Research On Six Axis Industrial Robot Control System And Friction Compensation

In view of the problem of industrial robot controller development and friction compensation,a six axis series industrial robot controller is designed and developed.Aiming at the reduction of tracking accuracy in low speed motion,the modeling and compensation of joint friction are studied.This paper first introduces the foundation of robot kinematics modeling.The forward kinematics model of six axis series industrial robot is established by D-H method.And the numerical solution for inverse kinematics of robot is studied with realization of speed planning and Cartesian space trajectory planning.At last,Simulation experiments verify the correctness of the kinematics and trajectory planning methods.On the basis of the above,the overall design of the controller is carried out.The hardware structure of the controller is introduced,and the general requirement of the software is analyzed.Software development is supported by supporting cross platform Qt,which improves the portability of software.Aiming at the high speed real-time control of servo driver,the realization method of EtherCAT bus communication technology is mainly studied.It also analyzes the reasons that affect the real-time performance of the communication,and modifies the network driver and the kernel of the operating system.The experimental results show that the real-time performance of the modified operating system satisfies the communication requirements completely.In practical application,in order to reduce the friction compensation failure and the tracking precision of the robot joint,a friction model considering variation is proposed.A nonlinear friction model under the influence of temperature is established by system parameter identification based on the nonlinear least square method.And the model is solved by Levenberg-Marquardt.In order to verify the validity of the model,a feedforward compensation method based on friction model is introduced,and the robot joint trajectory tracking experiment is designed.The experimental results show that the friction model considering the temperature can accurately describe the change law of friction at different temperatures.The application of the model can further improve the tracking precision of the robot joint.