I. Introduction
Degradation prediction of typical transmission components is vital in intelligent condition monitoring and health management of mechanical systems. Rolling bearing is a typical transmission component widely used in mechanical systems that work on variable loads and complex environments. It inevitably and slowly degrades, affecting the operating performance of the mechanical systems, such as accuracy, reliability, and even service life [1], [2], [3]. Thus, it is important to identify the health status of rolling bearing periodically and predict its remaining useful life (RUL) to reduce the downtime of mechanical systems and ensure efficient production [4], [5], [6].