Radar mining guidance control system

• US 7,659,847 B2
• Filed: 03/23/2008
• Issued: 02/09/2010
• Est. Priority Date: 06/29/2006
• Status: Expired due to Fees

• Current Assignee: Stolar Incorporated
• Original Assignee: Stolar Incorporated
• Inventors: Bausov, Igor Y., Main, Richard B., Stolarczyk, Gerald L., Stolarczyk, Larry G.
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): GALT, CASSI J
• Application Number:
  US12/053,611
• Publication Number:
  US 20080185903A1
• Time in Patent Office: 688 Days
• Field of Search: 342/22, 342/90, 342/129, 342/159, 342/175, 342/179, 342/195
• US Class Current: 342/22
• CPC Class Codes: E21C 27/24 by milling means acting on the full working face , i.e. the rotary axis of the tool carrier being substantially parallel to the working face similar machines for tunneling E21D9/1026
• CPC Class Codes: E21C 35/08 Guiding the machine
• CPC Class Codes: G01S 13/32 using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
• CPC Class Codes: G01S 13/885 for ground probing prospecting or detecting using electromagnetic waves G01V3/12
• CPC Class Codes: G01S 7/4052 by simulation of echoes
• CPC Class Codes: G01S 7/4056 specially adapted to FMCW
• CPC Class Codes: G01S 7/4082 using externally generated reference signals, e.g. via remote reflector or transponder

Abstract

A coal-mining machine uses a ground-penetrating radar based on a software-definable transmitter for launching pairs of widely separated and coherent continuous waves. Each pair is separated by a constant or variable different amount double-sideband suppressed carrier modulation such as 10 MHz, 20 MHz, and 30 MHz. Processing suppresses the larger first interface reflection and emphasizes the smaller second, third, etc. reflections. Processing determines the electrical parameter of the natural medium adjacent to the antenna. Deep reflections at 90-degrees and 270-degrees create maximum reflection and will be illuminated with modulation signal peaks. Quadrature detection, mixing, and down-conversion result in 0-degree and 180-degree reflections effectively dropping out in demodulation.

Claims

1. A radar mining guidance control system, comprising:

a radar pack including isolation devices to control mechanical vibrations;

a pocket mounting for protecting and enclosing said radar pack in a surface of a mining tool;

an antenna radome to enclose the pocket and cover said radar pack;

a radar transmitter included in said radar pack for launching pairs of separated and coherent continuous waves in a double-sideband suppressed-carrier modulation through the air;

a radar receiving antenna included in said radar pack for placement proximate to an air interface with a first layer of material, and having impedance characteristics that depend on a surrounding natural medium adjacent to the antenna and an operating frequency;

a radar receiver included in said radar pack with coherent demodulation for suppressing a first reflection of radio signals emitted by the radar transmitter from an air interface with a first layer of material and received by the radar receiving antenna;

a receiver processor included in said radar pack for determining any electrical parameters of the natural medium adjacent to the antenna from stored a priori data and impedance measurements of the radar receiving antenna;

a radar processor included in said radar pack for calculating the depth of an interface between said first layer of material and a second deeper layer of material, by measuring a signal delay of a second reflection of radio signals emitted by the radar transmitter from said first and second material interface which was received by the radar receiving antenna;

wherein, said earthpenetrating radar provides for guidance control of mining machinery according to said calculations of the depth of an interface between said first layer of material and a second deeper layer of material.

2. The radar mining guidance system of claim 1, wherein:

the pocket is flush mounted to the surface a coal-cutting drum on a mining machine;

a pack suspension disposed in the pocket and providing support of the radar pack and absorption of any shock loads; and

an angle transducer connected to the radar pack and providing for angular measurements of the rotational positions of said coal-cutting drum.

3. The radar mining guidance control system of claim 1, further comprising:

a software-defined radio transceiver with program software to implement the radar transmitter and radar receiver, wherein a software programming enables a switch in operational modes between a near-field and a far-field signal detection mode.

4. The radar mining guidance control system of claim 3, further comprising:

a modulation process for generating a frequency difference between pairs of frequencies in launched waves;

wherein, if a variable frequency is used by the software-defined transceiver, then pairs of tunable resonant microstrip patch antennas are included;

wherein, if a constant frequency difference is used by the software-defined transceiver, then a wide-bandwidth antenna is included with a swept or stepped-frequency continuous-wave (SFCW) function.

5. The radar mining guidance control system of claim 1, wherein:

the radar receiver accepts a received modulation signal with a phase range that starts at 0-degrees at a radar transmitter antenna, and suppresses said first reflection after coherent demodulation, then the modulation signal phase is changed by 90-degrees by the radar transmitter and said first reflection is measured again to determine in situ electrical parameters of any intervening natural medium.

