RU2447509C1 - Device for antivehicle mines detection - Google Patents

Abstract

FIELD: information technology.

SUBSTANCE: device contains Doppler UHF sensor 1, antenna 2, very-low-frequency seismic sensor 3 of vehicle body bouncing, controlled radio transmitter 5, as well as radio receiver 14 with radio frequency amplifier 15, phase doubler 16, spectrum analysers 17 and 18, comparator unit 19, key 20, amplitude limiters 21 and 25, phase-lock detector 22, audio signals amplifier 23, sound emitting device 24, narrow-band filters 26 and 28, phase-halving circuit 27, frequency detector 29, balance switch 31, phase detector 32, multipliers 34 and 35, phase shifters 36 - for +45°, 37 - for -45°, phase shifter 41- for +90°, low pass filters 38 and 39.

EFFECT: higher device resistance to narrow-band interference due to their suppression.

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Description

The proposed device relates to the field of technical means of combating terrorism and can be used to prevent the undermining of motor vehicles (vehicles) by identifying in advance the anti-vehicle mines installed on them.

Existing army and commercial mine detectors cannot detect mines and explosive devices against the background of interference from a nearby metal case of a power-driven vehicle [1].

Known devices for detecting anti-vehicle mines (RF patents No. 2142758, 2173889, 2212712; US patent No. 4752778: Ivlev S., Scherbakov G. et al. Search and disposal of explosive devices. - M .: AEN RF, 1996, p. 48- 51, 59-69; Dikarev V.I., Koinash B.V., Sandulov Yu.A., Salnikov V.P. Explosive Hazardous Objects: Methods and Means of Search, Detection, Disinfection and Disposal.- St. Petersburg: Lan, 2001 and others).

Of the known devices, the closest to the proposed one is the "Anti-vehicle mine detection device" (RF patent No. 2212712, G08B 13/14, 2001), which is selected as a prototype.

The known device provides an increase in the information content and reliability of detection of anti-vehicle mines by using complex signals with combined amplitude modulation and phase shift keying (AM-FMN) on a single carrier frequency.

However, the known device has a low noise immunity to narrowband interference.

An object of the invention is to increase the noise immunity of the device to narrowband interference by suppressing them.

The problem is solved in that the anti-vehicle mine detection device, comprising, in accordance with the closest analogue, a Doppler microwave sensor consisting of a generator, a receiver-indicator device and an antenna, an infra-low-frequency seismic sensor of vertical vibrations of the vehicle’s body, mechanically rigidly connected to its body, switchable an AND-OR logic circuit, a controlled radio transmitter and an autonomous radio receiver, while the outputs of the Doppler microwave and seismic sensors connected to the inputs of the AND-OR logic circuit, the output of which is connected to the control input of a controlled radio transmitter, the antenna of the Doppler microwave sensor is made of coaxial transmit and receive cables with perforations operating on the principle of “leakage of waves” and loaded with active resistances of equal magnitude their wave resistance, the transmission cable is attached to the metal bottom of the vehicle along its outer perimeter, and the receiving coaxial cable is attached inside to the bottom along l transmission cable at a distance of 0.1-0.3 m, the controlled radio transmitter is made in the form of a series-connected reference generator, phase manipulator, the second input of which is connected to the output of the source of discrete messages, an amplitude modulator, the second input of which is connected to the output of the analog source messages, a power amplifier and a transmitting antenna, an autonomous radio receiver is made in the form of a series-connected receiving antenna, a high-frequency amplifier, a phase doubler, a second analyzer spectrum, a comparison unit, the second input of which is connected through the first spectrum analyzer to the output of a high-frequency amplifier, a key, the second input of which is connected to the output of a high-frequency amplifier, a first amplitude limiter, synchronous detector, the second input of which is connected to the output of a key, an audio-frequency signal amplifier and acoustic emitter, the second amplitude limiter, the first narrow-band filter, the phase divider into two, the second narrow-band filter, are frequency-connected to the output of the phase doubler, the first detector, trigger, balance switch, the second input of which is connected to the output of the second narrow-band filter, and the phase detector, the second input of which is connected to the output of the first amplitude limiter, as well as the recording unit, differs from the closest analogue in that the stand-alone radio receiver is equipped with two multipliers , two low-pass filters, phase shifter + 45 °, phase shifter -45 °, phase shifter + 90 °, two subtraction units, and to the output of the first amplitude limiter sequentially by the first multiplier is switched on, the second input of which is connected through the + 45 ° phase shifter to the output of the balance switch, the first low-pass filter, the first subtraction block, the + 90 ° phase shifter and the second subtraction block, the second input of which is connected to the phase detector output, and the output is connected to the registration unit, to the output of the first amplitude limiter, a second multiplier is connected in series, the second input of which is connected through the phase shifter by -45 ° to the output of the balanced switch, and the second low-pass filter, for which it is connected to the second input of the first subtraction block.

