Self-check for a detector detecting the proximity of a transportation vessel

• US 6,734,796 B2
• Filed: 06/03/2002
• Issued: 05/11/2004
• Est. Priority Date: 04/04/2000
• Status: Expired due to Fees

• Current Assignee: Marconi Communications, Inc. (Marconi Holdings Company Limited)
• Original Assignee: Marconi Communications, Inc. (Marconi Holdings Company Limited)
• Inventors: Puleston, David J., Forster, Ian J., Horrell, Peter Robert George
• Primary Examiner(s): Wu, Daniel J.
• Assistant Examiner(s): Nguyen, Tai T.
• Application Number:
  US10/160,512
• Publication Number:
  US 20030006900A1
• Time in Patent Office: 708 Days
• Field of Search: 340/572.3, 340/572.1, 340/572.8, 340/988, 340/438, 340/825-49, 340/10.5, 340/10.51, 340/10.36, 340/514, 340/515, 375/376, 327/150, 327/155, 327/159
• US Class Current: 340/572.3
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G01S 2205/002 for traffic control, mobile tracking, guidance, surveillance or anti-collision
• CPC Class Codes: G01S 5/0018 Transmission from mobile station to base station

Abstract

A frequency detector that detects a frequency signal indicative of the proximity of a transportation vessel or an intrinsically-safe area. The frequency detector may be associated with any type of electronic device. The frequency detector detects the presence of a frequency signal that is emitted by a transportation vessel and/or a frequency beacon associated with the transportation vessel. The frequency detector and/or container may disable, shut down, or reduce power of any electro-magnetic field generating devices associated with the frequency detector and/or container if the frequency detector receives a frequency signal indicative of the inside or proximity of a transportation vessel or an intrinsically-safe area. The container also includes a self-check frequency generator that emits a frequency signal capable of being detected by the frequency detector. If the frequency detector is operating properly, the frequency detector will successfully receive the frequency signal emitted by the frequency generator.

Claims

1. An apparatus, comprising:

a tracking device configured to transmit and receive positioning information to a remote site over a wireless communications link, the tracking device including a power source for supplying power to the tracking device;

a control system;

a frequency detector coupled to said control system for receiving a frequency signal indicative of the proximity of the transportation vessel, the control system being configured to decrease the power supplied to the tracking device by the power source; and

a frequency generator coupled to said control system;

said control system being capable of determining whether said frequency detector is operating properly by causing said frequency generator to emit a self-check signal having a frequency substantially the same as said frequency signal and determining if said self-check signal was received by said frequency detector.

2. The apparatus of claim 1, wherein said frequency detector is comprised from the group consisting of a magnetic sensor and a capacitance sensor.

3. The apparatus of claim 1, wherein said frequency detector further comprises an amplifier that amplifies and filters said frequency signal to remove noise from said frequency signal to form a conditioned frequency signal.

4. The apparatus of claim 3, wherein said conditioned frequency signal is input into a threshold detector and said control system so that said control system is capable of determining if said conditioned frequency signal is above a threshold value indicative of the proximity of the transportation vessel.

5. The electronic device apparatus of claim 1, wherein said frequency signal is input into a threshold detector included in said frequency detector wherein said control system is capable of determining if said frequency signal is above a threshold value indicative of the proximity of the transportation vessel.

6. The apparatus of claim 5, wherein said control system causes said frequency generator to emit a band of frequencies to determine if said frequency detector has become de-tuned or inoperable.

7. The apparatus of claim 6, wherein said control system adjusts said threshold detector if said frequency detector has become de-tuned or inoperable.

8. The electronic device apparatus of claim 1, further comprising a field-emitting device coupled to said control system, said control system being configured to deactivate said field-emitting device when said frequency detector receives said frequency signal.

9. The electronic device apparatus of claim 1, further comprising a field-emitting device coupled to said control system, said control system being configured to reduce the power in said field-emitting device when said frequency detector receives said frequency signal.

10. The apparatus of claim 1, further comprising a field-emitting device coupled to said control system, said control system being configured to decouple the power in said field-emitting device when said frequency detector receives said frequency signal.

