RU19604U1 - ALARM DEVICE - Google Patents

Description

The proposed utility model relates to the field of burglar alarm technology, namely to radio-beam means of detecting an intruder using a radio beam to create an alarm line at a guarded object. In addition, the proposal can be used in organizing technical accounting systems (accounts) of moving objects.

Known security alarm device "Pion-V, with an operating frequency of the transmitter radiation of 10 GHz, containing a transmitter with amplitude modulation, consisting of a microwave generator, low-frequency modulator, a transmitting antenna and a direct gain receiver, containing a receiving antenna, a detection section, a low-frequency amplifier, an automatic device gain control, output device.

However, the Pion-V device (see 3) has insufficient reliability of detection of barrier disturbance and does not provide stealth when working at special-purpose facilities, because the operating radiation frequency

/ m-s

located in the transparency band and freely distributed in the atmosphere, while large transverse detection zones in width (more than four meters) have a clearly excess width relative to the average transverse size of the intruder (about 0.2 m) and, in addition, require organization at an object of an exclusion bandwidth of more than four meters, which is not always convenient and possible.

The closest analogue of the proposed utility model is a security alarm device, containing; its amplitude-modulated transmitter, consisting of a microwave generator, low-frequency modulator, amplitude modulator, transmitting antenna and direct gain receiver, containing a receiving antenna, a detection section, an amplifier, a detector, a low amplifier frequency, automatic gain control and output device (see 5,, MPKO08 Cl. G08B 13/00, 13/18, 13/181, 13/183, 13/189, 13/22, 13/24.) .

This device, with all other advantages, has an insufficient height of the protective barrier, and also, due to the presence of interference from the useful signal, it is unstable under certain changes in weather conditions (for example, when the height of the snow cover changes if there is icing), as well as reflection detection area

from objects with a large effective scattering area located outside this zone.

The technical result of the proposed utility model is to improve the operational characteristics of the device by increasing the height of the obstructed barrier, increasing the reliability of detection of the intruder in the conditions of multipath propagation (due to signal interference) and in changing weather conditions.

The essence of the technical solution lies in the fact that in a single-beam alarm device containing an amplitude-modulated transmitter, consisting of a transmitting antenna, a microwave generator, a low-frequency modulator, an amplitude modulator with a modulation frequency in the region of minimum noise of the detector of the receiver, and a receiver, consisting of a receiving antenna , an amplifier, a detector, a low-frequency amplifier, and an automatic gain control device, a second transmitting radio channel containing a transmitting antenna is additionally introduced A device consisting of a transmitting antenna, a microwave generator, a low-frequency modulator, an amplitude modulator with a modulation frequency in the region of minimum noise of a detector of a receiver, a pulse shaper of modulation of both channels, and a two-channel receiving device, additionally containing in each channel a subharmonic mixing section, a harmonic local oscillator, a band-pass amplifier, envelope detector imX t s - / 2

pulses in a packet, and in the second channel, a receiving antenna, amplifier, detector, low-frequency amplifier, and common elements belonging to both channels - a device for summing the signals received by both channels, an output comparison device containing an amplitude selector, an amplitude selector threshold adjuster, a number counter bursts of pulses, a generator of a counting time interval, a digital comparison device, a comparison threshold adjuster, the transmitting antennas being spaced apart in height by the amount of an additional barrier, and the receiving antennas We are spaced vertically and horizontally by multiples of an odd number of half-periods of interference of signals reflected from the underlying surface and objects located to the side, parallel to the main rays, respectively.

Analysis of the above signs of the claimed device shows that to solve the problem, their combination does not require the addition of other signs, that is, it is sufficient. Therefore, all these signs are significant, and their combination characterizes the completed technical solution.

