Thermal deformation recognition and correction method for coordinate measurement machine of articulated arm type

Abstract

The invention discloses a thermal deformation recognition and correction method for a coordinate measurement machine of an articulated arm type, and the method comprises the steps: setting thermal monitoring points on a substrate of an articulated arm, a measurement arm, a joint and a measurement head, and recording to the temperature rise-time changing curve of each monitoring point; operating the coordinate measurement machine to measure a standard gauge block, wherein each thermal monitoring point is equivalent to a temperature rise value of lab temperature; measuring errors, and building an experiment error compensation model of the temperature rise values of seven thermal monitoring points of the articulated arm and a thermal deformation error value according to an MLR (Multiple Linear Regression) algorithm; determining a to-be-determined parameter through the least square method, and carrying out the compensation for a measurement result of the coordinate measurement machine of the articulated arm type. The method can obtain the mapping relation of a length measurement error of the coordinate measurement machine of the articulated arm type with the temperature rise changes between the corresponding temperature monitoring points. A machine body thermal deformation error compensation model based on the MLF (Multiple Linear Fitting) is constructed based on the mapping relation, thereby achieving the compensation for the thermal deformation error, and improving the measurement error of the articulated arm.

Description

technical field [0001] The invention relates to the field of articulated arm coordinate measuring machines, in particular to a method for identifying and correcting thermal deformation errors of articulated arm coordinate measuring machines. Background technique [0002] The articulated arm coordinate measuring machine (hereinafter referred to as the articulated arm) is a high-precision instrument for coordinate measurement. During the coordinate measurement process, due to the thermal deformation of the body due to the change of the internal circuit of the articulated arm and the ambient temperature, the measurement force error is introduced. The thermal deformation of the body is an important factor affecting the measurement accuracy of the articulated arm. Due to the existence of thermal deformation, the real structural parameters of the articulated arm do not match its kinematic equations, resulting in large measurement errors. Although the probe error can be reduced by ...

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Problems solved by technology

[0002] The articulated arm coordinate measuring machine (hereinafter referred to as the articulated arm) is a high-precision instrument for coordinate measurement. During the coordinate measurement process, due to the thermal deformation of the body due to the internal circuit of the articulated arm and the change of the ambient temperature, the measurement force error is introduced. The thermal deformation of the body is an important factor affecting the measurement accuracy of the articulated arm. Due to the existence of thermal deformation, the real structural parameters of the articulated arm do not match its kinematic equations, resulting in large measurement errors.

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