RU2485019C1 - Aircraft crash point detection system - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to aircraft engineering. Proposed system comprises "black box" with signaling and search device arranged aboard the helicopter. Proposed black box is para dropped in the case of aircraft accident to emit electromagnetic waves and sound signals. In parachute opening, valve is opened to allow compressed air into rubber chamber to be inflated to make damping pad. Said electromagnetic waves and sound signals are also emitted from bottom in getting into water. Locating receiver arranged aboard the helicopter comprises measurement channel and four locating channels. Measurement channel comprises receiving antenna, HF amplifier, local oscillator, mixer, IF amplifier, demodulator of FM-signals, multipliers, narrowband filter, low-frequency filter and recording unit. Locating channels comprises receiving antenna, HF amplifiers, multipliers, narrowband filters, delay lines, phase detectors and master oscillator.

EFFECT: fast and accurate detection of "black box".

8 dwg

Description

The proposed system relates to the field of aviation and can be used to search for the "black box" during an airplane crash.

Known devices and systems for determining the scene of an airplane crash (RF patents Nos. 2,097.279, 2.113.380, 2.198.116, 2.415.781; US patents Nos. 3,520.503, 6.009.356; German patent No. 1.984.801; French patent No. 1.564.139 and others).

Of the known devices and systems closest to the proposed system is the "Black Box" with alarm (RF patent No. 2.415.781, B64D 1/00, 2009), which is selected as the base object.

The well-known “Black Box” with alarm in the event of a plane crash is thrown with a parachute, emitting electromagnetic waves and sound signals. The "black box" contains a rubber chamber, which, when the parachute is opened, is filled with air coming from the compressed air chamber. The ability to quickly find the "black box", and also reduces the likelihood of severe damage.

For quick and accurate detection of the “black box” emitting electromagnetic and sound waves, and consequently, the plane crash site, you need a search device, placed, for example, on board a helicopter.

An object of the invention is to provide the ability to quickly and accurately detect the black box, and therefore the crash site of an airplane by using a search instrument on board a helicopter.

The problem is solved in that a system for determining the scene of an airplane crash, containing, in accordance with the closest analogue, a “black box” with an alarm system that, in the event of an airplane crash, is parachuted from the compartment and lands or lands on the sea surface, while emitting electromagnetic waves and sound signals, the "black box" is placed in the tail section of the aircraft and is automatically thrown out, while during the opening of the parachute the crane opens and through the air duct from the compressed chamber air enters air into the rubber chamber, which is inflated and turns into a shock absorber-pillow, electromagnetic waves emitted by the black box and sound signals are also emitted at a depth that differs from the closest analogue in that it is equipped with a search device placed on board the helicopter and consisting of measuring and four direction finding channels, and the measuring channel contains serially connected receiving antenna, high-frequency amplifier, mixer, the second input of which is connected to the output of the local oscillator , an intermediate-frequency amplifier, a first multiplier, the second input of which is connected to the output of a low-pass filter, a narrow-band filter, a second multiplier, whose second input is connected to the output of an intermediate-frequency amplifier, a low-pass filter and a recording unit, each direction finding channel contains a receiving antenna in series, a high-frequency amplifier, a multiplier, the second input of which is connected to the output of the intermediate-frequency amplifier, and a narrow-band filter, to the output of the first narrow-band filter therefore, a fifth multiplier is connected, the second input of which is connected to the output of the second narrow-band filter, the fifth narrow-band filter and the first phase meter, the first delay line, the first phase detector, the second input of which is connected to the output of the second narrow-band filter, and the second phase meter are connected in series to the input of the second narrow-band filter , the sixth multiplier is connected to the output of the third narrow-band filter, the second input of which is connected to the output of the fourth narrow-band filter, the sixth a band-pass filter and a third phase meter, the second delay line, the second phase detector, the second input of which is connected to the output of the fourth narrow-band filter, and the fourth phase meter, the second inputs of the phase meters are connected to the output of the reference generator, the receiving antenna of the measuring channel is placed above the output of the fourth narrow-band filter helicopter rotor hub, receiving antennas of direction finding channels are located at the ends of the rotor blades, the engine is kinetically connected with the helicopter rotor and supporting generator.

