Localization device using magnetic field and positioning method thereof

• US 10,591,890 B2
• Filed: 12/14/2016
• Issued: 03/17/2020
• Est. Priority Date: 07/06/2016
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Sun, Kuan-Chun, Lo, Sheng-Wen
• Primary Examiner(s): Sun, Yu-Hsi D
• Application Number:
  US15/379,169
• Publication Number:
  US 20180011472A1
• Time in Patent Office: 1,189 Days
• CPC Class Codes: G05B 19/402 characterised by control arrangements for positioning, e.g. centring a tool relative to a hole in the workpiece, additional detection means to correct position G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/41332 Electromagnet driven core, position of core controlled
• CPC Class Codes: G05D 1/0261 using magnetic plots

Abstract

A localization device using a magnetic field for positioning a moving object is provided. The localization device includes a magnetic landmark, a set of at least four tri-axes magnetic sensors mounted on the moving object, and a logic operation processing unit. The set of at least four tri-axes magnetic sensors forms four non-coplanar points in a three-dimension coordinate system. The logic operation processing unit is connected to the set of at least four tri-axes magnetic sensors. The set of at least four tri-axes magnetic sensors senses the magnetic field of the magnetic landmark and generates at least four magnetic signals transmitted to the logic operation processing unit.

Claims

1. A localization device using a magnetic field for positioning a moving object, consisting of:

a magnetic landmark;

a set of only four tri-axes magnetic sensors mounted on the moving object, wherein the set of only four tri-axes magnetic sensors forms four non-coplanar points in a three-dimension coordinate system; and

a logic operation processing unit connected to the set of only four tri-axes magnetic sensors, wherein the set of only four tri-axes magnetic sensors senses the magnetic field of the magnetic landmark and generates four magnetic signals transmitted to the logic operation processing unit.

2. The localization device as claimed in 1, wherein the set of only four tri-axes magnetic sensors is positioned on three axes and an origin of the three-dimension coordinate system and the distance between any two of the four tri-axes magnetic sensors is a known distance.

3. The localization device as claimed in 2, wherein when the moving object passes through the magnetic landmark, the logic operation processing unit calculates a related-coordinate information and a distance information of the set of only four tri-axes magnetic sensors relative to the magnetic landmark according to the four magnetic signals transmitted from the set of at least four tri-axes magnetic sensors to generate an identification data.

4. The localization device as claimed in 3, wherein the logic operation processing unit calculates a position vector r of the set of only four tri-axes magnetic sensors relative to the magnetic landmark according to a magnetic moment B and a gradient tensor matrix G of the set of only four tri-axes magnetic sensors relative to the magnetic landmark to obtain the identification data, wherein r=−

3G<sup>−

1</sup>B.

5. A positioning method using a magnetic field for positioning a moving object relative to a magnetic landmark, wherein the moving object consists of a frame and a set of only four tri-axes magnetic sensors mounted on the frame, the set of only four tri-axes magnetic sensors forms four non-coplanar points in a three-dimension coordinate system, and the positioning method comprises:

sensing the magnetic field of the magnetic landmark and generating four magnetic signals by the set of only four tri-axes magnetic sensors;

receiving a first magnetic moment detected by each of the tri-axes magnetic sensors at a first distance relative to the magnetic landmark;

receiving a second magnetic moment detected by each of the tri-axes magnetic sensors at a second distance different from the first distance relative to the magnetic landmark;

calculating a difference vector between the first magnetic moment and the second magnetic moment; and

calculating a coordinate information and a distance information of each of the tri-axes magnetic sensors relative to the magnetic landmark according to the difference vector.

6. The positioning method as claimed in 5, wherein the set of only four tri-axes magnetic sensors is positioned on three axes and an origin of the three-dimension coordinate system and the distance between any two of the four tri-axes magnetic sensors is a known distance.

7. The positioning method as claimed in 6, wherein when the moving object passes through the magnetic landmark, the positioning method comprises calculating the related-coordinate information and the distance information of the set of only four tri-axes magnetic sensors relative to the magnetic landmark to generate an identification data.

8. The positioning method as claimed in 7, wherein a position vector r of the set of only four tri-axes magnetic sensors relative to the magnetic landmark is calculated according to a magnetic moment B and a gradient tensor matrix G of the set of only four tri-axes magnetic sensors relative to the magnetic landmark to obtain the identification data, wherein r=−

3G<sup>−

1</sup>B.

9. A localization device using a magnetic field for positioning a moving object, consisting of:

a magnetic landmark;

a set of only four tri-axes magnetic sensors mounted on the moving object, wherein the set of only four tri-axes magnetic sensors forms four non-coplanar points in a three-dimension coordinate system; and

a logic operation processing unit connected to the set of only four tri-axes magnetic sensors, wherein the set of only four tri-axes magnetic sensors senses the magnetic field of the magnetic landmark and generates four magnetic signals transmitted to the logic operation processing unit,

wherein the logic operation processing unit receives a first magnetic moment detected by each of the tri-axes magnetic sensors at a first distance relative to the magnetic landmark, and receives a second magnetic moment detected by each of the tri-axes magnetic sensors at a second distance different from the first distance relative to the magnetic landmark, and calculates a difference vector between the first magnetic moment and the second magnetic moment to obtain a gradient tensor matrix of three magnetic components on three axes of each of the tri-axes magnetic sensors and calculates a coordinate information and a distance information of each of the tri-axes magnetic sensors relative to the magnetic landmark according to the difference vector.