Comparison of the claimed device with the closest analogue shows that it has differences, the existence of which proves the novelty of the proposal. The closest analogue implements the principle of decision making, based only on the amplitude of the received signal, under which under

{{} {- интер interference, the signal-to-noise ratio can vary by approximately 500 times, which is the main reason for the high probability of false triggering of the closest analogue. The inventive device implements the addition of fractions of signals received by two spatially separated antennas and the amplitude-frequency decision-making method, which can significantly reduce the likelihood of false positives and ensure reliable operation of the device regardless of weather conditions and multipath propagation of signals between the transmitting one and the receiving one devices.

Thus, the positive effect created by the proposed device is the expansion of its functionality due to the possibility of its operation regardless of weather conditions, the height of the snow cover and the presence of reflective objects.

The study of the role of the above differences of the claimed device in the dynamics shows that the exclusion of any of them makes it impossible to obtain a full positive effect when using the proposal. This indicates the existence of a direct causal relationship between these differences and the positive effect.

in this proposal, all differences can be divided into absolute and relative or mutual, characterizing the interaction between absolute differences.

Differences of the absolute type such as transmit antenna diversity, receive antenna diversity, and the use of superheterodyne reception are known per se. However, in known solutions, they do not contribute to the creation of the same positive effect as in the claimed device. Therefore, the above absolute differences are significant.

As for the differences of the mutual type, modulation of the transmitters by sequences shifted by half the period, addition of the powers of the envelope of the packs, their amplitude separation and the frequency principle of decision making, they are either absent in the literature or are known as separately existing, but at the same time creating other positive effects, therefore should be assessed as significant.

Therefore, all of the listed differences of both types are significant.

The proposed utility model is presented in the drawings, where:

FIG. 1 - Dependence of the shading coefficients by the intruder of the detection zones K on the transverse dimensions of the detection zones of the compared mouth 5

alarm system with equal lengths of these zones, determined by the formula:

K A8 / 8f, where:

AS - area of overlapping of the zone by the intruder, sq. m;

SA is the cross-sectional area of the detection zone (first zone

Fresnel), apt. m

p. 1 - the perimeter of the cross-sectional area of the detection zone of the device

A.2 - the perimeter of the cross-sectional area of the detection zone of the device

Clause 2 and Clause 3 - the perimeter of the cross-sectional area of the detection zone of the claimed device;

p.p. 4, 5, 6 - the value of the coefficient K for devices 3, 5 and the claimed, respectively;

D is the width of the detection zone, m; H is the height of the detection zone, m;

The size of the offender, taken in the calculation: height (maximum) -2m; width (minimum) - 0.2 m.

FIG. 2 - Block diagram of the inventive device.

Fig.Z. - A variant of the placement of the inventive security alarm device, explaining its principle of operation.

FIG. 4. - Comparative characteristics of the reliability of detection of the claimed device and the closest analogue;

FIG. 5 - Improving the efficiency of the claimed device compared to the closest analogue, expressed in increasing the potential of the received useful signal and reducing the likelihood of false positives;

6 - Comparison of the power of the received useful signal in the inventive device compared with the closest analogue.

The security alarm device contains:

-first transmitting device;

-second transmitting device;

- two-channel receiving device.

The first transmitting device includes:

1- microwave generator;

2 - transmitting antenna;

3- low-frequency modulator;

4 - amplitude modulator;

5- pulse shaper modulation of both channels;

6 - low-frequency modulator;

7-amplitude modulator;

8 - microwave generator;

9 - transmitting antenna;

The two-channel receiving device includes:

10 - receiving antenna of the first radio channel;

11 - receiving antenna of the second radio channel;

12 - harmonics of the first radio channel;

13 - subharmonic mixing section of the first radio channel;

14 - subharmonic mixing section of the second radio channel;

15 - harmonics of the second radio channel;

16 - pulse envelope detector in the packet of the first radio channel;

17-band amplifier of the first radio channel;

18- device for automatic gain control;

19-band amplifier of the second radio channel;

20 - pulse envelope detector in the packet of the second radio channel;

21- amplifier of the first radio channel;

22 - low frequency amplifier of the first radio channel;

24- low frequency amplifier of the second radio channel;

25- amplifier of the second radio channel;

26 - detector of the first radio channel;

27 - setpoint rate of the amplitude selector;

28-amplitude selector;

29 - threshold adjuster;

30- detector of the second radio channel;

31- time interval generator;

32 - counter of the number of bursts of pulses;

33-digital comparison device The device operates as follows.

