A Random Forest and Model-Based Hybrid Method of Fault Diagnosis for Satellite Attitude Control Systems
Shaozhi Chen, Rui Yang, Maiying Zhong, Xiaopeng Xi, Chengrui Liu
Abstract
Fault diagnosis is the key technology to guarantee the reliability and safety of satellite attitude control systems. Although model-based methods have achieved good fault diagnosis performance, various factors (such as closed-loop design, model nonlinearity, and external disturbances) in the satellite attitude control systems still bring challenges to fault isolation. Meanwhile, data-driven methods can assist model-based methods for fault diagnosis based on residual signals (generated from model-based methods) and input/output data to relieve the difficulty. Based on the above motivations, a novel model and data dual-driven fault diagnosis approach is proposed in this paper for satellite attitude control systems. Firstly, an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H<sub>i</sub></i> / <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> optimization based fault detection filter is considered as a residual generator, which is designed to be robust against disturbance and sensitive to fault. Then, the occurrence of a fault can be detected based on the residual evaluation. Eventually, a random forest algorithm is developed to achieve fault isolation with system input/output and residual signals. A simulation experiment, including fault detection and fault isolation of single faults and multiple faults, is conducted to show that the proposed approach is effective and better than the other three methods.