Research On The Control Strategy Of Electro-hydraulic Servo Tele-manipulator

The master-slave tele-operation system with force tele-presence transforms theforce and position information of the remote to the feedback force and maps it to thehuman via the manipulator, which can make sense of reality for users. Meanwhile, thecommand of the operator is transmitted to tele-robot and conducts the robot to finishcomplex tasks successfully. The performance of the system has a huge influence onthe working quality and efficiency. As a result, how to improve the performance hasattracted on enormous researchers and scholars.This M.E. dissertation developed under the project named “Tele-operationmulti-DOF electro-hydraulic servo parallel manipulator with accurate force feedback”(No.50975118). From the view of the control strategy, theories and methods areresearched and discussed to modify and perfect the force tele-presence technology.The kinematics and dynamics characteristics of3-DOF serial manipulator areanalyzed, including D-H method for forward kinematics, geometric method forinverse kinematics and dynamics model based on Lagrange method. The performanceindex of workspace is also discussed by the Monte Carlo method. With a view to theelectro-hydraulic servo control system, the linear mathematical model of the system isestablished as well as disturbance observer controllers and PD controllers aredesigned.The bilateral servo control strategy is an indispensable link of the proposedtele-operation system, which is used for transmitting mutual information between themaster and slave side. To overcome the problems that both amplitude of feedbackforce is only taken consideration without direction and multi-DOF coupling leads topoor effect of feedback force belonging to most current control strategies, a novelbilateral servo control strategy is presented that is modified from position deviationfeedback control strategy. In the strategy, the position space matrix is transformedfrom kinematics Jacobian matrix and the manipulator form the same position space asthe slave side so that the operator can accurately grasp the environmental conditions.In addition, the stability is analyzed via Lyapunov method and the transparency is discussed.At last, Co-simulation of Adams and Matlab is applied to test the effectiveness ofthe proposed strategy. The simulation results show that under several type conditions,including unloaded, loaded and interference motion on the slave side, themanipulator of the tele-operation system can map the same position space as theslave side so that accurately reflects the interference force in the slave side and itschanges, the operator feel as if he personally operates the tasks in the slave side...