Research On Vibration Testing And Suppression Technology Of Satellite Active Thermai Control Equipment

On the satellite,the payload represented by the cryogenic optical detection system requires the active thermal control equipment to provide an appropriate low-temperature environment under normal operating conditions to ensure the quality of work.However,the use of active thermal control equipment will introduce new sources of vibration to the satellite,which in turn is inconsistent with the requirement for a good mechanical environment for normal payload operation.To solve this problem,it is necessary to fully understand the vibration characteristics of active thermal control equipment and conduct research on vibration suppression technology of such equipment.In this paper,two typical types of satellite active thermal control equipment,the fluid pump and the Stirling cryocooler,are studied.The pre-study and experimental methods are used to test and analyze the disturbance force/torque output in six directions during normal operation.During the research,the focus is on the direction and frequency domain characteristics of the disturbance force/torque output of each active thermal control device.The main direction of output,main characteristic frequencies,and the relationship between them and the design of the device itself has been investigated.Based on the study of the vibration output characteristics of the active thermal control equipment,a general mechanical model of the spatial six-degrees of freedom vibration isolation system with the single vibration isolator represented by threedimensional stiffness was established for the fluid pump.Using the potential energy method,the analytical expressions of the elements of the stiffness matrix of the vibration isolation system are deduced,and then the sixth-order natural frequency of the system is solved.According to the characteristics of the fluid pump's own structure,a vibration isolation system with a concentric arrangement of the vibration isolation system is designed.The vibration isolation frequency range,absolute transmission rate,system bandwidth,and coupling degree of the vibration isolation system are analyzed in detail.With those acted as optimization indicators,a prototype of a vibration isolation system was designed and fabricated for a specific fluid pump,and its vibration isolation performance was verified through experimental tests.For the Stirling cryocooler,the performance of the existing vibration suppression device,which consists of the flexible support and dynamic absorber,is examined through experimental tests.On this basis,the corresponding mechanical model of the existing vibration suppression device was established,the problems in its design were analyzed,and a specific optimization program was proposed.