Robust Remaining Useful Life Estimation Based on an Improved Unscented Kalman Filtering Method

摘要

In the Prognostics and Health Management (PHM), remaining useful life (RUL) is very important and utilized to ensure the reliability and safety of the operation of complex mechanical systems. Recently, unscented Kalman filtering (UKF) has been applied widely in the RUL estimation. For a degradation system, the relationship between its monitored measurements and its degradation states is assumed to be nonlinear in the conventional UKF. However, in some special degradation systems, their monitored measurements have a linear relation with their degradation states. For these special problems, it may bring estimation errors to use the UKF method directly. Besides, many uncertain factors can result in the fluctuations of the estimated results, which may have a bad influence on the RUL estimation method. As a result, a robust RUL estimation approach is proposed in this paper to reduce the errors and randomness of estimation results for this kind of degradation problems. Firstly, an improved unscented Kalman filtering is established utilizing the Kalman filtering (KF) method and a linear adaptive strategy. The linear adaptive strategy is used to adjust its noise term adaptively. Then, the robust RUL estimation is realized by the improved UKF. At last, three problems are investigated to demonstrate the effectiveness of the proposed method.