulated through a lumped-parameters model, having considered the predesign stage when the target overall behavior is being established. The stiffness behaviors of the bumper and of the spoiler have been estimated by means of more detailed numerical models. A parametric analysis has been performed to outline the effects of bumper and spoiler stiffness, bumper vertical height, and the longitudinal distance between the spoiler and the bumper. An analytical model has been introduced to predict tibial acceleration, knee shear displacement, and knee lateral bending, given the bumper and spoiler characteristics as input. Results:The parametric analysis has demonstrated that bumper stiffness, bumper profile height, and spoiler stiffness do have an impact on knee lateral bending, knee shear displacement, and peak tibial acceleration. Increasing bumper stiffness can result in higher knee bending, knee shear displacement, and peak tibial acceleration. Increasing bumper profile height produces lower knee bending and shear displacement. Increasing spoiler stiffness can determine higher knee shear displacement and peak tibial acceleration but lower knee bending. Spoiler stiffness and position have a strong correlation: higher bumper stiffness needs to be coupled to a moved forward spoiler position. The mechanical responses of the spoiler and of the bumper can be assumed to be linear: the softening behavior of the expanded polypropylene foam balances the hardening behavior of the fascia (due to contact area increase). The predictive model is well correlated to experimental findings (R2 > 0.74) Conclusions: This simplified computer model can be used as a prescreening design tool to demonstrate general vehicle front-end design trade-offs and provide approximate results without physical testing. © 2014 Copyright Taylor and Francis Group, LLC.

Keywords: bumper , lower leg , pedestrian , spoiler , vehicle front end

This work analyses blunt abdominal trauma produced by driver-handlebar collision, in low speed two-wheel accidents. A simplified dynamic model is introduced, whose parameters have been estimated on the basis of cadaver tests. This model allows calculating the peak impact force and the abdominal penetration depth; therefore the likelihood of occurrence of serious injuries can be estimated for different masses of contacting bodies and different speeds. Results have been checked against literature data and true-accident reports. Numerical simulations demonstrate that serious injuries (AIS>3) can occur even at low speeds (<20. km/h), therefore the design of protective clothing is recommendable. The model can allow both the analysis of true accident data and the virtual testing of protective equipment in the conceptual design phase. © 2013 Elsevier Ltd.

Keywords: Abdominal injury , Handlebar impact model , Road accidents , Two-wheel riders

The development of an automotive semi-active differential is described. The device is based on the use of a magnetorheological fluid and allows to control the locking torque and, consequently, to improve the vehicle handling. In order to evaluate the effectiveness of the proposed device, a physical prototype was realized and the first experimental tests were carried out.

Keywords: Automotive differential , Magnetorheological fluid , Vehicle dynamics

In this paper, two optimization approaches to improve the product design process have been analysed. Through the analysis of a case study, concerning the designing of a new High Energy Absorption Rear Underrun Protective Device (HEARUPD), two different optimization approaches (simplex and simulated annealing) have been compared. In the implemented optimization processes, the crash between an economy car and the rear part of a truck has been simulated by dynamic numerical (FEM) analyses. Moreover, authors have proposed the use of a suitable linear function of four variables with the purpose of reducing the multi-objective optimization processes to mono-objective ones. That has been made to simplify the analysis procedures without affecting the quality and the completeness of the optimization processes. The obtained results, as well as showing the high effectiveness of the integrated use of numerical crash analyses and optimization methods, demonstrate that simplex method is more effective than simulated annealing one for optimization problems where the single analysis loop requires much time. Even if the solutions are quite similar in terms of calculated values of the objective function, design and state variables, simplex method needs shorter computational time than simulated annealing to obtain an optimized solution. © 2012 Springer-Verlag London Limited.

Keywords: Numerical crash analysis , Optimization , Simplex , Simulated annealing

Space agencies are paying greater attention to solar sail technologies and missions. Actually, one of the most demanding issues when considering solar sailing is to assess the sail deformation as well as the following trajectory modifications. The main purpose of this paper is to show the order of accuracy that can be reached when coupling structural and dynamical behavior of a solar sail. Based on the application of the Finite Element Method, the deformations affecting the large structure of the sail, up to the second order of accuracy, are estimated, together with the real-time updated thrust vector according to such deformations. The new thrust vector, evaluated for an Earth-Venus mission, allows one to find a more realistic sailcraft trajectory. The results obtained show a change in the thrust's magnitude with a not negligible variation of the sailcraft trajectory with respect to the undeformed case. Another issue deserving particular attention concerns solar sail deployment. Both structural and dynamical behavior affecting a solar sail's performance will be analyzed even in the event of partial deployment. The results obtained show the importance of the right sizing of the attitude control, which may not be able to compensate such a failure and what strategies could be used to save the mission including the need for a new mission analysis. © 2012 Elsevier Ltd.

