JPH04115176A - Monitor - Google Patents

Abstract

PURPOSE:To fully monitor all area to be monitored by a simple device by radiating an electromagnetic wave to the region to be monitored, surrounded by a material for reflecting the wave, and generating a space distribution of electromagnetic wave power in the region. CONSTITUTION:Since an electromagnetic wave oscillated by an oscillator 1 is emitted 4 to an area 10 to be monitored, reflected by a wall 6, a door 7, etc., and reflected on stands 8a, 8b, 8c to be repeated, a standing wave is generated in the region 10, and a space distribution of electromagnetic wave power in the area is determined according to the position of a structure to become a constant value in a timing manner. When the door 7 is opened or a person enters the inside, the reflecting position of the wave in the area 10 is varied, a space distribution of the wave power is altered, an electromagnetic wave power to be detected by a receiver 5 is varied thereby, and hence the variation in the space distribution can be detected. Accordingly, the entire area 10 to be monitored of a wide range can be fully monitored by a simple device structure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for detecting abnormalities due to changes in conditions within a monitoring area.

[Conventional technology]

Conventional monitoring devices utilize the large attenuation of power when electromagnetic waves propagate through steam as a method for detecting steam leaks from boilers, as described in Japanese Patent Application Laid-Open No. 63-269032. There is.

That is, electromagnetic waves are emitted toward locations where steam leaks may occur, and the reflected wave power of the electromagnetic waves reflected by the boiler is measured. This is a steam leak monitoring device that determines that there is a steam leak when the reflected power is smaller than normal.

Another conventional example is JP-A-63-291190. This conventional example also has the same basic configuration as the above-mentioned conventional example, and has a structure in which only a limited path between an electromagnetic wave emitter and a receiver is monitored.

[Problem to be solved by the invention]

Each of the above-mentioned conventional technologies utilizes the property that electromagnetic waves are highly straight-travel waves, and are monitoring devices that apply radar technology. A monitoring device using radar technology cannot, in principle, monitor an area where it cannot see through the antenna that transmits and receives electromagnetic waves, so there are places within the monitoring area that cannot be monitored. Therefore, in order to monitor the entire area, it is necessary to provide a plurality of monitoring devices and complement each other's monitoring areas, which poses a problem that the system configuration of the monitoring device that covers the entire area becomes complicated. That is, in the conventional device, no consideration was given to simplifying the device configuration, and it was not possible to cover the entire monitoring area with a simple device configuration.

An object of the present invention is to provide a monitoring device that can thoroughly monitor a wide range of monitoring areas with a simple device configuration.

[Means to solve the problem]

To achieve the above object, electromagnetic waves are radiated into a monitoring area surrounded by a material that reflects electromagnetic waves, thereby creating a spatial distribution of electromagnetic wave power within the monitoring area.

Since the spatial distribution of power depends on the arrangement of structures within the monitoring area, the spatial distribution of electromagnetic power includes information on the arrangement of all structures within the monitoring area. Therefore, the spatial distribution of electromagnetic wave power is measured, and changes in the arrangement of structures within the monitoring area can be detected from changes in the spatial distribution.

That is, the present invention includes an oscillator that oscillates electromagnetic waves, a radiator that radiates oscillation power from the oscillator to a monitoring area, a receiver that measures electromagnetic wave power within the monitoring area, and a signal that is received from the receiver. In the monitoring device, the monitoring area consists of a closed space, all the members partitioning the closed space are made of a material that reflects electromagnetic waves, and the receiver detects the spatial distribution of electromagnetic wave power in the monitoring area. , and the detection unit is configured to detect a change in state within the monitoring area from a change in the spatial distribution.

