Design and Implementation of Adaptive Brake Pressure Controller

Abstract

Road safety has been the subject of interest for research from the time the first automotive was invented. Safety has been characterized by many factors but the most prominent is maintaining control over the vehicle motion in all situations. Modern safety systems especially Antilock Braking System (ABS) in combination with Electronic Stability Control (ESC) has brought down the uncontrollable occasions in driving and therefore, sheltering the passengers from accidents. This system ensures the control of the vehicle while braking in varying surface conditions by keeping the friction coefficient close to optimal which helps in preventing wheel lock up and minimizing the braking distance. The current methods employ complex heuristic rules and optimization is still required in algorithm development. The ABS provides reference pressure signals to be achieved in different wheel brake cylinders to a low level controller termed as the brake pressure controller. This low level controller needs to be as precise as possible considering the challenges of hydraulic line characteristics and unavailability of states. Some researchers have investigated this area earlier and there have been performance issues which are yet to be solved. Of these, the core issue was the inability of the controller to adapt to variable conditions. Hence, an adaptive control approach is proposed to this problem. The project aims to optimize the functioning of the brake pressure controller. This report will introduce the reader to the test vehicle and its braking system to be controlled. It will also identify the objectives of the controller and learn the limitations of the hydraulic circuit. Further, 2 models derived from the literature will be compared from analysis on experimental data. Finally, the formulation of adaptive control algorithm and the implementation strategy along with control of essential secondary components will be addressed. This implementation of reliable brake pressure controller along with its performance evaluation will serve as a foundation for realization for future novel ABS algorithms.