Gauge reading method and gauge reading device

Patent metadata

Field	Value
Publication number	US-2026099911-A1
Application number	US-202519324530-A
Country	US
Kind code	A1
Filing date	Sep 10, 2025
Priority date	Oct 8, 2024
Publication date	Apr 9, 2026
Grant date	—

Abstract

In a gauge reading method and a gauge reading device for reading an analog gauge, the gauge reading method includes: acquiring a first image including an environment including a gauge; extracting a second image from the first image using an object detector, the second image corresponding to at least a partial portion of the first image and including the gauge; inferring a zero point, a gauge end point, a needle center point, and a needle end point from the second image using a deep neural network; obtaining a converted needle end point such that a depth difference between a gauge plate and a needle of the gauge is eliminated by reprojecting a location of the needle end point; determining an angle formed by a scale start point or a scale end point, the needle center point, and the converted needle end point; and converting the angle into a gauge value.

First claim

What is claimed is:

1 . A gauge reading method for reading an analog gauge through a maintenance robot, the gauge reading method comprising:
acquiring a first image including an environment including a gauge; extracting a second image from the first image using an object detector, the second image corresponding to at least a partial portion of the first image and including the gauge; inferring a zero point, a gauge end point, a needle center point, and a needle end point from the second image using a deep neural network; obtaining a converted needle end point so that a depth difference between a gauge plate and a needle of the gauge is eliminated by reprojecting a location of the needle end point; determining an angle formed by a scale start point or a scale end point, the needle center point, and the converted needle end point; and converting the angle into a gauge value.

2 . The gauge reading method of claim 1 ,
wherein two or more markers are disposed around the gauge in the first image, and wherein the extracting of the second image includes:
extracting the second image from the first image, the second image corresponding to at least a partial portion of the first image and including the gauge and the two or more markers.

3 . The gauge reading method of claim 2 , wherein each of the two or more markers has a square shape, and includes a binary pattern including black and white colors.

4 . The gauge reading method of claim 2 , wherein the obtaining of the converted needle end point includes:
determining a camera intrinsic matrix; determining a camera extrinsic matrix based on the camera intrinsic matrix; and performing three-dimension point reconstruction based on the camera extrinsic matrix.

5 . The gauge reading method of claim 4 , wherein the determining of the camera intrinsic matrix includes:
determining the camera intrinsic matrix by estimating camera intrinsic parameters through camera calibration.

6 . The gauge reading method of claim 4 , wherein the determining of the camera extrinsic matrix includes:
obtaining real coordinates in a three-dimensional space for vertices of the two or more markers disposed around the gauge; obtaining projection coordinates on a projection image for the vertices of the two or more markers; and determining the camera extrinsic matrix using the real coordinates, the projection coordinates, and the camera intrinsic matrix.

7 . The gauge reading method of claim 6 , wherein the performing of the three-dimension point reconstruction includes:
obtaining the camera extrinsic matrix, an estimated location of the needle of the gauge on the projection image, and a real distance from the gauge plate to the needle; obtaining an inverse function of a projection matrix; obtaining three-dimensional coordinates of the needle by inputting the estimated location of the needle into the projection matrix; and obtaining final coordinates by adjusting the obtained three-dimensional coordinates of the needle.

8 . The gauge reading method of claim 1 , further comprising:
defining a vertical line extending perpendicular to a horizontal side of the second image while passing through the needle center point; determining a relative positional relationship by comparing coordinates of the needle center point and the needle end point in the second image; determining a first angle formed by a first intersection point where the vertical line intersects a lower horizontal side of the second image, the needle center point, and the needle end point when it is determined that the needle end point is located to the left of the needle center point; and converting the first angle into the gauge value.

9 . The gauge reading method of claim 8 , further comprising:
determining a second angle formed by a second intersection point where the vertical line intersects an upper horizontal side of the second image, the needle center point, and the needle end point when it is determined that the needle end point is located to the right of the needle center point; and converting the second angle into the gauge value.

10 . A gauge reading method for reading an analog gauge through a maintenance robot, the gauge reading method comprising:
acquiring a first image including an environment including a gauge; extracting a second image from the first image using an object detector, the second image corresponding to at least a partial portion of the first image and including the gauge; inferring a zero point, a gauge end point, a needle center point, and a needle end point from the second image using a deep neural network; reading an operation mode set in the maintenance robot; when the operation mode is set to a first operation mode, obtaining a converted needle end point so that a depth difference between a gauge plate and a needle of the gauge is eliminated by reprojecting a location of the needle end point, and determining an angle based on the converted needle end point; when the operation mode is set to a second operation mode, determining an angle based on a vertical line defined to extend perpendicular to a horizontal side of the second image while passing through the needle center point when the operation mode is set to the second operation mode; and converting the angle into a gauge value.

11 . The gauge reading method of claim 10 , further comprising:
evaluating a quality of the second image; setting the operation mode to the first operation mode based on that the quality of the second image is evaluated to be higher than or equal to a predetermined criterion; and setting the operation mode to the second operation mode based on that the quality of the second image is evaluated to be lower than the predetermined criterion.

12 . The gauge reading method of claim 10 , wherein the determining of the angle based on the converted needle end point includes:
determining an angle formed by a scale start point or a scale end point, the needle center point, and the converted needle end point.

13 . The gauge reading method of claim 12 , wherein the determining of the angle based on the converted needle end point includes:
determining a camera intrinsic matrix; determining a camera extrinsic matrix based on the camera intrinsic matrix; and performing three-dimension point reconstruction based on the camera extrinsic matrix.

14 . The gauge reading method of claim 10 , wherein the determining of the angle based on the vertical line includes:
determining a relative positional relationship by comparing coordinates of the needle center point and the needle end point in the second image; and determining, as the angle, a first angle formed by a first intersection point where the vertical line intersects a lower horizontal side of the second image, the needle center point, and the needle end point when it is determined that the needle end point is located to the left of the needle center point.

15 . The gauge reading method of claim 14 , wherein the determining of the angle based on the vertical line includes:
determining, as the angle, a second angle formed by a second intersection point where the vertical line intersects an upper horizontal side of the second image, the needle center point, and the needle end point when it is determined that the needle end point is located to the right of the needle center point.

16 . A gauge reading device for reading an analog gauge through a maintenance robot, the device comprising:
one or more memory devices configured to store instructions; and one or more processors configured to

Assignees

• Hyundai Motor Company
• Kia Corp

Inventors

• Kim Sohee

Classifications

• G06V10/82

  using neural networks · CPC title

• G06V10/245

  by locating a pattern; Special marks for positioning · CPC title

• G06T7/80

  Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration · CPC title

• G06T7/60

  Analysis of geometric attributes · CPC title

• G01D7/002

  giving both analog and numerical indication · CPC title