Large slenderness ratio shaft part straightness error detection method based on machine vision

Abstract

The invention, which belongs to a shaft part straightness error detection field, discloses a large slenderness ratio shaft part straightness error detection method based on machine vision. The method comprises the following steps: (1) installing standard components; (2) installing a camera; (3) installing workpiece; (4) collecting an image; (5) processing the image; (6) establishing a coordinate system; (7) calculating and acquiring a position coordinate of a center of a circle; (8) unifying the coordinate; (9) according to the coordinate of the center of the circle of a cross section, using a current straightness evaluation method to calculate the straightness. According to the invention, a position relation between the standard components is taken as a link and a coordinate position relation between the images is established so as to avoid using an image splicing technology with long time consuming. Simultaneously, a distance from the camera to the part does not need to be the same with the distance from the camera to the standard components. Measuring difficulty can be reduced and measuring precision can be increased.

Description

technical field [0001] The invention relates to a method for detecting the straightness error of a shaft part, more specifically, a method for detecting the straightness error of a shaft part with a large length-to-diameter ratio based on machine vision. Background technique [0002] Vision is the most important means for human beings to perceive and understand the surrounding world and acquire knowledge from nature. 80% of the information obtained by humans comes from vision, and the remaining 20% ​​comes from hearing, taste, touch and so on. Machine vision refers to the use of computers and some auxiliary equipment to realize human visual functions, so as to realize the perception of external things and the objective three-dimensional world through two-dimensional images. It is an emerging discipline and one of the most interesting frontier research fields. . [0003] With the development of machine vision technology, a new detection method that uses images as a means or...

AI Technical Summary

Problems solved by technology

[0010] (1) The data of straightness error cannot be given accurately;

[0011] (2) It is impossible to formulate a reasonable correction plan based on the data;

[0012] (3) The position is relatively dependent on the technical proficiency of the workers;

[0013] (4) The labor intensity of the workers is relatively high;

[0014] (5) The detection speed is relatively slow, and the production line automation cannot be realized

[0017] The shortcoming of prior art two: figure 1 The semiconductor laser projector is used in the device, which is a high-precision product and the price is relatively expensive.

[0020] Disadvantages of prior art 3: The straightness measurement method based on a single image uses one image to show the whole picture of the measured part, and the straightness error of the part is obtained by calculating and processing this image

However, since the field of view of the camera is inversely proportional to the accuracy, in order to obtain the whole picture of the part, a certain accuracy must be sacrificed; or in order to obtain higher detection accuracy, the geometric size of the measured part must be restricted within a certain range

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