RU2282897C1 - Sos-system for highways - Google Patents

Abstract

FIELD: engineering of devices for provision of safety, protection and rescue under conditions of movement on big highways.

SUBSTANCE: in proposed system, radio communication with closest stations for provision of medical and technical aid is performed by using complex signals with combined amplitude modulation and phase manipulation. System contains solar battery, optical concentrators, boards, photo-diodes, reflectors, selsyn motors, cap, waterproof box, microphones, call buttons, rod antenna and radio transmitter. The latter includes set-point generator, amplitude modulator, generator of modulating code, phase manipulator, power amplifier and transmitting rod antenna. In each station for provision of medical and technical aid, provided are: receiving antenna, high frequency amplifier, detector of complex signal, phase doubler, spectrum analyzers, comparison block, threshold block, key, amplitude limiters, synchronous detector, sound signaler, registration block, block for dividing phase in two, narrowband filter and phase detector.

EFFECT: increased reliability of radio communication.

5 dwg

Description

The invention relates to safety, protection and rescue equipment in traffic on major highways.

Recently, on major motorways of Western countries (USA, Germany, South Korea), in order to quickly report a traffic accident on both sides of the highway, SOS telephones of direct radio communication with the nearest medical and technical assistance centers are installed every kilometer.

These systems have autonomous power supplies and are constantly tuned to the wave of the corresponding item.

Most often, there are autonomous systems with solar energy sources (Fig. 1) and sometimes with a system of their orientation to the Sun.

The system is installed in the immediate vicinity of the highway on a concrete pillar 1 with a height of 12-15 meters, in the upper part of which there is a permanently fixed solar silicon battery 2 with an area of 0.12 m ² and a maximum electric power at noon of about 10 W, a three-pin radio antenna 3 and an airtight box with a microphone and a call button, inside of which there is a buffer alkaline battery, recharged from the solar battery for nighttime operation, and a radio transmitter. The solar battery is constantly directed to the South at an angle of 30 ° to the horizon.

The disadvantages of such a system are:

- the high cost associated with the use of high concrete poles to prevent theft of the solar battery;

- lack of efficiency on cloudy days and low efficiency in the sun-oriented position of the solar battery.

Also known are SOS systems for motorways (RF patents Nos. 2090777, 2183351; US patents Nos. 4753895, 4816893 and others).

Of the known systems closest to the proposed one is the "SOS-system for highways" (RF patent No. 2183351, G 08 B 25/12, 2000), which is selected as the base system.

The specified system for transmitting an alarm signal uses only a voice message and does not provide reliable radio communication with the nearest points of medical and technical assistance.

An object of the invention is to increase the reliability of radio communications with the nearest points of medical and technical assistance by using complex signals with combined amplitude modulation and phase shift keying.

The problem is solved in that the SOS system of radiotelephone communications in emergency situations on large highways, using solar energy to power the radio transmitter in the daytime and at night, and consisting of a multi-cell panel of solar paraboloid concentrators, in the foci of which are gallium arsenide photodetectors that can convert concentrated solar energy with an efficiency of up to 20% and with a specific power of 200 W / m ² , photodiodes in cylindrical installed on the sides of the solar battery reflectors, which are able to orient the battery in the sun using selsyn with an accuracy of ± 2 °, and the battery itself is placed in a sealed hemisphere, on top of which there is a whip antenna connected to a box that houses a buffer alkaline battery, radio transmitter, microphones and call buttons, at the same time, the boxes are attached to the dividing barrier of the highway at a distance of 0.8-1 km from each other, is equipped with medical and technical assistance points located along highways in settlements, each of which contains a receiving antenna in series, a high-frequency amplifier, a phase doubler, a second spectrum analyzer, a comparison unit, the second input of which is connected to the high-frequency amplifier output through a first spectrum analyzer, a threshold block, a key, the second input of which is connected to the high-amplifier output frequency, the first amplitude limiter and a synchronous detector, the second input of which is connected to the output of the key, and the output is connected to the sound signaling device and the registration unit, and to the output of the doubler The second amplitude limiter, a phase divider into two, a narrow-band filter and a phase detector, the second input of which is connected to the output of the first amplitude limiter and the output is connected to the second input of the recording unit, are connected in series, the radio transmitter is made in the form of a serially connected master oscillator, amplitude modulator, second the input of which is connected to the output of the microphone, phase manipulator, the second input of which is connected to the output of the modulating code generator, power amplifier and transmitting tyrevoy antenna.

