Research Of Trajectory Tracking Algorithms For Industrial Robot

After decades of development of industrial robot and it has been applied in many areasof industrial production. More and more scholars join the research work of the industrial robot.The control problem of industrial robots is the focus of the study of scholars from variouscountries. The industrial robot system is a very complicated non-linear system, which hasmultiple inputs and multiple outputs. It has the character of time-varying and non-linear. Thecontrol problem of robot is very complicated. Trajectory tracking control is an importantaspect of industrial robot control problem. Trajectory tracking control requires each joint ofthe robot to track the trajectory which is continuous and time-varying, so the control accuracyis difficult to guarantee.The research project is supported by the national863important project and the projectnumber is2009AA43901-3.This thesis is focused on the industrial robot trajectory tracking control algorithmresearch. The main contents are as follows:Firstly, this paper deeply analyzes the dynamics of industrial robots. In order to establishthe dynamics model this article analyzed the kinematics model of the robot. The author usesLagrangian method to establish the dynamic model of the6-dof robot and the dynamic modelis based on the kinematics model of the robot. In this paper, the dynamic model has beensimplified by the author in order to meet the requirements of real-time control.Secondly, in order to simulate the algorithm of the trajectory tracking conveniently, thispaper analyzes the problem about how to establish the simulation model of the robot. Thispaper uses the software named ADAMS to establish the block which can be used inMATLAB and completes the work which is about the creation of the trajectory trackingalgorithm.Thirdly, this paper analyzes some algorithm of trajectory tracking deeply, such as PIDalgorithm, PID feed-forward algorithm, the computed torque method and sliding modevariable structure algorithm. The author combined the variable structure control and PID+feed forward algorithm in which way to Propose based on variable structure compensationPID+feed forward control algorithm. This algorithm can reduce the error. The authorcombined the variable structure control and PID+feed forward algorithm in which way toPropose based on variable structure compensation PID+feed forward control algorithm. Thisalgorithm can reduce the error. Based on VSC, the author proposed two kinds of noveltrajectory tracking algorithm named fast VSC algorithm and adaptive fuzzy VSC algorithm. The fast VSC algorithm can improve the control effect by optimizing the reaching movement.By introducing adaptive processing and fuzziness into reaching law of traditional variablestructure control, the reaching motion was improved during sliding mode process. Based onunobvious buffeting, this algorithm can not only improve response rate, but also ensure theaccuracy of trajectory tracking, as well as the advantages of simple structure, high robustnessand adaptability. Simulation results show that the algorithms are superior in both the responserate and the accuracy of trajectory tracking.At last, the author designed a2-DOF to verify the control algorithms. The experimentswere implemented to study the effectiveness of the two algorithms, and the results showedthat the two algorithms are superior in both the response rate and the accuracy of trajectorytracking.