6. The radar mining guidance control system of claim 1, wherein:

the radar transmitter and receiver use deep reflections at 90-degrees and 270-degrees phase to create maximums in reflections that will be illuminated with modulation signal peaks, and the radar receiver uses quadrature detection, mixing, and down-conversion to effectively drop out any 0-degree and 180-degree reflections in its demodulation.

7. The radar mining guidance control system of claim 1, further comprising:

a software-definable transceiver programmed as a geologic media penetrating radar with a direct digital synthesizer (DDS) for synthesizing pairs of many coherent first and second continuous waves (CW) with frequencies of ω

o−

ω

1, and ω

o+ω

2 etc., as individual pairs separated in frequency by a constant or variable frequency difference;

wherein, said pairs of continuous waves create a double-sideband, suppressed-carrier waveform, and the suppressed carrier may be held constant, swept, or stepped in frequency across an operating frequency range of the radar.

8. The radar mining guidance control system of claim 7, wherein:

said suppressed carrier and a variety of modulation signal magnitudes and phases are software controlled, wherein the suppressed carrier phase is θ

c and the modulation phase is θ

m, and a difference in frequency between the sidebands ω

o−

ω

1, ω

o+ω

2 is the modulation frequency

${\mathrm{\omega <br><br>}}_m=\frac{{\mathrm{\omega <br><br>}}_2+{\mathrm{\omega <br><br>}}_1}{2}.$

9. The radar mining guidance control system of claim 7, further comprising:

a circuit to prevent spurious signals from conflict with a mixed-down intermediate frequency (IF) amplifier passband signal, wherein, a set of ω

o−

ω

1, ω

o+ω

2, ω

2 and ω

1, and a pair of heterodyne frequencies ω

3 and ω

4 are each outside the passband of any intermediate amplifier.

10. The radar mining guidance control system of claim 7, further comprising:

an intermediate frequency bandpass amplifier stage having a center frequency ω

_IF=ω

₄−

ω

₂=ω

₁−

ω

₃, wherein a set of synthesized frequencies ω

1, ω

2, ω

3, and ω

4 subject to bandpass filtering are such that, ω

2≠

ω

1 and ω

3 ≠

ω

4, a suppressed carrier frequency,

${\mathrm{\omega <br><br>}}_{\mathrm{cm}}=\frac{{\mathrm{\omega <br><br>}}_2-{\mathrm{\omega <br><br>}}_1}{2}+{\mathrm{\omega <br><br>}}_0$

and a heterodyne frequency is

${\mathrm{\omega <br><br>}}_{\mathrm{cH}}=\frac{{\mathrm{\omega <br><br>}}_4-{\mathrm{\omega <br><br>}}_3}{2}+{\mathrm{\omega <br><br>}}_0,$

and a distance estimate to a target can be derived from timing information received in a pair of phase terms ω

mτ and

ω

cmτ

.

11. A continuous mining machine system, comprising:

a continuous mining machine (CCM) with a boom arm that can raise and lower a rotating cutting drum;

a flushing mounted pocket mounted in a surface of the rotating cutting drum;

a radar pack including isolation devices to control mechanical vibrations, and disposed in the pocket;

an antenna radome to enclose the pocket and cover said radar pack;

a pack suspension disposed in the pocket and providing support of the radar pack and absorption of any shock loads;

an angle transducer connected to the radar pack and providing for angular measurements of the rotational positions of the rotating cutting drum,

a radar receiving antenna included in said radar pack placed proximate to an air interface with a first layer of material, and having impedance characteristics that depend on a surrounding natural medium adjacent to the antenna and an operating frequency;

a software-defined radio transceiver with program software that implement a radar transmitter and radar receiver, wherein a software programming enables a switch in operational modes between a near-field and a far-field signal detection modes according to measurements provided by the angle transducer;

wherein, said radar transmitter provides for launching pairs of separated and coherent continuous waves in a double-sideband suppressed-carrier modulation into a coalbed;

wherein, said radar receiver provides for coherent demodulation to suppress a first reflection of radio signals emitted by the radar transmitter from an air interface with a first layer of material and received by the radar receiving antenna;

a receiver processor included in said radar pack for determining electrical parameters corresponding to a natural medium adjacent to the antenna from a priori data and impedance measurements of the radar receiving antenna stored within;

a radar processor included in said radar pack for calculating the depth of an interface between said first layer of material and a second deeper layer of material, by measuring a signal delay of a second reflection of radio signals emitted by the radar transmitter from said first and second material interface which was received by the radar receiving antenna;

wherein, said earth-penetrating radar provides for guidance control of the CCM according to said calculations of the depth of an interface between said first layer of material and a second deeper layer of material.