Study On Multi-Axis Motion Control System Based On Real-Time Ethenet

Multi-axis motion control system becomes more and more popular in modem manufacturing. Synchronization motion between machine axes can be achieved by electrical method instead of the mechanism, which makes manufacturing system more flexible. In order to synchronize all machine axes effectively and achieve high precise of motion, it is necessary to establish a real-time and high-effective digital communication network. With its high bandwidth, low cost, good opening, mature technique, the Ethernet is especially suitable for Multi-axis motion control system. But still there is a great deal of problems to be solved. This dissertation makes deep research on the application of Ethernet in the Multi-axis motion control system, which mainly concerns the Multi-axis motion control algorithm, clock synchronization, real-time scheme of Ethernet.Firstly the problem on the application of Ethernet in the Multi-axis motion control system is analysed in this dissertation. On the premise of using CSMA/CD, a real-time Ethernet model is built, and a real-time scheme method based dynamic time-slot allocation is proposed. A fault- tolerance mechanism in such scheme method is proposed.The delay of the control network is important for predictive control. Message delay in TDMA system is studied. A delay model is built. The message overflow probability is discussed. The probability distribution and the expectation of message sojourn time are presented. This paper illuminates how to choice system parameters to meet the real-time requirements of the system.Using the clock synchronization, synchronous sampling could be realized on an asynchronous control network. Several time synchronization protocols are analysed in this dissertation and proves that the clock synchronization method based IEEE 1588 is the most suitable for industry control network. An FPGA-based implementation of the IEEE1588 pprotocol was developed in this paper. Basing on the lack of boundary clock in the line topology, an improved method is proposed.The basic structure of the multi-axis motion control system based on real-time Ethenet is discussed in this dissertation. And then the model of a multi-axis motion control system based on real-time Ethenet is built. Analyses of sampling period, sampling method and the influences of the nodes driven modes on the system performance are made. Three synchronization control strategies are analysed in this dissertation. The experiments demonstrate the differences of the tracking and synchronization performance using different strategies are presented. A cross-coupling generalized predictive control algorithm is proposed.At last, based on the researches above, a register control system of rotogravure printing press based on real-time Ethernet is designed.p...