The structural diagram of the proposed device is presented in figure 1. Timing diagrams explaining the principle of operation of the device shown in figure 2.

The device comprises a Doppler microwave sensor 1, including an antenna 2, an infra-low-frequency seismic sensor 3 of vertical oscillations of the vehicle body, mechanically rigidly connected to its body, a switchable AND-OR 4 logic circuit, a controllable radio transmitter 5 and an autonomous radio receiver 14. The outputs of the Doppler microwave and seismic sensors 1 and 3 are connected to the inputs of the AND-OR 4 logic circuit, the output of which is connected to the control input of the radio transmitter 5.

The radio transmitter 5 is made in the form of a series-connected reference generator 6, a phase manipulator 8, the second input of which is connected to the output of the discrete message source 7, an amplitude modulator 10, the second input of which is connected to the output of the analog message source 9, power amplifier 11 and transmitting antenna 12.

The radio receiver 14 is made in the form of a series-connected antenna 13, a high-frequency amplifier 15, a phase doubler 16, a second spectrum analyzer 18, a comparison unit 19, the second input of which is connected through the first spectrum analyzer 17 to the output of a high-frequency amplifier 15, key 20, and a second input which is connected to the output of the high-frequency amplifier 15, the first amplitude limiter 21, the synchronous detector 22, the second input of which is connected to the output of the key 20, the amplifier 23 of the sound frequency signals and acoustic emitter 24. The second amplitude limiter 25, the first narrow-band filter 26, the phase divider 27, the second narrow-band filter 28, the frequency detector 29, the trigger 30, the balance switch 31, the second input of which is connected to the output of the second narrow-band filter 28, are connected in series to the second phase doubler 16; a detector 32, the second input of which is connected to the output of the first amplitude limiter 21, the second subtraction unit 42 and the registration unit 33. The first multiplier 34 is connected in series to the output of the first amplitude limiter 21, the second input of which is connected through the phase shifter 36 to + 45 ° to the output of the balance switch 31, the first low-pass filter 38, the first subtraction unit 40, and the + 90 ° phase shifter 41, the output of which is connected with the second input of the second subtraction block 42. A second multiplier 35 is connected to the output of the first amplitude limiter 21, the second input of which is connected through the phase shifter 37 by -45 ° to the output of the balance switch 31, and the second low-pass filter 39, the output of which is connected to the second input of the first subtraction unit 40.

The principle of operation of the device is based on the combined use of a Doppler microwave sensor and a seismic sensor.

The Doppler microwave sensor is triggered when any item is placed in a protected area (for example, in a small room, car interior, etc.)

The disadvantages of the Doppler microwave sensor are:

- a large number of false positives;

- the occurrence in some cases, under the uneven bottom of the car, “zero” zones, that is, zones of passage of search objects;

- susceptibility to interfering (shielding) effects of a layer of a semiconducting medium (ice, dirt, etc.).

Moreover, to eliminate the "zero" zones, it is required to increase the sensitivity of the microwave sensor. But at the same time, the number of false positives from external electromagnetic fields, pedestrians passing close by the car, etc. sharply increases. All this leads to a decrease in the safety of operation of motor vehicles (cars).

This device provides increased safety for the operation of motor vehicles by the reliable detection of anti-vehicle mines installed by terrorists with a minimum number of false positives.

