Intrusion-object detection system, method of detecting intrusion-object and method of detecting malfunction

• US 7,994,912 B2
• Filed: 01/12/2006
• Issued: 08/09/2011
• Est. Priority Date: 01/12/2006
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Aizawa, Syuji, Miyake, Noriyuki, Hirai, Takashi, Inomata, Kenji
• Primary Examiner(s): TWEEL JR, JOHN ALEXANDER
• Application Number:
  US12/160,380
• Publication Number:
  US 20100238029A1
• Time in Patent Office: 2,035 Days
• Field of Search: 340552-554, 340/561, 340/565, 340/567, 340/568.2, 340/540, 340/541, 340/545.3, 342/7, 342/8, 342/27, 342/28
• US Class Current: 340/552
• CPC Class Codes: G08B 13/2497 using transmission lines, e.g. cable
• CPC Class Codes: G08B 29/26 by updating and storing reference thresholds

Abstract

A method determining a malfunction when a reception signal fluctuates at a receiver owing to malfunctions occurring on a leaky cable and its related devices. The method determines, among range bins correlating the reception signal with a distance from a feed end of a radio-wave radiation unit and a radio-wave reception unit, based on a correlation between a time-delay from a transmission time of a transmission signal until a reception time of the reception signal and a transmission path distance of the reception signal in the radio-wave radiation unit and the radio-wave reception unit, when, comparing the reception signal with the transmission signal with respect to the range bin corresponding to a far end, a level of amplitude reduction in the reception signal exceeds a predetermined ratio, that a malfunction is present in either the radio-wave radiation unit or radio-wave reception unit.

Claims

1. An intrusion-object detection system, comprising:

a radio-wave radiation unit, in a cable form with one end thereof as a feed end and the other end thereof as a far end, configured to radiate as a radio wave, a transmission signal on which a spread spectrum signal is superimposed fed into said radio-wave radiation unit from the feed end;

a radio-wave reception unit configured to receive the radio wave, in a cable form, placed approximately in parallel with said radio-wave radiation unit;

a signal reception unit configured to receive the transmission signal as a reception signal, connected to an end, on the feed-end side, of said radio-wave reception unit;

a signal demodulation unit configured to define the reception signal so as to calculate the amplitude of the reception signal with respect to range bins each correlated with a distance from a position of the feed end, on said radio-wave radiation unit and said radio-wave reception unit, based on a correlation between a time-delay from transmission time of the transmission signal until reception time of the reception signal and the distance along a transmission path according to route'"'"'s positions on said radio-wave radiation unit and said radio-wave reception unit in the transmission path through which the transmission signal passes after its transmission until reception as the reception signal, by comparing a code sequence of a spread spectrum signal extracted from the reception signal with a code sequence of a spread spectrum signal in the transmission signal; and

a malfunction distinguishing unit configured to determine that a malfunction is present in either said radio-wave radiation unit or said radio-wave reception unit, when, comparing the reception signal with the transmission signal for the range bins corresponding to the far end, a level of amplitude reduction in the reception signal exceeds a predetermined ratio.

2. An intrusion-object detection system, comprising:

a radio-wave radiation unit, in a cable form with one end thereof as a feed end, configured to radiate as a radio wave, a transmission signal on which a spread spectrum signal is superimposed being fed into said radio-wave radiation unit from the feed end;

a radio-wave reception unit configured to receive the radio wave, in a cable form, placed approximately in parallel with said radio-wave radiation unit;

a signal reception unit configured to receive the transmission signal as a reception signal, connected to an end, on the feed-end side, of said radio-wave reception unit;

a signal demodulation unit configured to define the reception signal so as to calculate the amplitude of the reception signal with respect to range bins each correlated with a distance from a position of the feed end, on said radio-wave radiation unit and said radio-wave reception unit, based on a correlation between a time-delay from transmission time of the transmission signal until reception time of the reception signal and the distance along a transmission path according to route'"'"'s positions on said radio-wave radiation unit and said radio-wave reception unit in the transmission path through which the transmission signal passes after its transmission until reception as the reception signal, by comparing a code sequence of a spread spectrum signal extracted from the reception signal with a code sequence of a spread spectrum signal in the transmission signal; and

a malfunction-range measurement unit configured to determine, by determining, with respect to each of the range bins, a level of amplitude reduction in the reception signal compared with the transmission signal, and by detecting, out of the range bins in which the level of amplitude reduction exceeds a predetermined ratio, a range bin that corresponds to the nearest position to the feed end, that a malfunction is present in a position corresponding to said range bin related to either said radio-wave radiation unit or said radio-wave reception unit.

