A Specific Geometric Relationship Method for Fault Diagnosis and Fault Tolerant Control in
ECAS
Chuanyin Tang, Hangda Shen, Keyi Liu, Yibin Liu, Shuhan Shen, Ruiguang Kou, Di Lu, Peng Zhang ABSTRACT
The research on the control and health management of electronically—controlled air suspension is an important branch in the field of intelligent chassis. Aiming at the problem that actuator faults cannot be detected quickly and intuitively during the vehicle height adjustment and attitude adjustment in the electronically—controlled air suspension system, a fault diagnosis and isolation method based on the special geometric relationship for actuator fault detection is proposed. Firstly, the air suspension height adjustment control based on PID/PWM control and the body posture are studied. When the specified target height is reached, the body posture can be adjusted, which improves the stability and safety of the vehicle in the height adjustment process. Secondly, for the actuator faults in the electronically—controlled air suspension system, a simpler and more direct method is proposed. This method designs fault detection and isolation indexes for fault diagnosis by using the corresponding geometric relationships under fault conditions, and different fault signals are set for testing. Then, according to the proposed fault diagnosis and isolation method, the fault‐tolerant control is designed to compensate for body attitude instability of the electronically controlled air suspension in the actuator fault state. Finally, the simulation results of vehicle height adjustment and attitude control are verified through simulation. The feasibility of the PID/PWM control method is verified through real‐vehicle experiments under normal conditions. Fault diagnosis and fault‐tolerant control strategies are verified through simulation. The results show that the designed controller can effectively perform fault diagnosis and isolation, and effectively improve the performance of vehicle height adjustment and attitude control.