For this, an infra-low-frequency seismic sensor for vertical oscillations of the vehicle’s body mechanically rigidly connected to its body, as well as an AND-OR switchable logic circuit, a controlled radio transmitter and an autonomous radio receiver, are introduced into the anti-vehicle mine detection device. In this case, the outputs of the Doppler microwave and seismic sensors are connected to the inputs of the AND-OR logic circuit, the output of which is connected to the controlled input of the radio transmitter. Moreover, to reduce the number of false positives and reduce the shielding effect of the semiconductor medium layer, the antenna of the Doppler microwave sensor is made of coaxial transmitting and receiving cables with perforations operating on the principle of “leaky waves” and loaded with active resistances equal in magnitude to their wave impedance, at this transmitting coaxial cable is attached to the metal bottom of the vehicle along its outer perimeter, and the receiving coaxial cable is attached inside to beggar along the transmission cable at a distance from 0.1 to 0.3 m. The value of this distance is due to the characteristic dimensions of the explosive device (VU) (from 0.1 to 0.3 m), as well as the working wavelength in the decimeter range.

The introduction of a seismic sensor together with a logic circuit operating in the And mode dramatically reduces the number of false alarms, since the operation of the entire detection device occurs only when both channels (microwave electromagnetic and seismic) are triggered. In this case, the microwave electromagnetic sensor is triggered due to the microwave field from the installed WU, and the seismic one due to the occurrence of mechanical vibrations in the car body when the WU is attached to its bottom. The probability of the simultaneous occurrence of interference on both channels operating on different physical principles (from passing vehicles passing near pedestrians, airborne interference, etc.) is very small.

The use of coaxial cables with holes in the braid as a transmitting and receiving antenna for a microwave Doppler sensor allows you to:

- localize the detection zone in the space between these cables and sharply reduce the number of false positives from more distant moving objects;

- reduce the shielding effect of a layer of a semiconducting medium (ice, dirt, snow) formed on the underbody of the car during the detection of anti-vehicle mines.

Such coaxial cables stably operate as communication antennas in the bulk of a semiconducting medium [4]. In this device, they are used as “receptors” of microwave sensors, and loading them with active resistances equal in value to the wave one allows you to create a uniform “traveling wave” mode and eliminate these interference “zero” detection zones of this sensor.

A controlled radio transmitter is also introduced into the device, while its controlled input is connected to the output of an AND-OR logic circuit. Information about the state of the monitored vehicle (that is, whether it is mined or not) is transmitted from the radio transmitter to the autonomous radio receiver that is included with this device. The introduction of this remote information retrieval channel provides increased security, since it is possible that a terrorist will undermine a pilot when the driver (or VIP person) approaches the vehicle.

The presence of switching the operating mode of the AND-OR logic allows you to discretely adjust the overall sensitivity and noise immunity of the entire device, depending on the specific operating conditions. These requirements are mutually contradictory [5, 6]. The main AND mode provides the minimum number of false positives in difficult operating conditions under the intense influence of various interferences, and the OR mode provides the highest probability of detecting a VU (almost close to unity), but with a minimum level of interference, which happens in some rare cases.

It should also be noted that the Doppler microwave sensor can be placed in a small radio-transparent plastic case. Its circuit includes a generator, a receiving-indicator device and a vibrating strip antenna. The current consumption is 12 mA, the supply voltage is 12 V. Experiments have shown that the maximum radius of the detection zone for a mine-like object is several meters, which is generally enough.

The device operates as follows.

When a terrorist introduces an explosive device under the vehicle’s bottom, the Doppler microwave sensor 1 fires, and when an explosive device is attached to its bottom, a seismic sensor 3 is triggered. Their operation is almost simultaneous or close in time and recorded in an AND-OR 4 logic operating in AND mode and including controlled radio transmitter 5. After turning on the radio transmitter 5 high-frequency oscillation (Fig.2, a)

u _c (t) = U _c · Cos (w _c t + φ _c ), 0≤t≤T _c , where U _c , w _c , φ _c , T _c are the amplitude, carrier frequency, initial phase, and duration of the high-frequency oscillation ;

from the output of the reference generator 6 started at the indicated switching on, it goes to the first input of the phase manipulator 8, the second input of which is supplied with the modulating code M (t) (Fig. 2, b) from the output of the source 7 of discrete messages. Moreover, the modulating code M (t) contains in digital form all the basic information about the state number of the vehicle, color, its owner and other technical and passport data.

