On the investigation of the integrated passive vibration isolation and active vibration absorption method to control the micro-vibration of spaceborne cryocooler

Abstract

In order to mitigate the adverse effects of the micro-vibration generated by the cryocooler on the imaging and pointing accuracy of the satellite space camera, this paper proposes an integrative vibration control strategy that combined the passive vibration isolation and active vibration absorption method. Firstly, the two separate vibration transmission paths of the working cryocooler are analyzed. Then, the passive vibration isolation of the compressor and the active vibration absorption of the cold finger are designed for each of the two vibration transmission paths. Among them, the passive vibration isolators in convergent configuration are adopted to suppress the micro-vibration transmitted from the compressor to the mounting plate. The dynamic model of the passive vibration isolation system is established and the vibration isolation performance is evaluated. Furthermore, three electromagnetic vibration absorbers are adopted to control the micro-vibration transmitted from the compressor to the detectors which connected to the cold finger. A multi-channel decoupling adaptive algorithm is proposed to achieve the decoupling control of three vibration-absorbing channels. The finite element model of the spaceborne cryocooler is constructed, and the vibration control performance of passive vibration isolation and active vibration absorption techniques are analysed. At the experimental step, the accelerometers and a six-component force table was employed to evaluate the general performance of the combined passive vibration isolation and active vibration absorption method. The results demonstrated that the integrative vibration control strategy, which incorporated vibration isolation and absorption, can effectively reduce the perturbation output of the cryocooler and provided an ultra-quiet dynamic environment for the detector.