Motion Control And Trajectory Planning Of Six Degree Of Freedom Engraving Robots

As the representative of the robot,manipulator has made great development in the industry,penetrated into all walks life,and plays an important role.It becomes a trend to process by engraving manipulator in stone industry.This urges engraving manipulator developed in a more intelligent and automatic way.At present,there are few researches on the application of multi axis robots to stone carving,most of which are numerical control machine.Therefore,this paper is based on the engraving method of numerical control machine to simulate,and the path is designed with CAM(Computer Aided Manufacturing).The contents of the paper include the following parts:(1)The kinematics of the six degree of freedom engraving manipulator is studied in this part,including the establishment of joint coordinate system,the acquisition of D-H parameters,the establishment of the kinematic equation,the solution of inverse kinematics.Through the simulation of path points and path trajectories,proved the correctness of the kinematic model.(2)The jacobian matrix is derived by homogeneous transformation matrix of joints,it describes the relationship between the angle change of joints and linear velocity and angular velocity.Using the Lagrange equation get dynamic equation of engraving manipulator.Then,the simulation model of the engraving manipulator control system is built to simulate for the dynamic.(3)The trajectory planning of engraving manipulator is studied in this part.The cubic polynomial interpolation method makes engraving manipulator to smoothly and stably move in the joint space.Trajectory planning includes linear and circular trajectory planning algorithm in cartesian space,it makes manipulator to accurately move along the target trajectory.In the end,the optimization algorithm of acceleration and deceleration is analyzed and compared by simulating.(4)In view of the low flexibility of traditional CNC engraving machines,and the shortage of planning without speed and acceleration,the stone engraving manipulator is studied in this paper.Combined sine-shape Acc/Dec(acceleration and deceleration)optimization and the smooth transition between curves with quintic polynomial equation is performed for trajectory optimization.This method reduces planning process and achieves flexible machining.The combined trajectory optimization makes the engraving manipulator move smoothly along the target trajectory in this paper,and the contour error is small.So the simulation experiment has important meaning to carry on engraving on machine.