Research on active vibration isolation system based on piezoelectric actuator for satellite laser communication terminal

During the on-orbit operation of space spacecraft, it is easy to be affected by the small vibration from the satellite platform, especially the key sensitive loads carried by the spacecraft. The traditional method is to install a passive damping vibration isolation system between the platform and the sensitive loads. However, the passive vibration isolation system only has a good suppression effect on the high-frequency and large amplitude vibration, and can suppress the low-frequency and large amplitude vibration below 10Hz, the vibration isolation effect in the resonance section is poor. Therefore, in order to solve this problem, an active vibration isolation system of 6-DOF Stewart platform driven by piezoelectric actuator is proposed in this paper. Firstly, the characteristics of Stewart platform are analyzed and modeled, and on this basis, the deformation and displacement of each leg are obtained through decoupling calculation, and each leg is servo controlled with high precision; Secondly, the inherent hysteresis nonlinearity of piezoelectric ceramics has a serious impact on the positioning accuracy. By analyzing the hysteresis mechanism of piezoelectric actuator, a phenomenal hysteresis mathematical model based on Maxwell-Slip operator is established. Finally, the feedforward inverse compensation and feedback linearization methods are proposed, and the system verification test is established. The test results show that, the active and passive vibration isolation system designed in this paper greatly improves the positioning accuracy of piezoelectric actuator and the active vibration isolation performance of the platform.