Study On Modeling And Trajectory Tracking Control Of Space Manipulator

As the most potential equipment of spacecraft, space manipulator has alwaysbeen a hot issue of aerospace technology. However, characters such as a floatingbase and susceptibility to interference determines the complexity of the model andcontrol. This thesis focused and studied on the problems of modeling and trajectorytracking control of space manipulator, the method of differential geometrycombined.Firstly, the current development of space manipulator and its research results ofmodeling and control were introduced. With GJM (Generalized Jacobian Matrix)method and Lagrange method, the kinematic model and dynamic model of spacemanipulator system were given.Secondly, the differential geometry of nonlinear control was studied. Takingthe planar two-link free-flying space manipulator as an example, through properdiffeomorphism and nonlinear state feedback, the control law to exact linearizationusing differential geometry method was given, and a linear decoupling model waspresented.Then the problem of trajectory tracking control in joint space was studied. Atfirst a PID controller was designed and simulated, showing a good response, whichproved the effectiveness of differential geometry exact linearization method.Analyzing the causes of parameter perturbation and external disturbance, a SMC(Sliding Mode Controller) was given. And the simulation results proved its strongrobustness. Further more, aiming at the sliding mode chattering, an AFSMC(Adaptive Fuzzy Sliding Mode Controller) was designed. The simulation results ofAFSMC showed that it can improve the dynamic and static characteristics as well asreduce the control torque fluctuation.Finally, in view of the superiority of differential geometry in handlingnonlinear problems, a space manipulator system model based on Lie group wasproposed, which had advantages of less calculation amount, unified form of modelsand definite physical meaning. Comparing the simulation result under the samecondition between Lie group model and classical model, a high similarity waspresented, proving the validity of Lie group method.