Design Of SCARA Robot Control System Based On PMAC

With the manufacturing industry to the direction of high efficiency,precision and intelligent transformation,the application of industrial robots is more and more extensive,its operation process of stability,accuracy and work efficiency are facing higher requirements.In order to ensure the stable and accurate running process of robot,trajectory planning is the core problem.In this thesis,a control system of SCARA robot based on PMAC is designed under the application background of plane spraying.The kinematics of the robot is analyzed,and the trajectory planning algorithm of the robot in the joint space is studied.A hybrid interpolation algorithm is proposed to improve the shortcomings of the existing algorithm.The defect of the algorithm is improved.The PMAC control program is designed,and the algorithm is tested on the hardware platform to verify the superiority of the hybrid interpolation algorithm.The main work of this thesis is as follows:(1)The hardware equipment is selected.The controller uses PMAC,the robot is driven by network servo and communicates through Ether CAT network.Based on this,the hardware platform is built.The characteristics and advantages of the hardware equipment are analyzed,and the technical parameters of the hardware equipment are introduced.(2)The kinematics of the SCARA robot is analyzed,and the D-H coordinate system is established.Based on this,the forward kinematics matrix equation of the robot is deduced,and a 3D simulation model of the SCARA robot is established by using Robotic Toolbox in Matlab,and the correctness of the kinematics coordinate system is verified.The inverse kinematics equation of the robot is deduced by analytic method.The forward and inverse kinematics of the robot are verified.(3)In order to solve the trajectory planning problem in joint space,a hybrid interpolation algorithm is proposed based on the research of existing algorithms.The polynomial interpolation algorithm,cubic quasi-uniform B-spline interpolation algorithm and cubic triangular Bézier spline interpolation algorithm are researched.In order to solve the problem that cubic triangular Bézier spline interpolation algorithm could not make the acceleration of the starting and ending positions equal to 0,a hybrid interpolation algorithm based on higher order polynomials and cubic triangular Bézier splines is proposed,which combines the advantages of the two algorithms.The simulation results show that the improved hybrid interpolation algorithm can ensure the acceleration of the starting and stopping positions equal to 0,which effectively suppress the mechanical vibration in the start and stop stage,and make the whole movement process of the robot is more stable.(4)The PMAC control program is designed in Power PMACIDE software.In the visual studio 2015 software,the human machine interface is designed by using C#.The spraying trajectory is selected in Cartesian space.The sample points is selected.Based on the hardware platform,three trajectory planning algorithms are tested.The error curve is obtained by comparing the actual trajectory with the command trajectory,which verified the superiority of the hybrid interpolation algorithm.