Three-dimensional measuring device, and three- dimensional measuringmethod

Patent metadata

Field	Value
Publication number	US-12326329-B2
Application number	US-202117801343-A
Country	US
Kind code	B2
Filing date	Mar 1, 2021
Priority date	Mar 5, 2020
Publication date	Jun 10, 2025
Grant date	Jun 10, 2025

Abstract

The objective of the present invention is to appropriately set a distance range for calculating a gradation degree, in accordance with the height of a workpiece. This three-dimensional measuring device is provided with: a three-dimensional sensor which images a workpiece to acquire three-dimensional information; a setting unit which, on the basis of the acquired three-dimensional information, sets a reference position serving as a height direction reference in the workpiece, and a height direction margin, relative to the reference position, for a gradation degree of a gradation image, and sets a distance range corresponding to the gradation degree of the gradation image; an image converting unit which converts the acquired three-dimensional information into the gradation image on the basis of the distance range; and a detecting unit which employs the gradation image to obtain, three-dimensionally, the shape and/or the position and attitude of the workpiece.

First claim

The invention claimed is:

1. A three-dimensional measuring device, comprising:
a three-dimensional sensor configured to capture an image of a workpiece and acquire three-dimensional information;
a setting unit configured to automatically set a reference position that defines as a reference in a height direction a position that is highest on the workpiece based on the three-dimensional information acquired, a first margin in the height direction of a gradation level in a gradation image, and a second margin of the gradation level in the gradation image, the first margin being toward the three-dimensional sensor in the height direction based on the reference position, the second margin being farther away from the three-dimensional sensor in the height direction based on the reference position, and the first margin and the second margin being set with reference to the reference position wherein a distance between the first margin and the reference position is different than a distance between the reference position and the second margin, and automatically set a distance range corresponding to the gradation level of the gradation image based on the first margin and the second margin;
an image conversion unit configured to convert the three-dimensional information acquired into the gradation image on the basis of the distance range; and
a detection unit configured to three-dimensionally obtain a shape or a position and posture of the workpiece using the gradation image.

2. The three-dimensional measuring device according to claim 1 , wherein the detection unit generates a histogram using the gradation level of the gradation image, and three-dimensionally obtains the shape or the position and posture of the workpiece on the basis of the generated histogram.

3. The three-dimensional measuring device according to claim 1 , wherein the shape of the workpiece is a front surface or a rear surface of the workpiece.

4. A non-transitory computer readable medium configured to store a three-dimensional measuring program for causing a processor to control a three-dimensional measuring device to execute steps of a three-dimensional measuring method, the three-dimensional measuring method comprising:
causing a three-dimensional sensor to capture an image of a workpiece and acquire three-dimensional information;
automatically setting a reference position that defines as a reference in a height direction a position that is highest on the workpiece based on the three-dimensional information acquired, a first margin in the height direction of a gradation level in a gradation image, and a second margin of the gradation level in the gradation image, the first margin being toward the three-dimensional sensor in the height direction based on the reference position, the second margin being farther away from the three-dimensional sensor in the height direction based on the reference position, and the first margin and the second margin being set with reference to the reference position wherein a distance between the first margin and the reference position is different than a distance between the reference position and the second margin, and automatically setting a distance range corresponding to the gradation level of the gradation image based on the first margin and the second margin;
converting the three-dimensional information acquired into the gradation image on the basis of the distance range; and
three-dimensionally obtaining a shape or a position and posture of the workpiece using the gradation image.

5. The non-transitory computer readable medium according to claim 4 , wherein the three-dimensional measuring program further causes the processor to control a three-dimensional measuring device to execute generating a histogram is using the gradation level of the gradation image, and
the shape or the position and posture of the workpiece is three-dimensionally obtained on the basis of the generated histogram.

6. The non-transitory computer readable medium to claim 4 , wherein the shape of the workpiece is a front surface or a rear surface of the workpiece.

Assignees

• Fanuc Corp

Inventors

• Oota Yuusuke

Classifications

• G06T2207/30108

  Industrial image inspection · CPC title

• G06V2201/12

  Acquisition of 3D measurements of objects · CPC title

• G06T2207/10028

  Range image; Depth image; 3D point clouds · CPC title

• G06V10/25

  Determination of region of interest [ROI] or a volume of interest [VOI] · CPC title

• G01B11/026

  by measuring distance between sensor and object (G01B11/0608 takes precedence) · CPC title