RU2360809C1 - Vehicle antitheft device - Google Patents

Abstract

FIELD: transportation.

SUBSTANCE: invention is related to devices for prevention of unauthorised use or theft of transport means (TM) with use of radio channel. Control post is equipped with transmitter, comprising master oscillator, modulating code generator, phase manipulator, power amplifier, duplexer, transceiving antenna, high frequency amplifier, heterodyne, two mixers, two multipliers, band filter, phase detector, computer, two phase changers of 90°, two amplifiers of intermediate frequency, summator, narrow-band filter 80, amplitude detector and switch. Receiver installed on TM comprises antenna, high frequency amplifier, heterodyne, two mixers, two amplifiers of intermediate frequency, two phase changers of 90°, summator, multiplier, narrow-band filter, amplitude detector, two switches, two meters of spectrum width, frequency doubler, comparison unit, two threshold units, frequency divider into two, narrow-band filter, phase detector, unidirectional valve and accumulator. Executive unit available on TM includes ignition switch, accumulator, ignition coil, switch, breaker, two relays, four signal lamps, sound alarm, unit of time delay, transistor, two resistors, voltage reference diode and capacitor. TM transponder comprises piezocrystal, set of reflectors, system of electrodes, microstrip antenna, two busbars.

EFFECT: increased noise immunity of receivers and reliability of remote search and detection of stolen TM by means of false signals suppression received by mirror and combination channels.

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Description

The proposed device relates to transport equipment, in particular to devices for preventing unauthorized use or theft of vehicles using a radio channel.

Anti-theft devices using a radio channel are known (for example, RF patents Nos. 2,006.394, 2.011.574, 2.011.575, 2.021.927, 2.033.352, 2.033.353, 2.042.548, 2.058.906, 2.061.320, 2.061 .321, 2.254.245, 2.302.953 and others).

Of the known devices, the closest to the proposed one is "Anti-theft device for a vehicle" (RF patent No. 2.302.953, B60R 25/04, 2006), which is selected as a prototype.

The specified device provides remote search and detection of a stolen vehicle located in the general traffic stream, and its detention, or being in a static de-energized state in a parking lot, in a garage or just outside.

In this technical solution, the receivers are implemented according to a superheterodyne circuit. This allows you to increase the sensitivity, dynamic range and range of the device.

However, in these receivers, the same value of the intermediate frequency ω _pr can be obtained by receiving signals at two frequencies ω _s and ω _zer , i.e.

ω _ol = ω _g -ω _s and ω _ol = ω _zer -ω _g

Therefore, if the tuning frequency ω _to take over the main receiving channel, along with it will be a mirror receiving channel frequency ω _zer which differs from the frequency ω _with 2ω _straight and located symmetrically (mirror) relative to frequency ω _g oscillator (FIG. four).

Conversion on the mirror channel of the reception occurs with the same conversion coefficient K _ol as on the main channel. Therefore, it most significantly affects the selectivity and noise immunity of receivers.

In addition to the mirror, there are other additional (combinational) reception channels. In general terms, any Raman receive channel occurs when the condition

where ω _ki is the frequency of the i-th Raman reception channel;

m, n, i are positive integers, including n = 0.

The most harmful combinational receiving channels are those generated by the interaction of the first harmonics of the signals with the harmonics of the frequency of the local oscillator of the small order (second, third, etc.), since the sensitivity of the receivers on these channels is close to the sensitivity of the main channel. So, for two combinational channels with m = 1 and n = 2 there correspond frequencies

ω _k1 = 2ω _g -ω _pr and ω _k2 = 2ω _g -ω _pr

The presence of false signals (interference) received via mirror and Raman channels leads to a decrease in the noise immunity of the receivers and the reliability of the remote search and detection of stolen vehicles.

An object of the invention is to increase the noise immunity of receivers and the reliability of remote search and detection of stolen vehicles by suppressing false signals (interference) received via mirror and Raman channels.

