Research And Development Of Six-axis Robot Control System Based On EtherCAT Bus

In the 21 st century,with the increasing types of robots,Application of robots is widely used.According to the International Federation of Robotics(IFR),China has become the world's largest industrial robot manufacturing country,and 27% global market supplied by China.And China also is the largest robot consumer.Chinese factories spent more than $ 3 billion on industrial robots in 2015.Despite the rapid development of the robot industry,domestic production level is still insufficient compared with foreign advanced technology companies.And many precision parts are dependent on imports.Therefore,the study of the robot system has far-reaching significance for promoting the development of China's industrial and manufacturing.An innovative servo motor control scheme is presented in this paper which applied to 6-axis robotic arm and achieved precise positioning control.In this context an innovative servo motor control scheme is proposed.TwinCAT3 and industrial computer(IPC)are used as EtherCAT master and the 32-bit microcontroller of the latest XMC4800 series is used as EtherCAT slave.In the paper,the field programmable device FPGA with rich I/O resources and powerful logic computing capability is used as the core device for instruction parsing,pulse distribution and receiving encoder information.This paper proposes an innovative method to integrate the EtherCAT slave node with the FPGA servo control circuit,use AltiumDesigner circuit design software to draw circuit schematics,make PCB board,weld and debug the hardware board,and design software algorithms and program configuration.The hardware platform and software configuration designed by this project as a new servo control system The XMC4800 communicates with the FPGA through SPI full duplex.The FPGA acquires control instructions and parses them,distributing the parsed control instructions to the servo drives.FPGA receiving the encoder data and other information returned by the servo drives.After processing,FPGA send the information to the XMC4800 through the SPI and finally through the EtherCAT communication feedback to the IPC or TwinCAT3.The control scheme can realize the fully closed loop control of the servo motors with the control accuracy up to 0.072°.If installed in multi-axis manipulator,the harmonic reduction devices will greatly improve the control accuracy.