JPH10221165A - Light beam intensity-measuring apparatus for light beam type intrusion-detecting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light beam intensity-measuring apparatus for a light-beam type intrusion-detecting system which can correctly measure an intensity of light beams of a light projector irrespective of a surrounding environmental condition. SOLUTION: A light beam intensity-measuring apparatus 1 is provided with a photodetecting part 10 which detects light beams of a light beam-type intrusion-detecting system detecting an invasion to a monitor area from a change of an output signal of a photodetector detecting light beams projected from a projector, a change-compensating unit 20 which determines a change of an intensity of light beams by a surrounding environment, and a signal-processing part 30 which corrects an output signal from the photodetecting part 10 on the basis of a change value determined by the compensating unit 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to light emitted from a projector in a light beam type intrusion detection system for detecting intrusion into a monitoring area from fluctuations in an output signal of a light receiver which receives a light beam emitted from the projector. The present invention relates to a light beam intensity measuring device for measuring a beam intensity.

[0002]

2. Description of the Related Art In general, in an intrusion detection system as described above, an infrared light emitter composed of an infrared light emitting diode and a light emitting lens and an infrared light receiver composed of a light receiving lens and a photodiode are arranged at both ends of a monitoring area. They are arranged with their axes aligned. If the level of the output signal output by the light receiving unit that receives the infrared beam emitted from the projector is evaluated to be lower than the preset reference level, it is considered that an intruder is present in the monitoring area and an alarm is issued. Or send an alarm signal to a monitoring center.

As described above, the illegal intrusion is notified by the decrease in the reception signal level. Therefore, the reception signal level decreases due to the deterioration of the infrared projector over time or the deterioration of the surrounding environment due to heavy rain or dense fog, or both. However, false notification of trespassing occurs even though there is no actual trespassing. In order to prevent such erroneous notification beforehand, it is necessary to periodically perform measurement and inspection of the infrared projector.

[0004]

SUMMARY OF THE INVENTION A light beam intensity measuring device having a light receiving portion for receiving a light beam emitted from a projector of an intrusion detection system and a signal processing portion for evaluating an output signal from the light receiving portion is used. When measuring the intensity of the light beam of the intrusion detection system on a regular basis, the ambient environment conditions are not always constant, especially on rainy days or when fog is occurring. Since the absolute intensity cannot be measured, in other words, it is not known how much the deterioration of the projector or the change in the surrounding environment has affected the measurement result. It becomes difficult. For this reason, there arise problems such as replacement of a light emitting device which can be used still or leaving a deteriorated light emitting device which has been replaced. An object of the present invention is to provide a light beam intensity measuring apparatus for a light beam type intrusion detection system capable of accurately measuring the performance of a projector itself, that is, the intensity of a radiated light beam, regardless of ambient environmental conditions. And to solve the above problem.

[0005]

In order to achieve the above object, a light beam intensity measuring apparatus for a light beam type intrusion detection system according to the present invention comprises a light receiving section for receiving a light beam of the intrusion detection system, and a light receiving section for receiving the light beam. A fluctuation compensating unit that determines a fluctuation of the light beam intensity due to the environment, and a signal processing unit that corrects an output signal from the light receiving unit based on the fluctuation value determined by the fluctuation compensating unit. I do.

In this configuration, the output signal from the light receiving unit that receives the light beam of the intrusion detection system is corrected by the signal processing unit in consideration of the fluctuation of the light beam intensity due to a change in the surrounding environment. A measurement result in which the influence of such disturbance is suppressed can be obtained even in the case of heavy fog. Therefore,
Irrespective of the surrounding environmental conditions that cause significant attenuation of the light beam used, regardless of this, accurate maintenance inspection of the projector of the intrusion detection system can be performed, and the timing of replacing the light emitting device of the projector can be adjusted. Not only can it be determined accurately, but also regular maintenance inspections can be performed without disrupting the schedule.

Although the fluctuation compensating unit for determining the fluctuation of the light beam intensity due to the surrounding environment can be implemented in various forms, in one of the preferred embodiments according to the present invention, a light beam equivalent to the projector of the intrusion detection system is used. An auxiliary light emitting unit that emits light, an auxiliary light receiving unit that receives a light beam from the light emitting unit, and compares the output signal of the auxiliary light receiving unit with a reference signal to determine a fluctuation value of the light beam intensity due to the surrounding environment. In some cases, a fluctuation compensating unit is configured by a fluctuation value calculating unit that performs the calculation. With this configuration, a fluctuation value of a change in the surrounding environment condition that adversely affects the light beam, which affects the reception intensity of the light beam, can be obtained by the light beam transmission / reception system for checking. When such a fluctuation value affecting the reception intensity of the light beam is obtained, if the output signal obtained from the light beam for measurement is corrected based on this, a measurement value independent of the surrounding environment conditions can be obtained.

