Design of actuator fault compensation with MRC in 2 DOF manipulator based on PID CTC

Abstract

All mechanical and electronic systems can run into performance degradation including robot Manipulators. One cause of such performance degradation is due to the occurrence of fault on the actuator. The occurrence of actuator fault on Robot Manipulator 2 DOF (Degree of Freedom) will make tracking of the robot shifted from its reference, cause signal deviation and enlarge overshoot. Estimation and compensation techniques can be a solution to this problem, but these techniques can only be done if the designed system is capable of generating residual signals. This signal is a comparison of the response signal between the actual system and the MRC response signal. This paper explains the design of an AFTC (Active Fault Tolerant Control) algorithm based MRC. When an actuator fault happened, it was estimated and compensated with Model Reference Control (MRC) using Proportional Integral Derivative (PID) based on Computed Torque Control (CTC) law. Simulation result shows that the designed system can compensate actuator fault with small error tracking error about 0.0068 rad and has time response less than 1s. It also reach minimum overshoot through 0.041 rad.