Brake Steer Torque Optimized Corner Braking of Motorcycles

This thesis deals with the Brake Steer Torque (BST) induced stand-up tendency of Powered Two Wheelers (PTW) and measures to lower the associated risk for running wide on curve accidents with sudden, unforeseen braking. Focus is set on the BST Avoidance Mechanism (BSTAM), a chassis design that eliminates the BST through lateral inclination of the kinematic steering axis. A simple mathematical model is used to identify its main influences on the driving behavior and derive an optimized system layout. Its theoretical potential is evaluated against the standard chassis using different cornering adaptive brake force distributions and riding styles. For the first time ever, a motorcycle with state-of-the-art brake system (Honda CBR 600 RR, C-ABS) is equipped with a BSTAM and tested in corner braking experiments. Compared to the baseline, it is significantly reducing BST related disturbances and improving directional control. The gained insights can be stepping stones to enhance PTW safety by enabling future assistance systems with autonomous corner braking

Sit-to-Stand and Mobility Assistance Device

ME450 Capstone Design and Manufacturing Experience: Winter 2010The main objective of our project is to design and manufacture a Sit-to-Stand and Mobility Assistance Device. This has been motivated by two sponsors: Dr. Mary-Anne Purtill at St. Joseph Mercy Hospital in Ann Arbor, and Professor Yoram Koren at the University of Michigan. Dr. Purtill seeks to study the beneficial effects of early mobility during a patient’s stay in an Intensive Care Unit, while Professor Koren seeks to improve the mobility of an individual with cerebral palsy at home.http://deepblue.lib.umich.edu/bitstream/2027.42/109378/1/me450w10project20_report.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/109378/2/me450w10project20_photo.jp

A Service Robot for Navigation Assistance and Physical Rehabilitation of Seniors

The population of the advanced countries is ageing, with the direct consequence that an increasing number of people will have to live with sensitive, cognitive and physical disabilities. People with impaired physical ability are not confident to move alone, especially in crowded environment and for long journeys, highly reducing the quality of their life. We propose a new generation of robotic walking assistants whose mechanical and electronic components are conceived to optimize the collaboration between the robot and its users. We will apply these general ideas to investigate the interaction between older adults and a robotic walker, named FriWalk, exploiting it either as a navigational or as a rehabilitation aid. For the use of the FriWalk as a navigation assistance, the system guides the user securing high levels of safety, a perfect compliance with the social rules and non-intrusive interaction between human and machine. To this purpose, we developed several guidance systems ranging from completely passive strategies to active solutions exploiting either the rear or the front motors mounted on the robot. The common strategy at the basis of all the algorithms is that the responsibility of the locomotion belongs always to the user, both to increase the mobility of elder users and to enhance their perception of control over the robot. This way the robot intervenes only whenever it is strictly necessary not to mitigate the user safety. Moreover, the robotic walker has been endowed with a tablet and graphical user interface (GUI) which provides the user with the visual indications about the path to follow. Since the FriWalk was developed to suit the needs of users with different deficits, we conducted extensive human-robot interaction (HRI) experiments with elders, complemented with direct interviews of the participants. As concerns the use of the FriWalk as a rehabilitation aid, force sensing to estimate the torques applied by the user and change the user perceived inertia can be exploited by doctors to let the user feel the device heavier or lighter. Moreover, thanks to a new generation of sensors, the device can be exploited in a clinical context to track the performance of the users' rehabilitation exercises, in order to assist nurses and doctors during the hospitalization of older adults

A Novel Universal Corner Module for Urban Electric Vehicles: Design, Prototype, and Experiment

This thesis presents the work of creating and validating a novel corner module for a three-wheeled urban electric vehicle in the tadpole configuration. As the urban population increases, there will be a growing need for compact, personal transportation. While urban electric vehicles are compact, they are inherently less stable when negotiating a turn, and they leave little space for passengers, cargo and crash structures. Corner modules provide an effective solution to increase the space in the cabin and increase the handling capabilities of the vehicle. Many corner module designs have been produced in the hopes of increasing the cabin space and improving the road holding capabilities of the wheel. However, none have been used to increase the turning stability of the vehicle via an active camber mechanism while remaining in an acceptable packaging space. Active camber mechanisms are also not a new concept, but they have not been implemented in a narrow packaging space with relatively large camber angle. Parallel mechanism research and vehicle dynamics theory were combined to generate and analyse this new corner module design. The corner module increases the stability of the urban electric vehicle by cambering the front wheels to -15 degrees when the vehicle is turning. The camber angle augmentation increases the track width which subsequently decreases the center of gravity height. These changes accumulated to increase the stability of the vehicle. The corner module uses two actuators to control the orientation of the wheel. Bias ply tires are incorporated into the corner module to enable the large camber angles. To increase the space in the cabin, the front left and right wheels are not connected by a mechanical linkage, and the motors are mounted to the wheel rim. While disc brakes are integrated into the corner module, the motor is also capable of regenerative braking. By integrating this corner module into urban electric vehicles, the vehicle size and pollution can be reduced while increasing the cabin space and public space

