Dynamic magnetic locator and method for the same

• US 7,164,270 B1
• Filed: 12/19/2005
• Issued: 01/16/2007
• Est. Priority Date: 10/07/2005
• Status: Expired due to Fees

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Chen, Po-Shen, Chen, Mu-Ping, Huang, Wen-Nan
• Primary Examiner(s): Aurora; Reena
• Application Number:
  US11/303,931
• Time in Patent Office: 393 Days
• Field of Search: 324/326, 324/67
• US Class Current: 324/326
• CPC Class Codes: G01V 3/104 using several coupled or uncoupled coils G01V3/101 takes precedence
• CPC Class Codes: G01V 3/15 specially adapted for use during transport, e.g. by a person, vehicle or boat

Abstract

A dynamic magnetic locator includes a linking mechanism linked with a first sensor to horizontal move or rotate the first sensor; a second sensor horizontally arranged beside the first sensor; a third sensor vertically arranged atop the second sensor; and a control module connected to the sensors and receiving magnetic signals of the underground metal pipe. The control module controls the linking mechanism to horizontal move or to rotate the first sensor to obtain a plurality of magnetic signals. The control module processes the magnetic signals to obtain a position and a depth of an underground metal pipe.

Claims

1. A dynamic magnetic locator used for three-dimensional positioning, cross-line positioning and depth calculation of an underground metal pipe, the magnetic locator comprising:

a linking mechanism linked with a first sensor to horizontally move or rotate the first sensor;

a second sensor horizontally arranged beside the first sensor;

a third sensor vertically arranged on top of the second sensor; and

a control module connected to the sensors and receiving magnetic signals of the underground metal pipe, which controls the linking mechanism to move or rotate the first sensor to obtain a plurality of magnetic signals, and processes the magnetic signals to obtain a position and depth of the underground metal pipe,

wherein the control module comprises;

a display showing the position and depth of the underground metal pipe;

a keyboard used to input commands to adjust the means for horizontally moving or rotating the first sensor;

a recorder used to record a maximal value of the magnetic signal; and

a processor connected to the sensors, the display, the keyboard and the recorder, to calculate the position and depth of the underground metal pipe the first sensor, the second sensor and the third sensor comprises a coil wound core,

wherein the processor calculates the position and the depth of the underground metal pipe by following formula;

$\mathrm{Co}<br><br>\left(\mathrm{Flx}\right)<br><br>\mathrm{\infty <br><br>}<br><br>\frac{f<br><br>\left(x_1,x_2\right)}{{d<br><br>}^2}$

wherein;

Co;

Magnetic flux at core;

Flx;

Function set of the flux;

f;

General flux function;

d;

Pipe depth;

x1;

Function set of flux for pipe; and

x2;

Function set of flux for core.

2. The dynamic magnetic locator of claim 1, wherein the sensor further comprises

an analog-to-digital converter connected to the coil of the sensor to convert the magnetic signal detected by the coil into a digital signal;

a sampling unit connected to the analog-to-digital converter and the control module, which sends the digital signal from the analog-to-digital converter to the control module.

3. A method for dynamically detecting three-dimensional positioning, cross-line positioning and depth calculation of an underground metal pipe with a magnetic locator, the method comprising the following steps:

providing a horizontally movable and rotatable first sensor;

providing a second sensor horizontal to the first sensor;

providing a third sensor vertical to the second sensor;

positioning the underground metal pipe when detected magnetic signals of the first sensor and the second sensor are the same; and

horizontally moving the first sensor to detect and calculate the depth of the underground metal pipe the first sensor, the second sensor and the third sensor comprises a coil wound core;

wherein, when horizontally moving the first sensor to detect and calculate the depth of the underground metal pipe, the depth of the underground metal pipe is calculated according to the following formula;

$\mathrm{Co}<br><br>\left(\mathrm{Flx}\right)<br><br>\mathrm{\infty <br><br>}<br><br>\frac{f<br><br>\left(x_1,x_2\right)}{{d<br><br>}^2}$

Where;

Co;

Magnetic flux at core;

Flx;

Function set of the flux;

f. General flux function;

d;

Pipe depth;

x1;

Function set of flux For pipe; and

x2;

Function set of flux for core.

4. The method of claim 3, wherein, in the step of horizontally moving the first sensor, when the magnetic signal measured by the first sensor is 70% of the maximal magnetic signal measured by the second sensor, the depth of the underground metal pipe is equal to twice the distance of the first sensor.

5. The method as in of claim 3, wherein, in the step of providing a third sensor vertical to the second sensor, when the magnetic signal detected by the third sensor is zero, it means there is another underground metal pipe, then the first sensor if horizontally moved or rotated to and the position of another underground metal pipe can be identified by a maximum of a magnetic signal of the first sensor.