Keywords: Elastic displacement effects , Incomplete deployment , Interplanetary trajectories , Solar sail

Recent developments in digital imaging techniques have allowed a wide spread of three-dimensional methodologies based on capturing anatomical tissues by different approaches, such as cone-beam computed tomography, three-dimensional photography and surface scanning. In oral rehabilitation, an objective method to predict surgical and orthodontic outcomes should be based on anatomical data belonging to soft facial tissue, facial skeleton and dentition (maxillofacial triad). However, none of the available imaging techniques can accurately capture the complete triad. This article presents a multi-modal framework, which allows image fusion of different digital techniques to create a three-dimensional virtual maxillofacial model, which integrates photorealistic face, facial skeleton and dentition. The methodology is based on combining structured light surface scanning and cone-beam computed tomography data processing. The fusion procedure provides multi-modal representations by aligning different tissues on the basis of common anatomical constraints. © IMechE 2012.

Keywords: Computer assisted , Cone-beam computed tomography scanning , Maxillofacial modelling , Multi-modal image fusion , Optical scanning , Three-dimensional medical imaging

Traffic calming devices on urban streets, such as elevated pedestrian crossings, speed bumps and roundabouts, are increasingly used, therefore bus passengers on-board comfort assessment is an actual problem. In order to measure vibrational on-board comfort for public transport standing passengers related to traffic calming, an acquisition system called ASGCM (Autonomous System for Geo-referenced Comfort Measurements) has been developed, taking as a reference the European regulations on rail transports. Thanks to ASGCM, each measurement of vibration, on-ground velocity and acceleration is linked with geographical information resulting from a GPS, so a map of a comfort index, as well as statistical surveys and correlation between on-board comfort and traffic calming, can be directly obtained using a Geographic Information System (GIS), querying a centralized remote database developed ad-hoc. A large number of experimental tests has been performed in order to define a vibrational comfort index and to collect a large statistics that allows a significant comparison between different infrastructures and their characterization. The proposed technique can also be useful for diagnostics purposes, such as vehicles comparison and vehicle and road maintenance state monitoring.

Traffic calming devices on urban streets, such as elevated pedestrian crossings, speed bumps and roundabouts, are increasingly used, therefore bus passengers on-board comfort assessment is an actual problem. In order to measure vibrational on-board comfort for public transport standing passengers related to traffic calming, an acquisition system called ASGCM (Autonomous System for Geo-referenced Comfort Measurements) has been developed, taking as a reference the European regulations on rail transports. Thanks to ASGCM, each measurement of vibration, on-ground velocity and acceleration is linked with geographical information resulting from a GPS, so a map of a comfort index, as well as statistical surveys and correlation between on-board comfort and traffic calming, can be directly obtained using a Geographic Information System (GIS), querying a centralized remote database developed ad-hoc. A large number of experimental tests has been performed in order to define a vibrational comfort index and to collect a large statistics that allows a significant comparison between different infrastructures and their characterization. The proposed technique can also be useful for diagnostics purposes, such as vehicles comparison and vehicle and road maintenance state monitoring.

The paper describes a novel application of real-time finite element analysis controlled by a haptic device. The user can impose displacement constraints to a virtual structure using a probe and sense in real-time the response in terms of forces on her/his hand. In addition, conventional color map results are visualized on a desktop monitor. The application has been developed with the aim of simplifying the teaching of the mechanical behavior of materials in engineering schools by transforming the learning phase into an enactive process. A set of examples commonly used in the mechanical engineering courses have been implemented and tested. The paper describes and discusses the system implementation, the potentialities and the issues of such approach. Copyright © 2013 by ASME.

This paper describes the design and implementation of a 1- DOF servo-actuated stylus, which is used as an end effector in a desktop haptic device. The desktop haptic device is part of a multimodal system aimed for the assessment, training and rehabilitation of the arm, forearm and hand while the user perform several tasks. Patients will use the haptic device which carries out the servo-actuated stylus in order to draw simple and complex sketches, in this way, the patient is able to feel the virtual sketch by using the haptic device, which acts as a virtual guide taking advantages of its force feedback capabilities. The therapist is able to control the 1-DOF-stylus rotation according to the requirements of the patient. © Springer-Verlag Berlin Heidelberg 2013.

Keywords: Haptic guidance , Multimodal system , Sketching task , Stroke patient