Speed control method used for numerical control machine

Abstract

The invention discloses acceleration and deceleration controlling means used in numerical control machine, the concept of 'add-acceleration' is introduced against the dynamic property of the controlled member, the add-acceleration is constant in stage of acceleration and deceleration, the two physical quantities of acceleration and add-acceleration are setting; the segmented handling method of add-accelerating sections, uniform accelerating sections, decelerated accelerating sections, uniform speed sections, add-decelerating sections, uniformly-retarded sections and decelerated deceleration sections is adopted, after the interval discrimination, the real-time interpolating calculation in every interval is exceeded based on the integral relation between the add-acceleration, acceleration, speed and displacement, the S type velocity curve is formed to realize the flexible acceleration and deceleration control; the destination discrimination process is proceeded before the interpolating calculation can increase the machining precision of the acceleration and deceleration control. The method is simple, the impact is small, the speed is smooth, the machining precision is high and the flexible control can be realized.

Description

technical field [0001] The invention relates to the acceleration and deceleration processing technology of a numerical control machine tool, belonging to the technical field of numerical control. Specifically, it is an S-shaped curve acceleration and deceleration control method that can ensure that the machine tool moves smoothly and can accurately stay at a given position when the machine tool starts and stops frequently. Background technique [0002] In order to achieve high precision of workpiece processing, CNC machine tools must perform acceleration and deceleration processing in the motion control between corner blocks to ensure that the machine tool does not produce impact, out of step, overtravel or oscillation when starting or stopping. Especially for high-speed and high-precision machining, because the cutting time of high-speed machining is shortened, the tool change interval is shortened, and the machine tool starts and stops frequently. It will have a great imp...

AI Technical Summary

Problems solved by technology

Compared with linear acceleration and deceleration, exponential acceleration and deceleration has better smoothness and higher motion precision, but the algorithm is complex and takes a long time, and there are still acceleration mutations at the start and end of acceleration and deceleration

This sudden acceleration change will cause the feed drive acceleration command generated by the speed processing to be unsmooth, and finally the torque applied to the ball screw of the machine tool and the force applied to the linear motor drive will contain high-frequency components, and these high-frequency components will excite Structural dynamic response to feed drives, causing unwanted vibrations, making them unsuitable for high-speed machining on CNC machines

Trigonometric function acceleration and deceleration rules can achieve smooth motion, but due to the complex calculation of trigonometric functions, it cannot meet the real-time requirements of the numerical control system, it must be processed in advance, and stored in the memory as a template in the form of a table, through the look-up table way to achieve

Images