Research On Trajectory Planning And Trajectory Tracking Control Of Multi-joint Manipulator

With the rapid development of society and technology,the demographic dividend has gradually disappeared,coupled with the impact of the novel coronavirus epidemic in recent years,the human cost is rising.Manipulator is widely used in various fields by virtue of its fast,stable and efficient working characteristics in the working space.Nowadays,in order to enable the manipulator to complete the scheduled task excellently in the complex and special working environment,the working efficiency and accuracy requirements of the manipulator are becoming higher and higher.Therefore,efficient and reliable trajectory planning and fast and stable trajectory tracking control are of significant research significance for multi-joint manipulator.The specific research content and results of this dissertation are as follows.(1)GLUON-6L3 six-joint manipulator was taken as the research object.The kinematics and dynamics models of the manipulator are established by standard D-H method and Lagrange method respectively,and the forward and inverse kinematics of the manipulator are analyzed and deduced in detail.According to the constraints of each joint of the manipulator,Monte Carlo method is used to analyze the workspace of the manipulator,and its simulation model is built in software.The reliability and effectiveness of the model established in this dissertation are verified by the simulation results.(2)Aiming at the problems of traditional manipulator trajectory planning,such as low efficiency,precocious intelligent algorithm and unstable operation,an improved particle swarm optimization(PSO)method was proposed to optimize the trajectory of six-joint manipulator with the goal of time optimization.Firstly,the forward and inverse kinematics principle of the manipulator is used to obtain its trajectory interpolation points in joint space.Secondly,in order to make the manipulator reach the target position quickly and smoothly,the 3-5-3 piecework polynomial is used to interpolate its trajectory.Finally,the improved PSO algorithm was used to optimize the trajectory constructed by piecewise polynomial interpolation to achieve the time optimal trajectory planning of the six-joint manipulator.The trajectory information of each joint variable of the manipulator can be obtained through simulation experiments.Under the premise of meeting the kinematic constraints of the manipulator,the position,velocity and acceleration motion curves of each joint have good continuity and smoothness.The results show that the improved PSO algorithm can effectively realize the trajectory planning of the six-joint manipulator with the optimal time.(3)Modeling error and external interference exist in the trajectory tracking control of the manipulator.In order to improve the accuracy and speed of trajectory tracking of manipulator,an adaptive fuzzy sliding mode control strategy based on interference observer is designed.Firstly,a new approach law is used to reduce the chattering effect in the sliding mode control system of manipulator.Secondly,the interference observer is used to estimate the modeling error and external interference of the manipulator,and the input torque of the manipulator is compensated according to the observed value of the interference observer.Finally,for the parts that cannot be observed,the universal approximation principle in fuzzy system is used to estimate the unknown interference,so as to further improve the trajectory tracking performance of the manipulator.Simulation results show that the control strategy is correct and effective.Therefore,the above control strategy can not only overcome the influence of modeling error and external interference,but also effectively weaken the chattering of the system and improve the precision and speed of position tracking of each joint of the manipulator...