Figure 1 shows an airplane with a compartment mounted therein; figure 2 shows the "black box" with its components; figure 3 - "black box" with the parachute open; figure 4 is a schematic structural diagram for the ejection of the "black box" from the compartment of the aircraft; figure 5 - socket with a plug; figure 6 - rubber chamber; Fig.7 shows the relative position of the "black box" and receiving antennas 38-42. On Fig presents a structural diagram of a search instrument placed on board a helicopter.

The "black box" 2 contains a block 5 of sound and electromagnetic wave generators, a power supply unit 6, a switch lever 7, an air compression chamber 8, a torus type rubber chamber 9, a parachute 11, a flexible antenna 12, a niche 13, a sound emitter 14, a cable cable 15, connector 16,

The following elements and parts are used to control the black box: airplane engine 17, telephone type sound sensor 18, electric signal amplifier 19, electric relays 20 and 21, fuse 22, electric current switch 23, power supply unit 24, electrical wires 25, 26 and 27. All wires 35 going to the tail of the aircraft 1 are connected through connector 16 to a “black box” 2 located in compartment 3, and when the “black box” exits the compartment, the plug 28 is disconnected from the outlet 29 located in compartment 3.

The search instrument, located on board the helicopter, contains a measuring channel and four direction finding channels.

The measuring channel contains a receiving antenna 38 connected in series, a high-frequency amplifier 43, a mixer 51, the second input of which is connected to the output of the local oscillator 50, an intermediate-frequency amplifier 52, a first multiplier 54, the second input of which is connected to the output of the low-pass filter 57, a narrow-band filter 56, a second multiplier 55, the second input of which is connected to the output of the intermediate frequency amplifier 52, a low-pass filter 57 and a recording unit 58.

The first 54 and second 55 multipliers, a narrow-band filter 56 and a low-pass filter 57 form a demodulator 53 phase-shift keyed (PSK) signals.

Each direction finding channel contains in series a receiving antenna 39 (40, 41, 42), a high-frequency amplifier 44 (45, 46, 47), a multiplier 59 (60, 61, 62), the second input of which is connected to the output of the intermediate frequency amplifier 52, and a narrow-band filter 63 (64, 65, 66).

The fifth multiplier 67, the second input of which is connected to the output of the second narrow-band filter 64, the fifth narrow-band filter 71 and the first phase meter 75, are connected in series to the output of the first narrow-band filter 63. The first delay line 68, the first phase detector 72, are connected in series to the output of the second narrow-band filter 64. the second input of which is connected to the output of the second narrow-band filter 64, and the second phase meter 76. The sixth multiplier 69, the second input of which is connected in series to the output of the third narrow-band filter 65 connected to the output of the fourth narrow-band filter 66, the sixth narrow-band filter 73 and the third phase meter 77. A second delay line 70, a second phase detector 74, the second input of which is connected to the output of the fourth narrow-band filter 66, and the fourth phase meter 78 are connected to the output of the fourth narrow-band filter 66. The second inputs of the phase meters 75-78 are connected to the output of the reference generator 49, and the outputs are connected to the block 58 registration. The engine 48 is kinematically connected with the helicopter propeller and with the reference generator 49.

A receiving antenna 38 of the measuring channel is located above the hub of the helicopter propeller. Receiving antennas 30, 40, 41 and 42 of direction finding channels are located at the ends of the rotor blades of the helicopter (Fig. 7).

The system for determining the location of an airplane crash works as follows.

To take off the plane 1, the pilot crew, located in the cockpit 4, turns on the switch 23 and electric current begins to flow from the power supply unit 24 through wire 25 to the engine 17 of the aircraft 1, the engine starts to work and from its generated noise in the sound sensor 18 mounted on the engine 17, an alternating electric current arises, which is fed through a wire 26 to the input of an electric amplifier 19, where it is converted into a direct electric current, which is amplified and fed through a wire 27 to the windings of relays 20 and 21. The relays operate at different times, rel 20 is activated earlier and with its contact 20 ′ opens the recording circuit 22. After some time, relay 21 is activated and with its contact 21 ′ prepares the igniter circuit 22. The ignition circuit opened by contact 20 ′ will be held until the engine 17 is running, and relay 20 will be under electric current.

After landing, the engine 17 stops working when the switch 23 is turned off, and in this case, all the devices of the "black box" come to their original position.