In another embodiment according to the present invention, a fluctuation compensating unit outputs a meteorological condition, such as rain or fog, of an ambient environment as an output signal, and a surroundings is obtained from an output signal from the viscometer. Some include a variation value calculation unit that determines a variation value of the light beam intensity due to the environment. The visibility meter mentioned here measures the transparency of the atmosphere based on the degree to which the light beam is absorbed or scattered by fine particles in the atmosphere, and objectively quantifies rain and fog conditions meteorologically and outputs it. It is a generic name and is a publicly known one. The relationship between the output signal from such a visibility meter and the intensity attenuation of the light beam, for example, by making a table,
A fluctuation value of the fluctuation of the ambient environment condition on the reception intensity of the light beam is obtained, and if the output signal obtained from the light beam for measurement is corrected based on this, a measurement value independent of the ambient environment condition is obtained. .

In a preferred embodiment according to the present invention, if a level is provided in the housing of the light beam intensity measuring device, the light beam intensity measuring device is arranged with respect to the optical axis of the projector of the light beam type intrusion detection system. The most important work in this measurement, that is, aligning the optical axes of the light receiving sections, is facilitated. This also contributes greatly to the speed and accuracy of the measurement operation. Other features and advantages of the present invention will become apparent from the following description of the embodiments with reference to the drawings.

[0010]

FIG. 1 is a block diagram showing a state in which a light beam intensity measuring device 1 according to the present invention is set in a light beam type intrusion detection system 100 having a general configuration. The light beam intensity measuring device 1 is disposed between the light emitter 101 and the light receiver 102 of the light beam intrusion detection system 100, and is positioned so as not to be inclined with respect to the optical axis connecting the light emitter 101 and the light receiver 102. As a result, a level 2 that facilitates this operation is provided in the housing of the light beam intensity measuring device 1.

The light projector 101 is composed of an infrared light emitting diode and a light projecting lens for shaping the infrared light emitted by the infrared light emitting diode into a beam having a desired width and emitting the beam, and is controlled by a controller (not shown). The driving unit 103, which operates upon receiving a signal, emits light at a predetermined frequency, thereby emitting an infrared beam composed of a pulse-modulated wave. The light receiver 102 includes a light receiving lens that collects the infrared beam emitted from the light projector 101 and a photodiode that receives the collected infrared beam and outputs an electric signal corresponding to the intensity of the infrared beam, that is, the amount of light. Have been. After the output signal of the optical receiver 102 is amplified by the amplifier 104, the output signal is converted by the detector 105 into an intensity signal corresponding to the intensity of the received signal only by the pulse-modulated wave, and compared with a determination reference value previously set by the evaluation unit 106. If the value is lower than the determination reference value, it is determined that intrusion has been detected, an alarm is issued via the alarm generator 107, or the intrusion detection is notified to the remote management center via the communication unit 108.

As shown in the block diagram of FIG. 2, the light beam intensity measuring apparatus 1 includes a light receiving section 10 having the same configuration as the light receiving section 102 of the light beam type intrusion detection system 100 described above, and a surrounding environment. And a signal for processing the output signal from the light receiving unit 10 and correcting the output signal from the light receiving unit 10 based on the fluctuation value determined by the fluctuation compensating unit 20. And a processing unit 30.

The fluctuation compensating unit 20 includes an auxiliary light projecting unit 21
, A photodiode as an auxiliary light receiving unit 22 that receives an infrared beam from the auxiliary light projecting unit 21, and a fluctuation value calculating unit 23 that processes an output signal from the auxiliary light receiving unit 22 to obtain a fluctuation value And the auxiliary light emitting unit 2
And a driving unit 24 for driving the driving unit 1. The fluctuation value calculation unit 23 calculates the intensity of the infrared beam received by the auxiliary light receiving unit 22 from the output signal from the auxiliary light receiving unit 22, and calculates the intensity of the same infrared beam in a state where there is no disturbance in the surrounding environment that has been obtained in advance. From the comparison with the received light intensity, a fluctuation value based on a change in the surrounding environment is calculated.

The signal processing unit 30 includes an amplifying unit 11 for amplifying an output signal of the light receiving unit 10, a detecting unit 32 corresponding to the above-described detector 105, and an intensity indicating the intensity of the received infrared light obtained by the detecting unit 32. A signal correction unit 33 that corrects the signal based on the fluctuation value obtained by the fluctuation value calculation unit 23 is provided. Further, the signal processing unit 30 includes a signal correction unit 33
Is displayed on the display unit 34. The maintenance staff may determine the deterioration of the infrared light emitting diode of the projector 101 of the corresponding light beam type intrusion detection system 100 with reference to the value displayed on the display unit 34.