The problem is solved in that the anti-theft device for a vehicle, containing, in accordance with the closest analogue, a transmitter installed at the control post and consisting of a serially connected master oscillator, a phase manipulator, the second input of which is connected to the output of the modulating code generator, power amplifier, a duplexer, the input-output of which is connected to the transceiver antenna, a second high-frequency amplifier, a second mixer, the second input of which is connected to the first output of the second about the local oscillator, and the second intermediate frequency amplifier, connected in series to the output of the master oscillator of the first multiplier, a bandpass filter, a second phase detector, the second input of which is connected to the first output of the second local oscillator, and a computer, a receiver mounted on the vehicle and consisting of a receiver connected in series antenna, the first high-frequency amplifier, the first mixer, the second input of which is connected to the first output of the first local oscillator, and the first amplifier of the intermediate part You are connected in series with a frequency doubler, a second spectral width meter, a comparison unit, the second input of which is connected to the output of the first spectral width meter, a first threshold block, a second key, a first phase detector, the second input of which is divided into two and the first narrowband frequency divider the filter is connected to the output of the frequency doubler, a unipolar valve, a drive and a second threshold block, the first and second relays installed on the vehicle, the first relocated contacting and disconnecting, and the second with making contacts, the winding of the first of which is connected to the vehicle’s battery through the ignition switch, and one of the contacts is connected to the ignition coil circuit, a time delay unit, a thyristor connected to the sound signal supply circuit parallel to the sound signal switch and connected by a control electrode to the output of the time delay unit, a first switch connected in series with the winding of the first relay, a control switch and signal lamas s, the first relay is made with an additional make contact, which is included in the control circuit of the time delay unit, and its first make contact is connected between the buzzer and the ignition switch, a control switch is connected between the first key, the second input of which is connected to the output of the second threshold block , and the vehicle body, and the winding of the second relay and the closing contact of the second relay and the signal lamps connected in parallel are connected to the battery the battery through the first closing contact of the first relay, a passive transponder mounted on the vehicle, made on a piezocrystal with an aluminum thin-film transducer deposited on its surface and a set of reflectors, while the transformer is made in the form of an interdigital structure, plays the role of a delay line on surface acoustic waves and contains two comb systems of electrodes connected to each other by buses that are connected to a microstrip antenna, also manufactured the surface of the piezocrystal differs from the closest analogue in that it is equipped with four 90 ° phase shifters, a third and fourth mixer, a third and fourth intermediate frequency amplifiers, two adders, a second and third multiplier, a second and third narrow-band filters, two amplitude detectors, the third and fourth keys, and the first phase shifter 90 °, the third mixer, the second input of which is connected to the output of the first amplifier, are connected in series to the second output of the first local oscillator I high-frequency, third intermediate frequency amplifier, second 90 ° phase shifter, first adder, the second input of which is connected to the output of the first intermediate frequency amplifier, the second multiplier, the second input of which is connected to the output of the first high-frequency amplifier, second narrow-band filter, first amplitude detector and a third key, the second input of which is connected to the output of the first adder, and the output is connected to the inputs of the first spectral width meter and frequency doublers and to the second input of the second key, to the second output at the second local oscillator, a third 90 ° phase shifter, a fourth mixer, the second input of which is connected to the output of the second high-frequency amplifier, a fourth intermediate frequency amplifier, a fourth 90 ° phase shifter, and a second adder, the second input of which is connected to the output of the second intermediate-frequency amplifier, are connected in series the third multiplier, the second input of which is connected to the output of the second high-frequency amplifier, the third narrow-band filter, the second amplitude detector and the fourth switch, the second input of which is single with the output of the second adder, and the output is connected to the second input of the first multiplier.

The structural diagram of the transmitter installed at the control post is presented in figure 1. The structural diagram of the receiver and the Executive unit mounted on the vehicle is presented in figure 2. A diagram of a transponder mounted on a vehicle is shown in FIG. 3. A frequency diagram explaining the formation of additional receiving channels is shown in FIG.

The transmitter 1 consists of a serially connected master oscillator 2, a phase manipulator 4, the second input of which is connected to the output of the modulating code generator 3, power amplifier 5, duplexer 46, the input-output of which is connected to the transceiver antenna 6, the second high-frequency amplifier 47, and the second mixer 61, the second input of which is connected to the first output of the second local oscillator 60, the second intermediate-frequency amplifier 62, the second adder 78, the third multiplier 79, the third narrow-band filter 80, the second amplitude detector ora 81, the fourth key 82, the second input of which is connected to the output of the adder 78, the first multiplier 63, the second input of which is connected to the output of the master oscillator 2, the bandpass filter 64, the second phase detector 48, the second input of which is connected to the first output of the local oscillator 60, and computer 49, from a series of connected to the second output of the second local oscillator 60 of the third phase shifter 74 90 °, the fourth mixer 75, the second input of which is connected to the output of the high-frequency amplifier 47, the fourth intermediate-frequency amplifier 76 and four rtogo phase shifter 77 by 90 °, the output of which is connected to the second input of the adder 78.

