IP Library › Granted Patent US 11,906,641
Granted Patent B2
US 11,906,641 · App. 17/274,923 · Granted Feb 20, 2024

Work machine

Inventors: Naoki Hayakawa (Ushiku, JP); Shiho Izumi (Hitachinaka, JP)
Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
G01S19/485G01S19/48E02F3/32E02F3/435E02F9/262E02F9/264G01S19/40
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 11,906,641
App. No.
17/274,923
Granted
Feb 20, 2024
Kind
B2
Abstract

A coordinate conversion system including a controller that converts geographic-coordinate-system coordinates of a certain point into site-coordinate-system coordinates includes: an image-capturing device that captures an image of a reference point; and a GNSS antenna that receives a navigation signal. The controller calculates geographic-coordinate-system coordinates of the image-capturing device on the basis of the navigation signal received at the GNSS antenna, and a distance between the image-capturing device and the GNSS antenna; calculates a distance and direction from the image-capturing device to the reference point by performing image processing on the image of the reference point captured by the image-capturing device; calculates the geographic-coordinate-system coordinates of the reference point on the basis of the calculated distance and direction from the image-capturing device to the reference point, and the calculated geographic-coordinate-system coordinates of the image-capturing device; and calibrates the coordinate conversion parameter on the basis of the calculated geographic-coordinate-system coordinates of the reference point, and the site-coordinate-system coordinates of the reference point.

Claims (35)

1. A work machine including a controller that is configured to convert geographic-coordinate-system coordinates of a certain point into site-coordinate-system coordinates by using a coordinate conversion parameter generated on a basis of geographic-coordinate-system coordinates and site-coordinate-system coordinates of a reference point installed at a work site, the work machine comprising:

a machine body;

a work implement that is attached to the machine body, and is driven by a hydraulic cylinder;

an image-capturing device that captures an image of the reference point;

a GNSS antenna that is attached to the machine body, and receives a navigation signal; and

a posture sensor that detects a posture of the work implement, wherein

the controller is configured to

calculate geographic-coordinate-system coordinates of the image-capturing device on a basis of the navigation signal received at the GNSS antenna, and a distance between the image-capturing device and the GNSS antenna,

calculate a distance and direction from the image-capturing device to the reference point by performing image processing on the image of the reference point captured by the image-capturing device,

calculate the geographic-coordinate-system coordinates of the reference point on a basis of the calculated distance and direction from the image-capturing device to the reference point, and the calculated geographic-coordinate-system coordinates of the image-capturing device,

calibrate the coordinate conversion parameter on a basis of the calculated geographic-coordinate-system coordinates of the reference point, and the site-coordinate-system coordinates of the reference point,

calculate geographic-coordinate-system coordinates of the machine body on a basis of the navigation signal received at the GNSS antenna,

calculate geographic-coordinate-system coordinates of a control point set for the work implement on a basis of the geographic-coordinate-system coordinates of the machine body, and information about the posture of the work machine detected by the posture sensor,

convert the geographic-coordinate-system coordinates of the control point into site-coordinate-system coordinates by using the coordinate conversion parameter calibrated by the controller, and

perform control on a basis of the converted site-coordinate-system coordinates.

2. The work machine according to claim 1 , wherein

information about the site-coordinate-system coordinates of the reference point is embedded in a marker installed at the reference point,

the image-capturing device captures an image of the marker along with the image of the reference point, and

the controller acquires the site-coordinate-system coordinates of the reference point on a basis of the image of the reference point and the image of the marker captured by the image-capturing device.

3. The work machine according to claim 1 , wherein

the controller associates the geographic-coordinate-system coordinates of the reference point calculated by the controller with identification information of the reference point, and outputs the associated geographic-coordinate-system coordinates and identification information to a server connected to the controller via a network.

4. The work machine according to claim 1 , wherein

the controller is configured to perform coordinate conversion by using the calibrated coordinate conversion parameter when the coordinate conversion parameter is calibrated by the controller.

5. The work machine according to claim 1 , wherein

the image-capturing device is pivotable in an upward/downward direction, and a leftward/rightward direction, and

the controller controls a direction of the image-capturing device such that the reference point is always included in an image-capturing range of the image-capturing device.

6. The work machine according to claim 1 , wherein the controller causes a positional relation between the control point and a predetermined target surface in the converted site-coordinate-system coordinates to be displayed on a monitor.

7. The work machine according to claim 6 , wherein

the controller controls the hydraulic cylinder such that the work implement is positioned above the target surface.

8. The work machine according to claim 6 , wherein

the controller associates the geographic-coordinate-system coordinates of the reference point calculated by the controller with identification information of the reference point, and outputs the associated geographic-coordinate-system coordinates and identification information to a server connected to the controller via a network.

9. The work machine according to claim 8 , wherein

the controller receives the calibrated coordinate conversion parameter, and is configured to perform coordinate conversion of the control point by using the received coordinate conversion parameter when the controller is notified that the coordinate conversion parameter has been calibrated from the server that calibrates the coordinate conversion parameter on a basis of the geographic-coordinate-system coordinates and the site-coordinate-system coordinates of the reference point when the geographic-coordinate-system coordinates of the reference point have been updated.

10. The work machine according to claim 1 , wherein

the controller is configured to repeatedly execute, at a predetermined cycle, a calibration process of the coordinate conversion parameter based on the calculated geographic-coordinate-system coordinates of the reference point, and the stored and identified site-coordinate-system coordinates of the reference point.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 10, 2021
From: HAYAKAWA, NAOKI; IZUMI, SHIHO
To: HITACHI CONSTRUCTION MACHINERY CO., LTD.
Reel/Frame 055548/0334 →
Priority Claims (1)
JP 2018-178039 · Sep 21, 2018 · national
Continuity (1)
Related Publication 20220026587A1 · Jan 27, 2022