Research And Development Of EtherCAT Master For Multi-axis Motion Control

With the proposal of "Made in China 2025" strategy,the trend of industrial manufacturing industry becoming more and more networked,open and intelligent is becoming more and more obvious.The motion controller based on real-time industrial Ethernet fieldbus technology is gradually replacing the traditional bus motion controller.EtherCAT bus has become a research hotspot of controllers in the field of motion control due to its advantages such as fast transmission rate,strong real-time performance and synchronization,flexible topology and so on.In this paper,the master controller based on EtherCAT bus is researched and developed for multi-axis motion control.The main contents are as follows:1.The development history of EtherCAT technology and its development status in the field of motion control are summarized.The typical implementation schemes of EtherCAT master station are compared and analyzed,and the EtherCAT technology is deeply analyzed.2.Determine the design indexes of EtherCAT master,and design its system architecture.The method of PC + PCI card is adopted to realize various functions of EtherCAT master system based on Zynq platform,IGH EtherCAT open source protocol stack and Xenomai/Linux real-time system.Then according to the function of the master station,the master station system is divided into three subsystems.The PC terminal completes the configuration function and motion control logic operation,the ARM0 terminal realizes the data parsing and EtherCAT protocol stack function,and the FPGA realizes the periodic sending and receiving of data frames.3.Based on the in-depth analysis of the IGH open source protocol stack,the application program of the master station is developed,and the API provided by the IGH protocol stack is used to complete the program development of the initial configuration of the master station and the real-time task of execution cycle.The configuration of the master station in the initial stage is optimized,and the flexible configuration of the master station is realized by designing configuration software.4.By adapting the master station to the mature motion control software,the data format and communication logic of the master station are designed.Then a series of experimental tests on the ultimate performance and stability of the master station are carried out by using motion control software.The results show that the master station developed in this paper is better than the commercial master station in terms of the number of axes that can be supported and jitter.5.The master station is applied to the labeling industry,and the EtherCAT master station developed in this paper replaces the traditional pulse axis card to realize the motion control of multiple axes of the labeling machine.It shows that the EtherCAT master station controller developed in this paper can well realize the multi-axis high-speed and high-precision motion control.