Fault-tolerant control for a pump-controlled electrohydraulic system

This paper proposes a fault-tolerant control strategy based on two observers and a backstepping sliding mode technique for a pump-controlled electro-hydraulic system (PCEHS) under the presence of faults and disturbances. Two different observers are established to estimate the internal leakage flow rate and the external loading force in the PCEHS. Then, the proposed controller is designed by considering the estimated information from observers to guarantee the working performance of the system. The robustness and stability of the controlled system are theoretically proven by using the Lyapunov approach. Finally, comparative simulation results are provided to demonstrate the effectiveness of the proposed algorithm through different testing conditions.