Finite frequency H∞ fault-tolerantcontrol for vehicle active suspension

Abstract

According to international comfort evaluation criteria ISO2631, the human body is most sensitive to the vertical vibration of 4 ~ 8Hz. The performance of the active suspension system depends mainly on the reliability of the actuator; Aiming at the partial actuator fault, an active suspension state feedback finite-frequency H ∞ fault-tolerant control strategy is proposed by using the generalized KYP lemma and the linear matrix inequality (LMI) technique; in order to compare and analyze conveniently, the H ∞ fault-tolerant control method of active suspension in the entire frequency domain is also deduced. In order to verify the feasibility and effectiveness of the proposed control strategy, a quarter-car model is taken as an example, random road and bump road are used as interference input; the finite frequency H ∞ fault tolerant control, H ∞ fault tolerant control in the entire frequency domain, passive suspension are simulated and compared. Simulation results show, the proposed state feedback finite frequency H ∞ fault tolerant control strategy is robust to actuator faults, not only can guarantee the stability of the suspension system, but also in the 4-8Hz frequency range of can further enhance the active suspension system ride comfort.