Design And Implementation Of Motion Control Kernel In Industrial Automation Control System

In the field of industrial automation control,motion control kernel is the core equipment,which is related to the precision control and intelligent manufacturing in the production process.Therefore,the development of high-performance motion control kernel can improve the level and strength of industrial manufacturing.In addition,in the industrial manufacturing,the number of sensors is more and more,the requirement of communication delay is higher and higher,the link structure is flexible and open,and the use of real-time Ethernet EtherCAT protocol to replace the traditional fieldbus is also the current development trend.Under the background of independent innovation of industrial manufacturing advocated by the state,facing the requirements of intelligent manufacturing and multi device real-time communication in the application scenario of industrial automation control,this paper proposes an open motion control kernel based on domestic processor Loongson 3A4000 and EtherCAT protocol.This research also provides a case for independent innovation of motion control kernel in China.The main contents of this paper are as follows:First of all,it analyzes all kinds of transformation schemes of Linux real-time operating system in detail,and determines the transformation scheme based on RTPreempt real-time patch,whose community is active and supports MIPS architecture processor.Finally,the Linux system is modified according to the construction steps provided by the patch.Secondly,this paper analyzes various construction schemes of EtherCAT master station,and finally selects Ig H EtherCAT Master station scheme.This paper analyzes that Ig H EtherCAT Master does not support Loongson's network card in the mode of native network card driver,and determines to modify Ig H's master code to make it work in the user mode.For the data packets driven by the network card,the packet is sent through PACKET?MMAP and original socket capture mechanism are used to map packets to user mode EtherCAT master station.And the state machine of EtherCAT master slave station is designed.Then,the synchronization mechanism between the real-time thread of the motion control module in the user mode and the real-time thread of the EtherCAT master module is realized,the mechanism of loading configuration file in the motion control kernel is designed,and a variety of servo control applications in the application layer are developed.Finally,an experimental platform is built to test the real-time performance of the motion control kernel,such as interrupt response and context switching,the real-time performance of the EtherCAT master station,and the real-time performance of the PACKET?MMAP and original socket capture data packet function are tested,and a variety of servo control applications are tested.The experimental results show that the motion control kernel has good real-time performance and scalability.