The receiver 7 includes a receiving antenna 8 connected in series, a first high-frequency amplifier 9, a first mixer 58, the second input of which is connected to the first output of the first local oscillator 57, the first intermediate-frequency amplifier 59, the first adder 69, and the second multiplier 70, the second input of which is connected to the output the first high-frequency amplifier 9, the second narrow-band filter 71, the first amplitude detector 72, the third key 73, the second input of which is connected to the output of the adder 69, the frequency doubler 12, the second spectral width meter 13, block 14 equalization, the second input of which through the first meter 11 of the spectrum width is connected to the output of the key 73, the first threshold block 15, the second key 16, the second input of which is connected to the output of the key 73, the first phase detector 19, the second input of which is connected through a frequency divider 17 to two and the first narrow-band filter 18 is connected to the output of the frequency doubler 12, the unipolar valve 20, the drive 21 and the second threshold unit 22, connected in series to the second output of the first local oscillator 57, the first phase shifter 65 by 90 °, the third mixer 66, the second input of which is connected to the output of the high-frequency amplifier 9, the third intermediate-frequency amplifier 67 and the second 90 ° phase shifter 68, the output of which is connected to the second input of the adder 69. Frequency doubler 12, spectral width meters 11 and 13, comparison unit 14, threshold blocks 15 and 22, a key 16, a phase detector 19, a frequency divider 17 into two, a narrow-band filter 18, a unipolar valve 20, and a drive 21 form a detector 10.

The Executive unit 27 consists of a series-connected to the positive bus of the battery 29 of the ignition switch 28, contact 25.1 and the first winding of the ignition coil 24. In parallel with the battery 29, the ignition switch 28, the relay coil 25, the first key 23, the second input of which is connected to the output of the second threshold unit 22, and the switch 26, the contacts 25.2, 30.1 and the signal lamps 31-34 connected in parallel in series, are connected in series, and winding 30 relay. To the positive bus of the battery 29, a terminal 25.2, an audible warning device 35 and a time delay unit 40 are connected in series. A transistor 41 shunted by thyristor 38 and a capacitor 39 are connected to the output of the audible alarm 35. A zener diode 44 is connected to the base circuit of the transistor 41. A resistor 42, a resistor 43, a terminal 25.3, and a capacitor 45 are connected in series to the audible alarm 35.

The transponder 50 is a piezocrystal 51 with an aluminum thin-film transducer deposited on its surface and a set of reflectors 56. Moreover, the transducer is made in the form of an interdigital structure, plays the role of a delay line on surface acoustic waves (SAW) and contains two comb systems of electrodes 53 connected to each other with another bus 54 and 55, which are connected to a microstrip antenna 52, also made on the surface of the piezocrystal 51.

The principle of remote search and detection in the general transport stream of a stolen vehicle is based on the use of a complex phase-shift (PSK) signal, which is emitted by the transmitter, received and selected by the receiver, detected, accumulated and used to turn on marker lamps, an audible warning device and turn off the engine. Moreover, the included lamps 31-34 and the audible warning device 35 are a sign of detection of a stolen vehicle, and the turned off engine provides a delay of the vehicle and the hijacker. In this case, the transmitter 1 is installed at the control posts or the traffic police cars, and the receiver 7 and the executive unit 27 - on vehicles.

The use of a complex FMN signal allows the use of a new type of selection - structural selection, which provides higher noise immunity and reliability of the isolation of the specified signal among other signals and interference operating in the same frequency band and at the same time intervals.

The principle of operation of the interdigital transducer is based on the fact that the electric fields in space and time created in a piezoelectric crystal by a system of electrodes cause elastic strains due to the piezoelectric effect, which propagate in the crystal as a surfactant.

The device operates as follows. After turning on the transmitter 1 high-frequency oscillation

U ₁ (t) = ν _c * Cos (ω _c t + φ _c ), O≤t≤T _c ,

where ν _c , ω _c , φ _c , T _c - amplitude, carrier frequency, initial phase and duration of high-frequency oscillations,

from the output of the master oscillator 2 is fed to the first input of the phase manipulator 4, the second input of which is supplied with a modulating code M ₁ (t) from the output of the generator 3 of the modulating code. As a result of phase manipulation, the output of the phase manipulator 4 produces an FMN signal

U ₂ (t) = ν _c * Cos [ω _c t + φ _к1 (t) + φ _c ], O≤t≤T _c ,

where φ _к1 (t) = {o, π} is the manipulated phase component that displays the phase manipulation law in accordance with the modulating code M ₁ (t), and φ _к (t) = const for K * τ _u <t <(К +1) * τ _u and can change abruptly at t = K * τ _u , i.e. at the boundaries between elementary premises (K = 0, 1, 2 ..., N-1);

τ _u , N is the duration and number of chips that make up the signal of duration T _c (T _c = N * τ _u ).

This signal after amplification in the power amplifier 5 is radiated by the antenna 6 into the air. In this case, the transceiver antenna 6 can be directional, for example parabolic, which ensures irradiation of only the transport stream passing by the control point.

