RU2370615C1 - Method of unlocking lock and device to this end - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: lock has a locking device, a key, contact, thermal radiator, heater, photodetector, signal analyser, key hole, electronic switch and transmitter. The transmitter has a master oscillator, modulation code generator, phase manipulator, power amplifier and transmitting antenna. The control point has a receiving antenna, high-frequency amplifier, reference voltage generating device, phase doubler, first and second narrow-band filter, phase doubler, phase detector, recording unit, frequency detector, trigger and a balance switch.

EFFECT: invention increases accuracy of synchronous detection of a received phase-shift keyed signal through detection and elimination of sign ambiguity.

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Description

The proposed method and device relates to the field of protection of various objects from unauthorized access by unauthorized persons and can be used to protect apartments, cottages, offices, warehouses and other objects.

Known methods for unlocking the lock and device for their implementation (ed. Certificate of the USSR No. 1323218, 1807207; RF patent No. 2081983, 2159836, 2182636, 2223376, 2233958, 2283412, 2299962, 2299298; CITA patent No. 4042970; French patent No. 2687240 ; UK patents Nos. 1453298, 2261254 and others).

Of the known methods and devices closest to the proposed are the "Method of unlocking the lock and device for its implementation" (RF patent No. 2299298, EV 47/00, 2005), which are selected as prototypes.

A device that implements the known method comprises a locking device, a key, a contact, a heat radiator, a heater, a photodetector, a signal analyzer, a keyhole, an electronic key, a transmitter, a master oscillator, a modulating code generator, a phase manipulator, a power amplifier, a transmitting antenna, a receiving antenna, high-frequency amplifier, a device for generating a reference voltage, a phase doubler, narrow-band filters, a phase divider into two, a phase detector and a recording unit.

The known method and device can improve the reliability of the lock by transmitting an alarm signal over the air to the owner of the object or department of internal security in case of unauthorized exposure to the lock with a key of a different design.

In these technical solutions, the reference voltage necessary for the synchronous detection of the received QPSK signal is extracted directly from the received QPSK signal. For this purpose, a device 18 for generating a reference voltage is intended, which consists of a series-connected doubler of a phase 19, a narrow-band filter 20, a phase divider 21 into two, and a narrow-band filter 22.

At the same time, a harmonic oscillation is formed at the output of the phase doubler 19 (Fig. 3, g)

which is allocated by a narrow-band filter 20 and enters the input of the phase divider 21 into two, the output of which is formed by harmonic oscillation (Fig.3, d)

This oscillation is distinguished by a narrow-band filter 22, used as a reference voltage, and fed to the reference input of the phase detector 23.

However, the initial phase of the obtained oscillation can have two

stable states: φ _s and φ _s + π. This is easy to show analytically.

If you make a division similar to the previous one, but after adding the angle 2π to the argument, which does not change the initial harmonic oscillation, then after dividing the phase by two, you get an oscillation shifted in phase by π:

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The ambiguity of the phase of the obtained oscillation follows from the process of phase division itself. The physically indicated ambiguity of the initial phase is explained by the unstable operation of the phase divider 21 by 2.

Therefore, the specified process of extracting the reference voltage from the received PSK signal is inherent in the phenomenon of reverse operation.

The indicated phenomenon is caused by spasmodic transitions of the initial phase of the reference voltage from one state φ _s to another φ _s + π under the influence of noise, short-term termination of reception, and other factors. These transitions during the reception of the QPSK signal can occur at random times, for example, t ₁ and t ₂ (figure 3, d). At the same time, at the output of the phase detector 23, a distorted modulating function M _and (t) is allocated (Fig. 3, e).

The phenomenon of "reverse work" is very harmful in the technique of coherent reception and synchronous detection of FMN signals. It is precisely because of the phenomenon of “reverse work” that classical phase-shift keying has not been widely used for a long time despite a number of its advantages.

Currently, there are several methods to eliminate the phenomenon of "reverse work". You can use, for example, special test packages to confirm the correct installation of the initial phase in the receiver (Petrovich N.T., Razmakhnin M.K. Communication systems with noise-like signals. M .: Sov. Radio, 1969), you can also use special codes, detecting and correcting errors caused by the phenomenon of “reverse work” (Yu.V. Khomenyuk On eliminating “reverse work” in a coherent receiver of phase-manipulated signals. Radioelectronics, No. 6, 1966).

However, these methods are associated with the introduction of a certain redundancy into the signal, which reduces the efficiency of using phase manipulation.

An object of the invention is to increase the reliability of the synchronous detection of the received phase-shifted signal by detecting and eliminating the phenomenon of "reverse operation".

