Measurement target top-surface estimation method, guide information display device, and crane

Patent metadata

Field	Value
Publication number	US-11414305-B2
Application number	US-201816632731-A
Country	US
Kind code	B2
Filing date	Jul 19, 2018
Priority date	Jul 21, 2017
Publication date	Aug 16, 2022
Grant date	Aug 16, 2022

Abstract

To estimate the top surface of a measurement target on the basis of a data point group that corresponds to the top surface of the measurement target and is obtained using a laser scanner. A data processing unit: selects two data points from the data point group which is contained within the thickness in the vertical direction of a hoisting load region, and calculates the distance between the selected two data points; determines the two data points are located in the same plane and calculates the gravitational center for each point determined to be in the same plane when the distance between the two points is equal to or less than a threshold; searches for a nearby point which is a data point for which the distance from the gravitational centers is equal to or less than the threshold, determines the nearby point is also in the same plane when the nearby point is discovered, and repeatedly performs the process in order each time a nearby point is discovered; obtains multiple data points determined to be in the same plane; and estimates plane clusters representing the top surfaces of a hoisting load and an object on the basis of the multiple data points.

First claim

The invention claimed is:

1. A guide information display apparatus, comprising:
a data display section;
a data acquisition section that acquires image data of a suspended load region, and point cloud data, the image data being taken by a camera, the point cloud data being acquired by scanning an object from a top surface, the object including a suspended load and a grounded object in the suspended load region; and
a data processing section that creates a guide frame from a planar cluster resulting from clustering the point could data and causes the guide frame to be displayed on the data display section while superimposing the created guide frame on the object in the image data, wherein
the data processing section creates the guide frame by structuring the point could data into a hierarchy in a distance direction from the laser scanner, calculating a center of gravity of a plurality of points for which an inter-point distance is equal to or smaller than a threshold in the point could data belonging to a same layer, and deeming, to be on a same planar cluster, point data for which a distance with the center of gravity is equal to or smaller than a threshold.

2. The guide information display apparatus according to claim 1 , wherein the data processing section
estimates a width of the planar cluster from an inter-point distance between two points that are most separate in a width direction of the planar cluster in planar view of the distance direction from the laser scanner, among the plurality of points that are deemed to be on the same planar cluster, and
estimates a depth of the planar cluster from an inter-point distance between two points that are most separate in a depth direction of the planar cluster.

3. A work machine, comprising the guide information display apparatus according to claim 2 .

4. A work machine, comprising the guide information display apparatus according to claim 1 .

5. A guide information display method, comprising:
a data acquisition step of acquiring image data of a suspended load region, and point cloud data, the image data being taken by a camera, the point cloud data being acquired by scanning an object from a top surface, the object including a suspended load and a grounded object in the suspended load region;
a data processing step of creating a guide frame by clustering the point could data; and
a data display step of causing the guide frame to be displayed on a data display section while superimposing the created guide frame on the object in the image data, wherein
the data processing step includes
a step of structuring the point could data into a hierarchy in a distance direction from the laser scanner and calculating a center of gravity of a plurality of pieces of the point cloud data which belong to a same layer and for which an inter-point distance is equal to or smaller than a threshold in the point could data, and
a step of creating the guide frame while deeming point data for which a distance with the center of gravity is equal to or smaller than a threshold to be on a same cluster.

6. The guide information display method according to claim 5 , wherein
the step of calculating a center of gravity of the point cloud data in the data processing step repeats a step of recalculating a center of gravity with addition of point data for which a distance with the calculated center of gravity is equal to or smaller than a threshold.

7. The guide information display method according to claim 6 , wherein
among the plurality of points that are deemed to be on the same planar cluster in the data processing step, a width of the cluster is estimated from an inter-point distance between two points that are most separate in a width direction of the planar cluster in planar view of the distance direction of the laser scanner from an inter-point distance between two points that are most separate in a width direction of the planar cluster in the data processing step, and
a depth of the cluster is estimated from an inter-point distance between two points that are most separate in a depth direction of the cluster.

Assignees

• Tadano Ltd
• The School Corporation Kansai Univ

Inventors

• Kosaka Takayuki
• Ishikawa Iwao
• Kubota Satoshi
• Tanaka Shigenori
• Nakamura Kenji
• Yamamoto Yuhei
• NAKAHARA Masaya

Classifications

• G06T7/521

  from laser ranging, e.g. using interferometry; from the projection of structured light · CPC title

• B66C13/00

  Other constructional features or details · CPC title

• G06T2207/10028

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

• G01B11/00

  Measuring arrangements characterised by the use of optical techniques · CPC title

• B66C13/46 Primary

  Position indicators for suspended loads or for crane elements · CPC title