| Multi-degree-of-freedom manipulator has been widely used in industrial production and daily life.Because the multi-degree-of-freedom manipulator is a highly coupled multi-input and multi-output strong nonlinear complex system,it is vulnerable to the impact of the working environment,as well as the friction between various joints and the interference of some uncertain factors,resulting in high-precision trajectory tracking control of the multi-degree-of-freedom manipulator Fast response speed and anti-interference performance are difficult to achieve.However,the traditional control strategy often cannot better meet the performance required by the system,so the adoption of reasonable and efficient control strategy has become the core content of the control technology of the multi-degree-of-freedom manipulator.Aiming at the multi-degree-of-freedommanipulator is a multi-input and multi-output nonlinear complex system,this paper designs a multi-degree-of-freedom manipulator control system based on sliding mode ADRC,which is expected to achieve high positioning accuracy,fast response speed and strong anti-interference performance.The main work of this paper is as follows:(1)This paper firstly introduces the working mode of the multi-degree-of-freedom manipulator,analyzes the working circuit of the DC torque motor of the actuator of the joint of the multi-degree-of-freedom manipulator,establishes the mathematical model of the DC torque motor according to the torque balance equation and electromagnetic balance equation of the DC torque motor,and then analyzes the mechanical structure of the multi-degree-of-freedom manipulator.The reference coordinate system of the whole system was selected as the base of the manipulator,and the Denavit-Hartenberg four-parameter modeling method was adopted to obtain the relation matrix of the adjacent connecting rod joints through transformation,thus deducing the kinematic model of the manipulator with multiple degrees of freedom,and then calculating the dynamic equation of the manipulator system with multiple degrees of freedom according to the Lagrange function.(2)In order to improve the response speed and tracking accuracy of the multi-degree-of-freedom robotic arm control system,a sliding mode active disturbance rejection control strategy was designed.Firstly,the traditional ADRC technology and Sliding mode control technology are introduced respectively.Then aiming at the problems of slow response speed of ADRC technology,complicated parameter tuning in the extended state observer and nonlinear error feedback control law structure,and buffeting effect of Sliding mode control,a sliding mode ADRC control strategy is designed by combining the traditional ADRC technology with Sliding mode control.This control strategy not only retains the original anti-interference performance of self disturbance rejection control technology,but also reduces adjustable parameters and improves the response speed and robustness of the system.(3)In order to Verify the feasibility of a multi-degree-of-freedom robotic arm control system based on sliding mode ADRC through experiments.Firstly,a simulation model of a multi-degree-of-freedom robotic arm control system based on sliding mode ADRC was built using Matlab/Simulink simulation software for experimental simulation.Secondly,based on the existing experimental equipment in the laboratory,including a drive motor control system and a multi-degree-of-freedom robotic arm,the built model is programmed in a PC host using MATLAB,and the designed sliding mode ADRC control algorithm is written in the supporting software for experimental verification.The effectiveness of the multi-degree-of-freedom robotic arm control system based on sliding mode ADRC is demonstrated through simulation and experiments.The control system of multi-degree-of-freedom manipulator based on sliding mode ADRC designed in this paper has good control performance.The control strategy can achieve good control effect under the condition of disturbance.There is no overshooting,which improves the response speed of the system and reduces the tracking error of the system.The multi-degree-of-freedom manipulator system has better following performance and research significance. |
