Dynamic Analysis And Control Research Of A Spherical 2-DOF Redundant Drive Parallel Robot System

The parallel robot has a wide application stage in modern machinery industry because of its good positioning precision,large bearing capacity and compact mechanical mechanism.In this paper,based on the spherical 2-DOF redundantly actuated parallel robot,the research is carried out on the mechanism kinematics,the global dynamics model of the robot system,the motion pair friction,the mechanism vibration theory and the control strategy of the robot system.In this paper,the whole solution model of the multi-energy domain spherical 2-DOF redundant driven parallel robot system considering the rotation pair and the system driving part friction is established,and the simulation verification is carried out by MATLAB software and ADAMS rigid Body dynamics simulation software,which lays the foundation for the subsequent dynamic parameter identification and control research.Based on the global dynamics model of the robot system,the friction parameters are identified.Based on the model of friction moment of the spherical prototype,the friction moment model of the mechanism body and the motor drive partial is deduced respectively,then the identification strategy is developed for the parameters of the above two models respectively,then the identification experiment and verification experiment are completed,and a more accurate dynamic model of the robot system is obtained.The vibration model of the mechanism is deduced,and the natural frequencies and the regular main modes are solved,then the vibration differential equations of the mechanism are solved,and the response of the mechanism to the given initial conditions is obtained.Finally,the test of the motor drive partial stiffness and the test of the vibration characteristic are carried out.This paper introduces the structure of the control system of the robot system motor drive partial.The three-loop closed-loop PID controller is designed and the control parameters are set;Then,according to the parallel mechanism,two control strategies of mechanism kinematics closed loop control and mechanism dynamic feedforward control are developed,and the simulation comparison is carried out.Finally,the experimental platform is built,complete the control experiment.