RU2526588C1 - Apparatus for detecting people under debris and searching for explosives and narcotics - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: apparatus for detecting people under debris and searching for explosives and narcotics comprises, worn on a tracker dog 1, a collar 2, a mobile primary converter 3 and a secondary converter 12. The primary converter 3 comprises tactile sensors 4.1 and 4.2, a switch 5, an amplifier 6, a modulator 7, a radio transmitter 8, a power supply 9, a light 10 a sound 11 beacon, a driving generator 18, a phase-shift modulator 19, a flip-flop 17, a unipolar rectifier diode 20, an integrator 21, a threshold unit 22, a switch 23, a power amplifier 24 and a transmitting antenna 25. The secondary converter 12 comprises a dipole antenna 26, a frame antenna 27, high frequency amplifiers 28 and 29, amplitude detectors 30 and 31, a divider unit 32, a threshold unit 33, a switch 15, demodulators 14 and 44, multipliers 34, 35, 38 and 39, narrow-band filter 36 and 40, low-pass filters 37 and 41, phase inverters 42 and 43, a subtractor unit 45 and a recorder 16.

EFFECT: high noise-immunity and reliability of receiving and demodulating phase-shift modulated composite signals by suppressing narrow-band interference.

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Description

The proposed device relates to control and search tools, namely, devices for detecting the location of people caught in rubble formed as a result of a natural (earthquake, tornado, tsunami, etc.) or other disaster, and the search for explosives and drugs, and can be used in case of technological accidents, natural disasters, terrorist acts and in the prevention of actions dangerous for the population.

Widely known are the mechanisms for detecting and searching for people trapped in rubble, explosives and narcotic substances with the help of a trained animal, for example, a service dog of the search service with a highly sensitive sense of smell (K. Chistyakov Education and training of a service dog. - St. Petersburg: Publishing House "North-West"; Rostov -on-Don: Phoenix Publishing House, 2005, - 336 s, pp. 152-153).

The nervous system of animals, especially the trained service dog of the search service, like humans, when an irritant (object), for example, a predatory animal, appears in their field of vision instantly causes a reaction in the form of stress. This stress is characterized by increased heart rate, which can be recorded by the amplitude and number of heartbeats. Moreover, the dog has an acute sense of smell, hundreds of times larger than that of humans, so the most important skills in dogs of the search service are the skills associated with instinct, i.e. trace work, selection of objects, search of the area. Consequently, the sense of smell is a more appropriate organ than vision, it must be developed, a dog must be trained to respond to the smells of humans, explosives and drugs, which, with the acquisition of skills, cause an increased heartbeat.

However, such a mechanism for detecting an anomalous phenomenon is functionally limited in that it is time-consuming (from the start of detection to decision making), and also does not allow the detection and search process to be automated. In addition, if the smells are insignificant, then the dog may not give a voice (barking), and at night it is difficult to notice if the dog handler has released the dog’s leash.

Known devices for detecting people under the rubble and search for explosives and narcotic substances (RF patents No. 2.079.100, 2.186.411, 2.206.107, 2.248.235, 2.248.593, 2.288.488, 2.426.141; US patent No. 4.641 .566; Dikarev V.I. Safety, protection and salvation of a person. St. Petersburg, 2007, p. 460-467 and others).

Of the known devices, the closest to the proposed one is the "Device for detecting people under the rubble and searching for explosives and narcotic substances" (RF patent No. 2.426.141, G01S1 / 02, 2010), which is chosen as a prototype.

The specified device contains a mobile primary transducer located on the service dog, and a secondary transducer located on the control point. The mobile primary transducer contains tactile sensors made in the form of piezoelectric elements fixed contact on the skin of a dog’s body in places of maximum sensation of a pulse beat.

When a subject is detected (person, drug, explosive), the heart rate of the dog increases, the light and sound beacons of the primary transducer are triggered, according to which the cynologist visually and hearing determines the location of the dog in the detected subject, which is important at night.

Under the conditions of a large metropolis at considerable distances between the service dog and the dog handler, reliable determination of the location of the dog in the detected subject is ensured by the radio channel using complex signals with phase shift keying and receiving antennas with circular and cardioid radiation patterns.

However, the receiver, which is part of the secondary converter, does not allow suppressing narrow-band interference and does not provide high noise immunity and reliability of reception and demodulation of complex signals with phase shift keying.

An object of the invention is to increase the noise immunity and reliability of reception and demodulation of complex signals with phase shift keying by suppressing narrow-band interference.

