JPH0347475B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an intrusion monitoring device for monitoring illegal intruders entering a building or the like.

[Prior art]

2. Description of the Related Art Generally, various security devices are used in buildings with safes and computer rooms, as well as power generation and substations and various plant facilities, to detect and notify illegal intruders.

Conventionally, as an intrusion monitoring device used in such a security device, there has been one in which, for example, a plurality of sets of optical intrusion sensors each consisting of a light projector and a light receiver are arranged along a specific area. Each of these intrusion sensors is configured to detect intrusion based on the interruption of a light beam exchanged between a light projector and a light receiver.

In this case, since the emitter and receiver are usually installed outdoors, the light beam is attenuated during snowfall, rain, fog, or when snow or dust adheres to the glass surfaces of the emitter and receiver. As a result, this was sometimes detected as an intrusion and a false alarm was issued even though there was actually no intruder. In response to such false alarms, officials had to rush to the site each time to confirm the intrusion or take measures equivalent to an actual intrusion.

This is true not only for optical intrusion sensors consisting of a light emitter and receiver, but also for ultrasonic intrusion sensors that transmit and receive ultrasonic waves, microwave intrusion sensors that transmit and receive microwaves, etc. In other words, this is a common drawback of intrusion monitoring devices that monitor intruders based on receiver signals generated by the interruptions and interruptions of energy waves.

[Summary of the invention]

The present invention has been made for the purpose of eliminating the above-mentioned drawbacks, and among the plurality of transmitter and receiver sets described above, the plurality of transmitter and receiver sets are affected by the same effect when rain or snow falls from a certain direction. energy level detection means for detecting that the amount of energy reaching each receiver has attenuated below a predetermined level, and based on the output signals of these energy level detection means, We propose an intrusion monitoring device that is equipped with a monitoring operation prohibition means that prohibits intrusion monitoring operations only for groups that include receivers that have attenuated below the level, thereby preventing false alarms and significantly reducing the burden on the monitoring staff. It is something to do.

[Embodiments of the invention]

Hereinafter, the arrangement relationship of a plurality of sets of transmitters and receivers, and the circuit configuration of each means, which are prerequisites for achieving the above object, will be explained with reference to the drawings.

FIG. 1 is a schematic diagram showing the arrangement of the emitter and receiver. The emitter and receiver are mounted at the intersections of two sides of a virtual rectangular prism surrounding an important area 10 with a building 20 in the center. cylinder body 11-1
4 are installed.

These light emitters and light receivers form pairs with those mounted on adjacent cylindrical bodies, and transmit and receive light beams L1 to L4, respectively, through the side surfaces of the virtual rectangular prism. In this case, the light beam L1 of the projector T1 mounted on the cylinder 11 is received by the light receiver R1 mounted on the cylinder 12, and similarly,
Light beam of floodlight Tn attached to n (n=2.3.4)
In is received by a light receiver Rn attached to a cylinder {1(n+1)} (n=2.3.0).

Here, the outer shapes of the cylindrical bodies 11 to 14 are equal to each other. For example, the cylindrical body 11 is fixed to a base 11a as shown in FIG. The light beam L1 reaches the light receiver R1 of the cylinder 12 through this glass window W1. Note that a light receiver R4 is also attached to this cylindrical body 11 and receives the light beam L4 through another glass window similar to the glass window W1, but these light receivers and the glass window are omitted.

Thus, the critical area 10 is exposed to light beams L1-L4.
If there is an intruder into this critical area 10, the light beam at at least one location will be cut off, so intrusion monitoring can be performed by detecting the signal level of the receivers R1 to R4. is becoming possible.

On the other hand, in response to false alarms that occur during snowfall, rain, fog, or when snow or dust adheres to the glass window of the cylindrical body, this intrusion monitoring device uses receivers R1 to R1 to A predetermined number of comparators 4a to 4d for detecting that the optical energy reaching R4 has attenuated below a predetermined level, and a predetermined number of receivers in which the optical energy has attenuated below a predetermined level based on the output signals of these comparators. counter 5 for prohibiting the intrusion monitoring operation when the
It includes NOR circuits 6a to 6d.

Note that the light receivers R1 to R4 each receive a light beam L.
1 to L4 and outputs a voltage (or current) signal corresponding to the strength of the light receiving element 1a, such as a phototransistor, and the output of this light receiving element 1a is amplified to obtain a voltage level signal optimal for handling. amplifier 2
A, and the output level of this amplifier 2a changes to logic level "L" (hereinafter, logic level will be omitted) only when the output level of this amplifier 2a becomes below a predetermined level corresponding to the interruption of the light beam, and the normal The voltage level detector 3a outputs a signal at "H" level.

Here, comparative examples 4a to 4d each have a light receiver R1.
〜R4, each with an amplifier 2a
The voltage signal at output point P of is applied to terminal A, and the reference voltage V _REF , which is slightly higher than the voltage at point P when the voltage level detector 3a outputs an "L" level signal, is applied to terminal B. , the voltage applied to terminal A V _A
When V A is lower than the voltage _REF applied to terminal B, that is, when V _A < V _REF , an "H" level signal is output. A device that outputs an "H" level signal only when more than two comparators reach the level is used.

