The Research Of Networked AC Servo System Based On Powerlink

At present, using real-time industrial Ethernet to build the AC servo system is very popular in industrial automation. Most famous industrial automation manufacturers have launched the servo system based on network. The research of AC servo system based on network is great significant. The Ethernet Powerlink has been used in practice, so it becomes the first choice of servo system based on network in this paper.The implementation of networked system based on Powerlink is mainly divided into two levels that are managing node and controlled node. The controlled node is mainly composed of two parts which are the AC servo driver with the communication interface of Powerlink and AC servo motor. The managing node is implemented by the X20series controller from B&R. They are connected as linear topology by Ethernet cables.At first, this paper introduces the implementations of controlled node. It is mainly divided four aspects. Firstly, the implementation of the controlled node adopts the Powerlink source code which is used to build the communication module. Secondly, the standard of IEC61800-7is used in controlled node. IEC61800-7is the standard of the motion control. This paper references motion control profile related to CiA402type in IEC61800-7.Thus the unified servo interface is established, and power drive state machine is realized. The control mode in this paper is cyclic synchronous position mode. Thirdly, it also implements the synchronicity compensation for the system. It mainly includes constant delay compensation. From this aspect, the synchronicity of the system will be improved. At last, this paper writes the XDD file for controlled node, which provides the information of controlled node for managing node.Secondly, this paper illustrates the implementation of managing node, managing node adopts the CPU CP1484, uses the Automation Studio development platform, and researches the main control program according to the working principle of ACP10software. The main work of control program includes three parts. They are the implementation of the interface of real axis based on SDC(Smart Device Controller), the added library based on IEC61800-7for the system, and the motion control application. The SDC provides the interface that can connect servo drive of other brands. Managing node needs to develop the motion library of IEC61800-7in order to build the relationship with the controlled node that has used the same standard.At last, we use the PC to test communication in Windows environment. And we use B&R controller to test the joint movement. Tested results are given. Test the synchronization of system, and give the result. From the result, the synchronization jitter is about1.945μs.