3. An intrusion-object detection system, comprising:

a radio-wave radiation unit, in a cable form with one end thereof as a feed end, configured to radiate as a radio wave, a transmission signal on which a spread spectrum signal is superimposed being fed into said radio-wave radiation unit from the feed end;

a radio-wave reception unit configured to receive the radio wave, in a cable form, placed approximately in parallel with said radio-wave radiation unit;

a signal reception unit configured to receive the transmission signal as a reception signal, connected to an end, on the feed-end side, of said radio-wave reception unit;

a signal demodulation unit configured to define the reception signal so as to calculate the amplitude of the reception signal with respect to range bins each correlated with a distance from a position of the feed end, on said radio-wave radiation unit and said radio-wave reception unit, based on a correlation between a time-delay from transmission time of the transmission signal until reception time of the reception signal and the distance along a transmission path according to route'"'"'s positions on said radio-wave radiation unit and said radio-wave reception unit in the transmission path through which the transmission signal passes after its transmission until reception as the reception signal, by comparing a code sequence of a spread spectrum signal extracted from the reception signal with a code sequence of a spread spectrum signal in the transmission signal; and

a breakage detection unit configured to determine, when there exists a range bin among the range bins in which the amplitude of the reception signal is increased in comparison to the transmission signal, that breakage is present in a position corresponding to said range bin related to either said radio-wave radiation unit or said radio-wave reception unit.

4. An intrusion-object detection system, comprising:

a radio-wave radiation unit, in a cable form with one end thereof as a feed end, configured to radiate as a radio wave, a transmission signal on which a spread spectrum signal is superimposed being fed into said radio-wave radiation unit from the feed end;

a signal reception unit configured to receive the transmission signal as a reception signal, connected to an end, on the feed-end side, of a radio-wave reception unit;

a signal demodulation unit configured to define the reception signal so as to calculate a quadrature-detection result by performing quadrature detection on the reception signal with respect to range bins each correlated with a distance from a position of the feed end, on said radio-wave radiation unit and said radio-wave reception unit, based on a correlation between a time-delay from transmission time of the transmission signal until reception time of the reception signal and the distance along a transmission path according to route'"'"'s positions on said radio-wave radiation unit and said radio-wave reception unit in the transmission path through which the transmission signal passes after its transmission until reception as the reception signal, by comparing a code sequence of a spread spectrum signal extracted from the reception signal with a code sequence of a spread spectrum signal in the transmission signal; and

a crack detection unit configured to determine, in a case in which a time-series distribution of the reception signal in a plane coordinated by I-components and Q-components of the quadrature-detection result of the reception signal is classified, when the distribution is classified into a plurality of classes and there exists a range bin among the range bins in which the location of the reception signal moves astride the plurality of classes as time passes, that a crack is present in a position corresponding to said range bin related to either said radio-wave radiation unit or said radio-wave reception unit.

5. An intrusion-object detection system, comprising:

a radio-wave radiation unit, in a cable form with one end thereof as a feed end, configured to radiate as a radio wave, a transmission signal on which a spread spectrum signal is superimposed being fed into said radio-wave radiation unit from the feed end;

a signal reception unit configured to receive the transmission signal as a reception signal, connected to an end, on the feed-end side, of a radio-wave reception unit;

a signal demodulation unit configured to define the reception signal so as to calculate a quadrature-detection result by performing quadrature detection on the reception signal with respect to range bins each correlated with a distance from a position of the feed end, on said radio-wave radiation unit and said radio-wave reception unit, based on a correlation between a time-delay from transmission time of the transmission signal until reception time of the reception signal and the distance along a transmission path according to route'"'"'s positions on said radio-wave radiation unit and said radio-wave reception unit in the transmission path through which the transmission signal passes after its transmission until reception as the reception signal, by comparing a code sequence of a spread spectrum signal extracted from the reception signal with a code sequence of a spread spectrum signal in the transmission signal; and

a crack immediate-report unit configured to determine, when there exists a range bin in which a larger eigenvalue in eigenvalues of a covariance matrix of I-components and Q-components of the quadrature-detection result of the reception signal is greater than a first predetermined value, and a smaller eigenvalue in the eigenvalues, less than a second predetermined value, that a crack is present in a position corresponding to said range bin related to either said radio-wave radiation unit or said radio-wave reception unit.

