Research On Trajectory Tracking Control Algorithm Of Multi Joint Manipulator

Since entering the 21 st century,multi joint series manipulator has played an indispensable role in industrial production,such as painting,welding,cutting,assembly and palletizing.It is precisely because it has the advantages of fast motion speed,high control precision and good controllability.At the same time,the modeling accuracy of the mechanical arm is not high and the mechanical coupling is not strong.It is technically difficult to achieve high-precision trajectory tracking,thence,scholars at home and abroad have conducted extensive analysis and research in the face of the above mentioned technical problems.Taking the multi joint manipulator as the research object,this paper mainly focuses on trajectory planning and trajectory tracking.Kinematics and dynamics are the basis of the two.Firstly,the kinematics and dynamics are analyzed,and then the strategies of trajectory planning and trajectory tracking are discussed.Finally,the theoretical analysis and simulation numerical comparative analysis of the system are carried out.The specific research contents are as follows:(1)The kinematics and dynamics of multi joint manipulator are analyzed.Firstly,the forward kinematics model of the multi joint manipulator is established by using the DenavitHartenberg Matrix(D-H Matrix)modeling method,and the inverse kinematics of the manipulator is analyzed by using the analytical method.The correctness of the forward and inverse kinematics analysis is verified by a numerical example.Then a simplified dynamic model of multi joint manipulator is established by using Lagrange dynamic modeling method.(2)On the basis of kinematics,the trajectory planning methods of cubic polynomial,quintic polynomial and 3-5-3 polynomial in joint space are compared.Aiming at the problem that the traditional particle swarm optimization algorithm is easy to fall into the local optimal value,the dynamic nonlinear inertia weight,shrinkage learning factor and adaptive mutation are introduced to optimize the time of 3-5-3 polynomial,and its feasibility and effectiveness are verified by simulation.(3)Under the conditions of internal uncertainty and external disturbance in the dynamic model described in the preceding section,for the traditional terminal sliding mode control,the convergence time is slowly and have problems such singularity,fast nonsingular terminal sliding mode control is employed.Then aiming at the sliding mode chattering problem of the traditional exponential reaching law,the power reaching law is improved,and the system stability is judged by Lyapunov function.Finally,the simulation shows that the fast nonsingular terminal sliding mode can improve the fast response of the system,and the improved power reaching law can weaken the chattering problem,but it also brings the problem of reducing the steady-state accuracy.(4)New issues raised in the previous chapter,Interference observers and adaptive controls are used for feed-forward interference compensation,the nonlinear disturbance observer is used to compensate the external observable disturbance,the unobserved disturbance is estimated and compensated by the design of adaptive law,the adaptive law is determined by Lyapunov function,and the fast nonsingular terminal sliding mode controller is used as the main controller to enhance the robustness of the system;Finally,the stability of the system is verified by Lyapunov function.The simulation results show that the control algorithm has good anti-interference ability and control accuracy,The simulation results show that the control algorithm has good anti-interference ability and control accuracy,and can realize fast,stable and accurate tracking of the planned desired trajectory.Figure[48] table[11] reference[83]...