The PSK signal U ₂ (t) is captured by the receiving antenna 8 of the vehicle and, through the high-frequency amplifier 9, is supplied to the first inputs of the mixers 58 and 66, the second inputs of which are supplied with the voltage of the first local oscillator 57:

U _g1 (t) = ν _g1 * Cos (ω _g t + φ _g1 );

U ' _g1 (t) = ν _g1 * Cos (ω _g t + φ _g1 + 90 °).

At the output of the mixers 58 and 66, voltages of combination frequencies are generated. Amplifiers 59 and 67 are allocated voltage intermediate (differential) frequency:

U _pr1 (t) = ν _pr1 * Cos [ω _pr t + φ _к1 (t) + φ _pr1 ],

U _pr2 (t) = ν _pr1 * Cos [ω _pr t + φ _к1 (t) + φ _pr1 -90 °], O≤t≤T _c ,

where ν _pr1 = 1 / 2K ₁ * ν _c * ν _g1 ;

K ₁ - gear ratio of the mixers;

ω _CR = ω _with -ω _g is the intermediate frequency;

φ _pr1 = φ _s -φ _g1 .

The voltage U _CR2 (t) from the output of the intermediate frequency amplifier 67 is supplied to the input of the phase shifter 68 by 90 °, at the output of which the following voltage is generated

U _pr3 (t) = ν _pr1 * Cos [ω _pr t + φ _к1 (t) + φ _pr1 -90 ° + 90 °] =

= ν _pr1 * Cos [ω _pr t + φ _k1 (t) + φ _pr1 ]

Voltages U _CR1 (t) and U _CR3 (t) are supplied to the inputs of the adder 69, at the output of which the total voltage is formed

U _Σ1 (t) = ν _Σ1 * Cos [ω _pr t + φ _k1 (t) + φ _pr1 ], O≤t≤T _c ,

where ν _Σ1 = 2ν _pr1 .

This voltage is supplied to the first input of the multiplier 70, to the second input of which the received FMN signal U ₂ (t) is supplied from the output of the high-frequency amplifier 9. The output of the multiplier 70 produces a harmonic voltage

U ₃ (t) = ν ₃ * Cos (ω _g1 t + φ _g1 ); O≤t <T _c ,

where ν ₃ = 1/2 * K ₂ * ν _Σ1 * ν _s ;

K ₂ is the transmission coefficient of the multiplier.

Since the tuning frequency ω _{n1 of the} narrow-band filter 71 is chosen equal to the frequency of the first local oscillator ω _n1 = ω _g , the harmonic voltage U ₃ (t) is extracted by the narrow-band filter 71, detected by the amplitude detector 72 and fed to the control input of the key 73, opening it. In the initial state, keys 73 and 82 are always closed.

In this case, the total voltage U _Σ1 (t) from the output of the adder 69 through the public key 73 is fed to the input of the detector 10, consisting of meters 11 and 13 of the spectrum width, frequency doubler 12, comparison unit 14, threshold block 15, key 16, frequency divider 17 on two, a narrow-band filter 18, a phase detector 19, a unipolar valve 20, a drive 21 and a threshold unit 22. A harmonic voltage is generated at the output of the frequency doubler 12

U ₄ (t) = ν _Σ1 * Cos (2ω _pr t + 2φ _pr1 ), O≤t <T _c ,

Since 2φ _k (t) = {o, 2π}, phase manipulation is already absent in the indicated voltage.

The width of the spectrum Δf _{2 of the} second harmonic is determined by the duration T _{s of the} signal (Δf ₂ = 1 / T _s ), while the width of the spectrum Δf _{s of the} FMN signal is determined by the duration τ _{u of} its elementary premises (Δf _c = 1 / τ _u ), i.e. . the width of the spectrum Δf _{2 of the} second harmonic of the signal is N times smaller than the width of the spectrum Δf _{from the} input signal (Δf _s / Δf ₂ = N).

Therefore, when the frequency of the FMN signal is doubled, its spectrum collapses N times. This makes it possible to detect the FMN signal among other signals, noise, and interference even when its power at the receiver input is less than the power of noise and interference.