The problem is solved in that the method of unlocking the lock, consisting in accordance with the closest analogue in the physical impact on the key by heating, determining its physical characteristics in the form of the distribution of the intensity of thermal radiation on the surface of the key, which pre-introduce internal defects, comparing it with the given and applying a signal to unlock the lock when these characteristics coincide, while when these characteristics do not coincide, a high-frequency oscillation is generated, the modules manipulate it in phase The code that carries information about the lock is amplified in terms of power and radiated into space in the form of a phase-shifted signal, and then it is received at the control point, doubled in phase, the harmonic voltage is extracted at twice the carrier frequency, it is divided in phase by two, and the harmonic voltage is isolated by carrier frequency and use it as a reference voltage for synchronously detecting the received phase-shift signal, allocate a low-frequency voltage proportional to the modulating code, register they analyze it, it differs from the closest analogue in that they perform frequency detection of the harmonic voltage obtained at the carrier frequency and, in the case of spasmodic changes in its initial phase, emit short unipolar pulses corresponding to the moments of spasmodic changes in the initial phase, use them to form positive rectangular pulses and act on them the initial phase of the harmonic voltage at the carrier frequency, returning it to its original state and thereby stabilizing for Phase-shift signal reception volume.

The problem is solved in that the unlocking device of the lock, containing, in accordance with the closest analogue, a key with internal defects, a lock having an element of formation in the form of a heat source, a receiver in series, a signal analyzer made in the form of a heat radiation intensity meter, and a locking unit, as well as a contact switch connected to an impact forming element, a receiver and a signal analyzer, a transmitter connected via an electronic key to a contact switch and the output of the signal analyzer, and the control point installed in the department of intra-departmental security or at the owner of the facility on which the lock is installed, the transmitter 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 and transmitting antenna, the control point is made in the form of series-connected receiving antenna, high-frequency amplifier, phase doubler, first narrow-band filter, phase divider n and two and a second narrow-band filter, connected in series to the output of a high-frequency amplifier of a phase detector and a recording unit, differs from the closest analogue in that it is equipped with a frequency detector, a trigger, and a balance switch, with a frequency detector, a trigger, and a series connected to the output of the second narrow-band filter a balanced switch, the second input of which is connected to the output of the second narrow-band filter, and the output is connected to the second input of the phase detector.

The structural diagram of the castle is presented in figure 1. The structural diagram of the control point is shown in figure 2. Timing diagrams explaining the principle of transmitting an alarm over the air are shown in FIG. 3.

The lock contains a locking device 1, a key 2, a heating system consisting of a heat emitter 4 connected to pin 3, and a heater 5. The device also includes a photodetector 6 connected to a signal analyzer 7 connected to the locking device 1, keyhole 8, an electronic key 9, the transmitter 10 and the control point. In the manufacture of key 2, internal defects are introduced into it (for example, by the action of proton radiation on it).

The transmitter is made in the form of series-connected master oscillator 11, a phase manipulator 13, the second input of which is connected to the output of the modulating code generator 12, power amplifier 14 and transmitting antenna 15. The photodetector 6, the signal analyzer 7 directly, and the transmitter 10 are connected via electronic key 9 to pin 3.

The control point is made in the form of series-connected receiving antenna 16, high-frequency amplifier 17, phase doubler 19, first narrow-band filter 20, phase divider 21 into two, second narrow-band filter 22, frequency detector 25, trigger 26, balance switch 27, the second input of which connected to the output of the second narrow-band filter 22, a phase detector 23, the second input of which is connected to the output of the high-frequency amplifier 17, and the registration unit 24.

Since each key has an individual distribution of surface defects that are formed in the mass of material during the manufacture of the key, the distribution of the radiation intensity over the surface of the key after its preliminary heating will be individual for each key.

Therefore, you can open the lock only with that key, the characteristic of which is pre-installed in the device that compares the characteristic of the key with a predetermined one. Thus, the method of unlocking the lock has a high degree of secrecy.

If the characteristic of the key does not coincide with the characteristic previously set in the device, the radio channel is turned on, through which the alarm signal is transmitted to the control point (to the department of internal security, to the owner of the facility on which the lock is installed) to decide on the detention of a person who does not have authorized access to castle, and therefore to the object.

The method is as follows.

For a key made with surface defects, the distribution of heat radiation over the surface of the key is determined in advance. To this end, the key is heated to a temperature to which it will be heated when the lock is unlocked. This characteristic is entered into the memory of the device, which can compare the actual characteristic of the key with the given one.

