RU2481978C1 - System of protection against unauthorized access to vehicles - Google Patents

Abstract

FIELD: transport.SUBSTANCE: invention relates to automotive industry and can be used for prevention of unauthorized access to automobiles. Proposed system comprises logical module 1, transponder reader 2, transponder 3, memory 4 of individual service settings, user warning unit 5, immobiliser relay component 6, and setting state signal converter 7. Transponder reader 2 incorporates oscillator 8, modulation code oscillator 9, phase-shift modulator 10, power amplifier 11, duplexer 12, transceiving antenna 13, HF amplifier 14, 1, 2, 3and 4multipliers 15, 16, 28 and 29, respectively, first and second narrowband filters 17 and 50, first and second LF filters 18 and 31, first and second demodulators 19 and 34 of FM-signals, memory 20, comparator 21, first and second phase inverters 32 and 33, and subtractor 35. Transponder 3 consists of piezocrystal 22, microstrip antenna 23, electrodes 24, first and second busses 25 and 26, and unit of reflectors 27. Technical effect is ensured by attenuation of narrowband interferences, increasing SNR at subtractor output by two universal demodulators with their inverses output voltages summed up in absolute value while unipolar interference voltages are mutually subtracted.EFFECT: higher noise immunity, validity of complex signals reception.4 dwg

Description

The proposed system relates to the field of transport technology, is designed to prevent unauthorized access to vehicles and can be used in road transport to prevent theft or theft.

Known devices and systems of protection against unauthorized access for vehicles (ed. Certificate of the USSR No. 823194, 844418, 850440, 1186543, 1437270, 1614984, 1657227, 1720908, 1730648; RF patents No. 2003523, 2006394, 2011575, 2032227, 2033354 , 2040416, 2058906, 2061323, 2123441, 2227100; US patents Nos. 4013995, 4023163, 4619603, 4751499; French patents Nos. 2063292, 2231213, 2591165; German patents Nos. 3606099, 3622793; UK patent No. 11651114; Dick . and others. Protection of vehicles and goods from theft and theft. St. Petersburg, 2009, etc.).

Of the known devices and systems closest to the proposed is the "System of protection against unauthorized access for vehicles" (RF patent No. 2227100, B60R 25/00, 2002), which is selected as a prototype.

The specified system contains a set of transponders and a stationary part installed on the protected vehicle and includes a logic module, a user warning unit, an immobilizer relay body, a transponder reader, a memory unit for individual service settings, and a unit status signal converter.

However, the known system does not allow suppressing narrowband interference and does not provide noise-tolerant and reliable reception of complex signals with phase shift keying.

An object of the invention is to increase the noise immunity and reliability of the reception of complex signals with phase shift keying by attenuation of narrowband interference.

The problem is solved in that a system of protection against unauthorized access for vehicles, consisting, in accordance with the closest analogue, of a set of transponders and a stationary part installed on a protected vehicle, which includes a logic module, a user warning unit, a relay body immobilizer, transponder reader, memory unit of individual service settings and a signal converter of the status of the installations, while the input of the transponder reader is inen with the output of the request gate of the logical module, the relay control output of which is connected to the input of the relay body of the immobilizer, the alarm control output - to the input of the user warning unit, the group output of the control of actuators - to the group of control buses, the group input of signal sensors is connected to the group of signal buses, and the output is connected to the information input of the memory block of individual service settings, the address and control inputs of which are connected respectively to the output of the reader transponder and to the control bus of the installation, and the output is connected to the input of the signals of the individual installation of the logic module, while the transponder reader is made in the form of series-connected master oscillator, phase manipulator, the second input of which is connected to the output of the modulating code generator, power amplifier, duplexer, input- the output of which is connected to a transceiver antenna, a high-frequency amplifier, a first multiplier, the second input of which is connected to the output of the first low-pass filter, the first a bandpass filter, a second multiplier, the second input of which is connected to the output of a high-frequency amplifier and a first low-pass filter, a memory block and a comparison unit connected in series, the output of which is the output of the transponder reader, and the transponder is made using a multi-tap delay line on surface acoustic waves, signals from the taps of which are multiplied by the corresponding weight coefficients and linearly summed, and is a piezocrystal with aluminum deposited on its surface a thin-film piezoelectric transducer and a set of reflectors, and the interdigital transducers of surface acoustic waves play the role of taps, and the piezoelectric transducer is connected to a microstrip antenna, which is made on the surface of the piezocrystal, differs from the closest analogue in that the transponder reader is equipped with a third and fourth multipliers, a narrow-band filter, a second low-pass filter, a subtraction unit, the first and second phase inverters, and the output of the high-frequency amplifier is connected in series to 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 inverter, the fourth multiplier, the second input of which is connected to the output of the high-frequency amplifier, the second low-pass filter and the second phase inverter, the outputs of the first and second low-pass filters through the subtraction unit are connected to the second input of the comparison unit.

