Research On Vibration Reduction Of Atomic Clock Assembly Platform Based On MSMA

The Global Navigation Satellite System(GNSS)is an important system for providing users with all-round high-speed ranging,timing and fixed-speed services in the sky,land and sea.People use it to get accurate location and time information.In the GNSS system,the on-board atomic clock plays a vital role in the accurate positioning of the user's position.Since the position information is determined from the transmission time of the satellite transmitted signal,any measurement error at any time will cause the positioning deviation.Therefore,in order to reduce the deviation of positioning,it is necessary to use a precise atomic clock.The cesium atomic clock is an ultra-high precision atomic clock developed by countries all over the world.The best cesium atomic clock reaches 20 million years before it differs by 1 second.It is now widely used in various fields such as astronomy,geodesy and national defense construction.The assembly accuracy of the atomic clock is one of the important factors affecting the timing accuracy.The focusing of the atomic clock assembly is an important means to ensure the assembly accuracy.However,it is restricted by the micro-vibration of the platform caused by the assembly adjustment process.Therefore,reducing the vibration problem of the assembly platform is an effective way to improve the accuracy of the cesium atomic clock.In view of the high energy conversion efficiency and high power density of MSMA materials,it is applied to the cesium atomic clock assembly platform to reduce the small vibration during assembly.The main work is as follows:(1)Aiming at the problem that the vibration of the cesium atomic clock assembly platform is difficult to suppress,an active vibration reduction scheme using MSMA material as the core component is proposed.The multi-field coupling model of the MSMA active vibration damping device was established,and the factors of the MSMA material performance on the active vibration damping control were analyzed.(2)Analyze the cause of nonlinear hysteresis of MSMA.For the problem of MSMA hysteresis nonlinear influence on the accuracy of damper,it is proposed to use temperature and phase compensation,select high-precision fitting model and improve control method to reduce hysteresis nonlinear.The simulation results show that the active vibration damping device with MSMA as the core can effectively suppress the vibration problems caused by the assembly process of the cesium atomic clock assembly platform.