| In recent years,the country attaches great importance to the development of industrial robots,and the hydraulic manipulator as one of the heavy equipment has been widely discussed.In this paper,the research on the trajectory tracking control of hydraulic manipulator based on fuzzy control is carried out on the basis of the dynamics of hydraulic manipulator for the problems of structural parameter variation,modeling error and external interference,etc.The main contents include:(1)The kinematic model of the five-degree-of-freedom hydraulic manipulator is derived by combining the improved D-H parameters;the analytical expressions of the five joint angles in the inverse kinematics of the hydraulic manipulator are obtained by the analytical method with the known information of the end operator’s posture;the correctness of the positive kinematic equation model derived in this paper is proved by calling the relevant functions in MATLAB Robots Toolbox.(2)The dynamics model of the simplified two-degree-of-freedom hydraulic manipulator is derived based on the Lagrangian modeling method,and the interference term is introduced into the dynamics model considering the existence of interference in the actual robotic arm system;the dynamics model of the hydraulic drive subsystem is derived with the basic principle of hydraulic servo valve;the Jacobin matrix about the two subsystems of hydraulic drive and robotic arm is obtained by analyzing the structure of the large arm and small arm in the hydraulic manipulator,and then the dynamics model of the complete two-degree-of-freedom hydraulic manipulator is derived.(3)Combining fuzzy control and PID control,a fuzzy PID controller is designed,and in MATLAB,the simulation analysis compares the tracking control of PID and fuzzy PID on the trajectory of hydraulic robot arm,and the results show that the designed fuzzy PID controller has faster response,higher accuracy and more stable performance.(4)The fuzzy adaptive control strategy is proposed to address the problems of over-reliance on fuzzy rules and cumbersome parameter adjustment of fuzzy PID control.An adaptive fuzzy controller is designed,and the uncertainty terms in the hydraulic manipulator model are calculated by using its fuzzy system approximation property;the corresponding adaptive law is derived by Lyapunov stability criterion under the premise of ensuring the stability of the fuzzy adaptive controller;the simulation of fuzzy adaptive under the trajectory tracking of the hydraulic manipulator is implemented in MATLAB,and the results show that under the same model parameters The results show that the fuzzy adaptive is better than PID and fuzzy PID in terms of accuracy and response speed,but its performance in terms of stability is poor.(5)To solve the problem of poor stability of fuzzy adaptive in the trajectory tracking process of hydraulic manipulator,the sliding mode control is integrated on the basis of fuzzy adaptive.The characteristics of the traditional convergence law are discussed,and a new sliding mode convergence law is designed after its improvement;the stability of the system is proved by using Lyapunov’s method,and the control law and adaptive law of the fuzzy adaptive sliding mode controller are derived;in the simulation experiment stage,the trajectory tracking control effect of the hydraulic robot arm under different control methods is analyzed and discussed,and the rationality and advancedness of the fuzzy adaptive sliding mode control strategy based on the new sliding mode convergence law are verified.The rationality and advancedness of the new sliding mode convergence law-based fuzzy adaptive sliding mode control strategy are verified. |