The spectral width Δf _{from the} input FMN signal is measured using meter 11, and the spectral width Δf _{2 of the} second harmonic of the signal is measured using meter 13. Voltages ν ₁ and ν ₂ proportional to Δf _s and Δf _2, respectively, from the outputs of the meters 11 and 13 of the width spectrum are fed to two inputs of the comparison unit 14. Since ν ₁ >> ν ₂ , a positive voltage is generated at the output of comparison unit 14, which exceeds the threshold level ν by _p1 in threshold block 15. The threshold level ν _por1 is chosen so that it is not exceeded by random noise. When the threshold level ν _pore1 is exceeded, a constant voltage is generated in the threshold block 15, which is supplied to the control input of the key 16, opening it. Keys 16 and 23 in the initial state are always closed. In this case, the FMN signal U _Σ1 (t) from the output of the adder 69 through the public key 16 is fed to the information input of the phase detector 19. The harmonic voltage U ₄ (t) from the output of the frequency doubler 12 is simultaneously input to the frequency divider 17 by two, at the output which stress is generated

U ₅ (t) = ν _Σ1 * Cos (ω _pr t + φ _pr1 ), O≤t <T _s .

This voltage is allocated by a narrow-band filter 18 and is supplied to the reference input of the phase detector 19. At the output of the latter, a low-frequency voltage is formed

U _n1 (t) = ν _n1 * _{Cosφ k1} (t), O≤t <T _s ,

where ν _n1 = 1 / 2K ₃ * ν _pr1 ² ;

K ₃ - the transfer coefficient of the phase detector,

corresponding in form to the modulating code M ₁ (t). The specified voltage is supplied to the input of a unipolar valve 20, the output of which produces only positive pulses. These pulses after accumulation in the drive 21 exceed the threshold level ν _pore2 in the threshold block 22. When this level is exceeded, a constant voltage is generated in the threshold block 22, which is supplied to the control input of the key 23, opening it. In this case, the constant voltage of the battery 29 through the closed ignition switch 28, the open key 23 and the closed device switch 26 is supplied to the relay coil 25. The device switch 26 is installed on the vehicle in a place known only to the owner. When the relay 25 is activated, contact 25.1 opens and contacts 25.2 and 25.3 close. Open contact 25.1 turns off the engine, causing the vehicle to stop.

The constant voltage of the battery 29 through a closed contact 25.2 is fed to the coil of the relay 30, which is activated and closes the contact 30.1. In this case, the signal lamps 31-34 are installed, mounted on the front and rear panels of the vehicle body. At the same time, the voltage of the battery 29 through a closed contact 25.2 is supplied to the audible warning device 35. The operation of the warning lamps 31-34 and the audible warning device 35 is a sign of detection of a stolen vehicle. The anti-theft device circuit uses the sound alarm and parking lamps already on the vehicle.

When the contacts 25.2 and 25.3 are closed, the supply voltage is also supplied to the time delay unit 40, consisting of a transistor 41, resistors 42 and 43, a zener diode 44, and a capacitor 45. The capacitor 45 starts to charge after a certain time interval (5-7 s), which is regulated by a variable resistor 43, the voltage across the capacitor 45 reaches the opening voltage of the zener diode 44, the thyristor 38 is unlocked and the buzzer 35 is activated. To maintain the thyristor 38 in the open state, the charge of the capacitor 37 is used. The buzzer p 35 and marker lamps 31-34 are still working to the detention of the vehicle and the car thief. If the audible alarm 35 is activated, it cannot be turned off only by turning off the ignition switch 28. To turn off the audible alarm 35, it is necessary to turn off the ignition and briefly press the switch 36. This ensures that the thyristor 38 is locked and its re-opening is prevented.

At the same time, the probing PSK signal U ₂ (t) irradiates a passive transponder 50, which can be mounted in one or more elements of the vehicle, camouflaged for a specific object, or can be made in the form of a separate miniature device that is placed in a secret place of the vehicle.

The principle of operation of the passive transponder 50 is based on the acoustic processing of the received FMN radio pulse using a delay line on surface acoustic waves (SAWs).

The basis of the operation of devices on surfactants are three physical processes:

- conversion of the input electrical signal into an acoustic wave;

- the propagation of an acoustic wave over the surface of a sound duct and its reflection;

- the inverse transformation of the surfactant into an electrical signal with parameters determined by the internal structure of the interdigital transducer.

For forward and reverse conversion, an interdigital converter is used, the passband of which is much larger than the spectrum width Δf _{from the} received signal.

An acoustic wave obtained in the transducer propagates along the surface of the piezocrystal 51 and after a while reaches the reflecting plates 56, which reflect the acoustic wave back with a phase determined by the position of the reflecting plates 56 and an amplitude proportional to the reflection coefficient. The surfactant converter converts the reflected acoustic wave back into a radio pulse with phase shift keying

U ₆ (t) = ν ₆ * Cos [ω _c t + φ _к2 (t) + φ ₂ ], O≤t≤T _s ,

where φ _к2 (t) = {o, π} - is determined by the internal structure of the interdigital transducer (modulating code M ₂ (t)).

