RU2230431C2 - Shipboard emergency radio communication system - Google Patents

Abstract

FIELD: emergency radio communication systems on board ships and surface facilities. SUBSTANCE: system has hollow metal cylinders in each shielded radio station compartment which are closed at ends by sound-conducting water-tight material and installed in pairs in bulkheads between compartments so that their butt-ends occur in adjacent compartments at distance multiple of

Description

The invention relates to the field of electrical engineering and can be used to organize emergency radio communications on ships, ships, underwater vehicles, i.e. between isolated, shielded rooms (compartments).

One of the main requirements for an emergency shipborne communication system (VKS) is to ensure stable communication between subscribers located in sealed and almost completely shielded rooms, for example compartments of underwater objects (PO). In this case, it is assumed that a fire, flooding of compartments or other emergency situation may occur on a ship or underwater object.

Known radio transmission device for communication used in a vehicle [Germany patent No. 3537107, N 04 7/155, 1987].

The device consists of a radio transmitter, an external antenna, a connecting feeder, an internal antenna, an amplifier, and a receiver.

The vehicle has an external antenna that receives signals sent by the radio transmitter. An antenna connecting feeder is introduced into the vehicle, where the received signal is amplified by an amplifier and radiated within the vehicle via an internal antenna.

The disadvantage of this device is the inability to establish guaranteed emergency communications on ships, ships, underwater objects, where there are a large number of rooms, compartments, which, as a rule, are in an aggressive external environment - water. When using such a device on a ship, the required reliability of emergency communications is not provided. This is due to the lack of a feeder input transition in the device and the use of an additional amplifier that requires external power. In addition, in a fire in the compartment, the device feeder is an unreliable element, because it is subject to burnout, which reduces the reliability of emergency communications in general.

Closest to the technical nature of the claimed object is the "System of intra-ship emergency communications" [RF patent No. 2108671, cl. 6 H 04 B 7/155 1985]. The system contains a symmetrical guide line along which the subscriber devices of battery-free telephone communication are located, small-sized transceivers, portable radios and the interface blocks of subscriber devices of battery-free telephone communication with transceivers. The physical circuit of a two-wire line is used to receive and transmit voice information, along which electromagnetic waves are transmitted. Signals from the transceiver are transmitted on a two-wire communication line in both directions and through the interface block are sent to other transceivers, the same signals pass through the transceivers, amplified in the interface blocks and emitted in the compartments of the ship. Radiation is received by portable radios.

The disadvantage of this system is that it does not provide guaranteed emergency communication on the ship due to the fact that when any of the compartments burn out, the wired communication lines also burn out.

At the same time, it should be pointed out that the violation of the electric line passing through the compartments of the ship, the underwater object caused by fire, mechanical damage, acid penetration, etc., leads to the loss of radio communication between the compartments of the ship and the underwater object separated by damage.

This is due to the nature of the propagation of the radiation from the radio station, determined only by interference on the cable electric trunk of a software or ship. Violation of cable electrical lines in the compartments due to the fire was observed on the emergency submarine Komsomolets.

Thus, the reliability and efficiency of the existing internal emergency communication system is insufficient and depends on external factors (the state of cable routes).

The aim of the present invention is to increase the reliability and survivability of emergency intra-ship communications.

где N - целое число, λ - длины рабочей волны радиостанции, причем указанные торцы закрыты герметическими крышками из термостойкого высокопрочного диэлектрика, например кварцевого стекла, при этом радиостанции излучают частоту, близкую к резонансной частоте указанных цилиндров.This goal is achieved by the fact that in the emergency system of intra-ship communication, consisting of portable radio stations located in each compartment of the ship, metal hollow cylinders are additionally installed, installed in pairs in inter-compartment bulkheads so that their ends are in adjacent compartments at distances that are multiple of

where N is an integer, λ is the working wavelength of the radio station, and these ends are closed with hermetic covers made of heat-resistant high-strength dielectric, for example quartz glass, while the radio stations emit a frequency close to the resonant frequency of these cylinders.

The set of essential features of the claimed device provides increased reliability of the shipboard internal radio communication system in emergency conditions.

