170 research outputs found

    MRacing: Improve Low Speed Cornering

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    ME450 Capstone Design and Manufacturing Experience: Fall 2020The MRacing team competes in the FSAE competition annually. In past years, MRacing vehicles have struggled in low speed cornering, specifically the Skid pad event. The aim of this project is to improve the low cornering performance of the 2021 MRacing vehicle to increase points achieved at FSAE competitions.MRacing Formula SAE, Wilson Student Team Project Centerhttp://deepblue.lib.umich.edu/bitstream/2027.42/164445/1/MRacing_Improve_Low_Speed_Cornering.pd

    State Estimation and Control of Active Systems for High Performance Vehicles

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    In recent days, mechatronic systems are getting integrated in vehicles ever more. While stability and safety systems such as ABS, ESP have pioneered the introduction of such systems in the modern day car, the lowered cost and increased computational power of electronics along with electrification of the various components has fuelled an increase in this trend. The availability of chassis control systems onboard vehicles has been widely studied and exploited for augmenting vehicle stability. At the same time, for the context of high performance and luxury vehicles, chassis control systems offer a vast and untapped potential to improve vehicle handling and the driveability experience. As performance objectives have not been studied very well in the literature, this thesis deals with the problem of control system design for various active chassis control systems with performance as the main objective. A precursor to the control system design is having complete knowledge of the vehicle states, including those such as the vehicle sideslip angle and the vehicle mass, that cannot be measured directly. The first half of the thesis is dedicated to the development of algorithms for the estimation of these variables in a robust manner. While several estimation methods do exist in the literature, there is still some scope of research in terms of the development of estimation algorithms that have been validated on a test track with extensive experimental testing without using research grade sensors. The advantage of the presented algorithms is that they work only with CAN-BUS data coming from the standard vehicle ESP sensor cluster. The algorithms are tested rigorously under all possible conditions to guarantee robustness. The second half of the thesis deals with the design of the control objectives and controllers for the control of an active rear wheel steering system for a high performance supercar and a torque vectoring algorithm for an electric racing vehicle. With the use of an active rear wheel steering, the driver’s confidence in the vehicle improves due a reduction in the lag between the lateral acceleration and the yaw rate, which allows drivers to push the vehicle harder on a racetrack without losing confidence in it. The torque vectoring algorithm controls the motor torques to improve the tire utilisation and increases the net lateral force, which allows professional drivers to set faster lap times

    Design and Testing of a Prototype Lunar or Planetary Surface Landing Research Vehicle (LPSLRV)

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    This handbook describes a two-semester senior design course sponsored by the NASA Office of Education, the Exploration Systems Mission Directorate (ESMD), and the NASA Space Grant Consortium. The course was developed and implemented by the Mechanical and Aerospace Engineering Department (MAE) at Utah State University. The course final outcome is a packaged senior design course that can be readily incorporated into the instructional curriculum at universities across the country. The course materials adhere to the standards of the Accreditation Board for Engineering and Technology (ABET), and is constructed to be relevant to key research areas identified by ESMD. The design project challenged students to apply systems engineering concepts to define research and training requirements for a terrestrial-based lunar landing simulator. This project developed a flying prototype for a Lunar or Planetary Surface Landing Research Vehicle (LPSRV). Per NASA specifications the concept accounts for reduced lunar gravity, and allows the terminal stage of lunar descent to be flown either by remote pilot or autonomously. This free-flying platform was designed to be sufficiently-flexible to allow both sensor evaluation and pilot training. This handbook outlines the course materials, describes the systems engineering processes developed to facilitate design fabrication, integration, and testing. This handbook presents sufficient details of the final design configuration to allow an independent group to reproduce the design. The design evolution and details regarding the verification testing used to characterize the system are presented in a separate project final design report. Details of the experimental apparatus used for system characterization may be found in Appendix F, G, and I of that report. A brief summary of the ground testing and systems verification is also included in Appendix A of this report. Details of the flight tests will be documented in a separate flight test report. This flight test report serves as a complement to the course handbook presented here. This project was extremely ambitious, and achieving all of the design and test objectives was a daunting task. The schedule ran slightly longer than a single academic year with the complete design closure not occurring until early April. Integration and verification testing spilled over into late May and the first flight did not occur until mid to late June. The academic year at Utah State University ended on May 8, 2010. Following the end of the academic year, testing and integration was performed by the faculty advisor, paid research assistants, and volunteer student hel