As an example, FIG. 3 shows an interdigital structure for code 10100101.

The generated radio pulse U ₆ (t) is radiated by the microstrip antenna 52, received by the antenna 6, and through the duplexer 46 and the high-frequency amplifier 47 is supplied to the first inputs of the mixers 61 and 75, to the second inputs of which the local oscillator voltage 60

U _g2 (t) = ν _g2 * Cos (ω _g t + φ _g2 ),

U ' _r2 (t) = ν _g2 * Cos (ω _g t + φ _g2 + 90 °).

At the output of the mixers 61 and 75, voltages of combination frequencies are generated. Amplifiers 62 and 76 are allocated voltage

U _pr4 (t) = ν _pr4 * Cos [ω _pr t + φ _к2 (t) + φ _pr4 ],

U _pr5 (t) = ν _pr4 * Cos [ω _pr t + φ _к2 (t) + φ _pr4 -90 °], O≤t≤T _c ,

where ν _pr4 = 1 / 2K ₁ * ν ₆ * ν _g2 ;

ω _CR = ω _with -ω _g is the intermediate frequency;

φ _pr4 = φ _s -φ _g2 .

The voltage U _pr5 (t) from the output of the intermediate frequency amplifier 76 is supplied to the input of the phase shifter 77 by 90 °, at the output of which a voltage is generated

U _pr6 (t) = ν _pr4 * Cos [ω _pr t + φ _к2 (t) + φ _pr4 -90 ° + 90 °] =

= ν _pr4 * Cos [ω _pr t + φ _k2 (t) + φ _pr4 ].

Voltages U _CR4 (t) and U _CR6 (t) are supplied to the two inputs of the adder 78, the output of which is formed by the total voltage

U _Σ2 (t) = ν _Σ2 * Cos [ω _pr t + φ _к2 (t) + φ _pr4 ],

where ν _Σ2 = 2ν _pr4 .

This voltage is supplied to the first input of the multiplier 79, the second input of which receives the received FMN signal U _pr6 (t) from the output of the high-frequency amplifier 47. The output of the multiplier 79 produces a harmonic voltage

U ₇ (t) = ν ₇ * Cos (ω _pr t + φ _pr4 ),

where ν ₇ = 1 / 2K ₂ * ν _Σ2 * ν ₆ .

Since the tuning frequency ω _{n1 of the} narrow-band filter 80 is chosen equal to the frequency ω _{g of the} second local oscillator 60, the harmonic voltage U ₇ (t) is emitted by the narrow-band filter 80, is detected by the amplitude detector 81 and fed to the control input of the key 82, opening it.

In this case, the total voltage U _Σ2 (t) from the output of the adder 78 through the public key 82 is supplied to the first input of the multiplier 63, the second input of which is supplied with a high-frequency oscillation U ₁ (t) from the output of the master oscillator 2. A voltage is generated at the output of the multiplier 63

U ₈ (t) = ν ₈ * Cos [ω _g t + φ _к2 (t) + φ _g ], O≤t≤T _c ,

where ν ₈ = 1/2 K ₂ * ν _s * ν _Σ2 ,

which is an FMN signal at the frequency of the local oscillator 60, is allocated by a band-pass filter 64 and fed to the first (information) input of the phase detector 48. The voltage U _g2 (t) of the local oscillator 60 is applied to the second (reference) input of the phase detector 48. As a result of synchronous detection, a low-frequency voltage is generated at the output of the phase detector 48

U _n2 (t) = ν _n2 * _{Cosφ k2} (t), O≤t <T _c ,

where ν _n2 = 1 / 2K ₃ * ν ₇ * ν _g2 ,

proportional to the modulating code M ₂ (t). This voltage from the output of the phase detector 48 is sent to the database of the computer 49 for identification. It is an individual marking of the inspected vehicle, for example, its identification number. Previously, individual numbers of stolen vehicles are registered by entering them into the computer database 49. Based on the identification results, a decision is made and the characteristics of the stolen vehicle are determined.

If the stolen vehicle is in a static de-energized state, then transmitter 1 and passive transponder 50 are involved in the operation.

Therefore, the specified device provides not only remote search and detection of a stolen vehicle located in the common traffic stream, and its delay, but also transmission to the control point of alarm information containing information about the stolen vehicle.

In addition, alarm information is transmitted to the control point via radio channel when the stolen vehicle is in a static de-energized state in the parking lot, in the garage or simply on the street with its corresponding exposure to the scanning device.

The main advantage of the automatic teleindication system of a stolen vehicle located in dynamics or statics is the ability to use passive, i.e. small power supply transponder.