The structural diagram of the proposed system is presented in figure 1. In this case, the dashed line is limited to the elements that make up the stationary part. The control bus group is marked with "Control tires", the signal bus group is marked with "Signal tires", and the control bus of the installation is marked with "Set".

The structural diagram of the transponder is presented in figure 2. The structural diagram of the transponder reader 2 is shown in Fig.3. Timing diagrams explaining the operation of the transponder reader 2 are shown in FIG. 4.

The output of the request strobe of the logical module 1 is connected to the input of the transponder reader 2, and the signal bus group “Signal buses” is connected to the group input of the signal sensors. The actuator control buses are designated as "Control Buses".

The memory unit 4 of individual service installations, to the control and address inputs of which are connected the “Ust” installation control bus and the transponder reader 2 output, is connected by its output to the input signal of the individual installation of logic module 1. Warning block 5 is connected to the alarm control output of logic module 1 user, which may include a set of light and sound indicators with corresponding input amplifiers-shapers. The relay control element of the immobilizer 6 is connected to the relay control output of the logic module 1, which is a set of relays with control circuits for turning on and off the vehicle units. The group of signal buses through the Converter 7 signals the status of the installations, which is a set of comparators and amplifiers-shapers, connected to the information input of the unit 4 of the memory of individual service installations.

The transponder 3 is made using a multi-tap delay line to the SAW, the signals from the taps of which are multiplied by the corresponding weights and linearly summed. The location of the taps and the weight coefficients are determined by expanding the required impulse response of the matched filter in the Kotelnikov series. The most simple structure of the matched filter is obtained in the processing of PSK signals with constant amplitude and a binary coding: the taps of the delay line is uniformly distributed over the surface acoustic line pitch Δh = V · τ _e, where τ _e - duration of a chip processed PSK signal, V - velocity surface waves. The elementary signals from the taps are summed with the same amplitude weights, and the form of the phase factor (1 or -1) is determined by the corresponding phase of the code sequence of the complex QPSK signal.

Using a delay line on a surfactant allows you to create a system of taps by applying metal electrodes directly to the surface of the piezomaterial. In this case, the electrodes of the terminals having the same phases are connected together. The result is an interdigitated structure, the form of which is specified by the code of the pseudo-random sequence used to form the complex QPSK signal. As an example, figure 2 shows the structure of the interdigital transducer (IDT) for code 1001010.

The work of IDTs is based on three physical processes:

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

- propagation of an acoustic wave along the surface of the sound duct;

- the inverse transformation of the surfactant into an electrical signal.

The interdigital SAW converter (Fig. 2) consists of two comb systems of electrodes 24 applied to the surface of the sound duct 22. The electrodes of each of the combs are connected to each other by buses 25 and 26. The tires, in turn, are connected to the microstrip antenna 23. Operation electrode transducers 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 deformations due to the piezoelectric effect, which propagate in the crystal in the form of surfactants and reflect press a set of 27 reflectors. The center frequency and bandwidth of the IDT are determined by the pitch of the electrodes and their number. IDT is fabricated by standard photolithography methods and by etching a thin metal film deposited on a piezoelectric crystal. The capabilities of modern photolithography allows you to create IDTs operating at frequencies up to 3 GHz.

