The Design Of Eight Degree Of Freedom Robotic Arm Control System For Sand Blasting Robot

With the "Made in China 2025" national strategy proposed,teaching robots have developed rapidly and have found new applications in the sandblasting industry.Industrial robots used for sandblasting on metal surfaces are called sandblasting robots.The traditional way of sandblasting is manual sandblasting,which has bad operating environment,low efficiency and very dangerous.With the repeatable operation of the teaching function,the sandblasting robot reduces the labor cost,improves the sandblasting efficiency,and gradually replaces the traditional manual sandblasting.The core of sandblasting robot is 8-DOF(eightdegree-of-freedom)robotic arm control system,whose performance will directly determine the final sandblasting effect.The automatic sandblasting market in China has just started and has a broad market prospect.Therefore,it is of great significance to study the control system of 8-DOF manipulator for promoting the development of sandblasting industry in China.The paper analyzes the mechanical structure of the 8-DOF robotic arm of the sandblasting robot.In this paper,D-H parameter method is used to establish the coordinate system of each articulated arm link,and then the mathematical model of the 8-DOF robotic arm is established by matrix.The kinematics and dynamics equations of the eight degrees of freedom Mechanical arm are obtained,which provides a theoretical basis for the control of the 8-DOF robotic arm.In this paper,the master-slave multi-CPU control scheme based on PLC is selected,and three kinds of PLC are used as the controllers of different functional modules in the control system.The controllers communicate through the PROFINET protocol,and the hardware circuit of the control system is designed.Based on the hardware circuit platform,a safe electrical program is developed to ensure the safety of the operator and the equipment during the operation of the system,and the driver program of eight servo motors is written to realize the preliminary control of the 8-DOF robotic arm.The idea of "position forward" puts forward a "teaching-reappear" motion control algorithm for the 8-DOF robotic arm,which realizes the core function of the 8-DOF robotic arm.Finally,the control system is tested.The operator controls the manipulator to teach in the cockpit of the 8-DOF manipulator,and the control system saves the teaching trajectory of the manipulator.After teaching,the system controls the manipulator to reproduce the saved teaching track.By comparing the trajectory of each axis of the manipulator in the teaching process with that in the reproduction process,it is proved that the manipulator controlled by the control system runs smoothly with high precision and meets the expected design requirements.