Method and system for measuring large part

Abstract

The invention discloses a method and a system for measuring a large part. The method comprises the following steps: determining a conversion relationship between a pixel coordinate system and a worldcoordinate system of each camera in a camera array; aiming at each camera in the camera array, the camera array is divided into a plurality of cameras; acquiring a part image corresponding to the camera; and determining a first image corresponding to each camera according to the part image, splicing the first images corresponding to all cameras according to the conversion relationship between thepixel coordinate system and the world coordinate system of each camera to obtain a second image, and finally determining the size of the part according to the second image. According to the method formeasuring the large part, image splicing of the camera array and an image super-resolution technology are used; the high resolution of the image is ensured while the view field range of the image isexpanded, more image details are provided, the measurement accuracy of the large part is improved, and the method can be applied to a production line to automatically measure the size of the part andhas a high automation degree.

Description

technical field [0001] The invention relates to the field of measuring industrial parts, in particular to a method and system for measuring large parts. Background technique [0002] At present, many parts manufacturing companies pay special attention to the pass rate of product shipments. In the era of industrial automation, although the production efficiency of products is very high, the quality inspection process is still in the manual inspection stage. For factories producing large quantities of products, this product quality inspection method not only increases manpower and cost, but also has slow manual inspection speed and is prone to problems such as missed inspections and wrong inspections. Although there are many high-precision measuring instruments on the market, such as three-coordinate measuring machines and visual imagers, these devices have drawbacks and are difficult to use to measure all parts, for example: three-coordinate measuring machines need to touch t...

AI Technical Summary

Problems solved by technology

[0002] At present, many parts manufacturing companies pay special attention to the pass rate of product shipments. In the era of industrial automation, although the production efficiency of products is very high, the quality inspection link is still in the manual inspection stage.

For factories that produce large quantities of products, this product quality inspection method not only increases manpower and cost, but also has slow manual inspection speed and is prone to problems such as missed inspections and wrong inspections.

Although there are many high-precision measuring instruments on the market, such as three-coordinate measuring machines and visual imagers, these devices have drawbacks and are difficult to use to measure all parts, for example: three-coordinate measuring machines need to touch the part through the probe multiple times Surface measurement is slow and time-consuming. In addition, this measurement method is contact, and the wear of the probe will have a great impact on the measurement accuracy, and it will inevitably cause bumps to the product during the product measurement process; The visual imager is based on machine vision technology. It can measure without touching the workpiece, and has high precision. However, there is a contradiction between the field of view and the measurement accuracy. Since the single measurement field of view does not exceed 20×20mm, The field of view is limited, so it can only be used for spot inspection of parts, not for measuring all parts in the production line

If the field of view is increased by increasing the object distance, the measurement accuracy will be reduced. If a relatively large part is measured, it is necessary to manually move the translation table multiple times to measure the part size at all positions of the workpiece.

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