Research On Dynamic Parameters Identification And Control Strategy Of Planar 2-DOF Redundant Actuated Parallel Robot

The object of this paper is a planar 2-DOF driven redundant parallel robot.Because of the existence of a redundant branch of the mechanism,it is beneficial to increase the stiffness of the mechanism and increase the working space.But there are also many problems.For example,redundant branches are easy to produce uncoordinated phenomena in motion.For example,the addition of redundant branches will increase the inertia force of the mechanism and so on.In order to give full play to the advantages of redundant mechanisms,the above problems attract extensive attention of a large number of scholars at home and abroad.In this paper,a planar 2-DOF driven redundant parallel mechanism is used as the research object to study the dynamic parameters identification of electromechanical coupling and control strategy.Firstly,the dynamic model of mechanism body including joint friction is established,and the bond graph model of AC synchronous servo motor and reducer is set up.Based on the above analysis,the dynamic model of the electromechanical coupling multi domain system is established.Secondly,through rigorous mathematical deduction,the linearized form of the electromechanical coupled multi energy domain system dynamics model is obtained.The excitation trajectory of identification is constructed by Fourier series improved by quintic polynomial form.The terminal excitation trajectory is optimized in the position space of the output shaft of the robot.The dynamic parameter identification experiment platform was built,and the dynamic parameters of the electromechanical coupled multi domain system were obtained by the weighted least square method.Thirdly,based on both the absolute error criterion and the suppression overshoot the parameters of the three loop controller are adjusted by genetic algorithm.An independent PID control strategy for each joint,a force/position hybrid control strategy based on calculation torque and a force/position hybrid control strategy with synchronizer are designed,and the correctness of the control strategy is verified through the joint simulation of Adams and Simulink.Finally,a control experiment platform is built based on the Beckhoff controller and the DELTA servo drive system.Through the comparison theory electromagnetic torque and the measured electromagnetic torque,the verification experiment of parameter identification is carried out.The three control strategies mentioned in the fourth chapter are applied to robot control,and when the robot is moving in two situations of high speed and low speed,the tracking effect of the robot is observed.Through the experimental curve,we can draw the following conclusion: the position tracking effect of two kinds of force/position hybrid control strategy are better than the independent PID control strategy of each joint at high speed and low speed,and the higher the speed is,the more obvious of the advantage.