Research On Kinetics Of The Image Stabilization System In Space Telescope

Along with the development and progress of science and technology, increasing attention has been turned to the space. The space astronomic telescope matters enough to the space exploration. Compared to the conventional ground-based telescope, the space one can get away from the distortions of the Earth’s atmosphere, so less background noise, wider optical wavebands, and higher imaging precision to the diffraction limit can be achieved. The present space telescope mostly was mounted on the satellite. The platform attitude change, Solar panel substrate vibration and the space stirling cryocooler rotating make the satellite dynamics environment complicated. Those environment vibration induced image degradation and distortion, which severely degrades the imaging accuracy. To make full use of the advantage of the space astronomic telescope, and raising the imaging precision to diffraction limit, the platform vibration must to be controlled by adopting the image stabilization system.Aiming the kinetics of the image stabilization system in space telescope, it mainly analyzed the working principle of the imaging stabilization system. The research focused on the designs of the VIS and the precision imaging stabilization subsystem, and verified test with experimental prototype was carried in laboratory scale. Firstly it investigated the famous telescope imaging stabilization design concept abroad and proposed a reasonable plan. It was highly focused on how to achieve the Image stabilization in a complicated dynamic environment containing the external disturbance and the internal residual vibration,and how to carry out the accuracy detection and compensation of micro-vibration. The kinetics of the image stabilization system design primarily included the VIS model design and the PISS prototype design. Based on theoretical analysis and experimental research, the kinetics model of the imaging stabilization system was verified.Based on the necessity, it proposed an isolate system to isolate the space telescope from high-frequency band vibration(above 10 Hz), this system scheme was verified through the simulation analysis; it also designed a precision imaging stabilization subsystem to compensate low-frequency band vibration(below 10 Hz). As one of the most important components of the subsystem, an adequate fine steering mirror(FSM) was built after structural analysis design and verification test. Finally the feasibility and the effectiveness of the system were proved with a physical model in laboratory, which could provide reference for subsequent study.The research main points of innovation as follow:It was the first research to the dynamic analysis on the imaging stabilization system of the future large aperture space telescope, and presented a series of scheme containing the VIS and The PISS. The integrated model method was adopted to analysis the Vibration response of the telescope. The micro-amplitude vibration magnitude of the space platform was estimated at 26.4 arc second. And it divided the different working frequency range of the two systems by the vibration sources and dynamic response. The advanced research of the dissertation has contributed to the technical support for the further researches in imaging stabilization system of the space telescope.A large-diameter(330×340mm) FSM mechanism was designed, and the arc second scale accuracy was obtained from the adoption of the inventive microdisplacement magnifying mechanism based on cross-spring flexural pivot. Response surface methodology and desirability function were used to optimize simulation for better mechanism performance. The FSM range was 64 arc second, the displacement resolution was 0.013 arc second, the base frequency was above 100 Hz, and the static error was lower than 5%. It satisfied the required property index based on the analysis of laboratory experiments.In the laboratory existing condition’s foundation, this dissertation has built a simulation telescope system. The system was mainly composed of a collimator, a laser source, the FSM, two high-speed cameras and a data-processing system. It could simulate the working environment on orbit of the space telescope. The vibration isolation station had a 100 dB vibration damping within the range above10 Hz. The Micro vibration value of the laboratory was 0.0125 arc second, the dynamic error of the FSM working at 10 Hz was lower than 1.2%. The simulated system solved the problem that high accuracy, large aperture space telescope working efficiently in laboratory scale.