The present invention also provides an oscillator that oscillates electromagnetic waves, a radiator that radiates oscillation power from the oscillator to a monitoring area, a receiver that measures electromagnetic wave power within the monitoring area, and a receiver that receives signals from the receiver. A monitoring device comprising: a detection unit that processes electromagnetic waves from a radiator into a monitoring area; the receiver measures and detects the spatial distribution of electromagnetic wave power that is generated as a result of multiple reflections within the monitoring area; The monitor is characterized in that it is configured to detect a change in the state within the monitoring area from a change in the spatial distribution.

In the monitoring device, instead of all the members partitioning the closed space being made of a material that reflects electromagnetic waves, some of the members partitioning the closed space may be made of a material that does not reflect electromagnetic waves. Further, instead of the monitoring area being a closed space, a part of the monitoring area may be a partially open space connected to the outside.

Further, in the monitoring device, it is preferable that the oscillation frequency of the electromagnetic waves to be oscillated can be set to a frequency that is largely absorbed by a specific object to be detected. Further, the oscillated electromagnetic waves are preferably formed so as to be able to combine frequencies with high absorption by a specific detection target and frequencies with low absorption.

Further, in the monitoring device, it is preferable that the monitoring area consists of a plurality of small chambers that communicate with each other, and that a receiver is disposed in each small chamber. Further, it is preferable that the monitoring area consists of a plurality of small rooms communicating with each other, and a television camera is installed in each small room.

Furthermore, a moving object such as a rotating body or a piston may be disposed within the monitoring area.

[Effect]

The electromagnetic waves radiated into the monitoring area are repeatedly reflected, thereby generating standing waves within the area.

This standing wave has the property that the spatial distribution of electromagnetic wave power within an area is determined by the position of structures within the area. Additionally, a detector will be installed within the area to measure the electromagnetic power, and the spatial distribution of electromagnetic power will be measured. If the arrangement of structures within the monitoring area changes, the spatial distribution of electromagnetic wave power will change, and therefore the power of the electromagnetic waves to be measured will also change. That is, if the arrangement of any structure within the monitoring area changes, the electromagnetic wave power detected by the detector will change. Therefore, even if a structure is out of line of sight to the radiator/receiver, the output of the detector changes. Therefore, we monitor the output of the detector and
By detecting a time change in the detector output, it is possible to detect an abnormality wherever it occurs within the monitoring area.

If a member that absorbs electromagnetic waves is included in a part of the closed space that partitions the monitoring area, the part of the absorbing member cannot be monitored, but a spatial distribution of electromagnetic wave power is formed based on other parts. It becomes possible to monitor that part. This also applies to the case where a part of the monitoring area is a partially open space that extends outside.

By oscillating electromagnetic waves with a frequency that is largely absorbed by a certain object to be detected, it is possible to monitor whether or not that object has entered the monitoring area.

If a large monitoring area is divided into small rooms and a receiver is provided for each small room, it is possible to identify that a state change has occurred in the small room where the receiver that detected the large state change is located. Alternatively, by placing a television camera in each small room, it is possible to visually grasp changes in the state of each small room.

Even if there is a non-static moving object such as a rotating body or a piston within the monitoring area, a change in state can be detected in the same way because a spatial distribution of electromagnetic wave power is formed based on the presence of the moving object.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1st
The illustrated embodiment is a building intruder monitoring device. If the outer wall or door of a building is made of a material that reflects electromagnetic waves, the entire interior of the building can be used as a surveillance area. Electromagnetic waves oscillated by an oscillator 1 are radiated from a radiator 4 to a monitoring area 10.

Further, in order to measure the electromagnetic wave power within the monitoring area 10, a receiver 5 is fixedly installed, and the received electromagnetic wave power is detected by the detector 2.

The electromagnetic waves radiated into the monitoring area 10 are reflected by the walls 6, doors 7, etc., and are also reflected by the screens 8a,
It is reflected by 8b and 8c. Therefore, standing waves are generated within the monitoring area 10, and the detected electromagnetic wave power has a constant value over time. However.

