Research On Cross-coupling Control Of Networked Multi-axis Motion Control System

With the development of electronic, communication and computer, the motion control system is in a trend towards the distributed and networked system. Networked motion control systems with high data-sharing capability, high reliability, high scalability, low maintenance costs, and many other advantages, have been widely applied in fields of numerical control equipment, mobile robots, etc. Meanwhile, in the networked multi-axis motion control system, coordination of axis is one of the key factors affecting the accuracy of the system. And the cross-coupling control theory is widely used to improve coordination between multi-axis, so the research on multi-axis cross-coupling control under networked environment is very important.This work in this paper is supported by National Natural Science Foundation and it studies the delay compensation of networked cross-coupling multi-axis motion control system. First, the network induced delay is divided into the feedback delay and the control delay, and its effects on cross-coupling control are studied quantitatively. On the basis, a kind of cross-coupling controller with delay compensation is proposed which uses time stamps to estimate feedback delay and uses a Kalman filter approach to predict control delay. After the total delay is obtained, a position prediction algorithm is introduced to estimate the current axis’actual position, and use this predicted position to run cross-coupling control. Then, the cross-coupled controller with delay compensation is designed based on TI TMS320F2812as well as a biaxial experimental system based on CAN bus is built to validate the proposed delay compensation method. Experimental results show that the proposed control method using cross-coupling controller with delay compensation can effectively reduce the effects of network induced delay to the accuracy of cross-coupling control.