A Method for Measuring Pit Depth with Variable Datum

Abstract

The invention discloses a variable-reference-surface pit depth measurement method. The method comprises the following steps of scanning a to-be-measured pit by a single laser beam along a semicircular track in a manner of n DEG each time, and forming an isometric graph according to data obtained in each scanning; if the isometric graph is not closed, abandoning ineffective values by means of an algorithm, selecting new effective values, and forming a closed isometric graph; and if the isometric graph is closed, obtaining an upper reference surface and a lower reference surface of the to-be-measured pint by means of the algorithm, wherein a difference between the upper reference surface and the lower reference surface is the depth DELTAdelta1 of the to-be-measured pint in this scanning, and finally comparing the depths in 180 / n times, wherein the maximal depth is the actual pit depth. According to the measurement method, selection of multiple reference surfaces can be performed, and measurement value comparison is performed so that higher accuracy is realized in pit reference surface selection; noncontact measurement is utilized, and the pits which cannot be contacted can be measured; measurement can be performed on the conditions such as tearing and penetrating; the measurement method can be used in field; furthermore the measurement method has advantages of simple and quick operation, and effective time and labor saving.

Description

technical field [0001] The invention belongs to a method for measuring depth, in particular to a method for measuring the depth of pits with variable reference planes, and is especially used for measuring the depth of pits on the surface of materials in industrial production, especially the depth of multiple bullets on the surface of anti-ballistic materials. Background technique [0002] In industrial production, pits and other defects may appear on the surface of some produced materials. According to product quality inspection requirements, it is usually necessary to detect the depth of these pits. In some other occasions, such as the anti-elasticity test of some materials, after the target test is completed, it is necessary to measure the depth of the crater, especially the crater of multiple bullets. Therefore, it is necessary to study the measurement method of pits. At present, the methods for measuring the depth size of pits include vernier caliper measurement and dep...

AI Technical Summary

Problems solved by technology

[0007] In order to overcome the deficiencies of the existing pit depth measurement methods, such as the diversity of the selection of the datum surface, the measurement results are diverse; some tiny pits are difficult to touch and measure; some measuring instruments have high requirements for the measurement environment and cannot be measured at any time; the measurement range Narrow; laser measurement is mainly used to measure the distance of a single target and cannot be used for depth measurement; the accuracy and precision of the measurement results are not high, time-consuming and labor-intensive. Depth measurement method, this measurement method combines the principle of laser distance measurement and adopts non-contact measurement, the reference plane is selected accurately, the application range is large, the accuracy and precision of the measurement results are greatly improved, the operation is simple and fast, saving time and effort

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