When the lock is unlocked, the key is inserted into the keyhole, where it is heated to a certain temperature, after which its physical characteristic is determined: the distribution of thermal radiation on the surface of the key. If this characteristic coincides with a predefined one, a signal is issued to unlock the lock.

The execution of the signal generator in the form of a source, and the receiver in the form of a meter of thermal radiation intensity allows you to determine the distribution of the radiation intensity over the surface of the key after its preliminary heating. Moreover, since each key has an individual distribution of internal defects that are not visible from the outside in the array of material from which it is made, the distribution of radiation intensity over the surface of the key is individual. This circumstance can significantly increase the secrecy of the proposed castle.

These keys are provided to all persons who have authorized access to the castle, and therefore to the object on which it is installed.

If the characteristic of the key does not coincide with the characteristic previously installed in the device, then a phase-shifted (PSK) signal is generated in the lock, which contains information about the number of the lock and the place where it is installed. This alarm signal is transmitted over the air to a control point, where measures are taken to detain the attacker.

After switching on, a device that implements the proposed method operates as follows.

When installing the key 2 in the keyhole 8, contact 3 turns on the heating system, consisting of a heat emitter 4 and a heater 5, as well as a photodetector 6 and a signal analyzer 7. After heating the key 2 to a certain temperature, the photodetector 6 captures the distribution of the thermal radiation intensity over the surface of the key 2 and sends a signal to the signal analyzer 7, in which the obtained characteristic is compared with the reference one, if they coincide, a control signal is applied to unlock the locking device 1 and to close the electronic key 9. In the initial state, the electronic key 9 is always open.

When you install the key 2, the characteristic of which does not coincide with the characteristic previously set in the device, contact 3 through the public key 9 turns on the transmitter 10. In this case, the master oscillator 11 generates a high-frequency oscillation (Fig.3, a)

where V _c , ω _s , φ _s , T _c is the amplitude, carrier frequency, initial phase, and duration of the high-frequency oscillation that arrives at the first input of the phase manipulator 13, the second input of which is supplied with the modulating code M (t) (Fig. 3, b) containing information about the castle number, its nature and location where it is installed.

At the output of the phase manipulator 13, the QPSK signal is generated (Fig. 3, c)

where φ _k (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), and φ _k (t) = const for K · τ _e ≤t≤ (K + 1) · τ _e and can change abruptly at t = K · τ _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 a signal of duration T _c · (T _c = N · τ _e ), which, after amplification in the power amplifier 14, is transmitted by the transmitting antenna 15 to the air, is received by the receiving antenna 16 at the control point and through the high-frequency amplifier 17 is fed to the information input of the phase detector 23 and to the input of the phase doubler 19. At the output of the latter a harmonic voltage is generated (Fig. 3, g)

Since 2φ _k (t) = {0, 2π}, phase manipulation is already absent in the indicated voltage. Harmonic voltage U ₂ (t) allocated narrowband filter 20, the tuning frequency ω _H1 is chosen equal to twice the carrier frequency ω _c · (ω _H2 = ω _s), and is supplied to divider 21, phase entry by two, the output of which is formed harmonic voltage (figure 3, d)

This voltage is allocated by a narrow-band filter 22, tuned to the carrier frequency ω _s · (ω _H2 = ω _s ), and applied to the inputs of the frequency detector 25 and the balance switch 27.

However, the initial phase of the voltage obtained can have two statutory states: φ _c and φ _c + π. This is shown above.

Therefore, under the influence of interference, short termination of reception and other factors, the initial phase of the voltage (Fig.3, d)

can pass from one state φ _s to another φ _s + π. These transitions during the reception of the QPSK signal can occur at random times, for example, t ₁ and t ₂ (figure 3, d).

When the initial phase of the reference voltage U ₃ (t) changes abruptly by 180 °, due, for example, to the unstable operation of the phase divider 21 into two under the influence of noise, the frequency detector 25 emits a positive short pulse, and when the initial phase of the reference voltage changes, U ₃ ( t) at -180 ° (returning the initial phase to its original state), the frequency detector 25 emits a negative short pulse (Fig.3, g).

In this case, the trigger 26 positive short pulse from the output of the frequency detector 25 is transferred to another stable state at time t ₁ , the output voltage of the trigger 26 at time t ₂ becomes and remains positive until the next jump in the initial phase at time t ₂ , which returns the initial phase of the reference voltage in the initial state (figure 3, h).

In the absence of phase jumps, the reference voltage U ₃ (t) from the output of the narrow-band filter 22 through the balance switch 27 is supplied to the reference input of the phase detector 23 without changes. In this case, the balance switch 27 is in the first steady state.