The structural diagram of the proposed SOS system for highways is presented in figure 2. The structural diagram of the radio transmitter is shown in figure 3. The block diagram of the point of medical and technical assistance is shown in Fig.4. Timing diagrams explaining the principle of the system are shown in Fig.5.

The solar battery 1 is a set of solar paraboloidal optical concentrators 2 focused on the arsenide-galium converters located on the rear side of the strips 3. For azimuthal-zenith orientation, photodiodes 4 with reflectors 5 are installed on the sides of the battery, which control selsyn 6.

The battery is installed in a sealed transparent hemispherical cap 7 on a sealed box 8, inside of which there is a buffer alkaline battery and a radio transmitter, and microphones 9 and call buttons 10 are located on opposite walls of the box. The pin antenna 11 is installed in the upper part of the hemisphere, and the whole system is mounted on the separation motorway barrier 12.

The radio transmitter is made in the form of series-connected master oscillator 13, amplitude modulator 14, the second input of which is connected to the output of the microphone 9, the phase manipulator 16, the second input of which is connected to the output of the generator 15 of the modulating code, power amplifier 17 and transmitting pin antenna 11.

The medical and technical assistance station contains a receiving antenna 18, a high-frequency amplifier 19, a phase doubler 21, a second spectrum analyzer 23, a comparison unit 24, the second input of which is connected to the output of a high-frequency amplifier 19 through a first spectrum analyzer 22, a threshold block 25 , key 26, the second input of which is connected to the output of the high-frequency amplifier 19, the first amplitude limiter 27 and the synchronous detector 28, the second input of which is connected to the output of the key 26, and the output is connected to an audible alarm Open 29 and registration unit 30. A second amplitude limiter 31, a phase divider 32, a narrow-band filter 33, and a phase detector 34 are connected in series to the output of the phase doubler 21, the second input of which is connected to the output of the first amplitude limiter 27, and the output is connected to the second input of the registration unit 30.

Phase doubler 21, spectrum analyzers 22 and 23, comparison unit 24, threshold block 25, and key 26 form a detector (selector) 20 of a complex signal with combined amplitude modulation and phase shift keying (AM-FMN).

The system operates as follows.

When a traffic accident occurs, its participants press button 10 and thereby turn on the power to the radio transmitter. In this case, the master oscillator 13 generates a high-frequency oscillation (Fig. 5, a)

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

where U _c , ω _s , φ _s , T _s - amplitude, carrier frequency, initial phase and duration of the oscillation;

which is fed to the first input of the amplitude modulator 14.

The second input of the latter is supplied with the modulating function m (t) (Fig. 5, b) from the output of the microphone 9, which displays the voice message of the victim, which contains information about the details of what happened. At the output of the amplitude modulator 14, a signal with amplitude modulation (AM) is generated (Fig. 5, c)

u ₁ (t) = U ₁ [1 + m (t)] · cos (ω _s t + φ _s ), 0≤t≤T _c ,

Where

K ₁ - transmission coefficient of the amplitude modulator;

m (t) is a modulating function that displays the law of amplitude modulation, which is transmitted to the first input of the phase manipulator 16. The second input of the latter is supplied with a modulating code M (t) (Fig. 5d), which contains an alarm signal (SOS), the name of the highway, the number of the separation barrier, which is applied in black on the white surface of the separation barrier, the number of kilometers on which the separation barrier is installed, and other necessary identification data.

At the output of the phase manipulator 16, a complex signal is formed with combined amplitude modulation and phase manipulation (AM-PSK) (Fig. 5, e)

u ₂ (t) = U ₂ [1 + m (t)] cos [ω _with t + φ _k (t) + φ _c ], 0≤t≤T _c ,

Where

K ₂ - the transfer coefficient of the phase manipulator;

φ _k (t) = {0, π} is the manipulated component of the phase that displays the law of phase manipulation in accordance with the modeling code M (t) (Fig. 5d), and φ _k (t) = const for kτ _E <t <(k + 1) τ _Oe and can change abruptly at t = kτ _Oe , i.e. at the boundaries between elementary premises (K = 1, 2, ..., N-1);

τ _E , N - the duration and number of chips that make up a signal of duration T _s (T _s = Nτ _E ).