The modulation pulse generator (5) generates two sequences of pulses of the same frequency, shifted relative to each other by half a period and with a duty cycle greater than 2. These sequences are transmitted to both transmitting devices by low-frequency modulators (3) and (6), respectively. Modulators (3) and (6) manipulate the amplitude of the pulse train in the amplitude modulators (4) and (7), thus forming pulse trains. The pulse repetition rate in a packet is selected in the range of minimum noise of subharmonic mixing sections and pulse envelope detectors in a packet of both receiving radio channels

. at

devices. Bursts of pulses serve as pulsed supply voltage for microwave generators (1) and (8).

Microwave generators (1) and (8) generate amplitude-manipulated microwave signals that are transmitted through the transmitting antennas (2) and (9) in the direction of the receiving antennas (10) and (11).

The microwave signals received by the receiving antennas (10) and (11) are fed to the subharmonic mixing sections (13) and (14), the heterodyne inputs of which receive signals from the harmonics (12) and (15). At the outputs of the subharmonic mixing sections (13) and (14), the intermediate frequency signals of each channel are allocated, respectively. These signals are filtered and amplified by strip amplifiers (17) and (19). Further, the amplified signals of the intermediate frequency are fed to the pulse envelope detectors in the packet (16) and (20), which emit voltages proportional to the power of each pulse inside the packet. At the outputs of the detectors (16) and (20), pulse sequences are formed with the modulation frequency of the amplitude modulators (4) and (7) of the transmitting devices. Amplifiers (21) and (25) amplify the signals from the outputs of the detectors (16) and (20), respectively. The amplified signals are then fed to detectors (26) and (30), at the outputs of which the envelopes of the bursts of pulses generated by low-frequency modulators (3), (5) and (6) are distinguished. Further, these voltages are added to the summing device (23). In the absence of naru H l

When the radio link of both radio channels is connected to the output of the summing device, a signal is generated with a double pulse repetition rate for each channel, i.e., each of the modulation signals of low-frequency modulators (3) and (6) of non-fading devices. Next, the total signal is fed to the amplitude selector (28), the response threshold of which is set by the threshold selector of the amplitude selector (27). From the output of the amplitude selector, the signal enters the counter of the number of bursts of pulses (32), the time interval of which is set by the generator of the time interval (31). The result of the calculation for a given time interval is digitally transmitted to a digital comparison device (33), the other input of which also receives the digital threshold value of the device response threshold threshold (29). If there is no violation of the barrier, the number in the counter (32) exceeds the threshold value from the threshold setter (29), therefore, an alarm signal is not generated. If the barrier is violated, the number from the counter (32) will be less than the threshold value from the threshold setter (29), and the comparison device (33) will generate an alarm signal, which is the output signal of the entire device. The AGC signal is generated by the automatic gain control device (18) from the total signal and controls the gain of the strip amplifiers (17) and (19).

The extension of the functionality of the device is achieved as follows.

When the height of the snow cover changes, the position of the interference dip is shifted in height relative to the receiving antenna. The distance in height of the installation of two receiving antennas is a multiple of an odd number of half periods of interference, while if one of the receiving antennas, when the height of the snow cover changes, is at the point of the minimum signal, i.e., in the interference dip, then the second antenna will be at the same time point of maximum signal. Regardless of the height of the snow cover, the sum of the powers of the signals received by both channels cannot always be less than the power received by the direct beam. The horizontal shift of the receiving antennas by a multiple of an odd number of half periods of interference similarly ensures that the total power of the signals of the two receiving antennas is independent of reflections by objects parallel to the direct signal propagation beam.

