Robust Sensor Fault Estimation for Control Systems Affected by Friction Force

Abstract

The paper presents an observer-based estimation of sensor fault for control systems affected by friction force. In such systems, the non-linearity of friction force leads to deteriorating sensor fault estimation capability of the observer. Hence, the challenge is to design an observer capable of attaining robust sensor fault estimation while avoiding the effects of friction. To overcome the highlighted challenge, an Unknown Input Observer (UIO) is designed to decouple the effects of friction as well as to estimate the state and sensor fault.The benefit of proposing UIO is to guarantee robust sensor fault estimation despite the highly non-linear disturbance in the form of friction. The gains of the UIO are computed through a single–step linear matrix inequality. Finally, an inverted pendulum simulation is presented to demonstrate the novel approach's performance effectiveness. Index Terms—Robust fault estimation, Fault-Tolerant control, unknown input observer, Friction force, estimation/decoupling approach.