For example, when the door 7 that borders the monitoring area 10 is opened or a person enters the monitoring area 10, the reflection position of electromagnetic waves within the monitoring area 10 changes. As a result, the spatial distribution of electromagnetic wave power within the region 10 changes, and the electromagnetic wave power detected by the fixedly installed receiver 5 also changes. Therefore, even if the spatial distribution of power is not measured, changes in the spatial distribution can be detected using only one detector 2. The detection unit 3 is a signal processing unit that determines that the arrangement of structures within the monitoring area 10 has changed in response to a temporal change in the output of the detector 2.

Further, in this embodiment, since it is sufficient to detect variations in the spatial distribution of electromagnetic wave intensity, abnormalities within the monitoring area 10 can be detected even when electromagnetic waves are emitted in a pulsed manner.

Since the spatial distribution of electromagnetic wave power depends on the arrangement of structures within the monitoring area 10, even if the arrangement of structures outside the line of sight changes from where the radiator 4 and receiver 5 are installed, The spatial distribution of power changes. Therefore, by using the present invention, it is possible to detect all abnormalities within the monitoring area 10 with one detector 2.

The configuration of the signal processing section for detecting an abnormality will be explained with reference to FIG. FIG. 2 shows an embodiment of the detection unit in the embodiment shown in FIG. 1 in which the oscillator 1 is caused to oscillate in a pulsed manner to detect an abnormality. Oscillation'! by the timing signal 14a sent from the control section 9! +1 oscillates and radiates electromagnetic power to the monitoring area 10. On the other hand, in order to measure the electromagnetic wave power within the monitoring area 10, the output of the detector 2 is sampled by the sampler 11 using a timing signal 14b synchronized with the oscillation pulse of the oscillator 1. The sampled electromagnetic wave power signal 15 is transmitted to the difference section 12, and the difference between it and the previous electromagnetic wave power intensity is determined.

Further, the obtained power difference signal 16 is sent to the determination section 13. The determination unit 13 determines that the detected power is normal if there is no time change, and that an abnormality has occurred within the monitoring area 10 if a time change occurs. According to this embodiment, even if the oscillator 11 oscillates in a pulsed manner, it can be detected in the same way as an oscillator that oscillates continuously.

In addition, in FIG. 1, if only the screen 8b is made of electromagnetic wave absorbing material, or if a part of the wall on which the screen 8b is installed is open, those parts cannot be monitored. Become. but.

Since a spatial distribution of electromagnetic wave power is generated based on other parts, it is possible to monitor the presence or absence of a state change from the change. Furthermore, even if there is a drive structure such as a motor in the monitoring area 10, that is, if there is a dynamic state object, a spatial distribution of electromagnetic wave power will occur based on the existence of such a structure, so changes in state cannot be monitored in the same way. can do.

An embodiment in which the present invention is applied to a steam leak monitoring device will be described with reference to FIG.

This embodiment is a monitoring device that uses two electromagnetic waves having different frequencies, and the two frequencies are designated fa and fb, respectively. As for the frequencies to be used, the frequency fa is selected to be a frequency at which the absorption of electromagnetic wave power by steam is large, and the frequency fb is selected to be a frequency at which absorption of electromagnetic wave power by steam is small. An example of the frequency to be selected is explained in the 4th @ (rPrinc
iple and ap-plication of
Quoted from LIMETER JAVE RADAR, PP9J). FIG. 4 is a diagram showing the attenuation rate with respect to the frequency of the electromagnetic wave, and the vertical axis shows the rate at which the 1b electromagnetic wave attenuates as it travels. In Figure 4, the frequency is 22GHz,
This shows that there is an absorption band due to water at 170 GHz. That is, fa is set to 170 GHz, and fb is set to another frequency, for example, 90 GHz.

If such a frequency band is selected, for electromagnetic waves with frequency fa, steam can be considered a foreign substance, so the spatial distribution of electromagnetic wave power will change, but with electromagnetic waves of frequency fb, steam is transparent, and the spatial distribution of electromagnetic wave power will change. do not.

