Research On High-speed,Real-time,Synchronous Communication Of Industrial Robot Based On EtherCAT

EtherCAT has the characteristics of fast communication rate,high synchronization accuracy,and low cost.It is currently one of the main communication methods in the field of industrial control.This thesis studies the high-speed,real-time,and synchronous EtherCAT communication system of industrial robots,based on the design and implementation of the software and hardware of EtherCAT master and slave,develops the robot host computer interface,and studies the real-time and synchronization improvement methods of industrial robot EtherCAT communication.The EtherCAT communication system adopts a master-slave structure.The IgH EtherCAT Master based on the Linux system is selected as the master,which runs on the industrial computer as the robot controller.Choose the ET1100+DSP scheme as the slave development program,design the EtherCAT communication circuit,and the communication software is embedded in the robot servo driver.The EtherCAT communication experiment verifies that the designed EtherCAT master-slave communication system realizes stable data transmission.Based on the realization of EtherCAT communication,the influencing factors of EtherCAT’s real-time and synchronization are deeply analyzed and an improvement plan is proposed.In terms of real-time improvement,the RT_PREEMPT real-time patch is selected to carry out real-time transformation of the Linux system.The real-time experimental results verify that the selected solution effectively improves the real-time performance of the Linux system and meets the real-time requirements of the EtherCAT master.In terms of synchronization improvement,an innovative clock drift compensation method based on real-time feedback closed-loop control strategy is proposed to solve the clock drift problem.The proportional,integer-order proportional-integral and fractional-order proportional-integral controllers are designed separately to improve the synchronization accuracy between EtherCAT slaves.Synchronization experiment results show that the proposed compensation strategy effectively reduces the synchronization error between slaves,and the fractional-order proportional integral controller has better error control effect than the traditional integer-order proportional integral controller.The experimental results of the whole robot system operation show that the designed EtherCAT communication system runs stably on the industrial robot experimental platform,and meets the needs of industrial robots for high real-time communication and high synchronization.The developed robot host computer interface realizes the basic operation of the industrial robot and completes the robot operation test.