Another advantage is the possibility of combining the functions of re-emission of energy, coding of individual information about a stolen vehicle and the functions of a sensor of any physical quantity in one device with a simple design.

In some cases, the positive property of a passive surfactant transponder for surfactants can be considered low costs for long-term operation (lack of battery and long MTBF).

In special cases, the reading of individual markings from stolen vehicles can be done covertly, without visible signs of their exposure.

The operation of the receivers described above corresponds to the case of receiving useful FMN signals along the main channel at a frequency ω _s (Fig. 4).

If a false signal (interference) is received on the mirror channel at a frequency ω _zer (figure 4)

_Zer U (t) = ν _zer * Cos (ω t + φ _{zer zer)} O≤t≤T _zer,

the amplifiers 59, 67, 62, and 76 distinguish the following voltages:

U _pr7 (t) = ν _pr7 * Cos [ω _pr t + φ _pr7 ],

U _pr8 (t) = ν _pr7 * Cos [ω _g t + φ _pr7 + 90 °],

U _pr9 (t) = ν _pr9 * Cos [ω _pr t + φ _pr9 ],

_Pr10 U (t) = ν _pr9 * Cos [ω t + φ _{straight pr9} + 90 °], O≤t≤T _zer,

where v _pr7 = 1 / 2v _zer * ν _d1,

_pr9 v = 1 / 2v _zer * v _r2,

ω _CR = ω _g -ω _ZER - intermediate frequency;

φ _pr7 = φ _g1 -φ _zer ;

_pr9 cp = φ -φ _{r2 zer.}

Voltages U _CR8 (t) ^and U _CR10 (t) from the outputs of amplifiers 67 and 76 of an intermediate frequency are supplied to the inputs of phase shifters 68 and 77 by 90 °, at the outputs of which the following voltages are formed:

U _pr11 (t) = ν _pr7 * Cos [ω _pr t + φ _pr7 -90 ° + 90 °] =

= _{-ν pr7} * Cos [ω _pr t + φ _pr7 ];

U _pr12 (t) = ν _pr9 * Cos [ω _pr t + φ _pr9 -90 ° + 90 °] =

= _{-ν pr9} * Cos [ω _pr t + φ _pr9 ], O≤t≤T _zer .

The _voltages U _CR7 (t), U _CR11 (t), U _CR9 (t) and U _CR12 (t) supplied to the two inputs of the adders 69 and 78, respectively, are compensated at their outputs.

Consequently, a false signal (interference) received through the mirror channel at a frequency ω _zer is suppressed.

For a similar reason, a false signal (interference) received on the first combinational channel at a frequency ω _{k1 is also} suppressed (Fig. 4).

If a false signal (interference) is received on the second Raman channel at a frequency ω _k2 (figure 4)

U _k2 (t) = ν _k2 * Cos (ω _k2 t + φ _k2 ), О≤t≤T _k2 ,

the amplifiers 59, 67, 62, and 76 distinguish the following voltages:

U _prl3 (t) = ν _prl3 * Cos (ω _pr t + φ _pr13 );

U _prl4 (t) = ν _prl3 * Cos (ω _pr t + φ _pr13 -90 °);

U _pr15 (t) = ν _pr15 * Cos (ω _pr t + φ _pr15) ;

U _pr16 (t) = ν _pr15 * Cos (ω _pr t + φ _pr15 -90 °)

where ν _pr13 = 1 / 2ν _k2 * ν _g1 ;

_pr15 ν = 1 / 2ν _k2 * _{ν, r2;}

_straight ω = ω _k2 -2ω _g - intermediate frequency;

φ _pr13 = φ _k2 -φ _g1 ;

φ _pr15 = φ _k2 -φ _g2 .

Voltages U _prl4 (t) and U _pr16 (t) are supplied to the inputs of the phase shifters 68 and 77 by 90 °, at the outputs of which the following voltages are formed:

U _pr17 (t) = ν _pr13 * Cos (ω _pr t + φ _pr13 -90 ° + 90 °) =

= ν _pr13 * Cos (ω _pr t + φ _pr13 );

U _pr18 (t) = ν _pr15 * Cos (ω _pr t + φ _pr15 -90 ° + 90 °) =

= ν _pr15 * Cos (ω _pr t + φ _pr15 ).

