Design and Experimental Study of a VCM-Based Whole-Spacecraft Vibration Isolation System

Spacecraft are subjected to various dynamic loads due to shock from stage and fairing separations, resonant burn of the rocket motor, pressure oscillation in liquid engines, wind and gust, etc. These dynamic loads are very detrimental to spacecraft components, electronics, and instruments. Hence, for the successful launching of a spacecraft, a whole-spacecraft vibration isolator (WSVI) is often applied to the launching process. In this paper, a novel active whole-spacecraft isolation system based on voice coil motors (VCMs) is designed, fabricated, and tested. The proposed WSVI system is composed of VCMs, supporting leaf springs, and actuator supports. It is nonintrusive to existing hardware, lightweight, and small, and it satisfies the design requirement of vibration isolation without changing the payload adaptor fitting structure. The characteristics of the spacecraft with and without the isolation system were tested. A controller design method based on the system identification and $H_{\infty }$ control law is proposed. A prototype was designed and tested to validate the isolation performance of the proposed system. Experimental results show that the novel WSVI system is valid for significant reduction of the amplitude of the spacecraft’s vibration response.