Thus, the proposed location of the receiving antennas can reduce the dependence of the received signal power both on the height of the snow cover and on reflections by objects that are on the side parallel to the main rays. The foregoing is illustrated in FIG. 3 and 6.

carried out by bursts of pulses, offset in time relative to each other by a time equal to half the period of succession of the packs. With the unshaded passage of signals from both transmitters to receivers, a sequence of pulses with a doubled repetition rate of the bursts will be observed at the output of the summing device. When the scammer crosses any of the rays, the upper or lower repetition rate of the packs will be reduced by half, while the decisive device will trigger and an alarm will be generated. When two upper and lower boundaries intersect at once, the pulse repetition rate will decrease to zero, which will also lead to the triggering of the deciding device and the generation of an alarm.

Thus, a new, in comparison with the closest analogue, principle of deciding on violation of the protected line is proposed. In the closest analogue, the amplitude principle was used, and the claimed device uses the frequency principle. The advantages of the frequency principle over the amplitude principle can be proved by calculating and comparing the probabilistic characteristics of the detection of barrier violations, which is done below 6.

The probability of erroneous reception of a signal element in the closest analogue is determined by the expression

Roche. a.

(2 + hV2)

Where is Roche. A.- the probability of an error in receiving one pulse in a packet

the closest analogue;

h is the ratio of signal energy to noise energy.

Since it is probing; its signal is a burst consisting of N pulses, then with an independent character of errors in the channel, the probability of an erroneous reception of a burst of N pulses with a majority criterion A of N will be equal to

Roche. P. a.

Where A is the number of pulses that have exceeded the decision threshold; N is the transmitted number of pulses in the packet.

Roche. P. a. - the probability of an error receiving the entire burst of pulses. The probability of erroneous reception of a signal element in the inventive device is determined by the expression

Roche UlCll b

(2 +)

(h72)

Where is Roche. 3 - the probability of an error in receiving one burst pulse in

the claimed device.

The probability of an error in receiving the entire burst of N pulses with the majority criterion A of N will be equal to

Rosh. Where is Roche. paragraph 3. device.

The gain in noise immunity will be equal to

2 //, N2A / N

(hV2)

Rosh.p.a

Roche. Section 3. ((2 + Г / 2) хЗП (6 + 3xhV2) Where (X - win

relative to the closest analogue.

When the expression for winning can be reduced to

24A / N

(hO Dependence Rosh. a., Rosh. z. and Rosh.p.

16

(B2 / 2) 2

(hV2)

2A / N

. the probability of an error in the reception of the entire packet in the noise immunity of the inventive device a., R osh. p.z. from h represented

An analysis of the expression for the gain in noise immunity shows that the gain increases in proportion to the signal-to-noise ratio h. noise

Ha 2 (

Where ha is the signal-to-noise ratio of the closest analogue.

For a given probability of error, the required signal-to-noise ratio

h 3 2xVz / Posh.

Where h 3 - the ratio of signal to noise of the claimed device. The energy gain p, determined by the increase in the signal-to-noise ratio at the receiver input at

the best analogue is determined by the expression:

R

h 3 l / W / Rosh.

itAJ 17

-2)

Roche. a.

1 / Rosh.a. -2 At a given probability of error, the required signal ratio for the closest analogue is determined by the expression for the inventive device is determined by the expression of the inventive device with respect to decibels p is determined by the expression

(3 101g (l / Pom.a. -2) - 101g (V3 / Pom.3.)

The dependence of P on Roche is shown in FIG. 5,

Since in the closest analogue there is a fundamental dependence of the received signal power and the probability of error on the height of the snow cover, it is advisable to determine the advantage of the claimed device over the closest analogue in real conditions of their use. Comparative characteristics of the power of the received signal depending on the height of the snow cover are shown in Fig.6. Joint dependency analysis in FIG. 4 and 6 shows that, depending on the height of the snow cover or reflections from objects located parallel to the main rays, the signal power in the closest analogue can decrease by 27dB, that is, the dynamic range of the signal-to-noise ratio h can reach 500. This means that under these conditions, the probability of error in the closest analogue will be 16 orders of magnitude higher than in the claimed device.

