Magnetic induction mine arming, disarming and simulation system

• US 5,027,709 A
• Filed: 11/13/1990
• Issued: 07/02/1991
• Est. Priority Date: 04/26/1990
• Status: Expired due to Fees

• Current Assignee: Slagle, Glenn B.
• Original Assignee: Slagle, Glenn B.
• Inventors: Slagle, Glenn B.
• Primary Examiner(s): JORDAN, CHARLES T
• Application Number:
  US07/617,470
• Time in Patent Office: 231 Days
• Field of Search: 102/293, 102/401, 102/417, 102/426, 102/427, 434/11
• US Class Current: 102/427
• CPC Class Codes: F42B 8/28 Land or marine mines; Depth charges
• CPC Class Codes: F42C 13/08 operated by variations in magnetic field

Abstract

A system for powering and communicating with a mine or mine simulator, involving magnetic induction coupling between a powered search unit with a resonating primary inductance coil and a secondary inductance loop in the mine device. The current in the secondary loop is rectified in the mine device to provide dc power. The magnetic induction frequency can be in the range from 40 kHz to 1 MHz. The search unit can resonate sequentially or simultaneously at different frequencies, and rectification of the different frequencies in the mine device can provide information to the mine device. Feedback to the search unit can be by the mine device modulating the impedance of its secondary loop, for instance at an audio frequency 1/10th of the frequency of the induction coupling, and by detecting in the search unit the corresponding change in the reflected impedance. A mine device can be armed or disarmed, and report on its status when queried by the search unit coming sufficiently close to the mine device. A mine device can have a selectable active period during which it can kill a tank and provide a corresponding kill signal to the tank crew, be limited to only one kill, delay its arming to allow its planting or withdrawal of the search unit providing the arm signal, etc. A kill signal can be received with a 10 watt power input into a search unit on a tank, while maintaining a clearance of 5 feet from the ground.

Claims

1. A system comprising

a transportable search unit including a primary loop in which ac current is resonated to generate an oscillating magnetic field of at least one respective predetermined frequency,

power supply means connected with said search unit for providing power to said search unit, including for said generating of said magnetic field,

a mine device including

a secondary loop for being inductively magnetically coupled with said primary loop and to resonate at said at least one predetermined frequency when said search unit approaches said mine device,

power conversion means for deriving power from said resonating secondary loop, and

signalling means powered by said derived power from said power conversion means for providing a signal indicating that said search unit attained sufficient proximity to said mine device as determined by the extent of the inductive magnetic coupling between said primary and secondary loops, and

reception means transported with said search unit for receiving said signal, for indicating thereby said attainment of said sufficient proximity,

wherein information is transferred from said mine device to said reception means at a frequency different from each said predetermined frequency of the resonation of the primary loop for the magnetic induction coupling with said secondary loop.

2. The system of claim 1, comprising

said search unit having means including said primary loop for generating a plurality of said oscillating magnetic fields at a corresponding plurality of different predetermined frequencies, and

said mine device having means including said secondary loop for detecting the inductive magnetic coupling therewith of each said oscillating magnetic field,

wherein information is transmitted to said mine device from said search unit by said inductive magnetic coupling of said magnetic fields oscillating at said corresponding different predetermined frequencies.

3. The system of claim 2, wherein a succession of said oscillating magnetic fields of said corresponding different predetermined frequencies are generated by said search unit, for determining said information transmitted to said mine device.

4. The system of claim 2, wherein said search unit and said reception means are mounted on a vehicle, said mine device is a mine simulator, and said signal from said signalling means of said mine device is a kill signal, indicating that said vehicle came sufficiently close to said mine device to have set off a mine simulated thereby.

