Research On EPA-FRT And Its Application On Motion Control

Prompted by the development of information and network technology, the motion control system has a trend to be intelligentized, informatized and networked. Because of the advantage of high versatility, the use of Real-time Ethernet in motion control field tends to be a research focus. EPA (Ethernet for Plant Automation) is the first Chinese developed standard with independent intellectual property in international industrial Ethernet, and it has been widely used in the field of factory automation and process control.However EPA standard is mainly developed to meet the needs of process control, and hasn't taken the actual needs of motion control for hard Real-time communication and precious clock synchronization into account. Therefore, in order to meet the high-performance demands of motion control system, the design and research of EPA-FRT (Fast Real-time Ethernet for Plant Automation) with better performances are significant in both theory and practice.This paper firstly introduces the development of motion control and the demands of motion control for communication. Then, some technical problems about the application of EPA-FRT in motion control are proposed and studied, and the corresponding solutions are designed. Finally, the performance of EPA-FRT network system is tested and the EPA-FRT technology is successfully applied to the invert motion control systems. The main contents of this paper include:1) The fast scheduling algorithm and the precise synchronization technology of EPA-FRT protocol are studied and designed, with whose help EPA-FRT could achieve better performances than EPA, such as the higher synchronization accuracy and the better real-time performance.2) With the increase of the network nodes, the communication performance of EPA-FRT network would become linear depredation. EPA-FRT multi-level cascaded network system is designed to solve the problem. With help of the technologies of multi-level scheduling, hierarchical synchronization and service agent, EPA-FRT multi-level cascaded network system could meet the communication demands of PLC control system with many network nodes.3) The EPA-FRT real-time redundancy network system with grid topology is designed. The grid real-time redundancy technology can greatly improve the availability and reliability of the network system and has many advantages, such as the data real-time redundancy, the fault rapid detection and zero recovery time.4) The General EPA-FRT stack is developed and tested. And the EPA-FRT network technology is successfully used in the invert motion control system.