As a result of phase manipulation at the output of the phase manipulator 8, a phase-shift (PSK) signal is generated (Fig. 2, c)

u ₁ (t) = U _c · Cos [w _c t + φ _к (t) + φ _c ], 0≤t≤T _c ,

where φ _к t = {0, π} is the manipulated phase component that displays the phase manipulation law in accordance with the modulating code M (t), and φ _к t = const for Kτ _e <t <(K + 1) τ _e and can change abruptly at t = Kτ _e , i.e. at the borders between elementary premises (K = 1, 2, ..., N-1);

τ _e , N is the duration and number of chips that make up the signal of duration T _c (T _c = N · τ _e );

which is fed to the input of the amplitude modulator 10. The modeling function m (t) of the amplitude modulation (Fig. 2, d) is transmitted to the second input of the last output from the source of 9 continuous messages, for example, transmitting the following voice information: “A VAZ 2108 car is mined, blue color, license plate number BO 352 LD ”. The output of the amplitude modulator 10 produces a complex signal with combined amplitude modulation and phase shift keying (AM-PSK) (figure 2, e)

u ₂ (t) = U _c · [1 + m (t)] · Cos [w _c t + φ _к (t) + φ _c ], 0≤t≤T _c .

The specified signal after amplification in the power amplifier 11 is emitted by the transmitting antenna 12 into the air. The radiation from the radio transmitter 5 of a special alarm indicates mining of the car.

When approaching the car, the driver at a safe distance (in practice, at least 50-70 m) includes an autonomous radio receiver from the kit of the inventive device.

The emitted complex alarm is picked up by the receiving antenna 13 and fed through the high-frequency amplifier 15 to the input of the phase doubler 16, at the output of which a voltage is generated

u ₃ (t) = U _c · [1 + m (t)] · Cos [2w _c t + 2φ _to (t) + 2φ _c ] = U _c · [1 + m (t)] · Cos [2w _c t + φ _c ], 0≤t≤T _c ,

in which phase manipulation is already absent. The spectrum width of the complex AM-QPSK signal is determined by the duration τ _{e of} its elementary signals (Δf _c = 1 / τ _e ). Whereas the width of the spectrum of its second harmonic is determined by the signal duration T _c (Δf ₂ = 1 / T _c ). Consequently, when the phase is multiplied by two complex AM-QPSK signals, its spectrum collapses N times

.

.

This circumstance makes it possible to detect and select a complex AM-FMN signal among other signals and interference.

The spectrum width of the complex AM-QPSK signal is measured using a spectrum analyzer 17, and the spectrum width Δf _{2 of} its second harmonic is measured using a spectrum analyzer 18. The voltages U ₁ and U ₂ are proportional to Δf _c and Δf _2, respectively, from the outputs of the spectrum analyzers 17 and 18 enter the two inputs of the comparison unit 19. If two inputs of the comparison unit 19 receive approximately the same voltage intensity, then there is no voltage at its output. If two inputs of the comparison unit 19 receive different voltages in intensity, then a constant voltage appears at its output.

Since U ₁ >> U ₂ , then at the output of the comparison unit 19, a constant voltage is generated, which is supplied to the control input of the key 20, opening it. In the initial state, the key 20 is always closed. In this case, the received AM-QPSK signal from the output of the high-frequency amplifier 15 passes through the public key 20 to the information input of the synchronous detector 22 and to the input of the amplitude limiter 21, the output of which is the PSK signal (Fig. 2 e)

u ₄ (t) = U ₀ · Cos [w _c t + φ _к (t) + φ _c ], 0≤t≤T _c ,

where U ₀ is the limit threshold.

This signal is used as the reference voltage and is supplied to the reference input of the synchronous detector 22. At the output of the latter, a low-frequency voltage is generated (figure 2, g)

u _н1 (t) = U _н1 · [1 + m (t)],

;Where

;

To ₁ - the transfer coefficient of the synchronous detector,

which is proportional to the modulating function m (t), is amplified by the power of the amplifier 23 audio frequency signals and is fed to an acoustic emitter 24, for example a loudspeaker that provides listening to a speech information signal: “VAZ 2108 car is lighted, color is blue, license plate number is BO 352 LD”.

Simultaneously, the voltage u ₃ (t) from the output of the phase doubler 16 is fed to the input of the amplitude limiter 25, at the output of which a harmonic voltage is generated (figure 2, h)

u ₅ (t) = U ₀ · Cos (2w _c t + 2φ _c ), 0≤t≤T _c .

This voltage is allocated narrow-band filter 26, and then is divided by phase into two in the phase divider 27 into two (figure 2, and):

u ₆ (t) = U ₀ · Cos (w _c t + φ _c ), 0≤t≤T _c .