The transponder reader 2 consists of a serially connected master oscillator 8, a phase manipulator 10, the second input of which is connected to the output of the modulating code generator 9, power amplifier 11, duplexer 12, the input-output of which is connected to the transceiver antenna 13, high-frequency amplifier 14, the first multiplier 15, the second input of which is connected to the output of the first low-pass filter 18, the first narrow-band filter 17, the second multiplier 16, the second input of which is connected to the output of the high-frequency amplifier 14, the first This filter 18, a lowpass subtraction unit 35 and comparator unit 21, the second input of which is connected to the output 20 of the storage unit, and the output is the output 2 of the reader transponder. A third multiplier 28 is connected to the output of the high-frequency amplifier 14, the second input of which is connected to the output of the second phase inverter 33, the second narrow-band filter 30, the first phase inverter 32, the fourth multiplier 29, the second input of which is connected to the output of the high-frequency amplifier 14, the second lower filter 31 frequencies and a second bass reflex 33. The second input of the subtraction unit 35 is connected to the output of the second low-pass filter 31.

The first 15 and second 16 multipliers, the first narrow-band filter 17 and the first low-pass filter 18 form the first FMN signal demodulator 19.

The third 28 and fourth 29 multipliers, a second narrow-band filter 30, a second low-pass filter 31, a first 32 and a second 33 phase inverters form a second PSK demodulator 34.

External manifestations of the system of protection against unauthorized access for vehicles are as follows.

The stationary part generates request signals. These signals can be generated periodically or, for example, after a certain period of time after receiving the impact (for example, after opening a door or trunk). On request signals, the stationary part awaits the receipt of the transponder identification package. If such a package does not arrive in the expected period of time, the stationary part goes into guard mode: all windows are closed, the lights and electronic devices (radio, tape recorder, etc.) are turned off, the stationary part checks the closing of doors, hood, trunk (if not everything is closed, sound and / or light signals are formed about incomplete perimeter protection), the bolts of locked locks are blocked and the immobilizer relay organ is switched on with a set delay (it is possible that when the engine is switched on, the security mode only partially).

Thus, the system is ready both for the arrival of the hijacker, and for the appearance of one of the users. The stationary part distinguishes the user from the hijacker by the presence or absence of an identification package of the required type for the next request signal. The protection system does not allow the hijacker to use the vehicle for their own purposes.

If, however, an identification package is received for any request, then the stationary part, analyzing the received package, determines the specific user and turns on the vehicle, making settings that are individually determined for this user (for example, specific window lifter positions for certain windows, set the selected position of the windows of certain windows, set the selected position of the seats, steering column, mirrors, includes Xia lighting, etc.).

Thus, for each of the possible users, the service settings selected by this user are individually implemented. If one user replaces another, then the first user must leave the vehicle, and the next user must enter the vehicle so that the stationary part detects the absence of the identification transponder package when changing users. Having received another authorized identification package, the stationary part changes the service settings, bringing them in accordance with the wishes of the next user.

The proposed system works as follows. The logic module 1 generates at its output of the request gate the control signals of the transponder reader 2, which are determined by the program of operation of the logic module 1. For each of the control signals, the transponder reader 2 generates the contactless request signals of the transponder 3. Complex signals with phase shift keying are selected as such contactless request signals (PSK).

