Numerically-controlled machine tool thermal error compensation method and system based on workpiece size data

Abstract

The invention discloses a numerically-controlled machine tool thermal error compensation method and system based on workpiece size data. The method comprises the steps: carrying out the analysis of aprocess capability index (Cpk) based on a machining process, and obtaining a key temperature point from the actual measurement temperature data of cutting work; according to the key temperature pointand workpiece size data machined under the machine tool load condition, a numerical control machine tool thermal error model based on workpiece size detection data is constructed through a multi-layerperceptron neural network (MLP), then obtaining the motion compensation amount of a motion axis corresponding to workpiece size features under the actual machining condition, and achieving thermal error compensation through the external coordinate zero offset function of a numerical control machine tool. According to the method, the thermal deformation of the machine tool and the workpiece causedby the machining process is considered, and the thermal error of the machine tool under the actual machining condition is effectively compensated.

Description

technical field [0001] The invention relates to a technology in the field of mechanical processing, in particular to a thermal error compensation method and system for a numerically controlled machine tool based on workpiece size data. Background technique [0002] Error is the main index to evaluate the accuracy of machine tool. Machine tool error can generally be divided into geometric error, thermal error and error caused by cutting force. Among them, the thermal error accounts for 40-70% of the total error. Therefore, the effective control of thermal error is very important to improve the accuracy of the workpiece. However, the establishment of the existing thermal error models of CNC machine tools is usually based on the test data of the machine tool under no-load conditions, and does not take into account the thermal deformation caused by the machining process and the thermal deformation of the workpiece, resulting in the accuracy of the model built in actual industri...

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Problems solved by technology

However, the establishment of the existing thermal error models of CNC machine tools is usually based on the test data of the machine tool under no-load conditions, and does not take into account the thermal deformation caused by the machining process and the thermal deformation of the workpiece, resulting in the accuracy of the model built in actual industrial applications. The drop and compensation effect are not good, and the thermal error modeling and compensation method of the machine tool under the load condition of the machine tool is not yet mature

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