Modeling and pressure tracking control of a novel electro-hydraulic braking system

• Published in: Advances in mechanical engineering 2018-03, Vol.10 (3)
• Main Authors: Xiong, Zhe, Guo, Xuexun, Yang, Bo, Pei, Xiaofei, Zhang, Jie
• Format: Article
• Language: English
• Subjects: Accumulators; Accuracy; Authorship; Brake by wire systems; Braking; Computer simulation; Control algorithms; Control stability; Controllers; Cost control; Cylinders; Design; Electric vehicles; Electric wire; Hybrid electric vehicles; Hybrid systems; Hydraulics; Identification; Intelligent vehicles; Maneuvers; Parameter identification; Predictive control; Pressure distribution; Pressure effects; Proportional integral derivative; Prototype tests; Sensors; Simulation; Sliding mode control; Tracking control; Valves
• ISSN: 1687-8132; 1687-8140
• DOI: 10.1177/1687814018764153

A brake-by-wire system is considered the best solution to realize advanced functions in electric vehicles/hybrid electric vehicles and intelligent vehicles. In this article, a novel electro-hydraulic brake system is proposed. The main issues in the development of the proposed electro-hydraulic brake system focus on hydraulic loop design and pressure tracking control. Instead of an accumulator, a large displacement piston pump coupled to a high-power motor is applied to meet the demand of pressure boost. A passive pedal feel simulator is designed to decouple the brake pedal and the wheel cylinders. The high pressure in the wheel cylinders is controlled by de/activating the motor and valves to track the reference pressure. To minimize the pressure instability observed in previous proportional–integral–derivative controller tests, a self-tuning generalized predictive controller is applied. Models of each system’s dynamic process are derived, and the parameters are identified through test data. A sliding mode differentiator is used to filter the sensor signals and improve the pressure boost performance in hard brake maneuvers. A rapid control prototype test environment based on dSPACE is built to verify and adjust the controller. The simulation results using MATLAB/Simulink and bench tests are presented and analyzed. Tracking performances show that compared to a proportional–integral–derivative controller, the proposed controller has a better effect in lowering pressure overshoots and start–stop frequency.