Two oscillators la and l whose oscillation frequencies are fa and fb
b is oscillated in a pulsed manner by the timing signals 14a and 14b, and after adding the electromagnetic wave powers oscillated by the two oscillators 1a and 1b in an adder 17, it is radiated to the monitoring area 10. The power of the radiated electromagnetic wave is determined by sampling the output of the detector 2 to obtain the electromagnetic wave power for each frequency, and after determining the time variation for each frequency in the difference section 12, the power is sent to the judgment section 13.

The determining unit 13 detects an abnormality within the monitoring area 10 based on the temporal fluctuation of the output of the detector 2 for each frequency.

The detection method is that if there is a change in the electromagnetic wave power relative to fa, and there is no change in the electromagnetic wave power relative to fa, the abnormality within the monitoring area 10 is determined to be a steam leak, and the fa
, fb, if the electromagnetic wave power changes, it is determined that the object is moving. This is because, as described above, vapor can be regarded as a foreign substance to fa, but can be regarded as transparent to -fb.

According to this example, a plurality of frequencies are used, one is selected as the electromagnetic wave absorption band of the gas to be detected, and the other is selected as a frequency band that is significantly deviated from the absorption band. This has the effect of identifying the type of gas.

An embodiment of the intruder monitoring device for a building in which the building is divided into a plurality of small rooms will be described with reference to FIG. Electromagnetic wave power oscillated by the oscillator 1 in response to a timing signal from the control unit 9 is radiated into the monitoring area 10 . Electromagnetic waves have standing waves in each small room. Furthermore, when considering the entire monitoring area 10, a small room can be considered to be equivalent to a configuration in which small monitoring areas 1o are connected in series and parallel. Therefore, electromagnetic wave power has a spatial distribution for each small room, and one small room influences the spatial distribution of electromagnetic wave power in other connected small rooms.

The electromagnetic wave power is measured by the receiving section 58 installed in each small room.
5g and detectors 2a to 2g connected to this receiver,
Detects each small room and detects abnormalities. The detection method is the second
Abnormalities are detected using the same method as in the embodiment described in the figures.

In this case, if an abnormality occurs in any of the small rooms, the electromagnetic wave power distribution of that small room changes, and the electromagnetic wave power distribution of the adjacent small room also changes, and the power distribution of the entire monitoring area 10 also changes.

Therefore, since the output value of the detector 2 changes over time, even in a building divided into small rooms, the output value of all the detectors 2 changes over time, making it difficult to detect abnormalities. can. On the other hand, the degree of change in electromagnetic wave power is greatest at the detector 2 in the small room where the abnormality has occurred. This is because the power distribution of each small room influences the neighboring small rooms, so the closer the abnormality is to the room where the abnormality occurs, the greater the influence. From this, detector 2
It can be seen that an abnormality has occurred in a small room with a large temporal change, and the location of the abnormality can be identified.

According to this embodiment, when monitoring intruders in a building divided into multiple rooms, it is possible to monitor the entire building simply by emitting electromagnetic waves at one location and measuring power at one location. . Further, by installing the detector 2 in each small room and measuring the power distribution of electromagnetic waves in each small room, the location where an abnormality has occurred can be identified, which has the effect of simplifying the configuration of the monitoring device.

Another embodiment of the intruder monitoring device for a building divided into small rooms described in FIG. 5 will be described with reference to FIG. 6. Control unit 9
The electromagnetic wave power oscillated from the oscillator 11 according to the timing signal is radiated into the monitoring area 10. The measurement of electromagnetic wave power uses one receiving section 5 installed in a certain small room and a detector 2 connected to this receiving section. Furthermore, the detection section 3 is configured to perform signal processing similar to that of the embodiment described in FIG. As described in the embodiment explained in FIG. It is possible to detect the presence or absence of an abnormality that has occurred within 10 days. When an abnormality is detected, a signal is sent to the location identifying section 19, which drives the television camera 18 installed in each small room to identify the location of the abnormality. Since the abnormality has occurred in the image data obtained by the television camera 18 at a location where there is a difference from the image data obtained immediately before, the location can be easily identified and accurately detected.