In this light beam intensity measuring device 1, even if the surrounding environment conditions change due to heavy rain or dense fog, the fluctuation compensation unit 20 checks the equivalent attenuation of the infrared beam under the surrounding environment conditions at the time of measurement. , The measured data is corrected and displayed based on the check,
The maintenance person can trust the displayed measurement data and can judge the exact replacement timing of the infrared light emitting diode. In addition, even if an intrusion alarm is issued and you rush to the site, it is easy to judge whether the alarm is a false alarm caused by a change in surrounding environment conditions due to heavy rain or dense fog, etc., or whether there was really an intrusion. be able to.

In the above embodiment, the fluctuation compensating unit 20 for checking the ambient environment conditions at the time of measurement using the auxiliary light projecting unit 21 and the auxiliary light receiving unit 22 is employed. Alternatively, it is possible to use a fluctuation compensation unit 20 using a visibility meter 25 that sends out meteorological conditions such as rain and fog as output signals as shown in the block diagram of FIG. The visibility meter 25 itself is known, and the present invention does not limit the characteristics of the visibility meter 25 itself. Therefore, the transparency of the atmosphere is measured from the degree of scattering, and the meteorological conditions of rain and fog are objectively measured. Only the principle of digitizing and outputting will be explained. The relationship between the value of the output signal from the visibility meter 25 and the attenuation rate of the infrared beam is tabulated and an LUT (look-up table) is created.
26, the fluctuation value calculation unit 23 can calculate the fluctuation value of the infrared beam received by the light receiver 10 based on the change in the surrounding environment, and the signal correction unit 33 uses this fluctuation value. Then, the intensity of the infrared light received by the light receiving unit 10 is corrected and displayed on the display unit 34. The data corrected and displayed in this way is also independent of the surrounding environment conditions, and is used by maintenance personnel to determine the exact replacement timing of the infrared light emitting diode and to judge false alarms caused by changes in the surrounding environment conditions. Great help.

In the above embodiment, an infrared beam is used as a light beam. However, the present invention is not limited to a light beam intensity measuring device for a light beam type intrusion detection system using an infrared beam. Instead, it can be used for various types of beam-emitting intrusion detection systems, where the auxiliary projector and auxiliary receiver are used for a beam substantially equivalent to the beam used in the intrusion detection system to be measured. The designed one is used.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a state in which a light beam intensity measuring device according to the present invention is set in a light beam type intrusion detection system.

FIG. 2 is a block diagram showing an example of a light beam intensity measuring device according to the present invention.

FIG. 3 is a block diagram showing another embodiment of the light beam intensity measuring device.

[Explanation of symbols]

 Reference Signs List 1 light beam intensity measuring device 10 light receiving unit 20 fluctuation compensation unit 30 signal processing unit

Continuation of front page (72) Inventor Hiroshi Dodo 60-1 Kitahanayama Obayashicho, Yamashina-ku, Kyoto City, Kyoto Prefecture Takenaka Engineering Co., Ltd. System Business Department

Claims (4)

[Claims] 1. A light beam intensity measuring device for a light beam type intrusion detection system for detecting intrusion into a monitoring area from a change in an output signal of a light receiver that receives a light beam emitted from a light projector, A light receiving unit for receiving the light beam of the intrusion detection system,
A fluctuation compensating unit that determines a fluctuation of the light beam intensity due to the surrounding environment; and a signal processing unit that corrects an output signal from the light receiving unit based on the fluctuation value determined by the fluctuation compensating unit. A light beam intensity measuring device for a light beam type intrusion detection system. 2. The fluctuation compensating unit includes: an auxiliary light emitting unit that emits a light beam equivalent to a light projector of the intrusion detection system; an auxiliary light receiving unit that receives a light beam from the light emitting unit; 2. The light beam type intrusion detection system according to claim 1, further comprising: a fluctuation value calculation unit that calculates a fluctuation value of the light beam intensity due to the surrounding environment by comparing an output signal of the unit and a reference signal. Beam intensity measuring device for 3. The fluctuation compensating unit, which outputs a meteorological condition such as rain or fog of the surrounding environment as an output signal, and a fluctuation value of the light beam intensity due to the surrounding environment from the output signal from the visibility meter. The light beam intensity measuring apparatus for a light beam type intrusion detection system according to claim 1, further comprising a fluctuation value calculating unit for determining. 4. The apparatus according to claim 1, wherein a level is provided on a housing of the light beam intensity measuring device.
3. A light beam intensity measuring device for a light beam type intrusion detection system according to claim 1.