Research On Trajectory Planning Method And Motion Control For Planar Redundant Robot System

In recent years, the development of 3C products tend to be smaller, which makes the assembly operations more complicated, the traditional manual assembly line to complete such operations will greatly improve the working strength of the workers. In order to improve assembly efficiency, reduce the work intensity of the workers, and improve the quality of product assembly, many plants adopt the axis SCARA and delta robots as auxiliary equipment of artificial assembly line. The safety of the Robot assisted assembly system is important problem. Combined with the national science and technology support program "electronic products assembly of precision automatic production line development and demonstration" project, a planar 3R redundant robot system was developed and that can avoid the obstacle and the singularity positions in the work area, and take force control to improve the safety of the system.Firstly, by analyzed the performance index of the robot system, a kind of planar 3R redundant robot was developed, and a transmission scheme which put the drive unit forward was proposed. The model of servo motor and planetary reducer were calculated and selected, and the 3D model of the robot was completed based on Solidworks, and the finite element strength analys e was carried out for the part of the connecting rod of the robot.Then, the planar 3R redundant robot kinematics was analyzed. Using D-H method to establish the joint coordinates of the robot, and according to the coordinate system using homogeneous transformation matrix of the kinematics model was established. And the simulation of the kinematics and the workspace of the robot was completed based on the MATLAB. Based on the real time requirement, an improved minimum distance calculation method was proposed,and complete obstacle avoidance in the null space of the redundant robot by the self motion and using the DLS method to avoid the singularity position.Then, in order to take the force control to the robot, the basic impedance control strategy was adopted, and the simulation experiment was carried out by adjusted the impedance parameters. In order to improve the stability of the a bove algorithm for uncertain environment, based on the above control method, the on-line parameter identification algorithm was introduced to modify the algorithm. In order to improve the adaptability of the algorithm to unknown environment, the adaptive control strategy was adopted to improve the robustness of the robot force control method, and the simulation analysis was carried out.Finally, the control system of the planar 3R redundant robot was established. The upper monitor and the multi axis motion controller was used to control the two level control structure, and the open distributed control system was established based on the Modbus bus and CAN bus. The human-computer interaction interface of upper computer was developed based on Visual C++, and the reasonable program of robot motion control was designed. The prototype experiment was carried out on the occasion of man-machine cooperation, and the effectiveness of the force control algorithm was verified.