Analytical and experimental validation of vibration isolation system with complementary stiffness and composite control

Abstract

In the spacecraft, optical payloads are greatly disturbed by micro-vibration. Therefore, the active-passive vibration isolation system (APVIS) with stable performance and high efficiency has become the focus of many scholars, with the increasing demand for vibration isolation. The voice coil motor (VCM) is often used to verify the APVIS. However, due to processing and installation errors, noncontact and low stiffness between the mover and stator of the VCM, the normal operation of the system will be affected. An APVIS based on the complementary pair of axial and radial stiffness is proposed in this paper. Structurally, the flexible joint and the membrane are used to compensate for each other and explained and verified from the mechanism and experiment. In the control algorithm, feedback control and feedforward control are used to build an active composite control (ACC) algorithm, and the two compensate each other to solve the problems of feedback control time delay and feedforward control instability. Experimental results show that the errors of the axial force transmission and the output force of the VCM are only 1.09% and −1.5%, respectively. The designed structure can ensure the co-axiality of the mover and stator, and the VCM can work normally. After control, the ACC algorithm can achieve vibration attenuation of 95.8%, the amplitude at natural frequency is decreased by 27.53 dB, which verifies the effectiveness of the ACC algorithm.