The problem is solved in that a device for detecting people under rubble and searching for explosive and narcotic substances, containing, in accordance with the closest analogue, a collar for placement on a trained animal, for example, a dog of the search service, a mobile primary transducer containing light and sound beacons and tactile sensors made in the form of piezoelectric elements fixed contact on the skin of the body of a trained animal in places of maximum sensation of heartbeat, outputs connected through a series of connections a commutator, amplifier, and modulator with an input to the radio transmitter, wherein the switch, amplifier, modulator, radio transmitter, light and sound beacon, and the power supply of the units of the primary mobile transducer are mounted on the collar, and the secondary transducer located at the control point and containing serially connected radio receiver and the first demodulator, as well as the registrar, while the modulator is made in the form of a trigger amplifier, phase manipulator, second input One of which is connected to the output of the master oscillator, and the first key, connected in series to the output of the trigger of a unipolar valve, integrator and the first threshold block, the output of which is connected to the second input of the first key, the radio transmitter is made in the form of series-connected to the output of the first key of the power amplifier and transmitting antenna , the light and sound beacons are connected to the output of the first threshold unit, the radio signal receiver is made in the form of a recorder of a vibrator and frame antennas, to the output of a vibrator a the antennas are connected in series to the first high-frequency amplifier, the first amplitude detector, the division unit, the second threshold block and the second key, the second input of which is connected to the output of the first high-frequency amplifier, the second high-frequency amplifier and the second amplitude detector are connected in series to the outputs of the vibrating and loop antennas, the output of which is connected to the second input of the division unit, the first demodulator is made in the form of series-connected to the output of the second key of the first multiplier, the second input of which o is connected to the output of the first low-pass filter, the first narrow-band filter, the second multiplier, the second input of which is connected to the output of the second key, and the first low-pass filter, differs from the closest analogue in that the secondary converter is equipped with a second demodulator and a subtraction unit, the second demodulator made in the form of series-connected to the output of the second key of the third multiplier, the second input of which is connected to the output of the second phase inverter, the second narrow-band filter, the first phase ertora fourth multiplier, a second input coupled to an output of the second switch, the second lowpass filter and a second phase inverter, the outputs of the first and second lowpass filters through subtractor connected to the logger.

The structural diagram of the device for detecting people under the rubble and searching for explosive and narcotic substances is shown in figures 1, 2 and 3. The type of receiving antennas, their radiation patterns and direction-finding characteristics are shown in figures 4, 5 and 6. Timing diagrams explaining the operation of the device, shown in Fig.7.

A device for detecting people under rubble and searching for explosive and narcotic substances comprises a collar 2 dressed in a service dog 1 with a highly sensitive sense of smell, a mobile primary transducer 3, and a secondary transducer 12.

The primary transducer 3 includes tactile sensors 4.1 and 4.2, made in the form of piezoelectric elements fixed on the skin of a trained animal in places of maximum sensation of heartbeat, the outputs of which are connected in series with a switch 5, amplifier 6, trigger 17, phase manipulator 19, the second input of which connected to the output of the master oscillator 18, the first key 23, the power amplifier 24 and the transmitting antenna 25, the unipolar valve 20, the integrator 21 and the first threshold block 22 are connected in series to the output of the trigger 17 the output of which is connected to the second input of the first key 23, to the light 10 and sound 11 beacons. The primary Converter 3 also contains a power source 9.

The trigger 17, the master oscillator 18, the phase manipulator 19, the unipolar valve 20, the integrator 21, the first threshold unit 22 and the first key 23 form a modulator 7. The power amplifier 24 and the transmitting antenna 25 form a radio transmitter 8.

The secondary Converter 12 contains a vibrating antenna 26 and a loop antenna 27. The first high-frequency amplifier 28, the first amplitude detector 30, the division unit 32, the second threshold unit 33, the second key 15, the second input of which is connected to the output of the first high-frequency amplifier 28, the first multiplier 34, the second input of which is connected to the output of the first low-pass filter 37, the first narrow-band filter 36, the second multiplier 35, the second input of which is connected to the output of the second key 15, the first low pass filter 37. A second high-frequency amplifier 29 and a second amplitude detector 31 are connected in series to the outputs of the vibrator antenna 26 and the loop antenna 27, the output of which is connected to the second input of the division unit 32.

A third multiplier 38 is connected to the output of the key 15, the second input of which is connected to the output of the second phase inverter 43, the second narrow-band filter 40, the first phase inverter 42, the fourth multiplier 39, the second input of which is connected to the output of the key 15, the second low-pass filter 41 and the second phase inverter 43.

