Fault Tolerant Control Based on GA-DRE for a Manipulator with Actuator Fault

To solve the trajectory tracking control problem of a rigid manipulator system in the case of unexpected actuator failure, considering the uncertainty of system parameters and bounded disturbance, an adaptive fault-tolerant tracking control strategy is proposed in this paper. Firstly, an adaptive strategy is designed to estimate and compensate the effects of actuator failure and system uncertainty, and the dynamic regression matrix is extended and mixed to improve the accuracy of parameter estimation without persistency of excitation (PE), which will enhance the trajectory tracking performance. Then, in the framework of sliding mode fault-tolerant control, combined with standard Gradient Adaptive and Dynamic Regressor Extension (GA-DRE) parameter estimation technology, a composite adaptive fault-tolerant controller is designed. Finally, theoretical analysis and numerical simulation results show that the proposed method can perform accurate parameter estimation in a finite time under the premise of matching the new conditions based on DRE additional terms, and the trajectory tracking errors of the expected positions and velocities of each joint of the manipulator can asymptotically converge to zero.