Method and apparatus for detecting a power line

• US 5,548,279 A
• Filed: 07/22/1994
• Issued: 08/20/1996
• Est. Priority Date: 07/22/1994
• Status: Expired due to Term

• Current Assignee: Mcdonnell Douglas Corporation (The Boeing Co.)
• Original Assignee: Mcdonnell Douglas Corporation (The Boeing Co.)
• Inventors: Gaines, Robert B.
• Primary Examiner(s): Peng, John K.
• Assistant Examiner(s): LIEU, JULIE BICHNGOC
• Application Number:
  US08/279,485
• Time in Patent Office: 760 Days
• Field of Search: 340/664, 340/660, 340/654, 324/133, 324/67, 324/256, 324/253, 324/254, 324/255, 324/117 R
• US Class Current: 340/664
• CPC Class Codes: B64D 45/00 Aircraft indicators or protectors not otherwise provided for camouflage F41H3/00

Abstract

A method and apparatus for detecting power lines including a pickup coil for detecting the magnetic field generated by the current conducted by a power line and for producing a sense current in response to the detected magnetic field, a gyrator circuit for generating a sense voltage in response to the sense current and tuning means for producing an output voltage in response to the sense voltage such that a power line can be detected thereby. The tuning means also tunes the power line detecting apparatus to the predetermined frequency of the current conducted by the power lines. The power line detecting method and apparatus also preferably analyzes the magnitude and frequency of the output voltage produced by the tuning means so as to distinguish output voltages generated in response to the magnetic fields produced by power lines from those generated by extraneous electromagnetic noise. In addition, the power line detecting method apparatus can also determine the direction of the detected power lines by sampling successive output voltages as the power line detecting apparatus moves relative to the located power line such that movement of the power line detecting apparatus in a direction generally toward the located power line is detected and a warning or alarm can be produced.

Claims

1. An apparatus for detecting a power line comprising:

sensing means for detecting a magnetic field generated by a current conducted by the power line and for producing a sense current in response to the detected magnetic field;

gyrating means, responsive to said sensing means, for generating a sense voltage in response to the sense current wherein said gyrating means has a predetermined inductance;

tuning means, responsive to said sensing means and said gyrating means, for tuning the power line detecting apparatus to a predetermined frequency and for producing a plurality of successive output voltages in response to the sense voltage such that a power line may be detected thereby,

power line direction determining means for sampling successive output voltages of said tuning means as the power line detecting apparatus moves relative to the power line to thereby differentiate between movement of the power line detecting apparatus in a direction generally toward the power line and movement of the power line detecting apparatus in a direction generally away from the power line, wherein said power line direction determining means detects movement in a direction generally toward the power line if the magnitude of any one of the successive output voltages is greater than the magnitude of the immediately preceding output voltage, and wherein said power line direction determining means detects movement in a direction generally away from the power line if the magnitude of any one of the successive output voltages is less than the magnitude of the immediately preceding output voltage; and

warning means, responsive to said power line direction determining means, for providing a warning signal in response to the detection of movement of the power line detecting apparatus in a direction generally toward the power line, but not in response to the detection of movement of the power line detecting apparatus in a direction generally away from the power line.

2. A power line detecting apparatus according to claim 1 wherein said gyrating means comprises a gyrator circuit for simulating an inductor.

3. A power line detecting apparatus according to claim 1 wherein said tuning means comprises a capacitor having a predetermined capacitance for tuning the power line detecting apparatus to optimize the detection of the magnetic field generated by a current having a predetermined frequency which is conducted by the power line.

4. A power line detecting apparatus according to claim 1 wherein said tuning means comprises a generalized impedance converter circuit for simulating a capacitor having a predetermined capacitance for tuning the power line detecting apparatus to optimize the detection of the magnetic field generated by a current having a predetermined frequency which is conducted by the power line.

5. A power line detecting apparatus according to claim 1 wherein said sensing means includes a pickup coil for conducting the sense current induced therein by the detected magnetic field.

6. A power line detecting apparatus according to claim 5 wherein said pickup coil includes a ferrimagnetic oxide core and at least one turn of wire positioned about the ferrimagnetic oxide core.

7. A power line detecting apparatus according to claim 6 wherein said ferrimagnetic oxide core is comprised of ferrite and wherein said at least one turn of wire is comprised of magnet wire.

8. A power line detecting apparatus according to claim 1 further comprising power line locating means, responsive to said tuning means, for analyzing the magnitude and frequency of the output voltage produced by said tuning means to thereby locate the power line conducting the current which generates the detected magnetic field.