Upon receipt of the control signal from the logic module 1, the master oscillator 8 generates a high-frequency oscillation (Fig. 4, a)

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

where U _c , w _c , φ _c ; T _c is the amplitude, carrier frequency, initial phase and duration of the high-frequency oscillation, which is supplied to the first input of the phase manipulator 10, the second input of which is supplied with the modulating code M ₁ (t) (Fig. 4, b). At the output of the phase manipulator 10, the PSK signal is generated (Fig. 4, c)

u ₁ (t) = U _c · Cos [w _c t + φ _к1 (t) + φ _c ], 0≤t≤T _c ,

where φ _к1 (t) = {0, π} is the manipulated component of the phase that displays the law of phase manipulation in accordance with the modulating code M ₁ (t), and φ _к1 (t) = const at Кτ _э <t <(К + 1 ) τ _e and can change abruptly at t = Кτ _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 with a duration of T _s (T _s = N · τ _e ),

which after amplification in the power amplifier 11 through the duplexer 12 enters the transceiver antenna 13 and is radiated by it as a request signal. Such a request signal is emitted, for example, five times per second.

After the formation of this signal, three variants of the system may occur.

Firstly, in the communication zone with the reader 2 of the transponder there may not be a single transponder 3 (that is, there is no inductive connection between the reader 2 and the transponder 3). In this case, the transponder 3 does not receive a response from the reader 2. From the transponder reader 2, an “empty” word (a set of logic zero signals) is received in the memory unit 4 of the individual service settings.

Secondly, in the communication zone with the reader 2 of the transponder, there may be a transponder 3, which is not included in the package of the considered system of protection against unauthorized access for a vehicle. In this case, the transponder reader 2 receives the identification package of an extraneous transponder 3. The transponder reader 2 compares the received modulating code with each of the stored valid ones and determines that a prohibited identification code has been received. For a forbidden identification package, an “empty” word is formed at the output of the transponder reader 2, which enters the memory unit 4 of the individual service settings.

Thirdly, in the communication zone with the reader 2 of the transponder there may be one of the transponders 3 included in the package of this system of protection against unauthorized access for a vehicle. The PSK signal u ₁ (t) emitted by the transponder reader 2 and received by the microstrip transponder antenna 23 is converted into a delay line into an acoustic wave that propagates along the surface of the piezocrystal, is reflected by a set of reflectors 27, and undergoes inverse transformation into an electromagnetic signal with phase shift keying, which enters the microstrip antenna 23 and is radiated by it into the space where it is received by the antenna 13.

Received FMN signal (figure 4, g)

u ₂ (t) = U ₂ · Cos [w _c t + φ _к2 (t) + φ _с ], 0≤t≤T _c ,

from the output of the antenna 13 through the duplexer 12 and the high-frequency amplifier 14 is supplied to the first inputs of the multipliers 15, 16, 28 and 29. The second inputs of the multipliers 16 and 28 from the outputs of the narrow-band filter 17 and the phase inverter 32 are supplied with reference voltages, respectively (Fig. 4, d , g):

u ₀₁ (t) = U ₀ Cos (w _c t + φ _c ),

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

The output of the multipliers 16 and 28 form the total voltage, respectively:

u _∑1 (t) = U _∑ · Cosφ _k2 (t) + U _∑ · Cos [2w _c t + φ _к2 (t) + 2φ _c ],

u _∑2 (t) = - U _∑ · CoSφ _к2 (t) -U _∑ Cos [2w _c t + φ _к2 (t) + 2φ _c ],

.Where

.

Filters 18 and 31 low frequencies allocated low-frequency voltage, respectively (Fig.4, e, s):

u _H1 (t) = U _Σ · Cosφ _k2 (t),

u _n2 (t) = - U _∑ · CoSφ _к2 (t), 0≤t≤T _c ,

proportional to the modulating code M ₂ (t). These low-frequency voltages are applied to two inputs of the subtraction unit 35. Subtracting one of the other specified low-frequency voltages taking into account their opposite polarity, the output of the subtraction unit 35 produces a doubled (total) low-frequency voltage (Fig. 4, and)

u _n (t) = u _n1 (t) -u _n2 (t) = U _n · CoSφ _к2 (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 amplitude additive noise passes through two demodulators 19 and 34 in the same way, changing the amplitudes of the detected voltages in the same direction. But in the subtraction block 35, they are subtracted, remaining unipolar, i.e. suppressed, mutually compensated.

