RU18783U1 - ADAPTIVE OPTICAL SIGNALING DEVICE - Google Patents

Description

ADAPTIVE OPTICAL SIGNALING DEVICE

The utility model relates to closed area monitoring devices that generate an alarm upon detection of penetration into a specified area.

There is a wide variety of alarm systems that work when the intruder crosses the optical beam (| irradiated by the emitter unit and received by the photodetector unit of the system.

One of such devices is given in the patent of Germany N3316010, MKI: G08B 13/18, E05G 5/00 (published in ISM N1 for 1985). A method of controlling an enclosed space. The device contains a transmitter of G-radiation and a signal receiver from it. The receiver generates an alarm in case of deviation of the infrared radiation received from it from the set value.

Such devices have low noise immunity, as they are triggered by an accidental violation of the protection zone, for example, by a fallen leaf or a flying bird.

More reliable devices contain several sources of the optical beam and, accordingly, several photodetectors, for example, photoEMKIs: G08B, 13/00

DS470 type electrical detectors from Detection Sistems, Ino. On the ryonka in the prospectus, it can be seen that the device forms 4 optical beams. In this case, an alarm is generated when either all four rays or two upper or two lower beams intersect simultaneously. Such a scheme is more protected from accidental alarm output, therefore, has increased noise immunity.

Known photoelectric protective screen according to the application of France N2620550, MKI: 608B 13/18 (publ. ISM, issue 119, N10 for 1989), which contains two transceiver units, each has a photodetector unit (KD), which is optically coupled to one or more light sources. The light sources of both transceiver units are connected through a pulse distributor to a master oscillator. The BF of each transceiver block is connected to the alarm block through a common control unit and a signal blocking unit.

The level of received BF signals is compared in the control unit, which activates the security alarm unit in case of inequality of signals from light sources.

A similar circuit can be supplemented by an automatic gain control unit (AGC) in the BF. Upon receipt of a weak signal at the BF input, the AGC block increases the amplifier gain, maintaining the necessary sensitivity of the system, including when weather conditions change. This helps to increase the noise immunity of the security system (see, for example, an infrared beam detector type AX-350 / 650MKII from ORTEX).

However, the capabilities of the psd system are limited by AGC parameters. In addition, the connection between you ask them the generator, the signal control unit and the transceiver units is carried out by wire, which complicates

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the organization of the security oiotema and limits its operational capabilities.

Thus, the known devices implement various mechanisms for generating an alarm and take into account various methods of increasing noise immunity and reducing cases of false alarms. However, all devices known to the authors fail when installed in tight places, for example, corridors, window openings, etc., where a controlled beam can be reflected from an object surrounding the device

In these cases, in addition to the direct optical beam 1, the reflected photo rays 2 and 3 fall on the photodetector block (see Fig. 2). Depending on the properties of reflective surfaces (walls, glass, etc.), the signal level of the reflected rays and 3 may exceed the threshold for the alarm of the device. The degree of protection of the object in such situations decreases sharply, since the intruder will alternately block the optical rays 1,2,3, and the photodetector unit will not give an alarm signal due to the impact of the remaining rays on it.

The prototype of the proposed solution can be considered the device described in the patent of Germany N13316010 (see above).

The objective of the proposed solution is to increase the noise immunity of the security system.

To solve the problem, an adaptive optical signaling device containing a source of study 11, a radiation receiver, a pulse generator, a direct signal level control unit and a security alarm unit, is supplemented by a reflected signal control unit and a comparison unit, and the outputs of the control units are connected to the input of the comparison unit , and its output is connected to the input of the security alarm unit.

The inclusion of additional blocks in the circuit allows you to take into account the level of reflected signals when generating an alarm. With this scheme, the security alarm unit generates an alarm when the signal level at the output of the direct signal control unit does not exceed the signal level at the output of the reflected signal control unit. This increases the noise immunity of the device, since the level of reflected 11X signals will be beyond the threshold of the system.

The proposed adaptive optical signaling device is shown in figure 1.

The device comprises a radiation source 1, a radiation receiver 2, a driving generator 3, a direct optical signal level control unit 4 and a security alarm unit 5. The device is supplemented by a reflected signal level control unit 6 and a direct and reflected signal level comparison unit 7. Moreover, the outputs of blocks 4 and 6 are connected to the input of the comparison unit 7, and the signal interrupt button 8 is installed at the input of the unit 6. The output of the comparison unit 7 is connected to the input of the security alarm unit 5.

The device operates as follows.

In the initial setup process, the button 8 is turned on and the radiation receiver 2 fixes the level of each reflected signal (2,3 of FIG. 2). The maximum level of reflected signals is stored in the control unit of reflected signals 6, and button 8 is turned off. Further, in the process of operation, the level of the direct signal from block 4 is fed to the input of the comparison block 7, which also receives the signal from the output of block 6, equal to the maximum value of the level of the reflected signal.

If the intruder crosses only the reflected signal, the system does not work out the alarm signal, since the direct controlled signal remains unchanged. If the intruder enters the direct zone

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 4 - - beam signal level at the direct beam control unit is diminished, but will not disappear due to reflected radiation entering the receiver. However, the proposed adaptive device in this case will give an alarm if the signal level at the output of the radiation receiver is equal to or lower than the maximum level of the reflected signal. Thus, the threshold of the signal system is selected taking into account the interference caused by the reflected signals.

The proposed adaptive device will provide effective protection of the closed zone in a bottleneck or if there are reflective surfaces in the zone along the path of the controlled optical signal. This scheme allows you to reduce the number of false alarms and increase the noise immunity of the security system.

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Claims (1)

An adaptive optical signaling device containing a radiation source, a radiation receiver, a master oscillator, a direct signal control unit and a security alarm unit, characterized in that it is equipped with a reflected signal control unit and a comparison unit, the outputs of the control units being connected to the input of the comparison unit, and its the output is connected to the input of the alarm block, which gives an alarm in the case when the signal level at the output of the direct signal control unit does not exceed the signal level at the output of the bl eye control of the reflected signal.