Robust fault detection for multi-motor winding system based on disturbance observer and sliding-mode observer

摘要

This paper considers the problem of fault detection for multi-motor winding system with unknown input uncertainties. By introducing nonlinear unknown input, a generalized system which contains a nonlinear uncertainties consisting of the unmodeled dynamics, parameters uncertainties and external disturbances is constructed. Then a disturbance observer is designed to estimate the unknown inputs so that the upper of the unknown inputs can be achieved. Subsequently, based on obtained upper of the unknown inputs and the idea of Walcott-Zak observer, a robust sliding mode observer is designed to reconstruct the states, and subsequently it is extended to detect the system fault. Finally, the simulation results show that the designed observer is robust to the unknown inputs uncertainties, and it can detect the system fault efficiently.