Voltage U _pr13 (t) and U _pr17 (t), U _pr15 (t) and U _pr18 (t) are supplied to the two inputs of the adders 69 and 78, respectively. At the output of the latter, the following total voltages are formed:

U _Σ3 (t) = ν _Σ3 * Cos (ω _pr t + φ _pr13 ),

U _Σ4 (t) = ν _Σ4 * Cos (ω _pr t + φ _pr15 ), O≤t≤T _k2 ,

where ν _Σ3 = 2ν _pr13 ;

ν _Σ4 = 2ν _pr15 ,

which are supplied to the first inputs of the multipliers 70 and 79, respectively, to the second inputs of which a received false signal (interference) U _k2 (t) is supplied. The outputs of the multipliers 70 and 79 form the following harmonic voltages:

U ₈ (t) = ν ₈ * Cos (2ω _g t + φ _g1 ),

U ₉ (t) = ν ₉ * Cos (2ω _g t + φ _g2 ),

where ν ₈ = 1/2 * ν _k2 * ν _Σ3 ;

ν ₉ = 1/2 * ν _k2 * ν _Σ4 ,

which do not fall into the passband of narrow-band filters 71 and 80, respectively. The keys 73 and 82 do not open and the false signal (interference) received on the second Raman channel at a frequency ω _k2 is suppressed.

Thus, the proposed device in comparison with the prototype provides increased noise immunity of the receivers and the reliability of the remote search and detection of stolen vehicles. This is achieved by suppressing false signals (interference) received via mirror and Raman channels.

Claims (1)

An anti-theft device for a vehicle, containing a transmitter installed at the control station and consisting of a serially connected master oscillator, a phase manipulator, the second input of which is connected to the output of the modulating code generator, power amplifier, duplexer, the input-output of which is connected to the transceiver antenna, and the second amplifier high frequency, the second mixer, the second input of which is connected to the first output of the second local oscillator, and the second intermediate frequency amplifier, sequentially Connected to the output of the master oscillator of the first multiplier, a bandpass filter, a second phase detector, the second input of which is connected to the first output of the second local oscillator, and a computer, a receiver mounted on the vehicle and consisting of a receiving antenna, a high-frequency amplifier, a first mixer, the second input of which is connected to the first output of the first local oscillator, and the first intermediate frequency amplifier, a frequency doubler in series, a second width meter s of the spectrum, the comparison unit, the second input of which is connected to the output of the first spectral width meter, the first threshold block, the second key, the first phase detector, the second input of which is connected to the output of the frequency doubler, a unipolar valve through successively connected frequency divider into two and the first narrow-band filter , a drive and a second threshold block mounted on the vehicle, the first and second relays, the first made with the closing and opening, and the second with the closing contacts, the winding of the first of which is connected to the vehicle’s battery through the ignition switch, and the NC contact is included in the ignition coil circuit, time delay assembly, thyristor included in the sound signal supply circuit and connected by the control electrode to the output of the time delay assembly, the first key connected in series with the winding of the first a relay, a control switch and signal lights, while the first relay is made with an additional make contact, which is included in the control circuit of the temporary assembly delays, and its first make contact is connected between the buzzer and the ignition switch, the control switch is connected between the first key, the second input of which is connected to the output of the second threshold unit, and the vehicle body, and the winding of the second relay and the make contact of the second relay in series and signal lights connected in parallel are connected to the battery through the first make contact of the first relay mounted on the vehicle passive reception a transponder made on a piezocrystal with an aluminum thin-film transducer deposited on its surface and a set of reflectors, the transducer made in the form of an interdigital structure, plays the role of a delay line on surface acoustic waves and contains two comb systems of electrodes connected to each other by buses, which connected with a microstrip antenna, also made on the surface of a piezocrystal, characterized in that it is equipped with four 90 ° phase shifters, a third and a fourth mixers, third and fourth intermediate frequency amplifiers, two adders, second and third multipliers, second and third narrow-band filters, two amplitude detectors, third and fourth keys, and the first 90 ° phase shifter, the third mixer, the second are connected in series to the second output of the first local oscillator the input of which is connected to the output of the first high-frequency amplifier, the third intermediate-frequency amplifier, the second phase shifter 90 °, the first adder, the second input of which is connected to the output a first intermediate frequency amplifier, a second multiplier, the second input of which is connected to the output of the first high-frequency amplifier, a second narrow-band filter, a first amplitude detector and a third switch, the second input of which is connected to the output of the first adder, and the output is connected to the inputs of the first spectral width meter and doubler frequency and to the second input of the second key, to the second output of the second local oscillator, a third 90 ° phase shifter, a fourth mixer, the second input of which is connected to the second output the first high-frequency amplifier, the fourth intermediate frequency amplifier, the fourth phase shifter 90 °, the second adder, the second input of which is connected to the output of the second intermediate-frequency amplifier, the third multiplier, the second input of which is connected to the output of the second high-frequency amplifier, the third narrow-band filter, the second amplitude a detector and a fourth switch, the second input of which is connected to the output of the second adder, and the output is connected to the second input of the first multiplier.

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