Sensor-Fault-Tolerant Controller for a Flexible-link Manipulator with Output Constraint

In this paper, a robust control strategy is proposed for a flexible-link manipulator to track the reference signal. The main framework of the controller is based on backstepping. First, a virtual control rule is designed by using a Barrier Lyapunov function such that the output constraint is satisfied. Then, the second tracking error is defined and the input torque is formulated. The control design parameters in each step are optimally tuned by PSO, which is an optimal technique. Furthermore, fault estimation and elimination are set to ensure the desirable reference tracking by adopting the concurrent learning technique. Finally, simulation results are given to verify the efficiency of the proposed controller.