The low-frequency voltage u _n2 (1) (Fig. 4, h) from the output of the low-pass filter 31 is fed to the input of the phase inverter 33, at the output of which a low-frequency voltage is generated (Fig. 4, k)

u _н3 (t) = U _∑ · CoSφ _к2 (t), 0≤t≤T _c .

Low-frequency voltages u _н1 (t) and u _н3 (1) from the output of the low-pass filter 18 and the phase inverter 33 are supplied to the second inputs of the multipliers 15 and 28, respectively, at the output of which harmonic voltages are formed:

u ₀₁ (t) = U ₃ · Cos (w _c t + φ _c ) + U ₃ · Cos [w _c t + 2φ _к2 (t) + φ _s ] = U ₀ · Cos (w _c t + φ _c ) ;

u ₀₃ (t) = U ₃ · Cos (w _c t + φ _s ) + U ₃ · Cos [w _c t + 2φ _k2 (t) + φ _s ] = U ₀ · Cos (w _c t + φ _s ) ,

; U₀=2U₃.Where

; U ₀ = 2U ₃ .

These voltages are allocated by narrow-band filters 17 and 30, respectively. The voltage u ₀₁ (t) (Fig. 4, d) from the output of the narrow-band filter 17 is supplied to the second input of the multiplier 16. The voltage u ₀₃ (t) is extracted by the narrow-band filter 30 and is fed to the input of the phase inverter 32, the output of which is generated (Fig. 4, g)

u ₀₂ (t) = - U ₀ Cos (w _c t + φ _s ),

which is fed to the second input of the multiplier 29.

Therefore, the multipliers 15 and 16 (28 and 29), the narrow-band filter 17 (30) and the low-pass filter 18 (31) form a universal demodulator 19 (34) of the FMN signals. Moreover, the reference voltage required for the synchronous detection of PSK signals is extracted directly from the PSK signal itself.

Known devices that provide the selection of the reference voltage directly from the received PSK signal, for example, Pistolkors A.A., Siforov V.I., Kostas D.F. and Travina G.A. (Radio receivers. Ed. By A.G. Zyuko. - M.: Svyaz Publishing House, 1975, p. 354-356, fig. 14.19, 14.20).

However, the phenomenon of “reverse operation” is inherent in these devices, which sharply reduces the noise immunity and reliability of the reception of PSK signals.

The proposed demodulators of FMN signals are free from the phenomenon of "reverse work".

The attenuation of narrowband interference is carried out by two universal demodulators 19 and 34. Due to the phase inverters 32 and 33, the output voltages of the demodulators 19 and 34 are of mutually opposite polarity. As a result of this, the mutually inverse output voltages of the demodulators 19 and 34 are added in absolute value, and the unipolar interference voltages are mutually subtracted.

The doubled low-frequency voltage u _n (t) (Fig. 4, and) from the output of the subtraction unit 35 is fed to the first input of the comparison unit 21, the second input of which is supplied with the codes recorded in the memory unit 20.

If the received code matches one of the code recorded in the memory unit 20, then the comparison unit 21 generates a transponder number code, which is received in the memory unit 4 of the individual service settings. For example, if four transponder 3 codes are stored in the memory unit 20, then when reading the transponder information (depending on which particular transponder 3 is in the communication zone with the transponder reader 2), one of four codes can be generated at the output of the comparison unit 21 : “001”, “010”, “011” or “100”.