Figure 1 presents the structural diagram of the system, where:

1 - strong submarine housing;

2 - intersection bulkheads;

3 - portable radio stations;

4 - metal hollow cylinders;

5 - sealed dielectric covers.

The robust housing 1 serves to accommodate personnel and equipment, the inter-compartment bulkheads 2 serve to form pressurized compartments and place metal hollow cylinders 4, radio stations 3 serve to transmit and receive information in the radio ranges of the electromagnetic wave scale, metal hollow cylinders 4 are resonators for operating frequencies radio stations 3 and are used to channel electromagnetic energy within a solid housing 1 through bulkheads 2, sealed covers 5 are used to seal the cylinder ditch 4 and provide conditions for re-emission of electromagnetic energy when sealing the compartment as a whole.

The fastening of the metal hollow cylinders 4 with dielectric caps 5 on the inter-compartment bulkheads 2 on a larger scale is shown in FIG.

The device operates as follows.

When the emergency radio station 3 is operating, its antenna excites in the space of the compartment formed by the robust housing 1 and the inter-compartment bulkheads 2 an electromagnetic field, which is a combination of standing electric and magnetic waves with a complex picture of the propagation of nodes and antinodes.

A complex picture of the spatial distribution of nodes and antinodes of standing electric and magnetic waves is determined by the non-ideal compartment shape, material properties, arbitrary distribution of equipment and other factors.

An electromagnetic field having a frequency close to resonant for hollow metal cylinders 4 excites directed waves of the E, H type, or simultaneously waves of these types. These waves propagate along cylinders 4 and are reradiated in adjacent compartments.

If the end face of one of the cylinders 4 is located in the node of an electric or magnetic wave (the worst condition for excitation), then another adjacent cylinder 4 is used to channel the energy of the field, located from the first one at a distance multiple of an odd number of a quarter of the wave (standing wave antinode condition, i.e. optimal excitation conditions).

Thus, the radiation propagates from compartment to compartment, experiencing re-radiation on the resonators formed by cylinders 4 with sealed covers 5. This radiation is received by the receivers of the remaining radio stations 3 located in other compartments. In this system, radios 3 operate using direct rather than induced radiation. Therefore, the range of emergency communications will be within the entire ship, and will not depend on the location of the radio station 3 within the compartment, which is determined by the increase in field strength and its distribution. In addition, for this reason, the system is independent of the integrity of the electric cable line caused by a fire or other reasons. The reliability of the system in emergency conditions is ensured by the use of 4 high-strength heat-resistant dielectrics for sealing metal cylinders, the fire resistance of which is higher than that of products of cable ship highways.

The parameters of system elements can be estimated as follows.

An H ₁₁ type wave has the lowest critical frequency in a circular waveguide _. For a given wavelength λ, energy can propagate in a circular waveguide if its radius is greater than

для волн H_mλ,

for waves H _mλ ,

для волн H_mλ,

for waves H _mλ ,

[cm. Eisenborg G.Z. and other VHF antennas. T. I, M .: Communication, 1977].

Given that, based on the conditions for ensuring strength, the inner diameter of the cylinders 4 can be 2a = 5 cm, and the length l = 15-20 cm, the working wavelength λ will be 5-10 cm.

Thus, as a radio station 3 for use in the system, a portable ship radio station P-622 having a specified frequency range and an omnidirectional antenna can be used.

As the material of the covers of 5 cylindrical resonators, it is possible to use special glasses with high strength, low dielectric losses and a melting point of 1200-2100 ° C (synthetic sapphire t _pl = 2030 °, magnesium oxide t _pl = 2080 °). [Krikunov L.Z. Guide to the basics of infrared technology. M .: Sov. Radio, 1978].

Let us justify the claimed system. So, an isotropic emitter installed in a closed room creates a field on its walls, the energy distribution of which is a complex interference picture.

