Research on trajectory control of rotor systems supported by a combination of rolling and hydrostatic bearings

This article presents a novel method for controlling spindle trajectory by matching errors between front and rear bearings. The proposed approach is implemented on a spindle equipped with rolling bearings as the rear support and a hydrostatic bearing as the front support. The proposed technique actively adjusts the amplitude and phase of the spindle trajectory at the hydrostatic bearing to match that of the rolling bearing using piezoelectric ceramic (PZT) membrane restrictors. This approach serves two goals: one is to reduce the rotation error of the machining component at the front end of the spindle, which is one of the critical factors affecting machining accuracy. The second goal is to achieve specific trajectory tracking control, such as an ellipse, to meet the machining requirements of non-circular surfaces. Additionally, a self-turning fuzzy PID controller (FPIDC) is designed based on the characteristics of the hydraulic system. The feasibility and effectiveness of this method are proven through control simulation and experimental research.