Model-based fault detection, isolation and fault-tolerant control for a class of nonlinear uncertain systems using information estimation

In this paper, we propose a fault detection, isolation and fault-tolerant control scheme for a class of nonlinear uncertain systems with possible state and sensor failures. First, a model-based nonlinear estimator using input-output information is designed by considering both state and sensor failures. This estimator is used to generate the residual signal which is for detecting both state and sensor failures. Second, multiple fault estimators are proposed to design fault isolation scheme for finding the fault type or location. Third, utilizing fault estimated, a fault tolerant control algorithm is designed to maintain the system operation continuously after a fault is detected. Finally, simulation is given to demonstrate how the proposed scheme can detect a fault occurrence, isolate the fault and engage the fault-tolerant control for the one degree of freedom robot.