Antennas 26 and 27, high-frequency amplifiers 28 and 29, amplitude detectors 30 and 31, division block 32, second threshold block 33 and second key 15 form a radio signal receiver 13. Multipliers 34 and 35, a narrow-band filter 36 and a low-pass filter 37 form a demodulator 14.

The multipliers 38 and 39, the narrow-band filter 40, the low-pass filter 41, the phase inverters 42 and 43 form a demodulator 44. The outputs of the filters 37 and 41 are connected to the registrar 16 through the subtraction unit 45.

The source 9 is autonomous (battery-powered), it feeds the blocks of the primary transducer 3. Tactile sensors 4.1 and 4.2 are fixed in contact with the skin of the dog’s body 1 at the places of maximum pulse beat sensation, and switch 5, amplifier 6, modulator 7, radio transmitter 8, power supply 9, beacons 10 and 11 of the mobile Converter 3 are installed on the collar 2.

The receiver 13 of the radio signals, the demodulator 14, the demodulator 44 and the recorder 16 of the secondary Converter 12 are connected in series and are powered by a current from a stationary power source (not shown). The transducer 12 can be placed both at a stationary point for detecting victims and searching for suspicious substances, and at mobile points constantly moving in the search area. The radio transmitter 8 and radio 13 are constructed on the principle of a mobile phone and do not require a repeater, since the debris from the destruction of residential buildings and engineering structures, for example, from terrorist acts, does not exceed 2-4 meters and the structure of the building material after destruction is not monolithic, but porous, therefore the radio signal is easily received by the radio receiver 13 located in the search area.

Tactile sensors 4.1 and 4.2 are installed on the body of dog 1 in an amount of at least two to increase the reliability of the device. It should be noted that it is inexpedient to train a dog to smell at the same time a person, a drug and an explosive. It is better to train dogs for the smell of one subject (either a person, or a drug, or an explosive).

The device operates as follows.

When an emergency signal is received, the search service personnel, equipped with an arsenal of the necessary means for detecting and searching for subjects of animate and inanimate origin, are sent to the site of this outbreak. In this case, the blocks of the primary 3 and secondary 12 converters are connected to voltage sources in advance for heating the equipment. At the site of the outbreak, a service dog 1 equipped with a primary transducer 3 is released by the dog handler from the leash, and the dog independently, for example, traces (smells), searches for the desired subject.

Piezoelectric sensors 4.1 and 4.2, fixed contact on the skin of the dog’s body in places of maximum sensation of heartbeat, convert the strokes of her pulse into short positive impulses (Fig. 7, a). These pulses through the switch 5 and the amplifier 6 are fed to the counting input of the trigger 17 and are converted into a sequence of rectangular bipolar pulses of duration τ _e (Fig.7, b), which in the form of a modulating code M (t) arrive at the first input of the phase manipulator 19. On the second input of the latter from the output of the master oscillator 18 is fed a high-frequency oscillation (Fig.7, c)

u _c (t) = U _c Cos (ω _c t + φ _c ), 0≤t≤T _s ,

where U _c , ω _s , φ _s , T _s - amplitude, carrier frequency, initial phase and

duration of high-frequency oscillation.

At the output of the phase manipulator 19, a complex signal with phase shift keying (QPSK) is generated (Fig. 7, g)

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

where φ _к (t) = {0, π} is the manipulated component of the phase that displays the law of phase manipulation in accordance with the modulating code M (t) (Fig. 7, b), and φ _к (t) = const at Кτ _э < 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); τ _e , N - the duration and number of chips that make up a signal of duration T _s (T _s = τ _e · N);

The modulating code M (t) (Fig. 7, b) from the output of the trigger 17 simultaneously enters the input of a unipolar valve 20, the output of which produces positive rectangular pulses (Fig. 7, d), which are fed to the input of the integrator (drive) 21. As an integrator 21 can be used, for example, a capacitor, which is sequentially charged and discharged (Fig.7, e). The voltage of the integrator 21 is compared with the threshold voltage U _then in the threshold block 22. The threshold level U _{then is} not exceeded if the dog is in a normal (not excited) state (Fig. 7, e).

When a subject (a person, a drug, an explosive substance) is detected in a dog, the heartbeat becomes more frequent and intensifies, which is recorded in places of blood flow by tactile sensors 4.1 and 4.2. These sensors generate short positive pulses of a higher repetition rate (Fig.7, g). At the output of the unipolar valve 20, in this case, a sequence of positive rectangular pulses is formed (Figs. 7, 3), which, after integration, exceed the threshold level U _nop in the threshold block 22 (Fig. 7, and). When the threshold level U _{nop is} exceeded, for example, at time t ₀ , a constant voltage is generated in the threshold block 22 (Fig. 7, k), which is supplied to the control input of the key 23, opening it. In the initial state, the keys 23 and 15 are always closed.

