Fault- Tolerant Control For Robotic Manipulator With Uncertain Dynamics And Disturbance

In this paper, a fault-tolerant tracking control approach is proposed for robotic manipulator with uncertain dynamics and actuator failure. Firstly, a nominal dynamics model considers modeling discrepancies and load changes of the manipulator is established. Secondly, to effectively deal with the actuator failure, an unknown input observer (UIO) is introduced. Own to deem actuator failure as a system unknown inputs (UIs), the complicated estimation of the fault-related parameters are successfully avoided. Moreover, through the state transform, a robust UIO is introduced to estimate the lumped UIs of the system. By accurately observing and compensating the compound UIs, the stability of the system is guaranteed, and the transient performance of the system post-failure is effectively improved. The Lyapunov's direct method is employed to ensure the validity of the proposed scheme, simulation experiment is provided to verify the effectiveness of the presented algorithm.