Этот случай, как наиболее неблагоприятный, и учитывает предложенные попарные расположения резонаторов-ретрансляторов.In the general case, under the assumption that the rays arriving at the receiving point have the same amplitudes and a uniform phase distribution within 0-2, the energy distribution of the field will be uniform. Then, with an increase in the number of described repeaters, the energy transferred to adjacent compartments will increase proportionally. In this case, the pairwise arrangement of repeaters will enhance the effect of re-radiation. Another extreme case will be the case considered in the application, when the interference pattern will be an alternation of minima and maxima spaced apart from each other at a distance

This case, as the most unfavorable, also takes into account the proposed pairwise arrangements of relay resonators.

To confirm the above, we consider the interference of arbitrarily taken two rays, presented in figure 2.

Let in a room having segments a ₁ a ₂ a ₃ a ₄ in plan (where a ₁ a ₂ = d = a ₃ a ₄ is the width of the room and a ₁ a ₃ = z is the length), two rays emanating from the points and ₁ a ₂ , and the picture has a maximum at point 0.

Point 0 is symmetric with respect to points a ₁ a ₂ and a ₃ a ₄ .

We also note that the points a ₁ and ₂ can be considered not only as the extreme points of the compartment, but also as any two points arbitrarily selected in space symmetrically with respect to the axis 00 ₁ .

We determine the distance from point 0 to the nearest minimum X of the interference pattern. Two rays emanating from points a ₁ a ₂ will have a ray path length r ₁ and r ₂ . The result of the interaction of the rays A (t) at the point X can be written as

- волновое число.where A is the amplitude, ω is the frequency,

is the wave number.

In accordance with the notation of figure 3, the length of the rays is determined:

Consider the course of the rays:

Thus, the function A (t) has a minimum when:

т.е.

those.

where from

при d≤2Z.

at d≤2Z.

которое может рассматриваться как крайний случай, учитываемый попарным размещением пассивных ретрансляторов.Usually Z = 1.5-2d, so in the real case, the minimum of the picture created by most of the reflected rays will be separated from the maximum by a distance

which can be considered as an extreme case, taken into account by the pairwise placement of passive repeaters.

The efficiency of the system in a fire will be determined by the propagation loss of the field in the plasma, that is, the value of the dielectric constant. As indicated in B.A. Ginzburg. “Plasma Radio Wave Propagation.” M .: 1969

where f _PL = 10 ⁷ Hz is the plasma frequency.

и величина E_пл, определяющая потери в плазме, практически не изменится. Это дает основание полагать, что в условиях пожара работоспособность сохранится.Since the system uses a centimeter frequency range for operation, then

and the value of E _PL , which determines the loss in plasma, practically does not change. This gives reason to believe that in a fire condition, operability will continue.

When the compartment is completely flooded, the overall system performance will slightly decrease, due to the fact that cable routes will play a leading role in the relayed section of the signal, which will remain in this case. With partial flooding of the compartment, when the transponders are not covered by water (the crew remains operational), the proposed system works efficiently.

The system is supposed to excite resonators with non-directional radiation of a P-622 type radio station, therefore, the excitation power of the resonator will be small, the opposite end of the resonator will also generate non-directional radiation, so after 1-2 compartments the radiation will be so small that no radio station will perceive it.

This remark is valid for conditions of free space or bounded half-space.

However, in a confined space limited by a conducting medium (the case of a sealed compartment of an underwater object or a spacecraft), regardless of the type of emitter (pin, dipole, etc.), all the energy emitted by it will be enclosed within the specified space.

Moreover, if there is an output device that is consistent with the wavelength and optimally placed (in this case, a resonator is proposed), in the ideal case, all the radiated energy will be transmitted through this device.

In this case, the radiation of the radio station will propagate in all directions within the radiation pattern, experiencing multiple reflections on each of the directions on the screening surface of the compartment and creating a complex interference pattern on it with alternating maxima and minima.

If you place a matched resonator in the antinodes of such a picture, then it will be the only source of “leakage” of all energy.

In this case, theoretically, all the energy beams emitted by the antenna in various directions, and not only the beams incident directly on the end of the waveguide, will contribute to its excitation. Thus, in the ideal case, the resonator will theoretically be excited by all the energy of the electromagnetic field emitted by the antenna.