On the other hand, the NOR gates 6a to 6d are also connected to the receiver R.
1 to R4, and the voltage of the output terminal a of the voltage level detector 3c is applied to one input terminal, and the output of the counter 5 is applied to the other input terminal.

Thus, when, for example, only the light beam L1 among the light beams L1 to L4 is interrupted, the output level of the voltage level detector 3a of the light receiver R1 becomes "L", and the output level of the counter 5 also becomes "L". , the output of the NOR gate 6a changes to the "H" level to notify the occurrence of an intrusion.

Next, if the glass window of the cylinder is gradually blocked by snowfall, or if the light beams reaching the receivers R1 and R3 are significantly attenuated by heavy rain or heavy snow, the light beams may be interrupted. The outputs of the comparators 4a and 4c become "H" before reaching "H", and at the same time the output of the counter 5 becomes "H". Therefore, the outputs of the NOR gates 6a to 6d are sent to the receiver R1.
It is held at "L" regardless of the state of ~R4, thereby inhibiting the intrusion monitoring operation.

This means that when a person trespasses, the probability that intrusion sensors with different planar positions are activated at the same time is small;
On the other hand, it is nothing but a distinction between situations in which multiple intrusion sensors are likely to operate simultaneously during rain, snow, and fog, and the prohibition of the above-mentioned intrusion monitoring operation can reduce false alarms caused by worsening weather conditions. Alternatively, the number of misjudgments can be significantly reduced.

Based on the above-mentioned intrusion monitoring operation, as an embodiment of the present invention that effectively prevents false alarms of intrusion occurrence due to deterioration of weather conditions, as stated in the premise of the above-mentioned intrusion monitoring operation, the amount of energy reached is In addition to prohibiting intrusion monitoring operations when the number of receivers attenuated below a predetermined level exceeds two, it also prevents intrusion monitoring from occurring if multiple transmitters or receivers face the same direction and snow or dust accumulates on these transmitters or receivers. Intrusion sensors that have the same energy level attenuation conditions as each other may be grouped together, and intrusion monitoring may be prohibited for each group when the number of intrusion sensors subject to level attenuation exceeds two. The operation of the entire intrusion monitoring device is prohibited only when intrusion monitoring is prohibited.

As a result, intrusion monitoring by other intrusion sensor groups that are operating normally can be continued without univocally prohibiting all intrusion monitoring operations simply because two or more intrusion sensors become inoperable. .

In addition, in the above embodiment, an optical intrusion sensor is used, and while the comparators 4a to 4d mainly detect that the intensity of the light beam reaching the light receiver becomes less than a predetermined value, two comparators When this is detected, counter 5 is set to prohibit intrusion monitoring.
Although the NOR gates 6a to 6d have been described, an ultrasonic intrusion sensor or a microwave intrusion sensor can be used instead of an optical intrusion sensor, and a current level can be used instead of the comparators 4a to 4d that detect voltage levels. Further, a microcomputer may be used in place of the counter 5 and the NOR gates 6a to 6d.In short, a plurality of sets of transmitters and receivers for transmitting and receiving energy waves are arranged, When monitoring intruders based on receiver signals generated by interruptions of energy waves, energy level detection means each detects that the amount of energy reaching the receiver has attenuated below a predetermined level; and monitoring operation prohibition means for masking the intrusion monitoring operation when the number of receivers whose reached energy amount is attenuated to a predetermined level or less exceeds two or more predetermined numbers based on the output signal of the energy level detection means. Similarly to the above, the number of false alarms can be significantly reduced.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, among the plurality of sets of transmitters and receivers, the plurality of sets of transmitters and receivers are affected by the same effect when rain or snow falls from a certain direction. are set as one group, and energy level detection means each detects that the amount of energy reaching each receiver has attenuated below a predetermined level; By providing the following monitoring operation prohibition means that prohibits intrusion monitoring operations only for groups that include attenuated receivers, it is possible to significantly reduce the number of false alarms due to worsening weather conditions, and significantly reduce the burden on monitoring personnel. In addition, since the intrusion monitoring system can be maintained while eliminating false alarms due to deterioration of weather conditions, the reliability of intrusion monitoring can be greatly improved.
An excellent effect can be obtained in that the intrusion monitoring device can be used effectively.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the arrangement of an intrusion monitoring sensor according to an embodiment of the present invention, FIG. 2 is a perspective view showing the detailed configuration of the main parts of the embodiment, and FIG. FIG. T1-T4: Emitter, R1-R4: Receiver, L
1 to L4: light beam, 1a: light receiving element, 2a: amplifier, 3a: voltage level detector, 4a to 4d: comparator, 5: counter, 6a to 6d: NOR gate,
10: Important area, 11-14: Cylindrical body, 20: Building.

Claims (1)

[Claims] 1 Intrusion monitoring in which multiple sets of transmitters and receivers that transmit and receive energy waves are placed around an intrusion monitoring area, and intruders are monitored based on receiver signals generated by interruptions of the energy waves. In the device, among the plurality of sets of transmitters and receivers mentioned above, the plurality of sets of transmitters and receivers that are affected by the same effect when rain or snow falls from a certain direction are considered as one group, and the energy reaching each receiver is Based on the output signals of these energy level detection means, the intrusion monitoring is performed only on the group that includes the receivers whose amount of reached energy has attenuated below the predetermined level. An intrusion monitoring device comprising: monitoring operation prohibition means for prohibiting the operation.