Design Of EtherCAT Distributed Control System Dased On IGH Master Station

With the continuous development of industrial automation and the increasing popularity of network information,big data and intelligence,traditional fieldbuses can no longer meet the requirements of modern industrial environment due to disadvantages such as slow transmission speed,poor compatibility and high cost.With the continuous development of industrial Ethernet,the EtherCAT technology introduced by German Beckhoff company has been gradually used by more and more industrial manufacturers due to its high data transmission efficiency,excellent real-time performance,flexible topology and low cost.Based on an in-depth study of industrial Ethernet and carrying Linux operating system on embedded hardware platform,this thesis makes the IGH EtherCAT master station run on the embedded platform,and designes the EtherCAT distributed control system based on IGH master.Firstly,in the design of master station,this thesis builds an embedded hardware platform installed with Linux operating system,with the Exynos 4412 processor chip of the ARM architecture and the 100M high-speed DM9621 Ethernet control chip as the core.The Linux operating system is installed with the open source IGH EtherCAT master station with superior real-time performance.The interface of master station is designed by QT,which further develops the IGH master station and realizes the interaction between the master station and the user.Secondly,in the design of slave station,with LAN9252 and ET1100 as the EtherCAT Slave Controller and STM32 as the slave station processor,the slave station Ethernet model architecture is built.Then the composition of EtherCAT data frame,addressing mode,CoE application layer protocol and state machine mechanism are studied.For the EtherCAT process data communication,PDO communication service is used to establish periodic data communication between master and slave stations.Thirdly,with the slave processor as the core,the conventional IO control function is realized,and the data acquisition module driven by FPGA is developed,in oder to realize the application performance of the system.Finally,in terms of testing,this thesis captures the communication data of the master and slave stations with Wireshark to verify the data communication performance of the system.According to the result,both data transmission delay and jitter of the system can be measured in μs,which meets the research expectations.Afterwards,the 10 module and the data acquisition module are respectively controlled through the master station interface,and it is found that the execution modules can operate normally and can realize the management and control functions through the master station interface.The real-time waveform is drawn for the data collected by the data acquisition module,and it is found that both the real-time performance and data accuracy of the system can reach the expected goal.According to the results of various tests,the EtherCAT distributed control system based on the IGH master station designed in this thesis has high real-time performance.Accordingly,this thesis reaches the expected goal and provides a foundation for further researches.