The initial phase of the voltage obtained can have two stable values φ _c and φ _c + π. This is easy to show analytically. If division is performed similar to the previous one, but after adding the angle 2π to the argument, which does not change the initial voltage, then after division by two, the voltage is shifted in phase by π:

.

.

Therefore, the ambiguity of the initial phase of the voltage obtained follows from the fission process itself. The physically indicated ambiguity of the initial phase is explained by the unstable operation of the phase divider 27 into two. The harmonic voltage u ₆ (t) obtained in this way is extracted by a narrow-band filter 28, used as a reference voltage, and fed through the balance switch 31 to the reference input of the phase detector 32, to the information input of which the PSK signal u ₄ (t) is supplied from the output of the amplitude limiter 21.

However, this causes the phenomenon of “reverse operation”, which is caused by spasmodic and transitions of the initial phase of the reference voltage from one state φ _c to another φ _c + π under the influence of noise, short termination of reception and other factors. These transitions during the reception of a complex signal occur at random times, for example t ₁ , t ₂ . At the same time, at the output of the phase detector 32, a distorted analog of the modulating function M _and (t) is allocated (Fig. 2, k).

To eliminate the phenomenon of "reverse work" voltage u ₆ (t) (figure 2, and) from the output of the narrow-band filter 28 is simultaneously supplied to the input of the frequency detector 29, which is designed to detect the occurrence of "reverse work". When the initial phase of the reference voltage u ₆ (t) changes abruptly by 180 ° at time t ₁ (Fig. 2, i), a positive short pulse appears at the output of frequency detector 29, and when the initial phase jumps by -180 ° at time t ₂ (the return of the initial phase of the reference voltage to its original state) is a negative short pulse (figure 2, l).

Alternating short pulses from the output of the frequency detector 29 control the operation of the trigger 30, the output voltage of which, in turn, is controlled by the double-balanced switch 31. In a stable state, when the initial phase of the reference voltage u ₆ (t) coincides, for example, with zero initial phase of the received QPSK signal, a negative voltage is generated at the output of the trigger 30 and the balance switch 31 is in its original position, at which the reference voltage comes from the output of the narrowband filter 28 to the reference input of the phase detector 32 without change.

When the initial phase of the reference voltage u ₆ (t) changes abruptly by 180 °, due, for example, to the unstable operation of the phase divider 27 into two under the influence of interference, the trigger 30 is transferred by a positive short pulse from the output of the frequency detector 29 to another stable state. The output voltage of the trigger 30 at time t ₁ becomes and remains positive until the next jump in the initial phase at time t ₂ , which returns the initial phase of the reference voltage to its original state.

The positive output voltage of the trigger 30 (Fig.2, m) transfers the balance switch to another stable state, in which the reference voltage from the output of the narrow-band filter 28 is supplied to the reference input of the phase detector 32 with a change in the initial phase by -180 °. This allows you to eliminate the instability of the initial phase of the reference voltage caused by its abrupt change under the influence of interference, and the associated "reverse work".

Therefore, the frequency detector 29 provides detection of the moment of occurrence of "reverse operation", and the trigger 30 and the double balance switch 31 eliminates it.

The reference voltage u ₆ (t) (Fig.2, n) with a stable initial phase is supplied to the reference input of the phase detector 32, the output of which is formed by a low-frequency voltage

u _n2 (t) = U _{n2 Cosφ to} (t),

;Where

;

K ₂ - the transfer coefficient of the phase detector,

proportional to the modulating code M (t) (Fig.2, b).

The operation of the device described above corresponds to the case of receiving complex signals with combined amplitude modulation and phase shift keying (AM-PSK) in the absence of narrow-band interference. This case does not always correspond to real conditions.

In real conditions, an input mixture containing a useful signal with combined amplitude modulation and phase shift keying (AM-FMN)

u ₂ (t) = U _c · [1 + m (t)] · Cos [w _c t + φ _к (t) + φ _c ]

and narrowband type interference

u _p (t) = U _p Cos (w _p t + φ _p ),

where w _p ≠ w _c , w _p -w _c = Δw≤Δw _n ,

Δw _n is the passband of the low-pass filter;

from the output of the amplifier 15 high-frequency through the public key 20 is fed to the input of the first amplitude limiter 21, the output of which is formed voltage:

u ₇ (t) = U ₀ · Cos [w _c t + φ _к (t) + φ _c ],

u _p1 (t) = U ₀ Cos (w _p t + φ _p ),

which go to the first (information) input of the phase detector 32, to the first inputs of the multipliers 34 and 35. The reference voltage

u ₆ (t) = U ₀ Cos (w _c t + φ _c )

from the output of the balance switch 31 simultaneously through the phase shifters 36 and 37 by + 45 ° and -45 °, respectively, is supplied to the second inputs of the multipliers 34 and 35.