This signal, after amplification in the power amplifier 17, is radiated by the transmitting pin antenna 11, captured by the receiving antenna 18, and fed through the high-frequency amplifier 19 to the input of the detector (selector) 20, consisting of a phase doubler 21, spectrum analyzers 22 and 23, and a comparison unit 24 threshold block 25 and key 26.

A voltage is generated at the output of the phase doubler 21

u ₃ (t) = U ₃ [1 + m (t)] ² cos (2ω _c t + 2φ _c ), 0≤t≤T _c ,

Where

To ₃ - the transfer coefficient of the phase doubler (multiplier).

As a phase doubler 21, a multiplier can be used, the two signal of which receives the same signal u ₂ (1).

Since 2φ _k (t) = {0.2π}, there is already no phase shift keying in the voltage u ₃ (t).

The spectrum width Δf _{2 of the} second harmonic of the signal is determined by the duration T _{c of the} signal

whereas the spectral width Δf _c of the received signal determined by the duration τ _e his chip

those. spectrum width Δf _{2 of the} second harmonic of the signal is N times smaller than the spectrum width Δf _{c of the} input signal

Therefore, when the phase of the AM-QPSK signal is multiplied by two, its spectrum is “rolled up” N times. This circumstance makes it possible to detect an AM-QPSK signal even when its power at the receiver input is less than the power of noise and interference.

The width of the spectrum Δf _{c of the} input signal is measured using a spectrum analyzer, and the spectrum width Δf _{2 of the} second harmonic of the signal is measured using the spectrum analyzer 23. Voltages U _I and U _II , proportional to Δf _c and Δf _2, respectively, from the outputs of the spectrum analyzers 22 and 23 are supplied to the two inputs of the comparison unit 24. Since U _I ≫U _II , a positive pulse is generated at the output of the comparison unit 24, which is compared with the threshold voltage U _then in the threshold block 25. The threshold voltage U _{then is} exceeded only when an AM-QPSK signal is detected. If the threshold level U _pores is exceeded, a constant voltage is generated in the threshold block 25, which is supplied to the control input of the key 26, opening it. In the initial state, the key 26 is always closed.

In this case, the received AM-QPSK signal u ₂ (t) from the output of the high-frequency amplifier 19 through the public key 26 is fed to the first input of the synchronous detector 28 and to the input of the first amplitude limiter 27.

At the output of the latter, an FMN signal is generated (Fig. 5, e)

u ₄ (t) = U _o cos [ω _c t + φ _k (t) + φ _c ], 0≤t≤T _c ,

where U _o is the limit threshold;

which is supplied to the reference input of the synchronous detector 28. As a result of synchronous detection, a low-frequency voltage is generated at the output of the synchronous detector 28 (figure 5, g)

u _H1 (t) = U _H1 [1 + m (t)],

Where

To ₄ - the transfer coefficient of the synchronous detector,

proportional to the initial modulating function m (t). This voltage is supplied to the first input of the registration unit 30, where it is fixed, and to the input of the audible alarm 29, where an alarm message is played.

PSK signal (Fig.5, e) u ₄ (t) from the output of the first amplitude limiter 27 is fed to the information input of the phase detector 34.

The voltage u ₃ (1) from the output of the phase doubler 21 is simultaneously fed to the input of the second amplitude limiter 31, the output of which is voltage (Fig. 5, h)

u ₅ (t) = U _o cos (2ω _c t + 2φ _c ), 0≤t≤T _c .

This voltage is supplied to the input of the phase divider 32 into two, at the output of which a voltage is generated (figure 5, and)

u ₆ (t) = U ₆ cos (ω _c t + φ _c ), 0≤t≤T _c ,

Where

To ₄ - the transfer coefficient of the phase divider by two.

This voltage is allocated by a narrow-band filter 33 and is supplied to the reference input of the phase detector 34.

At the output of the phase detector 34, a low-frequency voltage is generated (Fig. 5, k)

u _H2 = (t) = U _H2 cosφ _k (t)

Where

To ₄ - the transfer coefficient of the phase detector,

proportional to the modulating code M (t) (Fig. 5, d). This voltage is supplied to the second input of the registration unit 30, where it is fixed.

Therefore, the reference voltage necessary for synchronous detection of the PSK signal is extracted directly from the received AM-PSK signal.

