Shape evaluation method, shape evaluation device, and 3d inspection device

Abstract

To appropriately evaluate a surface shape of an object to be inspected regardless of the relative positions of a light source and an image-taking device with respect to the object. When evaluating a surface shape, it includes a shape recognition step for recognizing the surface shape of the object to be evaluated, a representative point extraction step for extracting a representing point from therecognized surface shape of the object to be evaluated, a shape specifying step for specifying a shape for a predefined area around the extracted representing point, a vector defining step for defining a light source direction vector with respect to each of the representing points, a representing point select step for selecting, from among all of the representing points, only representing points for which imaginary reflection vectors corresponding to the light source direction vectors are contained within a predefined range from an imaginarily defined direction, and a highlight line creation step for creating a highlight line that is imaginarily generated on the surface of the object to be evaluated based on the highlight point group, i.e., a group of all of the selected representing points, wherein an evaluation of the surface shape of the object to be evaluated is performed based on the created highlight line.

Description

technical field [0001] The present invention relates to a shape evaluation method and a shape evaluation device for three-dimensionally evaluating the surface shape of an evaluation object such as a vehicle, and also relates to a three-dimensional inspection device for three-dimensionally inspecting the surface shape of an inspection object. Background technique [0002] Generally, as a method of evaluating the appearance quality of automobiles and the like, shape inspection called highlight inspection is performed to three-dimensionally evaluate the surface shape of an object to be evaluated. In this high-brightness inspection, the light emitted from a light source such as a fluorescent lamp is parallelized, and the object to be evaluated is inspected based on the flow of a stripe-shaped light pattern formed on the surface of the object to be evaluated, which is obtained by irradiating the object through a slit or the like. surface shape. In such a highlight inspection...

AI Technical Summary

Problems solved by technology

However, in the inspection process of the surface shape that is usually carried out, the relative position of the imaging device that captures the highlighted line to the inspection object (that is, the imaging field of view) and the position of the light source are not strictly fixed. Therefore, even if the inspection object The surface shape of the object is the same, and the image reproducibility of the captured highlight line may not be sufficiently obtained.

Therefore, the surface of the object inspected by these methods cannot be strictly reproduced, and it is difficult to stabilize the inspection results.

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