At the same time, a constant voltage from the output of the threshold unit 22 is supplied to the light 10 and sound 11 beacons, which are triggered. Thereby, visually and by ear, the dog handler determines the location of dog 1 and the detected subject, which is important at night and is possible only at a short distance.

The generated complex QPSK signal uj (t) (Fig. 7, d) from the output of the phase manipulator 19 through the public key 23 and the power amplifier 24 enters the transmitting antenna 25, is radiated by it, is received by the antennas 26, 27 and through the amplifiers 28, 29 high-frequency and amplitude detectors 30, 31 is fed to two inputs of the block 32 division.

The amplitude of the signal at the output of the amplitude detector 30 does not depend on the direction of arrival of the input signal due to the circular pattern of the first receiving antenna 26 (figure 5). The second receiving antenna 27 together with the first receiving antenna 26 form a cardioid radiation pattern (FIGS. 4, 5). The cardioid radiation pattern is rotated manually or automatically (not shown) until the zero dip is combined with the direction of arrival of the signals (Fig. 5). The amplitude of the signal from this direction at the output of the amplitude detector 31 is close to zero, therefore, the voltage will be maximum at the output of the division unit 32 at this moment. The threshold value U _then set so that the threshold unit 33 is triggered only by signals coming from the zero direction. When the threshold unit 33 is activated, the latter generates a constant voltage, which is supplied to the control input of the key 15, opening it. In this case, the complex QPSK signal u ₁ (t) (Fig. 7, d) from the output of the high-frequency amplifier 28 through the public key 15 is supplied to the first inputs of the multipliers 34, 35, 38 and 39.

The second inputs of the multipliers 35 and 39 from the outputs of the narrow-band filter 36 and the phase inverter 42 are supplied with reference voltage, respectively:

u ₀₁ (t) = U ₀ Cos (ω _c t + φ _s ),

u ₀₂ (t) = - U ₀ · Cos (ω _c t + φ _s ), 0≤t≤T _c .

At the output of the multipliers 35 and 39, the total voltages are formed, respectively:

u _∑1 (t) = U _∑ · Cosφ _to (t) + U _∑ · Cos [2ω _c t + φ _to (t) + 2φ _s ],

u _∑2 (t) = - U _∑ · Cosφ _to (t) -U _∑ · Cos [2ω _c t + φ _to (t) + 2φ _s ], 0≤t≤T _c ,

.Where $$U_{\sum }=\frac{\mathrm{one}}{2}{U}_c\cdot U_0$$

.

Filters 37 and 41 distinguish low-frequency voltages, respectively:

u _H1 (t) = U _Σ · Cosφ _to (t),

u _n2 (t) = - U _∑ · Cosφ _k (t), 0≤t≤T _s ,

proportional to the modulating code M (t) (Fig.7, b). These low-frequency voltages are applied to two inputs of the subtraction unit 45. When you subtract one of the other specified low-frequency voltages, taking into account their opposite polarity, the output of the subtraction unit 45 produces a doubled (total) low-frequency voltage

u _n (t) = u _n1 (t) -u _n2 (t) = U _n Cosφ _k (t),

where U _n = 2U _∑ ,

those. it turns out the addition in absolute value of the stresses u _н1 (t) and u _н2 (t). In this case, the additive amplitude noise passes through two demodulators 14 and 44 in the same way, changing the amplitudes of the output detected voltages in the same direction. But in block 45 of subtraction, they are subtracted, remaining unipolar, i.e. suppressed, mutually compensated.

The voltage u _n (t) is supplied to the input of the recorder 16.

Therefore, the direction to the source of radio emissions (IRI) (dog) (true azimuth βand) is determined by the position of the loop antenna 27 at the time of the signal to the recorder 16.

The low-frequency voltage u _Н2 (t) from the output of the low-pass filter 41 is fed to the input of the phase inverter 43, the output of which is formed of a low-frequency voltage

u _n3 (t) = U _Cos · Cosφ _to (t), 0≤t≤T _s .