11. The apparatus of claim 1, wherein said frequency detector comprises three antennas positioned in three different dimensions with respect to each other that are capable of receiving said frequency signal so that said frequency detector is capable of detecting said frequency signal regardless of the orientation of said frequency detector.

12. The apparatus of claim 11, wherein said frequency detector further comprises a summer that sums said frequency signals received by said antennas.

13. The apparatus of claim 1, wherein said control system is comprised from the group consisting of a microprocessor, a micro-controller, a switch, and a transistor.

14. The apparatus of claim 1, wherein said frequency detector is comprised of coils and a tuned circuit to determine the presence of said frequency signal.

15. The apparatus of claim 1, wherein said frequency signal is comprised of a frequency of around about 400 Hz.

16. The apparatus of claim 1, wherein said control system causes said frequency generator to emit a band of frequencies to determine if said frequency detector has become de-tuned or inoperable.

17. The apparatus of claim 16, wherein said control system reports an error to a remote site if said frequency detector has become de-tuned or inoperable.

18. The apparatus of claim 1, wherein said frequency detector comprises a PLL circuit to detect said frequency signal and to generate a signal to said control system indicative of the locked condition of said frequency signal indicative of the proximity of the transportation vessel.

19. The apparatus of claim 18, wherein said PLL circuit comprises:

a converter to receive said frequency signal;

a phase and frequency comparator to receive an output signal from said converter; and

a filter and VCO that receives an output signal from said phase and frequency comparator indicative of the difference in phase between said frequency signal and said VCO;

said VCO generates an output signal that is fed back into said phase and frequency comparator.

20. The apparatus of claim 1, wherein said control system is associated with a device from the group consisting of a cellular phone, a PDA, a laptop computer, and an apparatus associated with a shipping container.

21. An apparatus for sensing the proximity of an intrinsically-safe area, comprising:

a tracking device configured to transmit and receive positioning information over a wireless communications link to a remote site;

a power source for supplying power to the tracking device;

a frequency detector coupled to said control system for receiving a frequency signal indicative of the proximity of the intrinsically-safe area;

a control system configured to decrease the power supplied to the tracking device in response to the received frequency signal; and

a frequency generator coupled to said control system;

said control system being capable of determining whether said frequency detector is operating properly by causing said frequency generator to emit a self-check signal having a frequency substantially the same as said frequency signal and determining if said self-check signal was received by said frequency detector.

22. The apparatus of claim 21, wherein said frequency detector is comprised from the group consisting of a magnetic sensor and a capacitance sensor.

23. The apparatus of claim 21, wherein said frequency detector further comprises an amplifier that amplifies and filters said frequency signal to remove noise from said frequency signal to form a conditioned frequency signal.

24. The apparatus of claim 23, wherein said conditioned frequency signal is input into a threshold detector and said control system so that said control system is capable of determining if said conditioned frequency signal is above a threshold value indicative of the proximity of the intrinsically-safe area.

25. The apparatus of claim 21, wherein said frequency signal is input into a threshold detector included in said frequency detector wherein said control system is capable of determining if said frequency signal is above a threshold value indicative of the proximity of the intrinsically-safe area.

26. The apparatus of claim 25, wherein said control system causes said frequency generator to emit a band of frequencies to determine if said frequency detector has become dc-tuned or inoperable.

27. The apparatus of claim 26, wherein said control system adjusts said threshold detector is said frequency detector has become de-tuned or inoperable.

28. The apparatus of claim 21, further comprising a field-emitting device coupled to said control system wherein said control system deactivates said field-emitting device when said frequency detector receives said frequency signal.

29. The apparatus of claim 21, further comprising a field-emitting device coupled to said control system wherein said control system reduces the power in said field-emitting device when said frequency detector receives said frequency signal.

30. The apparatus of claim 21, further comprising a field-emitting device coupled to said control system wherein said control system decouples the power in said field-emitting device when said frequency detector receives said frequency signal.