6. An intrusion-object detection system, comprising:

a radio-wave radiation unit, in a cable form with one end thereof as a feed end, configured to radiate as a radio wave, a transmission signal on which a spread spectrum signal is superimposed being fed into said radio-wave radiation unit from the feed end;

a signal reception unit configured to receive the transmission signal as a reception signal, connected to an end, on the feed-end side, of a radio-wave reception unit;

a signal demodulation unit configured to define the reception signal so as to calculate a quadrature-detection result by performing quadrature detection on the reception signal with respect to range bins each correlated with a distance from a position of the feed end, on said radio-wave radiation unit and said radio-wave reception unit, based on a correlation between a time-delay from transmission time of the transmission signal until reception time of the reception signal and the distance along a transmission path according to route'"'"'s positions on said radio-wave radiation unit and said radio-wave reception unit in the transmission path through which the transmission signal passes after its transmission until reception as the reception signal, by comparing a code sequence of a spread spectrum signal extracted from the reception signal with a code sequence of a spread spectrum signal in the transmission signal; and

an intrusion-object immediate-report unit configured to determine, when there exists range bin in which a larger eigenvalue in eigenvalues of a covariance matrix of I-components and Q-components of the quadrature-detection result of the reception signal is greater than a first predetermined value, and a smaller eigenvalue in the eigenvalues, greater than a second predetermined value, that an intrusion-object is present in a position corresponding to said range bin related to either said radio-wave radiation unit or said radio-wave reception unit.

7. An intrusion-object detection system, comprising:

a radio-wave radiation unit, in a cable form with one end thereof as a feed end and the other end thereof as a far end, configured to radiate as a radio wave, a transmission signal on which a spread spectrum signal is superimposed being fed into said radio-wave radiation unit from the feed end;

a radio-wave reception unit configured to receive the radio wave, in a cable form, placed approximately in parallel with said radio-wave radiation unit;

a terminator configured to absorb the radio wave, connected to the far end of either said radio-wave radiation unit or said radio-wave reception unit;

a reflector configured to reflect the radio wave connected to the far end of either said radio-wave radiation unit or said radio-wave reception unit to which said terminator is not connected;

a signal reception unit configured to receive the transmission signal as a reception signal, connected to an end, on the feed-end side, of said radio-wave reception unit;

a signal demodulation unit configured to define the reception signal so as to calculate the amplitude of the reception signal with respect to range bins each correlated with a distance from a position of the feed end, on said radio-wave radiation unit and said radio-wave reception unit, based on a correlation between a time-delay from transmission time of the transmission signal until reception time of the reception signal and the distance along a transmission path according to route'"'"'s positions on said radio-wave radiation unit and said radio-wave reception unit in the transmission path through which the transmission signal passes after its transmission until reception as the reception signal, by comparing a code sequence of a spread spectrum signal extracted from the reception signal with a code sequence of a spread spectrum signal in the transmission signal; and

a malfunction-information detection unit configured to determine that a malfunction is present in the unit to which said terminator is connected, out of said radio-wave radiation unit and said radio-wave reception unit, when the amplitude of the reception signal is larger than a predetermined value in the range bin corresponding to the far-end position.

8. An intrusion-object detection system, comprising:

a radio-wave radiation unit in a cable form with one end thereof as a feed end and the other end thereof as a far end, configured to radiate as a radio wave, a transmission signal on which a spread spectrum signal is superimposed being fed into said radio-wave radiation unit from the feed end;

a radio-wave reception unit configured to receive the radio wave, in a cable form, placed approximately in parallel with said radio-wave radiation unit;

a terminator configured to absorb the radio wave, connected to the far end of either said radio-wave radiation unit or said radio-wave reception unit;

a reflector configured to reflect the radio wave connected to the far end of either said radio-wave radiation unit or said radio-wave reception unit to which said terminator is not connected;

a signal reception unit configured to receive the transmission signal as a reception signal, connected to an end, on the feed-end side, of said radio-wave reception unit;

a signal demodulation unit configured to define the reception signal so as to calculate the amplitude of the reception signal with respect to range bins each correlated with a distance from a position of the feed end, on said radio-wave radiation unit and said radio-wave reception unit, based on a correlation between a time-delay from transmission time of the transmission signal until reception time of the reception signal and the distance along a transmission path according to route'"'"'s positions on said radio-wave radiation unit and said radio-wave reception unit in the transmission path through which the transmission signal passes after its transmission until reception as the reception signal, by comparing a code sequence of a spread spectrum signal extracted from the reception signal with a code sequence of a spread spectrum signal in the transmission signal; and

a malfunction-position detection unit configured to detect, when there exists a range bin, corresponding to a position on the opposite side of the feed end with respect to the far end, in which the amplitude of the reception signal is larger than a predetermined value, by obtaining the distance X from the position corresponding to said range bin to the far end, that a malfunction is present in the unit to which said terminator is connected, out of said radio-wave radiation unit and said radio-wave reception unit, and for defining a position of the malfunction based on the distance X and the length of said radio-wave radiation unit and said radio-wave reception unit.

