DETECTION METHOD AND DETECTION DEVICE OF BURIED METAL

• US 20170082769A1
• Filed: 03/13/2015
• Published: 03/23/2017
• Est. Priority Date: 03/17/2014
• Status: Active Grant

• Current Assignee: Fuji Tecom, Inc.
• Original Assignee: Fuji Tecom, Inc.
• Inventors: Tsunasaki, Masaru, KUBOTA, Kenshi
• Granted Patent: US 9,939,546 B2
• Time in Patent Office: Days
• CPC Class Codes: G01V 3/06 using ac
• CPC Class Codes: G01V 3/10 using induction coils
• CPC Class Codes: G01V 3/15 specially adapted for use during transport, e.g. by a person, vehicle or boat

Abstract

A detection method and detection device of buried metal which are capable of detecting singular points, in horizontal and vertical directions, of metal tubes, telecommunication cables, and electric power cables, or the like buried in the ground. A magnetic field component of the direction of 3 axes of a XYZ axis is detected by two or more magnetic sensors installed in the detectable direction, and detects a magnetic field induced to buried metal. While carrying out synchronous detection of these magnetic field components and calculating for each amplitude and each phase of a magnetic field component of the direction of 3 axes, image processing is carried out and it is outputted to a display. While calculating for the position of a singular point, a singular point distinguishes whether it is an over-crossing state, it is an under-crossing state, or it is a branched state from these image data

Claims

1. A detecting method of buried metal which detects said buried metal by sending an alternating current through buried metal from a transmitter, and detecting the magnetic field generated by the alternating current which flows into said buried metal with the magnetic sensor of a receiver, the detection method of buried metal comprising:

said receiver consists of two or more magnetic sensors installed in the direction to detectable the magnetic field component of the direction of 3 axes, namely the XYZ axes, respectively,

a detector which detects the magnetic field component of said direction of 3 axes detected with this magnetic sensor, respectively,

a CPU which has the function to perform signal processing each amplitude and each phase of the magnetic field component of said direction of 3 axes,

a display which displays the result which carried out signal processing by this CPU,

calculating for each amplitude and each phase of a magnetic field component of the direction of 3 axes, namely the XYZ axis, respectively,

calculating for the position of a singular point from each amplitude,

determining whether said singular point is in an over-crossing state, in an under-crossing state, or in a branched state from each phase.

2. The detecting method of buried metal of claim 1, wherein said detector calculates for each phase of the magnetic field component of the direction of 3 axes, namely the XYZ axes, from said magnetic field by synchronous detection using the transmitted signal of the transmitter for sending an alternating current through said buried metal as a reference signal.

3. The detecting method of buried metal of claim 1, wherein said CPU creates image data about a magnetic field component of a XYZ axis, respectively by carrying out image processing of each amplitude and each phase of a magnetic field component of said direction of 3 axes,

the image data is outputted to said display, while calculating for a position of a singular point from said these image data,

said singular point is determined whether it is an over-crossing state, it is an under-crossing state, or it is a branched state.

4. The detecting method of buried metal of claim 1, wherein said receiver is installed apart from a magnetic sensor installed in the direction which can detect a magnetic field component of the direction of the X-axis,

and it has the 2nd magnetic sensor installed in the direction which can detect the magnetic field component of the direction of the X-axis,

said detector detects the 2nd magnetic field component of the direction of the X-axis detected with said 2nd magnetic sensor,

said CPU calculates for the amplitude and the phase of the 2nd magnetic field component of the direction of the X-axis, respectively,

it calculates for the depth of said singular point from the amplitude and the phase of the 2nd magnetic field component of the direction of the X-axis, and the amplitude and the phase of the magnetic field component of the direction of the X-axis,

said display displays the depth of said singular point.

5. A detection device of buried metal which detects said buried metal by sending an alternating current through the buried metal from a transmitter, and detecting the magnetic field generated by the alternating current which flows into said buried metal with the magnetic sensor of a receiver, the detection device of buried metal comprising:

said receiver consists of two or more magnetic sensors installed in the direction to detectable the magnetic field component of the direction of 3 axes, namely the XYZ axes, respectively,

a detector which detects the magnetic field component of said direction of 3 axes detected with said magnetic sensor, respectively,

a CPU which has the function to perform signal processing of each amplitude and each phase of a magnetic field component of said direction of 3 axes,

an display which shows the result which carried out signal processing by this CPU,

and the signal-processing function of said CPU has at least

the function to calculate for each amplitude and each phase of a magnetic field component of the direction of 3 axes, namely the XYZ axes, from said magnetic field, respectively,

the function to calculate for a position of a singular point from each amplitude,

the function to determine whether said singular point is in an over-crossing state, in an under-crossing state, or in a branched state from each phase.

6. The detection device of buried metal of claim 5, wherein said detector has the function to calculate for each phase of the magnetic field component of the direction of 3 axes, namely the XYZ axis, from said magnetic field, respectively, by synchronous detection using the transmitting signal of the transmitter for sending an alternating current through said buried metal as a reference signal.

7. The detection device of buried metal concerning any of claim 5, said CPU has

the function which creates image data about the magnetic field component of the XYZ axis, respectively by carrying out image processing of each amplitude and each phase of said magnetic field component of the direction of 3 axes,

the function which outputs these image data to said display,

the function which calculates for the position of a singular point, and determines whether said singular point is in an over-crossing state, in an under-crossing state, or in a branched state from said these image data.

8. The detection device of buried metal of claim 5, said receiver is installed apart from the magnetic sensor installed in the direction which can detect the magnetic field component of the direction of the X-axis,

and it has the 2nd magnetic sensor installed in the direction which can detect the magnetic field component of the direction of the X-axis,

said detector has the function to detect the 2nd magnetic field component of the direction of the X-axis detected with said 2nd magnetic sensor,

said CPU has the function to calculates for the amplitude and the phase of the 2nd magnetic field component of the direction of the X-axis, respectively,

and the function to calculate for the depth of said singular point from the amplitude and the phase of the 2nd magnetic field component of the direction of the X-axis, and the amplitude and the phase of the magnetic field component of the direction of the X-axis,

said display has a function which displays the depth of said singular point.