Fast response analysis in CNC machining

In the machining of numerical control system, under the traditional method, the control process is a sequential process, and the links are mutually restricted, so it is difficult to achieve rapid response of errors.

The closed-loop control method based on the interpolation buffer utilizes the modern advanced multi-task parallel processing technology, and adopts the front-back control model to improve the closed-loop response speed. The basic principle is to establish a high-speed interpolation buffer interpolation area, and the control data interpolated by the interpolation process is stored in this buffer. The position control system takes the machining data from the buffer according to the machining speed, and combines it with the error data detected by the feedback system, and then directly controls the servo motor.

Under this method, the position control process and the interpolation process are relatively independent. They only pass the interpolation buffer for data transfer, interpolate and send data, which is implemented in the foreground; the position control extracts data, which is implemented in the background. of.

This front-end and back-end control model is a multi-task parallel processing process, which enables interpolation and position control to be implemented sequentially. The position control system can process multiple interpolation data at the same time without waiting for the execution of the interpolation process, so it can The error data and the interpolation data are combined at any time to track the error in real time, thereby improving the accuracy of the closed loop control.

For example, the same interpolation data, the position control task will be reset according to the error data before being sent to the servo motor. It is assumed that there is an error in the positive direction of the X direction (not moved enough), and the position control system performs the combined processing according to the control data of the X direction. , X does not move (x000), merges to become x101, even if the motor is rotating forward; if the X direction is reverse (x010), it is merged into x100, that is, the motor does not turn; if the X direction is positive (x001) ) leave the error to merge with the next data. After processing, the position control system compensates the machining error in time, which improves the response speed of the feedback compensation.