Research And Implementation Of Multi-layer Cross-coupling Control System On DSP

With the development of modern manufacturing industry, the contour error controlof multi-axis motion controllers is becoming more and more important. In this sphere,the cross-coupled controller (CCC)is a widely used approach to improve the contouraccuracy. Although some control schemes for CCC have been proposed, they generallyfocused on the control of two-axis. Multi-axis controller for CCC often brought incomplicated algorithm.A layered modeling method is proposed to resolve the problems resulted from thecomplexity of the error model of a multi-axis motion control system. This model isconstructed by the essential idea that a low level layer can be considered as a virtual axiswhich can be used by the high level layer. There are two advantages in the proposedmodel. First, the complex error model of a four-axis motion control system can bedivided into several simple layers and every layer has different coupling strength, whichcan match the real control system. Second, the controller in every layer can be designedspecifically for certain purpose. The proposed method is used to model a four-axismotion control system, and a three-layered cross coupling scheme is proposed tocompensate the contouring error of the motion control system. Based on the proposedmodel, many improvements are proposed.This CCC will be built on a platform based on DSP+FPGA。The overall structureas well as the hardware and software system of this platform is concisely presented inthe article. Interpolation block, acceleration and deceleration block and other importantblocks is illustrated at great length.Simulations will be made to prove the effectiveness of the proposed method. Thesuperiority of this method will also be proved through simulations in comparison withthe traditional ones.