5. The system of claim 1, wherein

said reception means comprises means at least connected with said search unit for detecting change in the reflected impedance in said primary loop of the impedance of said secondary loop in said mine device, as a result of said magnetic induction coupling, and

said signalling means in said mine device comprises means for changing the impedance of said secondary loop, and accordingly said reflected impedance in said primary loop, said change in impedance caused by said signalling means comprising said signal provided by said signalling means for detection by said reception means.

6. The system of claim 5, wherein

said mine device is a mine simulator,

said search unit is mounted on a vehicle, and

said reception means outputs a kill signal to the crew of said vehicle corresponding to said receiving of said signal from said mine device as a result of said changing of said reflected impedance.

7. The system of claim 6, wherein each said at least one predetermined frequency is and rf frequency, and said changing of said impedance of said secondary loop is repeated at an audio frequency, said repeated changing providing said kill signal.

8. The system of claim 7, wherein said reception means comprises a relay which is switched to provide said kill signal.

9. The system of claim 7, wherein said reception means comprises a speaker which is caused to emit a noise as at least a part of said kill signal.

10. The system of claim 1, said mine device comprising

capacitor means for storing electrical energy for a time period during which it is desired that said mine device be in an active status,

wherein said signalling means in said mine device provides said signal that said search unit has attained said sufficient proximity only while said mine device is in said active status, and

wherein said electrical energy stored in said capacitor means is initially transmitted into said mine device for such storage by magnetic induction coupling with said secondary loop, by placing said mine device against said search unit.

11. The system of claim 10, said mine device comprising means for setting said desired active time period during which said mine device is in said active status.

12. The system of claim 11, said mine device comprising means for visually indicating the active status of said mine device at least during said initial transmitting of said electrical energy for storage in said capacitor.

13. The system of claim 11, said mine device comprising means for delaying the entry of said mine device into said active status for a selectable period of time after said initial transmission of said energy into said mine device for said storage therein.

14. The system of claim 1, wherein said search unit is mounted on a vehicle, said mine device is a mine simulator, and said signal from said signalling means of said mine device is a kill signal, indicating that said vehicle came sufficiently close to said mine device to have set off a mine simulated thereby.

15. The system of claim 14, said mine simulator comprising means for effectively limiting the number of kill signals said mine simulator will provide.

16. The system of claim 15, wherein said effective limiting of said number of kill signals occurs by limiting the total length of time that said kill signal is provided.

17. The system of claim 10, wherein said mine device comprises

a counter powered by said electrical energy initially stored in said capacitor means, said counter being set to determine said active time period, and

means for discharging charge remaining in said capacitor means after said predetermined count value is attained by said counter.

18. The system of claim 17, wherein while said counter is counting, corresponding to said mine simulator being in said active status, and said secondary coil subsequently commences to be magnetically inductively coupled with said primary coil as a result of said search unit attaining said sufficient proximity, said counter is switched into a fast counting mode and said signal is provided from said signalling means to said reception means as a kill signal which continues until said predetermined count is achieved.

19. The system of claim 18, said mine device comprising means for delaying the entry of said mine device into said active status for a predetermined period of time after said initial transmission of said electrical energy into said mine device for said storage therein.

20. The system of claim 1, wherein

said search unit and said reception means are mounted on a vehicle, said mine device is a mine simulator, and said signal from said signalling means of said mine device is a kill signal, indicating that said vehicle came sufficiently close to said mine device to have set off a mine simulated thereby,

said reception means comprises means at least connected with said search unit for detecting change in the reflected impedance in said primary loop of the impedance of said secondary loop in said mine device, as a result of said magnetic induction coupling,

said signalling means in said mine device comprises means for changing the impedance of said secondary loop, and accordingly said reflected impedance in said primary loop,

said search unit as mounted on said vehicle provides a clearance of up to 5 feet from the ground, while powering said mine simulator and receiving said kill signal, with a maximum power supplied to said search unit of 10 watts, and

said primary coil in said search unit is approximately as wide as said vehicle, and approximately at least an order of diameter larger in linear scale than said secondary loop in said mine simulator.