Thus, the proposed SOS system for highways, in comparison with the prototype and other technical solutions of a similar purpose, provides increased reliability of radio communications with the nearest points of medical and technical assistance. This is achieved by using complex signals with combined amplitude modulation and phase shift keying (AM-FMN).

These signals open up new possibilities in the technology of messaging. They allow you to apply a new type of selection - structural selection. This means that there is a new opportunity to separate signals operating in the same frequency band and at the same time intervals. In principle, one can abandon the traditional method of dividing the operating frequencies of the used range between operating SOS systems and selecting them on the receiving side using frequency filters. It can be replaced by a new method based on the simultaneous operation of each SOS system through its structural selection.

Due to the frequency redundancy of broadband radio communication systems, they can successfully operate if there are several narrow-band radio stations in the frequency band of the received AM-FMN signal.

Among other problems, the solution of which largely determines the further progress of radio communications, should include the problem of establishing reliable communication in channels in the presence of a multipath nature of the propagation of radio waves. The presence of multipath propagation of radio waves leads to a distortion of the received signals, which complicates the reception and reduces the reliability of information transmission. Attempts to overcome the harmful effects of multipath have been made for a long time. These include: diversity reception, signal selection by time and angle of arrival, corrective coding, and some other methods. However, they all do not provide a fundamental solution to the problem.

Due to its good correlation property, a signal with a complex structure can be “folded” into a narrow pulse, the duration of which is inversely proportional to the used bandwidth. Choosing such a frequency band so that the duration of the “folded” pulse is less than the delay time, it is possible to separately receive pulses arriving at the receiving point in various ways, and by summing their energy, it is also possible to increase the noise immunity of complex AM-FMN signals. Thus, this problem gets a fundamental solution.

From the point of view of detection, complex AM-FMN signals have high energy and structural secrecy.

The energy secrecy of these signals is due to their high compressibility in time and spectrum with optimal processing, which reduces the instantaneous radiated power. As a result, a complex AM-QPSK signal at the receiving point may be masked by noise and interference. Moreover, the energy of a complex 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 AM-QPSK signals is caused by a wide variety of their forms and significant ranges of parameter changes, which makes it difficult to optimize or at least quasi-optimally process complex signals of an a priori unknown structure in order to increase the sensitivity of the receiver.

In addition, the proposed SOS-system provides duplication of the transmission of alarm messages.

If the button 10 is pressed and the microphone 9 is used, then a voice analog message and an automatic digital message containing information about the location of the traffic accident are transmitted.

If only button 10 is pressed, this situation is possible during a traffic accident, then only an automatic digital message is transmitted and the audible warning device 29 does not work in this case.

Claims (1)

SOS-system for radiotelephone communications in emergencies on major highways, using solar energy to power the radio transmitter in the daytime and at night, and consisting of a multi-cell panel of solar paraboloid concentrators, the focuses of which are gallium arsenide photodetectors that can convert concentrated solar energy from efficiency to 20% and with a specific power of 200 W / m ² at each side of the solar battery installed in the photodiodes cylindrical reflectors having the possibility ori mount the battery in the sun using selsyn with an accuracy of ± 2 °, and the battery itself is placed in a sealed transparent hemisphere, on top of which there is a whip antenna connected to a box that houses a buffer alkaline battery, radio transmitter, microphone and call buttons, while the boxes are attached to the dividing barrier of the highway at a distance of 0.8 ... 1 km from each other, characterized in that it is equipped with medical and technical assistance points located along the highway in the settlements each of which contains a receiving antenna in series, a high-frequency amplifier, a phase doubler, a second spectrum analyzer, a comparison unit, the second input of which is connected to the high-frequency amplifier output through a first spectrum analyzer, a threshold block, a key, the second input of which is connected to the high-amplifier output frequency, the first amplitude limiter and a synchronous detector, the second input of which is connected to the output of the key, and the output is connected to the sound signaling device and the registration unit, and to the output of the phase doubler a second amplitude limiter, a phase divider into two, a narrow-band filter and a phase detector are connected in series, the second input of which is connected to the output of the first amplitude limiter, and the output is connected to the second input of the recording unit, the radio transmitter is made in the form of series-connected master oscillator, amplitude modulator, second input which is connected to the output of the microphone, phase manipulator, the second input of which is connected to the output of the modulating code generator, power amplifier and transmitting w yrevoy antenna.

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