Ground surface estimation method, measurement region display system, and crane

Patent metadata

Field	Value
Publication number	US-2022003544-A1
Application number	US-201917296807-A
Country	US
Kind code	A1
Filing date	Dec 9, 2019
Priority date	Dec 10, 2018
Publication date	Jan 6, 2022
Grant date	—

Abstract

A ground surface estimation method includes: a continuous region recognizing step for recognizing, when a difference in altitude value between a representative point of one grid and a representative point of another adjacent grid out of the plurality of grids is equal to or less than a threshold, the one grid and the other adjacent grid as a continuous region that is a region where the one grid and the other adjacent grid are continuous; and a ground surface estimation step for estimating a continuous region having the largest number of grids among the continuous regions as a ground surface.

First claim

1 . A ground surface estimation method comprising:
acquiring, by a laser scanner, point cloud data by radiating laser on a measurement region, and calculating an altitude value of a radiation point from the point cloud data; generating, by a data processing section that performs arithmetic processing on the point cloud data, a grid by dividing the measurement region into a plurality of grids, calculating a center-of-gravity position of each of the grids and an average altitude value of the point cloud data in each of the grids, and setting the center-of-gravity position at the average altitude value as a position of a representative point for each of the grids; recognizing, by the data processing section, a continuous region by recognizing one grid and another adjacent grid of the plurality of grids as the continuous region when a difference in altitude value between the representative point of the one grid and the representative point of the other adjacent grid is equal to or less than a threshold, the continuous region being a region where the one grid and the other adjacent grid are continuous; and estimating, by the data processing section, a ground surface by estimating the continuous region having a largest number of the grids among the continuous regions as the ground surface.

2 . The ground surface estimation method according to claim 1 , wherein
in the generating of the grid, each of the grids is sliced in a horizontal direction and the average altitude value of the point cloud data within a range is calculated, the range being formed by slicing each of the grids.

3 . The ground surface estimation method according to claim 1 , wherein
in the recognizing of the continuous region, the threshold is changed in accordance with a distance between the laser scanner and the representative point.

4 . The ground surface estimation method according to claim 1 , wherein
in the generating of the grid, a width of the grid is changed in accordance with a number of the continuous regions within a predetermined range of the measurement region.

5 . A measurement region display system comprising:
a data acquisition section including a laser scanner, the laser scanner acquiring point cloud data by radiating laser on a measurement region; a data processing section that performs arithmetic processing on the acquired point cloud data; and a data display section, wherein: the data processing section
acquires the point cloud data from the data acquisition section, and calculates an altitude value of a radiation point from the point cloud data;
divides the measurement region into a plurality of grids, calculates a center-of-gravity position of each of the grids and an average altitude value of the point cloud data in each of the grids, and sets the center-of-gravity position at the average altitude value as a position of a representative point for each of the grids;
recognizes one grid and another adjacent grid of the plurality of grids as a continuous region when a difference in altitude value between the representative point of the one grid and the representative point of the other adjacent grid is equal to or less than a threshold, the continuous region being a region where the one grid and the other adjacent grid are continuous;
estimates the continuous region having a largest number of the grids among the continuous regions as a ground surface; and
displays the continuous region estimated as the ground surface on the data display section, the continuous region estimated as the ground surface being distinguished from the continuous region other than the continuous region estimated as the ground surface.

6 . A crane comprising:
a swivel base; a boom provided on the swivel base; a laser scanner attached to the boom and acquiring point cloud data; a control apparatus that performs arithmetic processing on the acquired point cloud data; and a display apparatus, wherein: the point cloud data for each position of the laser scanner when radiating laser is acquired by laser radiation while the laser scanner is caused to move in accordance with a swiveling operation of the swivel base, an extending and retracting operation of the boom, and/or a luffing operation of the boom, and the control apparatus
acquires the point cloud data for each position of the laser scanner when radiating the laser, superimposes the point cloud data for each position of the laser scanner when radiating the laser based on each position and attitude of the laser scanner when radiating the laser, and calculates an altitude value of a radiation point;
divides a measurement region into a plurality of grids, calculates a center-of-gravity position of each of the grids and an average altitude value of the point cloud data in each of the grids, and sets the center-of-gravity position at the average altitude value as a position of a representative point for each of the grids;
recognizes one grid and another adjacent grid of the plurality of grids as a continuous region when a difference in altitude value between the representative point of the one grid and the representative point of the other adjacent grid is equal to or less than a threshold, the continuous region being a region where the one grid and the other adjacent grid are continuous;
estimates the continuous region having a largest number of the grids among the continuous regions as a ground surface; and
displays the continuous region estimated as the ground surface on the display apparatus, the continuous region estimated as the ground surface being distinguished from the continuous region other than the continuous region estimated as the ground surface.

Assignees

• Tadano Ltd
• The School Corporation Kansai Univ

Inventors

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

Classifications

• G06T2207/30252

  Vehicle exterior; Vicinity of vehicle · CPC title

• G06T2207/20021

  Dividing image into blocks, subimages or windows · CPC title

• G06T2207/10028

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

• G06T7/11

  Region-based segmentation · CPC title

• B66C13/22

  for electric drives (transmitting control pulses B66C13/40; systems or devices of general application H02P) · CPC title