31. The apparatus of claim 21, wherein said frequency detector comprises three antennas positioned in three different dimensions with respect to each other that are capable of receiving said frequency signal so that said frequency detector is capable of detecting said frequency signal regardless of the orientation of said frequency detector.

32. The apparatus of claim 31, wherein said frequency detector further comprises a summer that sums said frequency signals received by said antennas.

33. The apparatus of claim 21, wherein said control system is comprised from the group consisting of a microprocessor, a micro-controller, a switch, and a transistor.

34. The apparatus of claim 21, wherein said frequency detector is comprised of coils and a tuned circuit to determine the presence of said frequency signal.

35. The apparatus of claim 21, wherein said frequency signal is comprised of a frequency of around about 400 Hz.

36. The apparatus of claim 21, wherein said control system causes said frequency generator to emit a band of frequencies to determine if said frequency detector has become de-tuned or inoperable.

37. The apparatus of claim 36, wherein said control system reports an error to a remote site if said frequency detector has become de-tuned or inoperable.

38. The apparatus of claim 21 wherein said frequency detector comprises a PLL circuit to detect said frequency signal and to generate a signal to said control system indicative of the locked condition of said frequency signal indicative of the proximity of the intrinsically-safe area.

39. The apparatus of claim 38, wherein said PLL circuit comprises:

a converter to receive said frequency signal;

a phase and frequency comparator to receive an output signal from said converter; and

a filter and VCO that receives an output signal from said phase and frequency comparator indicative of the difference in phase between said frequency signal and said VCO;

said VCO generates an output signal that is fed back into said phase and frequency comparator.

40. The apparatus of claim 21, wherein said control system is associated with a device from the group consisting of a cellular phone, a PDA, a laptop computer, and an apparatus associated with a shipping container.

41. A transportation vessel detection system, comprising:

an electronic device containing a control system;

a frequency detector coupled to said control system for receiving a frequency signal indicative of when said container is in proximity to the transportation vessel;

and

a frequency generator coupled to said control system;

a tracking device coupled to said control system, the tracking device being configured to receive positioning information from a positioning system concerning said electronic device and a remote communication device coupled to said control system to transmit said positioning information remotely wherein said control system is adapted to deactivate said remote communication device if said frequency detector detects said frequency signal, said control system being capable of determining whether said frequency detector is operating properly by causing said frequency generator to emit a self-check signal having a frequency substantially the same as said frequency signal and determining if said frequency detector received said self-check signal.

42. The system of claim 41, wherein said frequency detector further comprises an amplifier that amplifies and filters said frequency signal to remove noise from said frequency signal to form a conditioned frequency signal.

43. The system of claim 42, wherein said conditioned frequency signal is input into a threshold detector and said control system so that said control system is capable of determining if said conditioned frequency signal is above a threshold value indicative of the proximity of the transportation vessel.

44. The system of claim 41, wherein said frequency signal is input into a threshold detector included in said frequency detector wherein said control system is capable of determining if said frequency signal is above a threshold value indicative of the proximity of the transportation vessel.

45. The system of claim 44, wherein said frequency beacon is located in proximity to the transportation vessel.

46. The system of claim 44, wherein said control system causes said frequency generator to emit a band of frequencies to determine if said frequency detector has become de-tuned or inoperable.

47. The system of claim 46, wherein said control system adjusts said threshold detector is said frequency detector has become dc-tuned or inoperable.

48. The system of claim 41, further comprising a field-emitting device coupled to said control system wherein said control system deactivates said field-emitting device when said frequency detector receives said frequency signal.

49. The system of claim 41, further comprising a field-emitting device coupled to said control system wherein said control system reduces the power in said field-emitting device when said frequency detector receives said frequency signal.

50. The system of claim 41, further comprising a field-emitting device coupled to said control system wherein said control system decouples the power in said field-emitting device when said frequency detector receives said frequency signal.

51. The system of claim 41, wherein said frequency detector comprises three antennas positioned in three different dimensions with respect to each other so that said frequency detector is capable of detecting said frequency signal regardless of the orientation of said frequency detector.

