Actuator Fault Detection for Autonomous Underwater Vehicle Using Interval Observer

A new actuator fault detection method for autonomous underwater vehicle (AUV) was proposed in this paper, based on interval observer. Firstly, the nonlinear vertical motion model of AUV is simplified and a linear time invariant (LTI) system is obtained. For this LTI system, interval observer is projected and it has two parts: one for the estimate of the upper bound of the states and the other for the estimate of the lower bound of the states. Using the information from interval observer, residual and threshold are generated simultaneously, which is quite different from the conventional method where the generation of residual and the choice of threshold are separated. Hence the proposed method provides a more simple realization of actuator fault detection. In the end, the availability of the presented method are conducted to verity by simulations.