Fault detection and fault tolerant control of vehicle semi-active suspension system with magnetorheological dampers

In engineering application the sensor or actuator fault will lead to seriously damage to mechanical systems. The research of sensor or actuator fault diagnosis and fault-tolerant control is very important to improve the safety and reliability of the system. The paper investigates the fault diagnosis and fault-tolerant methods of vehicle suspension system with Magnetorheological (MR) dampers (actuators). The whole-vehicle suspension system model is established. The fault diagnosis strategy is realized through designing a state observer, which not only can obtain the fault diagnosis position but also extent of the damaged actuator. Once the fault is identified, then fault tolerant control schemes compensate influence of faults automatically in presence of faults such that stability can be guaranteed and dynamic performance can be recovered as possible in the post-fault systems. So a semi-active fuzzy fault-tolerant controller for the whole vehicle suspension system with four MR dampers is designed. Based on linear matrix inequality (LMI), the controller and observer parameters are solved. Numerical simulation and experiments are carried out to verify the effectiveness of proposed methods, respectively.