Modeling and compensation method of heat error of numerical control machine tool

Abstract

The invention discloses a modeling and compensation method of a thermal error of a numerical control machine tool. The method includes the first step of searching heat points of the machine tool by means of an infrared imager, finding an area with a highest temperature in each heat area by means of heat infrared images of all portions of the machine tool displayed by the infrared imager, and arranging a temperature sensor at a position with the highest temperature in each heat area; the second step of taking heat source temperatures measured through tests as input signals and hot deformation of the machine tool as an output signal, and obtaining system pulse response models in the method of deconvolution; and the third step of sequentially inputting temperature change sequences and the corresponding machine tool pulse response models in compensation and carrying out the deconvolution to obtain a heat error predicted value of the machine tool. According to the modeling and compensation method, searching for best temperature measurement points is simple and quick; by the method of the deconvolution, the modeling precision is high; by means of the pulse response models, transportability is good; and the response speed is high, and real-time performance requirements for compensation of the machine tool can be completely met.

Description

technical field [0001] The invention belongs to the technical field of precision machine tool processing, and relates to a method for modeling and compensating thermal errors of numerical control machine tools. Background technique [0002] In the process of machining parts by machine tool, the thermal deformation of the machine tool will be caused by the increase of the ambient temperature of the workshop and the internal temperature of the machine tool, which will cause the original relative position of the tool and the machine tool table to change, thus causing the machining error of the workpiece. However, due to the small geometric error of precision machine tools, thermal error becomes the biggest factor affecting machining accuracy. Studies have shown that thermal errors can account for up to 70% of machining errors, so modeling and compensation for thermal errors of precision machine tools is a key factor in improving machining accuracy. [0003] At present, there h...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a method for modeling and compensating the thermal error of CNC machine tools, which solves the problem of finding the best temperature measurement point from a large number of temperature measurement points in the prior art, which is time-consuming and laborious; at the same time, it may also occur due to improper arrangement of temperature sensors The situation of missing the best temperature measurement point; and when the measurement position changes, the model output will change greatly, and the model has poor portability and low stability.

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