A line-structured light measurement method for the assembly depth of bullet primer

Abstract

The invention provides a line-structured light measurement method for the assembly depth of the primer of the bullet, including a measurement model for the assembly depth of the primer of the bullet, a calibration method, and a method for extracting the center of the laser speckle light bar. In the measurement model, under the camera coordinate system, two calibration blocks are introduced for the calibration of structured light parameters, and straight line fitting is performed on multiple special points on the calibration blocks. In the camera coordinate system, calculate the intersection point of the line and the laser curve. According to the principle of cross-ratio invariance, the laser plane calculation formula is obtained, and the calibration process of structured light parameters is completed. Through the new mathematical model, the world coordinate value corresponding to two points on any laser line on the image can be calculated, and the real-time calibration and measurement method can be used to realize the real-time measurement requirements of the assembly depth measurement of the bullet primer and reduce the cumulative error. The image enhancement operation is performed on the speckle part of the image according to the high-frequency gain coefficient, which solves the problem of decreased accuracy and stability of the measurement accuracy and stability of the primer fire depth caused by the laser stripe speckle.

Description

technical field [0001] The invention relates to the field of industrial vision detection and measurement, and in particular to key technologies such as construction and calibration of a structured light measurement model, extraction of centerline structured light centers in images, and the like. Background technique [0002] In the process of bullet production and assembly, if the primer assembly depth is not up to standard, it will have a serious impact on the quality of the bullet. The effective detection area of ​​the bullet primer is less than 100mm 2 , the depth detection accuracy standard is required to be less than 0.02mm. Most domestic bomb factories still use the traditional contact mold detection method, which requires a lot of manual cooperation and is efficient and low cost. The detection accuracy depends on the dimensional accuracy of the mold. As time goes by, the size of the mold changes, and the detection accuracy decreases. In recent years, in the field of...

AI Technical Summary

Problems solved by technology

When the laser bar is projected onto the bottom of the bullet under the same lighting conditions, there will be alternating light bars and speckles in the camera imaging. The traditional method cannot extract the center of the light bar with high precision, which affects the accuracy and stability of the bullet’s primer depth measurement.

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