On-line non-contact measurement method for straightness of shaft parts

Abstract

The invention relates to an online non-contact method for measuring the straightness of shaft parts, belonging to the technical field of image measurement. The invention can measure the straightness of shaft parts in real time. Firstly, a structured light vision measurement model for the straightness measurement of shaft parts is established, so that the direction of the light strip is approximately parallel to the axis direction; secondly, the internal parameters, distortion coefficient and structured light plane parameters of the CCD camera are calibrated by the plane calibration method; thirdly, a For the calibration shaft with a known diameter, through the calibration model, the points on the intersection line between the structured light plane and the shaft surface are calculated in space, and these space points are used to fit the calibration axis; finally, the obtained space points and The axis equation can be solved to obtain the straightness of the measured axis. The invention adopts machine vision measurement technology, realizes online non-contact measurement, and ensures higher measurement speed and better measurement accuracy. For shaft parts with a length less than 200mm, the measurement accuracy is less than or equal to ±0.015mm.

Description

technical field [0001] The invention relates to the technical field of image measurement, in particular to an online non-contact method for measuring the straightness of shaft parts. Background technique [0002] A large number of shaft parts are used in machinery, automobiles, motors and other industries, including automobile drive shafts, gear shafts, main shafts of machine tools, roller shafts of textile machines, twist drills, broaches, drill rods, etc. However, these parts will inevitably appear various degrees of bending deformation during processing, manufacturing or after heat treatment. According to statistics, the total annual output of shafts in my country is about 1 billion pieces, and about 100 million shafts need to be straightened before use. 70%. If the bending deformation of shaft parts during machining or heat treatment cannot be effectively straightened, it will have various effects in the subsequent finishing process, which will directly affect the qualit...

AI Technical Summary

Problems solved by technology

However, shaft parts are three-dimensional entities, and the surface of the object where the measurement size is located is no longer an imaging plane, so the measurement method for two-dimensional dimensions is no longer applicable

Moreover, since the reference size of the measured part is often tens to hundreds of millimeters, which is much larger than the size of the camera lens, at this time, the machine vision measurement method is no longer applicable

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