| With the introduction and promotion of "intelligent manufacturing" in industry,manufacturing,etc.,industrial robots are playing an increasingly important role in promoting the realization of "intelligent manufacturing".Among them,6-DOF industrial robots are widely used because of their higher flexibility.However,most of the existing 6-DOF industrial robot systems adopt PID control with constant feedback gain,which is lack of dynamic control of the robotIn this thesis,PID control algorithm,robot dynamics model and feedforward control algorithm are combined to solve the lag problem of PID control in robot trajectory tracking,which effectively improves the dynamic response speed and trajectory accuracy of the 6-DOF industrial robot control system.The specific work contents are as follows:Firstly,aiming at the problem of poor real-time performance of robot system using traditional pulse mode and unable to realize feedforward control combined with robot model,a research platform of robot control system based on high-speed EtherCAT bus is built,which creates conditions for studying kinematics,dynamics model and feedforward control of 6-DOF industrial robot.Secondly,the modified D-H parameter model of the 6-DOF industrial robot is established by establishing the coordinate system,and the kinematics model of the 6-DOF industrial robot is deduced and established,and the simulation verification is carried out,which lays the foundation for the establishment of accurate robot dynamic model.Then,the parameter identification method of robot dynamics model is studied in detail,and the accurate 6-DOF industrial robot dynamic model is established.Firstly,the dynamic model established by the iterative Newton Euler method is linearized and the parameters are reorganized;Secondly,the optimal excitation trajectory for dynamic model identification is designed;Then,the low-pass filter,zero phase filter and smoothing filter are selected to filter the collected data to eliminate the high-frequency noise interference,and the central difference method is selected to calculate the joint velocity and acceleration;Finally,the parameters of the model are estimated by the least square method,and the identified parameters are verified,thus the accurate dynamic model of the robot is obtained.Finally,the dynamic torque feedforward control system of 6-DOF industrial robot is analyzed and studied.Based on the identified dynamic model,the feedforward control simulation system of PD+robot dynamic model based on Simulink is built,and the feedforward control experiment is carried out on the robot control system platform developed in this project.The effectiveness of PD+dynamic model feedforward control method is verified by simulation and experiment.Through this method,the dynamic response characteristics of the robot are improved and the trajectory tracking accuracy of the robot is improved. |
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