Research On Trajectory Planning Of In Space Manipulator

With the development of technologies such as space stations and space robots,space robots have received more and more attention.They are capable of transporting loads,allowing astronauts to walk freely in space,conducting experiments in outer space,on space stations and space robots.Carry out routine maintenance,etc.Due to the needs of space station exploration,higher requirements are placed on the stability and safety of space manipulator operation in onorbit service.The space manipulator has strong adaptability to the working environment.However,the space environment is very special and complex,and there are many uncertain factors.Therefore,further study of the space manipulator trajectory planning to improve the stability and safety of the space manipulator system during motion.It is of great significance.Based on the study of space manipulator trajectory planning at home and abroad,this paper studies the trajectory smoothness and pedestal stability of the space manipulator system in two different states.And a trajectory planning strategy for the improved CS(Cuckoo Search)algorithm is designed.Firstly,the research results of the space manipulator and its trajectory planning algorithm at home and abroad are introduced,and the general model of the space manipulator is deeply understood.On this basis,the kinematics equations and dynamic equations of the space manipulators under free floating and free flight are established respectively.Secondly,the improved CS algorithm is introduced to overcome the problem of insufficient smoothness and stability of the space manipulator system in trajectory planning.Aiming at the space manipulator system in free-floating state,combined with the kinematics equations and joint angles,joint angular velocity and joint angular acceleration,the trajectory planning model with minimum pedestal disturbance is constructed,and the trajectory planning model is solved by improved CS algorithm to realize the trajectory planning goals.Aiming at the space manipulator system in free flight state,combined with the kinematics equation and dynamic equation and the constraint indexes such as joint angle,joint angular velocity and joint acceleration,the minimum trajectory of the mechanical arm motion to the pedestal is constructed.The planning model is also solved by the improved CS algorithm to achieve the trajectory planning goal under free flight conditions.Finally,trajectory planning strategy based on the above design,the space robot arm joint angle,joint angular velocity,joint angular acceleration and pedestal attitude angle in freefloating state are simulated and verified.The space robot arm joint angle,joint angular velocity,joint angular acceleration and the interference torque generated by the pedestal in free-flight state are simulated and verified.And compared with the simulation of the traditional trajectory planning method S-type velocity curve planning.The results show that the joint angle trajectory smoothed by the improved algorithm is smoothed.Within the constraint range of the mechanical arm system,the two states can effectively reduce the interference of the arm movement on the pedestal and enhance the stability of the space manipulator system.