Degradation Modeling and Remaining Useful Life Prediction of Control Moment Gyroscope

With the rapid development of space technology and the increasing functions of spacecraft such as satellites and space stations, the requirements for pointing accuracy and attitude stability of satellites have increased. Therefore it is vital to develop large satellites with higher precision and stability in order to enhance the space strategic strength. Control moment gyroscope (CMG) is the key actuator of this kind of spacecraft, which can achieve accurate attitude control. So the quality monitoring and the remaining useful life (RUL) prediction of CMG is the main emphasis of spacecraft's Prognostics and Health Management (PHM). As for CMG, the degradation phase can be divided into multiple stages. This paper plans to use a method based on stochastic process model to predict the RUL of CMG. At first, the statistical process control (SPC) is used to divide the trend of CMG operation process and identify the time of stage change point. It is mainly divided into health stage and degradation stage, and a degradation Wiener process model is established for the degradation stage. Afterwards, the model parameters estimation and RUL prediction can be conducted. This paper uses the high-speed motor current (HSMC) data of a certain model for CMG to divide different stages and estimate the RUL. Then the working condition and residual life of CMG can be evaluated.