    Rotorcraft Blade Pitch Control Through Torque Modulation

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    Micro air vehicle (MAV) technology has broken with simple mimicry of manned aircraft in order to fulfill emerging roles which demand low-cost reliability in the hands of novice users, safe operation in confined spaces, contact and manipulation of the environment, or merging vertical flight and forward flight capabilities. These specialized needs have motivated a surge of new specialized aircraft, but the majority of these design variations remain constrained by the same fundamental technologies underpinning their thrust and control. This dissertation solves the problem of simultaneously governing MAV thrust, roll, and pitch using only a single rotor and single motor. Such an actuator enables new cheap, robust, and light weight aircraft by eliminating the need for the complex ancillary controls of a conventional helicopter swashplate or the distributed propeller array of a quadrotor. An analytic model explains how cyclic blade pitch variations in a special passively articulated rotor may be obtained by modulating the main drive motor torque in phase with the rotor rotation. Experiments with rotors from 10 cm to 100 cm in diameter confirm the predicted blade lag, pitch, and flap motions. We show the operating principle scales similarly as traditional helicopter rotor technologies, but is subject to additional new dynamics and technology considerations. Using this new rotor, experimental aircraft from 29 g to 870 g demonstrate conventional flight capabilities without requiring more than two motors for actuation. In addition, we emulate the unusual capabilities of a fully actuated MAV over six degrees of freedom using only the thrust vectoring qualities of two teetering rotors. Such independent control over forces and moments has been previously obtained by holonomic or omnidirection multirotors with at least six motors, but we now demonstrate similar abilities using only two. Expressive control from a single actuator enables new categories of MAV, illustrated by experiments with a single actuator aircraft with spatial control and a vertical takeoff and landing airplane whose flight authority is derived entirely from two rotors

    Advancing the development of hybrid electric vehicles in motorsport : innovation report

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    Club motorsport, a low cost, amateur form of motorsport, forms a significant part of the motorsport industry in the United Kingdom. If efforts are not made to move towards more environmentally friendly technologies, then this form of motorsport is at risk of becoming irrelevant. One approach taken by other motorsport sectors has been to implement hybrid electric vehicle technology, which can result in improved vehicle performance on the race track. However, the companies that operate in the club motorsport sector do not typically have the resources and experience necessary to develop these technologies. An innovative process was used to guide the design of a new hybrid electric vehicle drivetrain for use in club motorsport. This process made use of the ability for vehicle manufacturers to set the vehicle specifications in club motorsport. A conjoint analysis of customer requirements was carried out, a first for the industry, and led to the development of a market simulation tool. A vehicle simulation tool was then developed to assist in the evaluation of the hybrid electric drivetrain design options. The result of following this process was a new and innovative hybrid electric drivetrain installed in a Westfield Sportscars Sport Turbo, reducing 0-60mph acceleration time from 5.4 seconds to 3.8 seconds. An innovative type of system control was implemented, by where the driver is given a finite amount of boost energy for use throughout the race. The drivetrain can also be easily transferred to other vehicle platforms, as the first shelf engineered hybrid drivetrain for motorsport, allowing its use by multiple manufacturers across the club motorsport and niche vehicle sectors. This project has shown that it is possible to implement environmentally friendly technologies, such as hybrid electric vehicle technology, into club motorsport and be able to meet customer, technical and cost requirements. The process that has been developed enables innovation in hybrid electric race car design. This has been shown in the development of a hybrid electric vehicle suitable for use, and sale, in the club motorsport industry

    Real-time path-tracking MPC for an over-actuated autonomous electric vehicle

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    This paper illustrates the development of a nonlinear constrained predictive path-tracking controller, including realistic vehicle dynamics and multiple actuator inputs and its implementation in real time on an experimental vehicle platform. The controller is formulated for a particular over-actuated vehicle equipped with Torque Vectoring (TV) as well as All-Wheel-Steering (AWS) functionalities, which allow for the enhanced control of vehicle dynamics. The proposed Nonlinear Model Predictive Controller (NMPC) takes into account the nonlinearities in vehicle dynamics across the range of operation up to the limits of handling as dictated by the adhesion limits of the tyres. In addition, crucial constraints regarding the actuators’ physical limits are included in the formulation. The performance of the controller is demonstrated in a high fidelity simulation environment, as well as in real-time on a test vehicle, during the execution of demanding driving scenarios