9. An intrusion-object detection system, comprising:

a radio-wave radiation unit in a cable form with one end thereof as a feed end and the other end thereof as a far end, configured to radiate as a radio wave, a transmission signal on which a spread spectrum signal is superimposed being fed into said radio-wave radiation unit from the feed end;

a radio-wave reception unit configured to receive the radio wave, in a cable form, placed approximately in parallel with said radio-wave radiation unit;

a terminator configured to absorb the radio wave, provided for each of said radio-wave radiation unit and said radio-wave reception unit;

a reflector configured to reflect the radio wave, provided for each of said radio-wave radiation unit and said radio-wave reception unit;

a changeover unit provided for each of said radio-wave radiation unit and said radio-wave reception unit, configured to select either said terminator or said reflector, to connect the same to said corresponding radio-wave radiation unit and radio-wave reception unit each;

a signal reception unit configured to receive the transmission signal as a reception signal, connected to an end, on the feed-end side, of said radio-wave reception unit;

a signal demodulation unit configured to define the reception signal so as to calculate the amplitude of the reception signal with respect to range bins each correlated with a distance from a position of the feed end, on said radio-wave radiation unit and said radio-wave reception unit, based on a correlation between a time-delay from transmission time of the transmission signal until reception time of the reception signal and the distance along a transmission path according to route'"'"'s positions on said radio-wave radiation unit and said radio-wave reception unit in the transmission path through which the transmission signal passes after its transmission until reception as the reception signal, by comparing a code sequence of a spread spectrum signal extracted from the reception signal with a code sequence of a spread spectrum signal in the transmission signal; and

a malfunction-information detection unit configured to determine that a malfunction is present in the unit to which said terminator is connected, out of said radio-wave radiation unit and said radio-wave reception unit, when the amplitude of the reception signal is larger than a predetermined value in the range bin corresponding to the far-end position.

10. An intrusion-object detection system, comprising:

a radio-wave radiation unit in a cable form with one end thereof as a feed end and the other end thereof as a far end, configured to radiate as a radio wave, a transmission signal on which a spread spectrum signal is superimposed being fed into said radio-wave radiation unit from the feed end;

a radio-wave reception unit configured to receive the radio wave, in a cable form, placed approximately in parallel with said radio-wave radiation unit;

a terminator configured to absorb the radio wave, provided for each of said radio-wave radiation unit and said radio-wave reception unit;

a reflector configured to reflect the radio wave, provided for each of said radio-wave radiation unit and said radio-wave reception unit;

a changeover unit provided for each of said radio-wave radiation unit and said radio-wave reception unit, configured to select either said terminator or said reflector, to connect the same to said corresponding radio-wave radiation unit and radio-wave reception unit each;

a signal reception unit configured to receive the transmission signal as a reception signal, connected to an end, on the feed-end side, of said radio-wave reception unit;

a signal demodulation unit configured to define the reception signal so as to calculate the amplitude of the reception signal with respect to range bins each correlated with a distance from a position of the feed end, on said radio-wave radiation unit and said radio-wave reception unit, based on a correlation between a time-delay from transmission time of the transmission signal until reception time of the reception signal and the distance along a transmission path according to route'"'"'s positions on said radio-wave radiation unit and said radio-wave reception unit in the transmission path through which the transmission signal passes after its transmission until reception as the reception signal, by comparing a code sequence of a spread spectrum signal extracted from the reception signal with a code sequence of a spread spectrum signal in the transmission signal; and

a malfunction-position detection unit configured to determine, when there exists a range bin, corresponding to a position on the opposite side of the feed end with respect to the far end, in which the amplitude of the reception signal is larger than a predetermined value, by obtaining the distance X from the position corresponding to said range bin to the far end, that a malfunction is present in the unit to which said terminator is connected, out of said radio-wave radiation unit and said radio-wave reception unit, and for defining a position of the malfunction based on the distance X and the length of said radio-wave radiation unit and said radio-wave reception unit.