9. An apparatus for detecting a power line conducting a current, the power line detecting apparatus comprising:

a pickup coil for detecting a magnetic field generated by the current conducted by the power line and for producing a sense current in response to the detected magnetic field;

a gyrater circuit, responsive to said pickup coil, for generating a sense voltage in response to the sense current wherein said gyrater circuit has a predetermined inductance;

tuning means, responsive to said pickup coil and said gyrater circuit, for tuning the power line detecting apparatus to a predetermined frequency and for producing an output voltage in response to the sense voltage, wherein said tuning means comprises a generalized impedance converter circuit for simulating a capacitor having a predetermined capacitance for tuning the power line determining apparatus to optimize the detection of the magnetic field generated by a current having a predetermined frequency which is conducted by the power line; and

power line locating means, responsive to said tuning means, for analyzing the magnitude and frequency of the output voltage produced by said tuning means to thereby locate the power line conducting the current which generates the detected magnetic field, wherein said power line locating means further comprises power line direction determining means for sampling successive output voltages of said tuning means as the power line detecting apparatus moves relative to the located power line to thereby detect movement of the power line detecting apparatus in a direction generally toward the located power line.

10. A power line detecting apparatus according to claim 9 wherein said tuning means comprises a capacitor having a predetermined capacitance for tuning the power line detecting apparatus to optimize the detection of the magnetic field generated by a current having a predetermined frequency which is conducted by the power line.

11. A power line detecting apparatus according to claim 9 wherein said pickup coil includes a ferrimagnetic oxide core and at least one turn of wire positioned about the ferrimagnetic oxide core.

12. A power line detecting apparatus according to claim 11 wherein said ferrimagnetic oxide core is comprised of ferrite and wherein said at least one turn of wire is comprised of magnet wire.

13. A power line detecting apparatus according to claim 9 further comprising warning means, responsive to said power line direction determining means, for indicating that the power line detecting apparatus is moving in a direction generally toward the located power line.

14. A method for detecting a power line from a platform in motion, the method comprising the steps of:

generating a plurality of successive output voltages having a respective magnitude and a respective frequency related to a magnetic field generated by a current conducted by the power line;

comparing the magnitude of at least one of the output voltages to a predetermined noise level and comparing the frequency of the at least one output voltage to a predetermined range of frequencies;

detecting the power line if the magnitude of the at least one output voltage is greater than the predetermined noise level and the frequency of the at least one output voltage is within the predetermined range of frequencies;

comparing the magnitude of each output voltage to the magnitude of an immediately preceding output voltage if a power line has been detected by said power line detecting step;

detecting movement of the platform in a direction generally toward the detected power line if the magnitude of any one of the successive output voltages is greater than the magnitude of the immediately preceding output voltage;

detecting movement of the platform in a direction generally away from the detected power line if the magnitude of any one of the successive output voltages is less than the magnitude of the immediately preceding output voltage; and

providing a warning signal in response to detecting movement of the platform in a direction generally toward the power line, but not in response to detecting movement of the platform in a direction generally away from the power line.

15. An apparatus for detecting a power line conducting a current, the power line detecting apparatus comprising:

a pickup coil for detecting a magnetic field generated by the current conducted by the power line and for producing a sense current in response to the detected magnetic field, said pickup coil extending between opposed first and second ends;

a gyrator circuit, electrically connected between the first end of said pickup coil and a reference voltage, for generating a sense voltage in response to the sense current;

a tuning circuit, electrically connected between the second end of said pickup coil and the reference voltage, for tuning the power line detecting apparatus to a predetermined frequency and for producing an output voltage in response to the sense voltage, wherein said tuning circuit comprises a generalized impedance converter circuit for simulating a capacitor having a predetermined capacitance for tuning the power line detecting apparatus to optimize the detection of the magnetic field generated current having a predetermined frequency which is conducted by the power line; and

a controller, responsive to said tuning circuit, for analyzing the magnitude and frequency of the output voltage produced by said tuning circuit to thereby locate the power line conducting the current which generates the detected magnetic field, wherein said controller comprises power line direction determining means for sampling successive output voltages of said tuning circuit as the power line detecting apparatus moves relative to the located power line to thereby detect movement of the power line detecting apparatus in a direction generally toward the located power line.

16. A power line detecting apparatus according to claim 15 wherein said tuning circuit comprises a capacitor having a predetermined capacitance for tuning the power line detecting apparatus to optimize the detection of the magnetic field generated by a current having a predetermined frequency which is conducted by the power line.

17. A power line detecting apparatus according to claim 15 further comprising warning means, responsive to said power line direction determining means, for indicating that the power line detecting apparatus is moving in a direction generally toward the located power line.