    Nonlinear Optimal Control of Automated Vehicles in a Connected Environment

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    This thesis is based around the University of Waterloo EcoCAR Team (UWAFT) and the EcoCAR Mobility Challenge. The overall objective of the competition is to design and build a hybrid electric vehicle with SAE Level 2 Autonomous capability. The vehicle platform used in this thesis was based on the 2019 Chevrolet Blazer – the vehicle that General Motors has donated to UWAFT as part of the EcoCAR Mobility Challenge. The scope and objective of this thesis is comprised of three parts: First, various vehicle models were considered and developed using MATLAB and Simulink, as well as ADAMS Car. These models were developed and used for the simulation of the vehicle as well as for the development of vehicle dynamics controllers. Second, various control architectures and strategies were developed and evaluated to understand the benefits and limitations of each controller design under varying situations. Controllers for generating viable and optimal paths, as well as controllers for controlling the vehicle to track a path were developed. Third, a visualization framework was developed for streamlining the development of connected and automated vehicle (CAV) systems. Simulation environments for these models were also developed in Simulink (visualized using the Unreal Engine) as well as using ADAMS Car

    Simulation study investigating the novel use of drive torque vectoring for dynamic post-impact vehicle control

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    The work presented here investigates the use of drive torque vectoring as a method of post-impact vehicle control. Crash statistics show a high number of serious injuries occurring on British roads, with 46% of the 1713 fatalities in 2013 being car occupants. In total there were 21657 serious injuries sustained across all road users in the same time period. Research has highlighted that people involved in multiple impact crashes have an increased risk of sustaining serious injury compared to those involved in a single impact event (Transport 2013). This highlights post-impact control, as a means to avoid secondary impacts, as an important area of study, an area that is still in its infancy. Work carried out so far that aims to control a vehicle after impact makes use of the braking and/or steering systems. This work has produced reasonable levels of success, however the use of drive torque vectoring control has received little attention. To this end, a non-linear 8 Degree of Freedom model is developed that is capable of simulating a vehicle’s behaviour and trajectory during a crash instigated by an impulse disturbance. These crash impulse disturbances are calculated using momentum theory, taking into account energy loss during the impact. They are used to simulate two vehicle crash scenarios: a rear impact, and a side swipe impact. Simulation of these crash scenarios is carried out on the vehicle model before drive torque vectoring control is implemented to produce a benchmark set of results against which the controlled system is evaluated. The control system presented is a six-phase switched PID controller scheme using a set of ‘Settling’ and ‘Holding’ controllers. The control objective is to settle the vehicle at a heading angle that is parallel to the original (e.g. 00, 1800 or 3600), such that the final trajectory re-aligns the main crash structures of the vehicle with the carriageway so as not to expose the side of the vehicle to a secondary collision. Re-aligning the vehicle with the carriageway before it has come to a stop has the additional benefit of reducing lateral displacement when compared with the benchmark results. This control action results in a reduced risk of a secondary impact and thus of serious injury. This system resulted in safe heading angles for all simulations compared with the current work in the field, leading to safer outcomes for occupants

    Tire-Suspension-Steering Hardware-in-the-Loop Simulation

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    Safety and performance have always been important factors in automotive testing. These factors are highly dependent on the tires and suspensions, which should be simulated and tested throughout the development process. During development, Hardware-In-the-Loop (HIL) simulations may be used so that testings and tunings can be done earlier in the process. In this paper, designs and configurations of a newly developed tire-suspension-steering HIL are shown. An actual wheel assembly with suspension and steering components can be installed for testing with dynamic models of the rest of the car. The slip angle of the tire can be imposed in the test rig while actual tire forces can be measured and used in the dynamic model. Comparisons of HIL simulations and real experiments using the skidpad test and the step steering test are given using Formula SAE race cars. It was found that the HIL simulation results are more accurate compared to non-HIL simulations
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