Low-frequency voltages u _н1 (t) and u _н3 (t) from the output of the low-pass filter 37 and the phase inverter 43 are supplied to the second input of the multipliers 34 and 38, respectively, at the output of which harmonic oscillations are formed:

u ₀₁ (t) = U ₁ · Cos (ω _c t + φ _s ) + U ₁ · Cos [ω _c t + 2φ _to (t) + φ _s ] = U ₀ · Cos (ω _c t + φ _s ) ,

u ₀₃ (t) = U ₁ · Cos (ω _c t + φ _s ) + U ₁ · Cos [ω _c t + 2φ _to (t) + φ _s ] = U ₀ · Cos (ω _c t + φ _s ) ,

, U₀=2U_l, 2φ_к(t)={0,2 π}.Where $$U_{\sum }=\frac{\mathrm{one}}{2}{U}_c\cdot U_{\Sigma }$$

, U ₀ = 2U _l , 2φ _k (t) = {0.2 π}.

These oscillations are highlighted by narrow-band filters 36 and 40, respectively. The oscillation U ₀₁ (t) is used as a reference voltage and from the output of the narrow-band filter 36 is fed to the second input of the multiplier 35. The oscillation U ₀₃ (t) is allocated by the narrow-band filter 40 and is fed to the input of the phase inverter 42, the output of which oscillates

u ₀₂ (t) = - U ₀ · Cos (ω _c t + φ _s ), which is used as a reference voltage and is fed to the second input of the multiplier 39.

Under the conditions of a large metropolis at considerable distances between the service dog and the dog handler, a reliable location of the dog in the detected subject (person, drug, explosive) is provided by the radio channel using complex signals with phase shift keying and receiving antennas with circular and cardioid radiation patterns.

Complex QPSK signals have high energy and structural secrecy.

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

The structural secrecy of complex QPSK signals is due to the wide variety of their shapes and significant ranges of parameter changes, which makes it difficult to optimize or at least quasi-optimal processing of complex signals of an a priori unknown structure in order to increase the sensitivity of the receiver.

Demodulators of complex QPSK signals constructed according to the “self-service” scheme extract the necessary reference voltage from the received QPSK signal itself and are free from the phenomenon of “reverse work” inherent in the well-known demodulators of complex QPSK signals (A. A. Pistolkors and V. Siforov schemes. I., Kostas D.F. and Travin G.A.).

Thus, the proposed device in comparison with the prototype provides increased noise immunity and reliability of reception and demodulation of complex signals with phase shift keying. This is achieved by suppressing narrow-band interference and increasing the signal-to-noise ratio at the output of the subtraction unit using two universal demodulators, the inverse output voltages of which are added in absolute value, and unipolar interference voltages are mutually subtracted.

Claims (1)

A device for detecting people under rubble and searching for explosive and narcotic substances, containing a collar for placement on a trained animal, for example, a dog of the search service, a mobile primary transducer containing light and sound beacons and tactile sensors made in the form of piezoelectric elements fixed contact on the skin of the trained body animal in places of maximum sense of heartbeat, outputs connected through a series-connected switch, amplifier and modulator with the input of the radio transmitter, while a switch, an amplifier, a modulator, a radio transmitter, a light and sound beacon, and a power source for the blocks of the primary mobile converter are installed on the collar, and a secondary converter located at the control point and containing serially connected radio signal receiver and the first demodulator, as well as a recorder, the modulator is made in in the form of a trigger amplifier, a phase manipulator connected in series to the output of the trigger, the second input of which is connected to the output of the master oscillator, and the first key, after connected to the output of the trigger of a unipolar valve, integrator and the first threshold block, the output of which is connected to the second input of the first key, the radio transmitter is made in the form of series-connected to the output of the first key of the power amplifier and transmitting antenna, a light and sound beacon are connected to the output of the first threshold block, the radio signal receiver is made in the form of a recorder of a vibrator and loop antennas, the first high-frequency amplifier is connected in series to the output of the vibrator antenna, the second amplitude detector, the division block, the second threshold block and the second key, the second input of which is connected to the output of the first high-frequency amplifier, the second high-frequency amplifier and the second amplitude detector, the output of which is connected to the second input of the division block, are connected in series to the outputs of the vibrator and frame antennas , the first demodulator is made in the form of series-connected to the output of the second key of the first multiplier, the second input of which is connected to the output of the first low-pass filter, the first narrow-band a filter, a second multiplier, the second input of which is connected to the output of the second key, and a first low-pass filter, characterized in that the secondary converter is equipped with a second demodulator and a subtraction unit, the second demodulator made in the form of series-connected to the output of the second key of the third multiplier, the second input which is connected to the output of the second phase inverter, the second narrow-band filter, the first phase inverter, the fourth multiplier, the second input of which is connected to the output of the second key, the second of the low-pass filter and the second bass reflex, the outputs of the first and second low-pass filters through the subtraction unit are connected to the input of the recorder.

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