According to this embodiment, the presence or absence of an abnormality is determined by measuring the temporal change in electromagnetic wave power, which has the effect of simplifying signal processing, and since it is performed using image data that identifies the location, the accuracy of location identification is improved. It has the effect of being good.

〔Effect of the invention〕

The present invention uses a phenomenon in which the spatial distribution of electromagnetic wave power radiated into a monitoring area depends on the position of structures existing within the monitoring area. Therefore, the temporal change in the spatial distribution of electromagnetic power can correspond to changes in the structure's position, foreign objects entering the structure, etc., so it is possible to detect various changes in the structure, such as the movement of the structure, and This has the effect of being able to detect the movement of even structures.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of an intruder monitoring device according to the present invention, FIG. 2 is a configuration diagram of an embodiment of a signal processing section showing the configuration of the detection section in FIG. 1, and FIG. 3 is an overall configuration diagram of one embodiment of the steam leak monitoring device according to the present invention, FIG. 4 is a diagram showing frequency dependence of electromagnetic wave absorption rate, and FIG. 5 is an overall configuration diagram of another embodiment of the intruder monitoring device. 6 are overall configuration diagrams of an embodiment of the intruder monitoring device combined with other systems. DESCRIPTION OF SYMBOLS 1... Oscillator, 2... Detector, 3... Detection part, 4...
...Radiator, 5...Receiver, 10...Monitoring area.

Claims (1)

[Claims] 1. An oscillator that oscillates electromagnetic waves, a radiator that radiates oscillation power from the oscillator to a monitoring area, a receiver that measures electromagnetic wave power within the monitoring area, and a signal from this receiver. In the monitoring device, the monitoring area consists of a closed space, all the members partitioning the closed space are made of materials that reflect electromagnetic waves, and the receiver detects the electromagnetic wave power in the monitoring area. A monitoring device that measures a spatial distribution, and a detection unit is configured to detect a change in state within a monitoring area from a change in the spatial distribution. 2. An oscillator that oscillates electromagnetic waves, a radiator that radiates the oscillated power from the oscillator to a monitoring area, a receiver that measures the electromagnetic wave power within the monitoring area, and a detector that receives and processes signals from this receiver. In the monitoring device, the receiver measures the spatial distribution of electromagnetic wave power generated as a result of multiple reflections of the electromagnetic waves emitted from the radiator into the monitoring area within the monitoring area, and the sensing unit measures the spatial distribution of the electromagnetic wave power in the monitoring area. A monitoring device characterized in that it is configured to detect a change in state within a monitoring area from a change in distribution. 3. The monitoring device according to claim 1, wherein instead of all the members partitioning the closed space being made of a material that reflects electromagnetic waves, some of the members partitioning the closed space are made of a material that does not reflect electromagnetic waves. . 4. The monitoring device according to claim 1 or 3, wherein instead of the monitoring area being a closed space, a part of the monitoring area is a partially open space connected to the outside. 5. The monitoring device according to any one of claims 1 to 4, wherein the oscillation frequency of the oscillated electromagnetic waves can be set to a frequency at which absorption by a specific detection object is large. 6. The monitoring device according to any one of claims 1 to 4, wherein the oscillated electromagnetic waves are configured to be able to combine frequencies that are more absorbed by a specific detection object and those that are less absorbed. 7. The monitoring device according to any one of claims 1 to 6, wherein the monitoring area is made up of a plurality of small chambers that are communicated with each other, and a receiver is disposed in each small chamber. 8. The monitoring device according to any one of claims 1 to 6, wherein the monitoring area consists of a plurality of small rooms that communicate with each other, and a television camera is installed in each small room. 9. The monitoring device according to any one of claims 1 to 6, wherein a moving object is disposed within the monitoring area.