Then the output of the phase detector 32 can be written

u ₈ (t) = [u ₇ (t) + u _п1 (t)] · u ₆ (t) = U ₀ · {Cos [w _c t + φ _к (t) + φ _c ] + Cos (w _п t + φ _p )}

· U ₀ · Cos (w _c t + φ _s ) = U ₁ · Cosφ _to (t) + U ₁ · Cos [(w _p -w _c ) t + φ _p -φ _c ],

.Where

.

Thus, when w _p -w _c = Δw≤Δw _n at the output of the phase detector 32, along with the useful component, a component appears, caused by the influence of narrow-band interference on the radio receiver 14.

At the output of the first low-pass filter 38 in this case we will have

u ₁₀ (t) = [u ₇ (t) + u _п1 (t)] · u ₉ (t) = U ₀ · {Cos [w _c t + φ _к (t) + φ _c ] + Cos (w _п t + φ _p )}

· U ₀ · Cos (w _c t + φ _s + 45 °) = U ₁ · Cos [φ _to (t) -45 °] + U ₁ · Cos [(w _p- w _c ) t + φ _p -φ _c -45 °]

Similarly, at the output of the second low pass filter 39 we will have

u ₁₂ (t) = [u ₇ (t) + u _p1 (t)] · u ₁₁ (t) = U ₀ · {Cos [w _c t + φ _к (t) + φ _c ] + Cos (w _p t + φ _p )}

· U ₀ · Cos (w _c t + φ _s -45 °) = U ₁ · Cos [φ _k (t) + 45 °] + U ₁ · Cos [(w _p- w _c ) t + φ _p -φ _c + 45 °]

The output of the first block 40 subtraction we get the difference

u ₁₃ (t) = u ₇ (t) -u ₁₀ (t) = 2U ₁ · Sin [(w _n -w _c ) t + φ _n -φ _s ] · Sin45 °.

From the difference obtained, it can be seen that it is an estimate of the interference component, which differs from the interference component U ₁ · Cos [(w _p -w _c ) t + φ _p -φ _s ] at the output of the phase detector 32 with a constant amplitude factor of 2Sin45 ° and rotation at + 90 ° phase.

The voltage u ₁₃ (t) from the output of the first subtraction unit 40 is fed to the input of the phase shifter 41 by + 90 °, at the output of which a voltage is generated

u ₁₄ (t) = U ₁ · Cos [(w _p -w _c ) t + φ _p -φ _s ].

This voltage is supplied to the second input of the second subtraction unit 42, the first input of which is supplied with voltage u ₈ (t) from the output of the phase detector 32.

After subtracting from u ₈ (t) the voltage u ₁₄ (t) at the output of the second block 42, we obtain

u ₁₅ (t) = u ₈ (t) -u ₁₄ (t) = U ₁ Cosφ _to (t).

The interference component at the output of the second subtraction block 42 is absent.

The voltage u ₁₅ (t) is fixed by the registration unit 33. Therefore, in block 33 registration is recorded in digital form information about the mined vehicle. At the same time, signals with combined amplitude modulation and phase shift keying (AM-PSK) are used on one carrier frequency.

From the point of view of detection, these signals have energetic and structural secrecy.

The energy secrecy of complex AM-FMN signals is due to their high compressibility in time or spectrum with optimal processing, which reduces the instantaneous radiated power. As a result, a complex AM-QPSK signal at the receiving point may be masked by noise. Moreover, the energy of a complex AM-QPSK signal is by no means small; it is simply distributed over the time-frequency domain so that at each point in this region the signal power is less than the noise power.

The structural secrecy of complex AM-FMN signals is caused by a wide variety of their forms and significant ranges of parameter values, which makes it difficult to optimally or at least quasi-optimally process complex AM-FMN signals of an a priori unknown structure in order to increase the sensitivity of the receiving device.

Complex AM-FMn signals allow the use of a new type of selection - structural selection. This means that there is a new opportunity to distinguish these signals from other signals and interference operating in the same frequency band and at the same time intervals.

