Research On Dynamic Modeling, Friction Compensation And Control For Space Flexible Manipulator

Space manipulator has the important application in space station assembly, maintenance, construction, orbit service and space attack defense task. Because of the space flexible manipulator has the advantages of reducing launch costs and energy consumption, improve the operating speed and load capacity etc., it has got more and more applications in space missions now. But the most important disadvantage is the strong vibration in flexible link during the execution of the task. It is very difficult to accurately positioning, also will have an adverse effect on the design of control system. It is of great significance in theory and engineering practice to research flexible manipulator system kinematics, dynamics model in-depth and master its law, realize the precise control.The source and significance of this topic, as well as the current status of relevant technical research at home and abroad, are introduced firstly. In the second chapter, the modeling tool “Spatial Operator Algebra” is introduced firstly. Then, the chain rigid body forward and inverse dynamics algorithm was established based on this theory. And this method is extended to the flexible multi-body system, the efficient recursion algorithm was established based on the finite segment method. In the third chapter, through the analysis of the characteristics of the space environment in detail, Two different friction model of the space flexible manipulator was established on the basis of the existing friction models. These models provide a great convenience for the design of the control system. The fourth chapter first introduced the concept of Robust Integral of the Sign of the Error(RISE) control strategy, and in this method for spatial rigid manipulator was designed on the basis of the global convergence of the adaptive friction compensation strategy. In the fifth chapter, the space flexible manipulator model will be decomposed using singular perturbation theory. The controller is designed for fast-varying subsystem and slow-varying subsystem respectively. Then the validity of the method is proved by theory and simulation. The last chapter summarizes the whole thesis, and points out the problems existing in the research and the further work in the future.