AN INTEGRATED SYSTEMS ENGINEERING METHODOLOGY FOR DESIGN OF VEHICLE HANDLING DYNAMICS

The primary objective of this research is to develop an integrated system engineering methodology for the conceptual design of vehicle handling dynamics early on in the product development process. A systems engineering-based simulation framework is developed that connects subjective, customer-relevant handling expectations and manufacturers\u27 brand attributes to higher-level objective vehicle engineering targets and consequently breaks these targets down into subsystem-level requirements and component-level design specifications. Such an integrated systems engineering approach will guide the engineering development process and provide insight into the compromises involved in the vehicle-handling layout, ultimately saving product development time and costs and helping to achieve a higher level of product maturity early on in the design phase. The proposed simulation-based design methodology for the conceptual design of vehicle handling characteristics is implemented using decomposition-based Analytical Target Cascading (ATC) techniques and evolutionary, multi-objective optimization algorithms coupled within the systems engineering framework. The framework is utilized in a two-layer optimization schedule. The first layer is used to derive subsystem-level requirements from overall vehicle-level targets. These subsystem-level requirements are passed on as targets to the second layer of optimization, and the second layer derives component-level specifications from the subsystem-level requirements obtained from the first step. The second layer optimization utilizes component-level design variables and analysis models to minimize the difference between the targets transferred from the vehicle level and responses generated from the component-level analysis. An iterative loop is set up with an objective to minimize the target/response consistency constraints (i.e., the targets at the vehicle level are constantly rebalanced to achieve a consistent and feasible solution). Genetic Algorithms (GAs) are used at each layer of the framework. This work has contributed towards development of a unique approach to integrate market research into the vehicle handling design process. The framework developed for this dissertation uses Original Equipment Manufacturer\u27s (OEM\u27s) brand essence information derived from market research for the derivation and balancing of vehicle-level targets, and guides the chassis design direction using relative brand attribute weights. Other contributions from this research include development of empirical relationships between key customer-relevant vehicle handling attributes selected from market survey and the various scenarios and objective metrics of vehicle handling, development of a goal programming based approach for the selection of the best solution from a set of Pareto-optimal solutions obtained from genetic algorithms and development of Vehicle Handling Bandwidth Diagrams

Kineto-Dynamic Analyses of Vehicle Suspension for Optimal Synthesis

Design and synthesis of a vehicle suspension is a complex task due to constraints imposed by multiple widely conflicting kinematic and dynamic performance measures, which are further influenced by the suspension damper nonlinearity. In addition, synthesis of suspension for hybrid vehicles may involve additional design compromises among different measures in view of the limited lateral packaging space due to larger sub-frame requirements for placing the batteries. In this dissertation research, a coupled kineto-dynamic analysis method is proposed for synthesis of vehicle suspension system, including its geometry and joint coordinates, and asymmetric damping properties. Quarter-car and two-dimensional roll plane kineto-dynamic models of linkage suspensions are proposed for coupled kinematic and dynamic analyses, and optimal suspension geometry and damper syntheses. The kinematic responses of quadra-link and double wishbone types of suspensions are evaluated using the single-wheel kinematic models. Laboratory measurements were performed and the data were applied to demonstrate validity of the 3- dimensional kinematic model. A sensitivity analysis method is proposed to study influences of various joint coordinates on kinematic responses and to identify a desirable synthesis. A kineto-dynamic quarter car model comprising linkage kinematics of a double wishbone type of suspension together with a linear, and single- and two-stage asymmetric damper is subsequently proposed for coupled kinematic and dynamic analyses. The coupling between the various kinematic and dynamic responses, and their significance are iv discussed for suspension synthesis. The effects of damping asymmetry on coupled responses are thoroughly evaluated under idealized bump/pothole and random road excitations, which revealed conflicting design requirements under different excitations. A constrained optimization problem is formulated and solved to seek design guidance for synthesis of a two-stage asymmetric damper that would yield an acceptable compromise among the kinematic and dynamic performance measures under selected excitations and range of forward speeds. The coupled kinematic and dynamic responses in the roll plane are further analyzed through development and analysis of a kineto-dynamic roll-plane vehicle model comprising double wishbone type of suspensions, asymmetric damping and an antiroll bar. The results are discussed to illustrate conflicting kinematic responses such as bump/roll camber and wheel track variations, and an optimal geometry synthesis is derived considering the conflicting kinematic measures together with the lateral space constraint. A full-vehicle model comprising double wishbone type of suspensions is also developed in the ADAMS/car platform to study influences of faults in suspension bushings and linkages on the dynamic responses. The results of the study suggest that an optimal vehicle suspension synthesis necessitates considerations of the coupled kinematic and dynamic response analyse

Cerberus : a human powered vehicle

A recumbent trike was designed and built for the ASME Human Powered Vehicle Challenge held at San Jose State University in April of 2013. The vehicle was designed to be low cost for use by commuters and as primary transportation in developing countries. The vehicle placed 11th overall in the competition out of 29 teams, and scored 8th in the innovation event, which was its best ranking out of the 5 individual events