执行器故障下电液伺服系统固定时间容错控制OA

A fixed-time fault-tolerant control method was proposed for the piston rod position control of electro-hydraulic servo systems subjected to actuator faults and external disturbances,with the presence of parameter uncertainties.First,a reduced-order fixed-time extended state observer was designed based on the homogeneity theorem to estimate the system lumped uncertainty.The estimation error of this observer converged in fixed time,and the estimation accuracy could be improved by increasing the bandwidth.Then,a fixed-time fault-tolerant controller was developed by combining backstepping control technique,without requiring any information regarding the lumped uncertainty.Finally,verification was carried out on an experimental platform.Results show that the proposed method demonstrates strong fault-tolerant capability against actuator faults,ensuring high position control accuracy of the piston rod,and guaranteeing that the convergence time upper bound is independent of the initial system state.