52. The system of claim 41, wherein said positioning system receives said positioning information from at least one satellite.

53. The system of claim 41, wherein said remote communication device communicates said positioning information remotely to a remote site.

54. The system of claim 41, wherein said remote communication device communicates said position information remotely to a remote site through satellite communications.

55. The system of claim 41, further comprising a power system under control of said control system that deactivates power from said tracking device when said frequency detector detects said frequency signal.

56. The system of claim 41, further comprising a frequency beacon associated with the transportation vessel that emits said frequency signal.

57. The system of claim 56, wherein said frequency beacon is attached to the transportation vessel.

58. The system of claim 41, wherein said control system causes said frequency generator to emit a band of frequencies to determine if said frequency detector has become de-tuned or inoperable.

59. The system of claim 58, wherein said control system reports an error to a remote site if said frequency detector has become de-tuned or inoperable.

60. The system of claim 41, wherein said frequency detector comprises a PLL circuit to detect said frequency signal and to generate a signal to said control system indicative of the locked condition of said frequency signal indicative of the proximity of the transportation vessel.

61. The system of claim 60, wherein said PILL circuit comprises:

a converter to receive said frequency signal;

a phase and frequency comparator to receive an output signal from said converter; and

a filter and VCO that receives an output signal from said phase and frequency comparator indicative of the difference in phase between said frequency signal and said VCO;

said VCO generates an output signal that is fed back into said phase and frequency comparator.

62. The system of claim 41, wherein said electronic device is comprised from the group consisting of a cellular phone, a PDA, a laptop computer, and a shipping container.

63. A method of verifying that a frequency detector used to detect the proximity of a transportation vessel is operational, comprising the steps of:

detecting a frequency signal indicative of the proximity of the transportation vessel using a frequency detector;

reducing power in a tracking device based on the detected frequency signal, the tracking device being configured to receive positioning information over a communications link;

generating a second signal at substantially the same frequency as said frequency signal; and

verifying that said frequency detector is operating properly by determining if said frequency detector detected said second signal.

64. The method of claim 63, further comprising determining if said frequency signal is above a threshold value in order to determine the proximity of the transportation vessel.

65. The method of claim 64, further comprising filtering said frequency signal to eliminate any noise in said frequency signal.

66. The method of claims 65, further comprising communicating information to a remote site indicative of the proximity of the transportation vessel.

67. The method of claim 63, wherein said generating a second signal further comprises generating a band of second signals to determine if said frequency detector has become de-tuned or inoperable.

68. The method of claim 64, wherein said generating a second signal further comprises generating a band of second signals to determine if said frequency detector has become de-tuned or inoperable and further comprising adjusting said threshold value if said frequency detector has become de-tuned or inoperable.

69. The method of claim 63, wherein said detecting further comprises determining if said frequency signal is in a locked condition.

70. A method of verifying that a frequency detector used to detect proximity to an intrinsically-safe area, comprising the steps of:

detecting a frequency signal indicative of the proximity of the intrinsically-safe area using a frequency detector;

reducing power in a tracking device based on the received frequency signal;

generating a second signal at substantially the same frequency as said frequency signal; and

verifying that said frequency detector is operating properly by determining if said frequency detector detected said second signal.

71. The method of claim 70, further comprising determining if said frequency signal is above a threshold value in order to determine the proximity of the transportation vessel.

72. The method of claim 71, further comprising filtering said frequency signal to eliminate any noise in said frequency signal.

73. The method of claim 72, further comprising communicating information to a remote site indicative of the intrinsically-safe area.

74. The method of claim 70, wherein said generating a second signal further comprises generating a band of second signals to determine if said frequency detector has become de-tuned or inoperable.

75. The method of claim 71, wherein said generating a second signal further comprises generating a band of second signals to determine if said frequency detector has become de-tuned or inoperable and further comprising adjusting said threshold value if said frequency detector has become de-tuned or inoperable.

76. The method of claim 70, wherein said detecting further comprises determining if said frequency signal is in a locked condition.