The positive output voltage of the trigger 26 (Fig.3, h) transfers the balance switch 27 to another stable state, in which the reference voltage U ₃ (t) (Fig.3, d) from the output of the narrow-band filter 22 is supplied to the reference input of the phase detector 23 s a change in the initial phase by - 180 °.

This allows you to eliminate the instability of the initial phase of the reference voltage U ₃ (t) (Fig.3, d), caused by its abrupt changes under the influence of interference, and the associated phenomenon of "reverse operation".

Therefore, the frequency detector 25 provides detection of the moment of occurrence of the phenomenon of "reverse operation", and the trigger 26 and the double balance switch 27 eliminate it. As a result, a reference voltage with a stable initial phase is supplied to the reference input of the phase detector 23 (Fig. 3, and)

At the output of the phase detector, a low-frequency voltage is generated (Fig. 3, k)

Where

K is the transfer coefficient of the phase detector, proportional to the modulating code M (t) (Fig.3, b), which is registered by the registration unit 24.

Analyzing the low-frequency voltage, determine the number and place of installation of the lock, subjected to unauthorized exposure, and take measures to detain the attacker.

Serially connected phase doubler 19, narrow-band filter 20, phase divider 21 into two, narrow-band filter 22, frequency detector 25, trigger 26 and balance switch 27, the second input of which is connected to the output of narrow-band filter 22, form a device for generating a reference voltage with a stable initial phase .

It should be noted that a necessary condition for the phase detector 23 to operate is the presence of a reference voltage having the same frequency as the received PSK signal.

In the proposed technical solutions, the reference voltage with a stable initial phase, necessary for synchronous detection of the received PSK signal, is extracted directly from the received PSK signal.

In case of unauthorized exposure to the lock with a key of another design or a master key, the control point (the owner of the facility on which the lock is installed, or the department of internal security) receives an alarm signal over the radio channel, which uses phase-shift keying signals with energy and structural secrecy.

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

Thus, the proposed method and device in comparison with the prototypes provide increased reliability of the synchronous detection of the received phase-shift signal. This is achieved by detecting and eliminating the phenomenon of "reverse work". In this case, the frequency detector provides detection of the moment of occurrence of the phenomenon of "reverse operation", and the trigger and double balanced switch eliminate it.

Claims (2)

1. The method of unlocking the lock, which consists in physically affecting the key by heating, determining its physical characteristics in the form of a distribution of the intensity of thermal radiation over the surface of the key, into which internal defects are introduced in advance, comparing it with the given one and applying a signal to unlock the lock when these characteristics coincide at the same time, if these characteristics do not coincide, they form a high-frequency oscillation, manipulate it in phase with a modulating code that carries information about the lock, amplify it in power and emit t into space in the form of a phase-shifted signal, and then received at the control point, doubled in phase, isolated harmonic voltage at twice the carrier frequency, divided it in phase into two, isolated harmonic voltage at the carrier frequency and use it as a reference voltage for synchronous detection the received phase-manipulated signal, a low-frequency voltage proportional to the modulating code is isolated, it is recorded and analyzed, characterized in that the frequency detection is performed The obtained harmonic voltage at the carrier frequency and in the case of spasmodic changes in its initial phase emit short bipolar pulses corresponding to the moments of spasmodic changes in the initial phase, use them to form positive rectangular pulses and act on the initial phase of the harmonic voltage at the carrier frequency, returning it to the original state and thereby stabilizing while receiving the phase-shift signal. 2. A device for unlocking a lock containing a key with internal defects, a lock having a forming element in the form of a heat source, a receiver connected in series, a signal analyzer made in the form of a heat radiation intensity meter, and a locking unit, as well as a contact switch connected to the forming element exposure, by the receiver and the analyzer of the signal, the transmitter connected via an electronic key to the contact switch and the output of the signal analyzer, and the control point installed in the department the internal security guard or the owner of the object on which the lock is installed, the transmitter is made in the form of a serially connected master oscillator, phase manipulator, the second input of which is connected to the output of the modulating code generator, power amplifier and transmitting antenna, the control point is made in the form of serially connected receiving antennas, high-frequency amplifier, phase doubler, first narrow-band filter, phase divider into two and second narrow-band filters, connected in series to a high-frequency amplifier of a phase detector and a recording unit, characterized in that it is equipped with a frequency detector, a trigger, and a balance switch, and a frequency detector, a trigger, and a balance switch, the second input of which is connected to the output of the second narrow-band filter, are connected in series to the output of the second narrow-band filter, and the output is connected to the second input of the phase detector.

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