Analysis Of Contour Error And Contour Algorithms Of CNC Machine

For current high-speed CNC machining equipment, PID control method is commonly adopted to reduce the tracking error. But in fact reducing the tracking error controlling can not strictly ensure the contour errors reduced. It means that the traditional PID closed-loop controller does not guarantee the accuracy. Therefore, a contour error controller should be considered to analyze and solve accurace problem of the high-speed CNC machining.This subject is base on the definition of space contour error model, the purpose is to builde and analyze a three-dimensional contour error model and carry out the feedback control algorithm. The main contents are given as follows:First, the CNC system is modeled to obtain a mathematical expression. Second, mathematical modeling based on measurable disturbance and contour error is study. A feedback control algorithm is designed. The simulation experiment are carried out by MATLAB. And then, baseing on the uncertaintily interference and the passive theory, a control algorithm is proposed and studied by MATLAB simulation. Last, the control system platform is set up by the technology of DSP and FPGA, a hardware systems is designed and software programs is developed based on NURBS interpolation algorithm and error compensation of CNC control.