The high information content and the availability of remote radio communications determine the feasibility of widespread use of the device for detecting mined cars. So, for example, when equipping a post or operational traffic police officers with simple and, therefore, small-sized wearable receiving devices, any of the vehicles equipped with a Doppler microwave sensor, seismic sensor and radio transmitter can be quickly detected, inspected and cleared using special means by appropriate specialists .

The advantage of the device is also the high efficiency of using the frequency range, since a radio channel of the same frequency can be used to detect many mined cars, for example f _c = 26945 kHz, allocated for remote security alarm.

Thus, the proposed device in comparison with the prototype and other technical solutions for a similar purpose provides increased noise immunity of the detection device anti-vehicle mines. This is achieved by suppressing narrow-band interference by the phase-compensation method and using two additional processing channels for the received additive mixture of the useful signal and narrow-band interference.

Information sources

1. Ivlev S., Scherbakov G. et al. Search and disposal of explosive devices. - M.: AEN RF, 1996, p. 48-51, 59-69.

2. Another banker was blown up in a car. - Moscow Komsomolets, 1994, December 12.

3. The foreign car exploded when you turn the ignition key. - Moscow Komsomolets, 1997, June 22.

4. Cable with holes // Radio, 1997, 8. - S.68-69.

5. Walker F. Electronic security systems. - Translation from English, ed. JSC "Technopolis" and the magazine "Behind the Wheel", 1991. - P.25-67.

6. Dikarev V.I., Koinash B.V., Sandulov Yu.A., Salnikov V.P. Explosive Hazards: Methods and means of search, detection, neutralization and disposal. - St. Petersburg: "Doe", 2001.

Claims (1)

An anti-vehicle mine detection device comprising a Doppler microwave sensor consisting of a generator, a receiver-indicator device and an antenna, an infra-low-frequency seismic sensor of vertical vibrations of the vehicle body mechanically rigidly connected to its body, a switchable AND-OR logic circuit, a controlled radio transmitter and an autonomous radio receiver, while the outputs of the Doppler microwave and seismic sensors are connected to the inputs of the AND-OR logic circuit, the output of which is connected to the control the antenna input of the controlled radio transmitter, the antenna of the Doppler microwave sensor is made of coaxial transmitting and receiving cables with perforations operating on the principle of "leakage of waves" and loaded with active resistances equal in magnitude to their wave impedance, the transmitting cable is attached to the metal bottom of the vehicle its external perimeter, and the receiving coaxial cable is attached inside to the bottom along the transmitting cable at a distance of 0.1-0.3 m from it, controlled radio transmission The IR is made in the form of a series-connected reference generator, a phase manipulator, the second input of which is connected to the output of a source of discrete messages, an amplitude modulator, the second input of which is connected to the output of a source of analog messages, a power amplifier and a transmitting antenna, an autonomous radio receiver is made in the form of a series-connected receiving antenna, high-frequency amplifier, phase doubler, second spectrum analyzer, comparison unit, the second input of which through the first analyzer the device is connected to the output of a high-frequency amplifier, a key, the second input of which is connected to the output of a high-frequency amplifier, a first amplitude limiter, a synchronous detector, the second input of which is connected to the output of a key, an audio signal amplifier, and an acoustic emitter, a second is connected in series to the output of the phase doubler amplitude limiter, first narrow-band filter, phase divider into two, second narrow-band filter, frequency detector, trigger, balance switch, the second input of which is connected with the output of the second narrow-band filter, and a phase detector, the second input of which is connected to the output of the first amplitude limiter, as well as a registration unit, characterized in that the stand-alone radio receiver is equipped with two multipliers, two low-pass filters, a phase shifter at + 45 °, a phase shifter at - 45 °, phase shifter by + 90 °, two subtraction units, and the first multiplier is connected in series to the output of the first amplitude limiter, the second input of which is connected to the output through the phase shifter at + 45 ° ohm of the balance switch, the first low-pass filter, the first subtraction unit, the phase shifter + 90 ° and the second subtraction unit, the second input of which is connected to the output of the phase detector, and the output is connected to the registration unit, the second multiplier is connected in series to the output of the first amplitude limiter, the second whose input is connected through the -45 ° phase shifter to the output of the balance switch, and a second low-pass filter, the output of which is connected to the second input of the first subtraction unit.

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