Abnormality detection apparatus and abnormality detection method

• US 5,859,590 A
• Filed: 09/19/1997
• Issued: 01/12/1999
• Est. Priority Date: 05/08/1996
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Otani, Hiroshi
• Primary Examiner(s): Wu, Daniel J.
• Application Number:
  US08/913,629
• Time in Patent Office: 480 Days
• Field of Search: 340/635, 340/540, 340/657, 340/659, 324/520, 324/521, 324/536, 324/544, 324/545, 324/546, 324/547, 324/551, 361/113, 361/115
• US Class Current: 340/635
• CPC Class Codes: H02H 1/0015 Using arc detectors
• CPC Class Codes: H02H 5/005 responsive to ionising radiation; Nuclear-radiation circumvention circuits radiation detectors G01T; nuclear-explosion detection G21J5/00

Abstract

A fault sensor device comprising a receiver (3; 3A; 3B) for receiving microwaves (2, 8) radiated from an object to be monitored (1; 1A; 1B; 1C; 1D; 1E; 1F), a detector (4) connected to the receiver (3; 3A; 3B) for converting and outputting the microwaves (2, 8) into a video signal (2S4; 2S21), and a signal processor (5) for converting the video signal (2S4, 2S21) output by the detector (4) into a presentation signal (2S5) and outputting the presentation signal (2S5) to an external presentation device (91; 91A), and for determining whether or not the microwaves (2, 8) received are associated with a fault, based on one of the duration and the frequency of the video signal (2S4; 2S21) and the level of the video signal, and for issuing an alarm signal (2S6) when the determination reveals that the microwaves are associated with the fault.

Claims

1. A fault sensor device comprising

receiver means for receiving microwaves radiated from an object to be monitored;

detector means connected to said receiver means for converting components of the microwaves into a video signal; and

signal processor means for converting the video signal output by said detector means into a presentation signal and outputting the presentation signal to an external presentation device, and for determining whether or not the microwaves radiated are associated with a fault, based on one of the duration and the frequency of the video signal and the level of the video signal, and for issuing an alarm signal when the determination reveals that the microwaves are associated with the fault.

2. The fault sensor device according to claim 1, wherein said receiver means comprises:

an antenna for receiving the microwaves;

a bandpass filter connected to said antenna for picking up and outputting components of a predetermined frequency band from the microwaves; and

a limiter connected to said bandpass filter for limiting the components of the predetermined frequency band to a predetermined level and outputting the limited components to the detector means.

3. The fault sensor device according to claim 1, wherein said receiver means comprises:

an antenna for receiving the microwave;

a bandpass filter connected to said antenna for picking up and outputting components of a predetermined frequency band from the microwaves, and

an attenuator connected to said bandpass filter for attenuating the components of the predetermined frequency band below a predetermined level without altering the variation of the components of the predetermined frequency band over time and outputting the attenuated components to the detector means.

4. The fault sensor device according to claim 1, wherein said receiver means comprises:

an antenna for receiving the microwaves; and

a bandpass filter connected to said antenna for picking up and outputting the components of a predetermined frequency band from the microwaves.

5. The fault sensor device according to claim 1, wherein the object to be monitored radiates microwaves when the object is at a predetermined step in normal operation or is at fault, said predetermined step being initiated by an external start signal, and

said fault sensor device further comprises a first lock means connected to said signal processor means for disabling the output of the alarm signal from the signal processor means for a predetermined period of time from the moment the start signal is entered.

6. The fault sensor device according to claim 1 further comprising memory means connected to said signal processor means for storing the process results of the signal processor means.

7. The fault sensor device according to claim 1 further comprising amplifier means connected between the receiver means and the detector means for amplifying the components of the microwave received from the receiver means.

8. The fault sensor device according to claim 1, wherein the object to be monitored radiates the microwaves when the object is at a predetermined step in normal operation or is at fault, said predetermined step being initiated by an external start signal;

and

said fault sensor device further comprising a second lock means connected between the output side of said receiver means and a ground terminal for grounding the signal output by said receiver means to prohibit the signal by the receiver means from entering said detector means for a predetermined period of time from the moment the start signal is entered.

9. The fault sensor device according to claim 1, wherein said receiver means is mounted a predetermined distance apart from the object to be monitored, and said receiver means receives the microwave that is radiated from the object to be monitored and arrives after being transmitted through the atmosphere.

10. The fault sensor device according to claim 9, wherein a plurality of said receiver means are provided, and said receiver means are shifted to scan the object to be monitored.

11. The fault sensor device according to claim 10 further comprising phase-adjusting means connected between said plurality of receiver means and said detector means for shifting the phase of the microwaves from the receiver means by a predetermined angle and for outputting the phase shifted signal.

12. The fault sensor device according to claim 1, wherein the object to be monitored has a shield covering for shielding the object from external electromagnetic waves, a window being formed in the shield covering to allow microwaves to be transmitted therethrough, with said receiver means being mounted on the window, said receiver means receiving the microwaves generated within the shield covering.

13. The fault sensor device according to claim 1, wherein the object to be monitored has a shield covering for shielding the object from external electromagnetic waves, partitioning means through which the microwave is transmitted being provided in the shield covering, the partitioning means dividing the interior of the shield covering into a plurality of partitions, a window through which the microwaves are transmitted being provided in each of the partitions in the shield covering, with said receiver means being provided on each of the windows, whereby the microwaves generated in a partition in the shield covering are received by said receiver means mounted on the corresponding partition and the microwaves coming into a neighboring partition next to the partition after being transmitted through the partitioning means are received by said receiver means mounted on the neighboring partition.

14. A fault sensing method comprising:

a receiving step of receiving the microwaves radiated from an object to be monitored;

a detecting step of converting components of the microwaves into a video signal;

a presentation signal output step of converting the video signal into a presentation signal and outputting the presentation signal to an external presentation device; and

an alarm signal generating step of determining whether or not the microwaves radiated are associated with a fault, based on one of the duration and the frequency of the video signal and the level of the video signal, and for issuing an alarm signal when the determination reveals that the microwaves are associated with the fault.