Research On Ground Semi-physical Simulation Experiment And Trajectory Planning Of Free Floating Space Robot

As astronauts are difficult to operate in dangerous and complex space environment,the development of space robots to assist mankind to develop space is inevitable.Because the object of this study is free floating space manipulator which the base position not controlled,and the movement of the robot will cause the base position pose disturbance,and the change of the base position will affect the control precision of the end of the arm.Therefore,this paper studies a trajectory planning algorithm for free-floating space manipulators to achieve the optimal target for minimizing the attitude of the base.In order to verify the effectiveness of the algorithm for the application of the real space manipulator,a set of terrestrial semi-physical simulation system which can simulate the three-dimensional motion of the space manipulator can be simulated and the proposed algorithm is verified.Firstly,the paper introduces the space robot project of each country,analyzes the trajectory planning algorithm of space robot,and discusses the kinematics and dynamics modeling method of space robot.Then,the ground experiment system based on different principles is introduced and compared,and the ground verification system based on semi-physical simulation is selected.Then,the differential kinematics of the free-floating space manipulator is deduced,and the kinematics equation is verified based on the actual manipulator simulation.Then,the forward dynamics based on the hinge algorithm is studied,and the virtual prototype model is built and compared with the modular software.The correctness of the dynamic model is proved.Later,a kinematic optimization algorithm based on zero space velocity saturation is studied for the problem of joint speed overrun in the movement of space manipulator.When the joint exceeds the velocity constraint,the zero space of the redundant manipulator is used to limit the joint To optimize,when the zero space can not compensate for all overrun joints,the implementation of global speed scaling.Based on the algorithm,the problem of mapping Cartesian space constraints to joint space is studied.The simulation results show that the algorithm can accomplish the task accurately and efficiently under the condition of joint speed constraint.Furthermore,it is considered that the pose disturbance is minimized by planning the end of the Cartesian trajectory for the problem of attitude and attitude control at the end of the manipulator.By using the Bezier curve to implement the parameterization of the Cartesian trajectory and setting the optimal objective function based on the constraint correction,a dual adaptive sort particle swarm optimization algorithm based on natural selection is proposed.The improved algorithm satisfies the minimum attitude of the pedestal The simulation results show the effectiveness of the proposed algorithm.Finally,the ground experiment system of three-dimensional motion of simulated space manipulator is established based on semi-physical simulation.The algorithm is used to verify the trajectory optimization algorithm and zero space velocity kinematics.The results show that the two algorithms are in the real space manipulator Optimized efficiency in the system.