Comparative characteristics of the reliability and energy gain of the claimed device and the closest analogue are shown in FIG. 4 and 5.

Thus, the proposed security alarm device under real operating conditions, i.e., when the closest analogue operates in the interference dip, it reduces the probability of error by 16 orders of magnitude compared to the closest analogue 5, the energy gain improves the noise immunity by 12 dB (see Fig. . 5) which significantly expands its functionality and ensures reliable operation of the device as a whole.

SOURCES OF INFORMATION.

1.USA / March 1993, Copyright 1993 Racon Incorpora ted. Advertising catalog of the company Racon, USA.

2.Preliminary A310 sensor, Microwave Intrusion Sensor. BURLE Advertising Directory, USA

3. Equipment Pion-V, Technical description and operation manual АВЯ.400.006.Т.

4.M.P. Dolukhanov. Radio Wave Propagation, Svyaz Publishing House, MOSCOW, 1972, p. 104.

5. Security alarm device. Patent No. 2109343 Cl. G08B 13/00, 13/18, 13/181, 13/183, 13/189, 13/22, 13/24.

6.P. I. Penin "Digital Information Transmission Systems, ed. “Owls. Radio, 1976

 /- from

), /)

1 - microwave generator; 2 - transmitting antenna; 3- low-frequency modulator; 4 - amplitude modulator; 5- pulse shaper modulation of both channels; 6 - low-frequency modulator; 7 - amplitude modulator; 8 - microwave generator; 9 - transmitting antenna; 10 - a receiving antenna of the first radio channel; 11 - a receiving antenna of the second radio channel; 12 - the local oscillator of the harmonics of the first radio channel; 13 - subharmonic mixing section of the first radio channel; 14 - subharmonic mixing section of the second radio channel; 15 - the local oscillator of the harmonics of the second radio channel; 16 - pulse envelope detector in the packet of the first radio channel; 17 - band amplifier of the first radio channel; 18 - device for automatic gain control; 19 - band amplifier of the second radio channel; 20 is a pulse envelope detector in a packet of a second radio channel; 21 - amplifier of the first radio channel; 22 - low frequency amplifier of the first radio channel; 23 - summation device; 24 - low frequency amplifier of the second radio channel; 25 - amplifier of the second radio channel; 26 - detector of the first radio channel; 27 - threshold selector amplitude selector; 28 - amplitude selector; 29 - threshold adjuster; 30 - detector of the second radio channel; 31 - time interval generator; 32 - counter of the number of bursts of pulses; 33 is a digital comparison device.

Claims (1)

A security alarm device comprising an amplitude-modulated transmitter consisting of a transmitting antenna, a microwave generator, a low-frequency modulator, an amplitude modulator, and a receiver comprising a receiving antenna, an amplifier, a detector, a low-frequency amplifier, an automatic gain control device, characterized in that in the transmitter additionally introduced a second transmitting channel containing a transmitting antenna, spaced in height relative to the first height of an additional barrier, a microwave generator, low-frequency th modulator, amplitude modulator, and pulse shaper modulating both radio channels, and the receiver consists of two identical radio channels, the first channel of which is additionally injected with a harmonic local oscillator, a subharmonic mixing section, a pulse envelope detector in the packet and a band amplifier, and the second radio channel contains a receiving antenna, an amplifier, a detector, a low-frequency amplifier, a harmonic local oscillator, a subharmonic mixing section, a pulse envelope detector in a packet, a strip amplifier, and also contains for both radio channels, the nodes are a summing device, an amplitude selector threshold adjuster, an amplitude selector, a comparison threshold adjuster, a counting time interval generator, a pulse packet number counter, a digital comparison device, and the receiving antennas of both radio channels are mutually spaced vertically and horizontally by multiple values an odd number of mean values of half-periods of repetition of interference minima.