Dynamical Research Of Space Motive Controlable Multi-dof Vibration Isolation Platform

This aritcle focuses on space motive controlable multi-DOF vibration isolation platform. With the development of production technology and control theory , it makes the precision equipment carried by spacecraft request railway-supporting platform to have the ultra-quiet mechanical environment by space developing and researching. Because of the movement of solar panels and satellite attitude, it influents the sensitive load, and makes some devices of high accuracy, high stability can't operate normally. therefore, experiment platform with the vibration isolation capcility began to be studied and applied. In this article, the Stewart platform with six degrees of freedom is selected as the actice vibration isolator, and establish the dynamic modal of Stewart platform applying on the satellite in space by Newton-Eular method in the inertial coordinate system. Considering passive or active vibration isolation control, it simulates the vibration isolation effect. Simulation results show that Stewart platform can be located in the target state stability.First,the article introduces the principle of vibration isolation technology and space isolation, and put forward three configurations of vibration isolation platform by different legs'structure, that are spring-damper isolation system, the active and passive vibration isolation system composed of spring-damper combined with actuator, and active vibration isolation system composed of actuator. By that way, the dynamic model of Stewart platform in the body coordinate system is established, and the result of simulation verifies the correctness of the dynamic characteristics.Second, the model of this article is established. Considering the base platform is connected with satellite, the orbit and attitude models of the satellite is established. then the dynamic function and the simplified form of vibration isolation in the inertial coorinate is derived by the Newton-Euler method and the transform relationship of numbers of coordinate conversion matrix. Considering the legs'structural characteristics, the damping vibration isolation dynamic model is simulated, the simulation result shows that legs can be used as vibration damping structure.Last, the controller of legs is designed, and then active vibration isolation control system is established. Through the initial and desired space position and orientation, the actuator made of rigid legs completes the location. Substitute the space disturbance for the sine wave or the random signal to simulate the vibration environment of space, and the tendency of the vibration isolation platform attitude and position is simulated through the feedback of task space by the relationship between the task and driven space. Separately using passive form ,active combined with passive form and active vibration isolation form, from the compare results of these simulation above it is concluded thatthat the active combined with passive form is more suitable for space isolation.