Under real conditions, in each direction of radiation there will be losses determined by the losses in the material at the places of reflections at the air-metal interface. Nevertheless, in spite of the losses, the excitation energy of the resonator will be greater than the energy determined by the rays incident directly on its end, which will make it possible to obtain a communication range greater than 1-2 compartments. However, even in the case of excitation of the resonator by direct radiation only (the worst case), the energy relations on the propagation path will provide a communication range much greater than two compartments.

To assess the energy ratios of emergency communications, we consider the route model. The model is presented in figure 3.

The model assumes that the compartment walls are coated with an absorbent coating. In the model, a dipole was chosen as the emitter (the omnidirectional antenna of the radio station is formed by two crossed dipoles), as the receiving antenna, also a dipole having a cosine radiation pattern of one lobe, as well as the end face of the resonator.

In the calculations we use the technical characteristics of the radio station R-622 [A. Katanovich Ship light-signal communication. St. Petersburg: Shipbuilding, 2002]

- transmitter power 50 mW;

- sensitivity 5 · 10 ^-15 W;

- communication range:

for narrowly directed antennas - up to 20 km;

omnidirectional antennas - up to 3 km.

The radiation resistance of a half-wave vibrator R _prd = R _pp = 75 Ohms.

Then the maximum current in the transmitting antenna

The maximum E _{mgn prd} instantaneous value of the field strength created by the transmitting antenna at a distance of r = 10 m (compartment length) is determined [A.S. Dribkin. Antenna feeder devices. M .: Sov. radio, 1961] how

- волновое число;Where

- wave number;

θ is the angle of direction to the measuring point (reception);

r is the distance to the measurement point;

l is the length of the elementary dipole.

From the same source it is known that the EDO excited in the receiving antenna can be determined from the relation

where σ is the antenna gain (for the dipole, σ = 3.28);

F (φ, θ) is the radiation pattern depending on the spatial angles of orientation of the receiving antenna to the radiation source (can be taken equal to unity due to the limited angular displacement of the transmitter and receiver).

Where from

The power transmission coefficient for two adjacent compartments will be:

The energy reserve of the “transmitter-receiver” is

Thus, the number of compartments served by one radio station in one direction:

When placing the control radio station in the middle of the underwater object, the total number of compartments of which does not exceed 10, you can use the proposed system to communicate within the entire underwater object.

The above calculation was performed for the worst propagation conditions of radio waves. However, taking into account the additional contribution of reflected beams to the excitation of resonators, there is the possibility of direct radio communication through all compartments of the underwater object.

For the best conditions (ideal energy distribution without loss on the compartment walls and optimal resonator excitation), no calculation is given, because the length of the underwater object is up to 150 m, which is significantly less than the range of the radio station - 3 km.

It can be noted that, reflected from the bulkheads, waves reaching the resonators will experience interference, which will lead to random fading of the signal at the inputs and, therefore, the outputs of the resonators.

С учетом этого предлагается попарная установка резонаторов на расстояниях, кратных нечетному количеству четверти длины волны.Indeed, antenna radiation creates a complex interference picture of the field on the compartment walls with alternating maxima and minima at distances that are multiples of

With this in mind, a pairwise installation of resonators at distances multiple of an odd number of a quarter of the wavelength is proposed.

Thus, for one of the resonators, the excitation conditions will be close to optimal.

The feasibility study is as follows:

1. Provides stable operation of the system in emergency conditions in case of violation of the integrity of the cable electrical lines caused by fire and mechanical damage or other reasons.

2. A non-relaying reception of signals from radio stations in all compartments of the ship is provided simultaneously with an arbitrary arrangement of the radio station inside each of the compartments.

Claims (1)

An emergency shipboard radio communication system containing a portable radio station in each compartment of the ship, characterized in that metal hollow cylinders (resonators) of 20 cm length are introduced, their internal diameter is 5 cm, closed from the ends by a soundproof waterproof substance, which are installed in pairs in the inter-compartment bulkheads that their ends are in adjacent compartments at distances that are multiples of

where N is an integer, λ is the length of the working wave, while the radios emit a frequency close to the resonant frequency of the hollow cylinders.

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