Research On Motion Planning And Control System Of 6-ptrt Surface Machining Parallel Robot

6-PTRT parallel robot is used for surface processing,overcome the inherent defects of traditional series machine tool,for example,cutting tools move only along the fixed rail,have the low degree of freedom homework tool,equipment processing have not enough flexibility and mobility,and have the advantage,such as simpleness in structure,low prices,high stiffness,Fast processing and low inertia.These advantages make the parallel mechanism represented by 6-PTRT robot in the field of CNC surface machining have broad application prospects.In this paper,using the method of matrix - vector,analyse the kinematics of the 6-PTRT parallel robot.By solving homogeneous matrix transformation,complete the transformation between the robot coordinates,and give the position inverse formula of the parallel robot,then complete the speed inverse solution by solving the Jacobian matrix of the 6-PTRT robot in the condition of inverse kinematics.Using the mechanical structure parameter of the 6-PTRT parallel robot,the scope of the driving joints activities,Hooke joint angle range and the inverse kinematics,get the space and posture ranges.It is a limited scope for follow-up of surface processing tool pose.After analyzing a variety of surface processing path planning algorithms,select one of them,which is suitable for the processing of planning to circular cavity surface.This is,get cutter location paths by using the method of Cut-off plane,and optimize tool axis orientation by using the algorithm which uses curvatures of the surface,then,on the condition of getting the parameters of the cutter contact point' position,make gesture planning with profile-driven method.The purpose is,to ensure the well gesture planning capability in the range of posture.After completing surface machining path planning,design the the control system of the 6-PTRT parallel robot。The superior machine of the system make motion planning,and lower computer PMAC implement motion control program.Using the AC servo control system,complete the real-time control to the drive motor.The control system uses a built-in PID algorithm of PMAC,and the algorithm gives full play to the control functions which of PMAC to the servo motor.The limit switch sensor equipped in the system achieve high-speed high-precision moving platform back to the origin.After completing the path planning of surface machining and the control system design of the 6-PTRT parallel robot,using Microsoft Visual C + +6.0 program,realize that the position and orientation data is generated,the displacement of the driving joints and the pulse numbers of the axis are calculated,and the motor are controlled in real-time.Ultimately,make the processing of motion planning realized in the 6-PTRT parallel robot.Experimental results show that the system is running well.