Adaptive fault-tolerant control for electro-hydraulic servo actuator based on multiple unmodeled dynamics estimation and compensation

The internal leakage fault-tolerant control problem of the electro-hydraulic servo actuator under influence multiple unmodeled dynamics is investigated in this paper, and an adaptive scheme based on estimation compensation proposed. model divided into two subsystems, which extended-state observers are respectively constructed to estimate matched mismatched dynamics. Combined with results dynamics, controller designed by using backstepping method. In a reconfiguration mechanism fault parameter online adaptation used accommodate fault, feedforward strategy suppress Semi-physical simulation test proposed conducted serious cylinder leakage. result shows that when maximum flow reaches 10.53 L/min, accounting for about 56.77% load flow, at moment opening servovalve close can still achieve high-precision position tracking control, where errors transient post-fault steady state both limited within ±1.5% given position.