Control And Experiment Of The Fine Tuning Stewart Platform For The Large Radio Telescope

In this paper, based on a completely new design project of next generation large radio telescope (LT) integrating mechatronics and optics technologies proposed by professor Duan, for realizing requirement of high precise trajectory tracking of the feed-supporting system with large span cable, With the fine tuning Stewart platform being an object, dynamic modeling, control strategies and control methods of the fine tuning Stewart platform are analyzed and researched. A robust and resist disturbed auto-disturbances rejection controller in the joint space is designed to realize high precise trajectory tracking of the fine tuning Stewart platform.Based on Newton-Euler method a dynamic model for Stewart platform is constitu- ted which involves the inertias of the platform and six legs and frictions at joints. Suppose the movement programming is already being known, the inverse dynamic problem of actuator force in the joints for Stewart platform is solved during the process of establishing the model, which has laid a foundation for Stewart platform control used for LT500m.The base methods of robot control are analyzed and researched. Considering that the fine tuning Stewart platform is a non-linear, multi-input and multi-output system with strong coupling, on analysis and research control strategies and control methods of the fine tuning Stewart platform, the distributed control strategy in the joint space is adopted. A robust and resist disturbed auto-disturbances rejection controller in the joint space is designed from engineering application perspective to put into effect high precise trajectory tracking of the fine tuning Stewart platform.With LT50m reduced scale model of the fine tuning Stewart platform being an object, Simulation analysis and experiment research are made. A large number of simulation and experiment results prove that the proposed trajectory tracking control strategies and control methods are feasible and valid in engineering. A firm foundation for realizing high requirement of trajectory tracking control of the feed-supporting system with large span cable for large radio telescope is established.