Fault Detection and Robust Control for Robots with Passive Joints

Fault Detection and Robust Control for Robots with Passive Joints

In this paper, a robust control scheme including fault detection, identification and accommodation for robots is presented to overcome the actuator failures. The joint fault considered in this paper is the free-swinging joint failure that causes the loss of torque on a joint. The presented fault-tolerant Cartesian control framework includes a normal control with normal (non-failed) operation, a fault detection and a fault recovery control to achieve task completion and fault accommodation. After the detection and identification of joint failures, the robot manipulator with failed actuators can be considered as the underactuated robot manipulator. To show the feasibility of the proposed robust control scheme, simulation results for a three-link robot are presented.