Interface Design Of PMSM Digital Servo System Based On EPA

AC servo drivers("AC servo system") are widely used in CNC (Computerized Numerical Control) systems. The performance of the servo system seriously influences the whole CNC system. Recently, full-digital servo system is developing in a fast speed. Full-digital system has the merit of high accuracy, fast response, permitting more complicated algorithms and parameters adjusting, and so on. In this thesis, a full-digital system based on EPA is introduced:First, full-digital servo system's back ground, merits and shortcomings compared to analog servo system are introduced. The advantages and shortcomings of the three kinds of interface techniques are presented in detail.Second, the mechanism and the communication protocols of SERCOS, ETHERNET PowerLink, EtherCAT are also described in detail , as three kinds of popular CNC buses, with emphasis on their definite communicating dispatch and accurate synchronizing capabilitiy, which guarantee the CNC use.Third, EPA (Ethernet for Plant Automation) protocol is introduced with emphasis on its definite communicating dispatch and its accurate synchronizing method.Fourth, based on the analog servo system SUP-D of Zhejiang Supcon Electric Co,.ltd, a Ethernet interface is designed to connect the servo driver and the Ethernet, using TMS320LF2407 as processor, AX88796 as network card and ESP to implement the EPA protocol.Fifth, a experiment is designed on CNC system based on EPA . The experiment result proves that the system can perform well in network environment.