Actuator fault detection and isolation for robot manipulator using higher order sliding mode observers

Abstract

Fault detection and isolation (FDI) approach for actuator faults on a robot manipulator using a model-based FDI fault, which can occur on a specific component of the system. To detect actuator faults, higher order sliding mode Unknown Input Observers (UIO) are proposed to make analytical redundancy. The observers input laws are designed according to the so-called Super-Twisting Second Order Sliding Mode Control (SOSMC) approach and they are proved to be capable of guaranteeing the exponential convergence of the fault estimate to the actual fault signal. The proposed approach is verified in simulation on a robot manipulator.