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No full textDr. Reem Alzahabi
Assistant Professor of Psychologyhttps://digitalcommons.kettering.edu/fs_currentmembers/1031/thumbnail.jp
Formulation and Comparison of Coupled Path Tracking and Vehicle Dynamic Controls Using Co-Simulation
No full textAutonomous vehicles are expected to increase in the future, with most if not all of them being electric vehicles possible with all-wheel drive layout. Autonomous vehicles utilize path-tracking algorithm which comprises lateral and longitudinal motion controls. Fundamentally the lateral controllers provide steering angle inputs which are general slip angles on front and rear axles, generating lateral force which finally produces lateral acceleration shifting the car laterally. This response is highly nonlinear as characterized by the understeer gradient characteristics of the vehicle. This non-linearity can cause deterioration in tracking performance at high lateral accelerations. With a wheel drive layout and the ability to distribute wheel torques, it may be possible to linearize vehicle response using vehicle dynamic controls which should improve the performance of the lateral control algorithms. Briefly summarizing this work, an architecture was developed where lateral control and torque vectoring controller were combined to test the aforementioned idea. Two opposite types of lateral control strategies were used – the first one was the Stanley controller which is highly linear in operation and another was state-of-the-art MPC control which can control nonlinear systems better given its optimization algorithm. Novel slip ratio control and torque vectoring strategies were developed to augment these lateral control algorithms. The controllers were then tested with a high-fidelity Carsim vehicle model in the loop. The test scenarios subjected the controllers to a variety of operating conditions such as low and high lateral acceleration, velocity variations, road camber, elevation, and friction variations. The metrics for evaluation were maximum lateral error and integral of lateral error. It was identified that in almost all the cases there was a forty to ninety percent improvement in tracking performance when torque vectoring augmented the lateral control algorithms except in the case of a double lane change simulation where MPC performed slightly worse by the addition of torque vectoring
Design & Verification of a Solar-Assisted Hybrid Battery Balancing System & ULEV Battery Pack
No full textThe solar-assisted hybrid battery balancing system developed in this thesis is a response to the growing demand for energy conservation and the use of renewable energy in the mobility industry. The hardware to support this novel method of battery cell balancing was designed and assembled for a ULEV application following initial simulation to quantify range and energy consumption benefits. Once the assembled hardware was tested, observations for further study and production-intended improvements were noted before recommending full integration of the hardware into the designed battery pack. The benefits to range extension, breadth of acceptable balancing conditions, and relative ease of vehicle integration of this technology are expected to improve the return on investment for future implementation of advanced battery balancing in production applications