If the reader 2 of the transponder generates an "empty" word at its output, then this means the need to establish a security regime for the vehicle. Upon transition to the security mode, the logic module 1 generates on its group output for controlling the actuators the signals for launching the windows to close all windows, the signals for turning off the lighting and electronic devices (radio, tape recorder, etc.). By the value of the parameters (analog or code) received via the signal buses, the logic module 1 checks the closing of the doors, hood, trunk (if not everything is closed, the logic module 1 gives a signal to the user warning unit 5 to generate sound and / or light signals about incomplete perimeter protection), locks the deadbolts of locked locks and, with a specified delay, turns on the immobilizer relay organ 6.

Logic module 1 performs installation in the vehicle of the required mode, acting on the control bus of the vehicle. The signals from the sensors that determine the required individual installation are fed to the converter 7 of the status signals of the installations and are converted into a code supplied to the memory unit 4 of the individual service settings.

At the end of the disarming mode, the logic module 1 stops the influence on the control buses (by setting them, for example, in a high impedance state) and the user gets the opportunity to change, for example, the position of the mirrors, steering column, etc. This changed position can be stored in memory unit 4 service settings so that the next time you use the vehicle by this user it would be installed after disarming (for example, in the summer the user may want to have windows open In the autumn open windows become superfluous for him).

To memorize the changed position, it is necessary to send a signal via the installation control bus (for example, press the corresponding button for a specified period of time). After the signal is generated via the installation control bus, the transponder 3 identification message is read and its code number is determined in the transponder reader 2. Such a reading is necessary, since in the general case a user changing his service settings does not have to be the main user.

The system is convenient to use. The transponder is made in the form of a keychain, ring or small medallion, and the user does not need to take any action to remove and arm the vehicle. It does not complicate the normal life of the user. The use of a delay line on surface acoustic waves makes it possible to fabricate a passive transponder, i.e. small-sized transponder that does not require power sources.

Thus, the proposed system of protection against unauthorized access for vehicles in comparison with the prototype and other technical means of a similar purpose provides increased noise immunity and reliability of the reception of complex signals with phase shift keying. This is achieved by attenuation of narrow-band interference, by 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)

The system of protection against unauthorized access for vehicles, consisting of a set of transponders and a stationary part installed on a protected vehicle, which includes a logic module, a user warning unit, an immobilizer relay body, a transponder reader, a memory unit for individual service settings and a signal converter the status of the settings, while the input of the transponder reader is connected to the output of the request gate of the logic module, the relay control output is It is connected to the input of the immobilizer relay organ, the alarm control output to the input of the user warning unit, the actuator control group output to the control bus group, the signal sensor group input is connected to the signal bus group, the signal bus group is connected to the information bus through the signal state converter the input of the memory block of individual service installations, the address and control inputs of which are connected respectively to the output of the reader the onder and to the control bus of the installation, and the output is connected to the input of the signals of the individual installation of the logic module, while the transponder reader is made in the form of series-connected master oscillator, phase manipulator, the second input of which is connected to the output of the modulating code generator, power amplifier, duplexer, input- the output of which is connected to a transceiver antenna, a high-frequency amplifier, a first multiplier, the second input of which is connected to the output of the first low-pass filter, the first narrow-field a second filter, a second multiplier, the second input of which is connected to the output of a high-frequency amplifier and a first low-pass filter, a memory block and a comparison block connected in series, the output of which is the output of the transponder reader, and the transponder is made using a multi-tap delay line on surface acoustic waves, signals from the taps of which are multiplied by the corresponding weights and linearly summed, and is a piezocrystal with aluminum t deposited on its surface a piezoelectric transducer and a set of reflectors, the role of taps being played by interdigital transducers of surface acoustic waves, and the piezoelectric transducer is connected to a microstrip antenna, which is made on the surface of the piezoelectric crystal, characterized in that the transponder reader is equipped with a third and fourth multipliers, the second narrow-band filter low-pass filter, subtraction unit, first and second phase inverters, and to the output of the amplifier high On the other hand, a third multiplier is connected in series, the second input of 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 high-frequency amplifier, the second low-pass filter and the second phase inverter, the outputs of the first and second low-pass filters through the subtraction unit are connected to the second input of the comparison unit.

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