When an airplane crashes, its engine 17 stops working and after that the engine noise stops and no electric current will appear in the sound sensor 18, the relay 20 is de-energized and closes the ignition circuit 22 with its contact 20 ′, because the relay 21 is delayed, therefore contacts 21 ′ remain closed. The fuse 22 is triggered by the electric current received from the block 24 through the contacts of the switch 23, and throws a black box out of the compartment 3 with its components, breaking through the cellophane film 34, which closes the entrance of the compartment 3, preventing any objects from entering the outside compartment (figure 1).

At this time, the switch lever 7, mounted on the black box power supply unit 6, is released from the compartment 3 and switches the “black box” from the aircraft power supply unit 24 to the “black box” power supply unit 6.

The ejected “black box” from compartment 3 continues to fall down with the sound emitter 14 released from the niche 13, which is held by the cable cable 15 behind the “black box” and additionally acts as a guide.

When the "black box" reaches a certain height from the ground or from the surface of the sea, the parachute 11 automatically opens, the antenna 12 from this takes a vertical position (figure 3) and begins to emit electromagnetic waves even when the "black box" is on the ground.

When the parachute is opened, one sling 30, mounted on the handle, is still triggered, while the sling 32 opens during the opening of the parachute, the crane 32 opens and through the air duct 33 from the compressed air chamber 8, air will enter the rubber chamber 9 (Fig. 6). The camera will inflate and turn into shock absorbers when the black box lands on the ground, and when brought to sea, the rubber camera will serve as a float for the black box and will keep it afloat.

When the sound emitter 14 is in an aqueous medium, its electrical circuit is connected via a cable 15 to the sound generator located in block 5, through contacts 36 separated by a piece of sugar 37 mounted on the sound emitter 14. After some time, sugar 37 dissolves in sea water and due to this, contacts 36 are closed and after that the sound emitter will be connected via a cable to the sound generator unit 5 and will begin to produce intermittent sound signals at a frequency of 1000 Hz in the deep sea, as the best way zom perceived by the human auditory organ.

In such an environment, the search for the "black box" is carried out both by electromagnetic waves using a direction finder, and direction finding hydrophones operating in the deep sea. This "black box" on the device is autonomous and can be used on any aircraft for its operation.

For quick and accurate detection of the "black box", and therefore the crash site of the aircraft, it is advisable to use a search device (direction finder), placed on board the helicopter (Fig.7, 8). The presence of a rotary rotor of the helicopter is used for accurate and unambiguous direction finding of the "black box" using receiving antennas 38-42, placed on the sleeve and at the ends of the rotor blades (Fig.7).

The signal emitted by the black box, for example, with phase shift keying (PSK), is received by antennas 38-42:

,

,

where U ₁ -U ₅ , ω _c , φ _c , T _c are the amplitudes, carrier frequency, initial phase and duration of the signal emitted by the black box;

± Δω - instability of the carrier frequency of the signal due to various destabilizing factors, including the Doppler effect;

φ _k (t) = {0, π} is the manipulated phase component that displays the phase manipulation law in accordance with the modulating code M (t), which is the identified black box number containing all the necessary information about the plane that crashed;

R is the radius of the circle on which the receiving antennas 39, 40, 41, 42 are placed (the length of the blades);

Ω = 2πR is the rotation speed of the receiving antennas 39, 40, 41 and 42 around the receiving antenna 38 (rotational speed of the helicopter rotor);

α, β — bearing (azimuth) and elevation angle to the “black box” of the CE (FIG. 2).

The complex QPSK signal u ₁ (t) from the output of the receiving antenna 38 through the high-frequency amplifier 43 is fed to the first input of the mixer 51, the second input of which is the voltage of the local oscillator 50

u _Г (t) = U _Г cos (ω _Г t + φ _Г ).

At the output of the mixer 51, voltages of combination frequencies are generated. Amplifier 52 is allocated voltage intermediate (differential) frequency

u _pr (t) = U _pr cos [(ω _pr t ± Δω) t + φ _k (t) + φ _pr ], 0≤t≤T _c ,

;Where

;

ω _CR = ω _with -ω _G - intermediate (difference) frequency;

φ _CR = φ _s -φ _G ,

which goes to the first inputs of the multipliers 54 and 55.

The second input of the multiplier 55 is supplied with a reference voltage

u ₀ (t) = U ₀ cos [(ω _ol ± Δω) + φ _ol ]

from the output of the narrow-band filter 56.

The output of the multiplier 55 produces a total voltage

u _Σ (t) = U _H cosφ _k (t) + U _H cos [(2ω _pr ± 2Δω) t + φ _k (t) + 2φ _pr ],

;Where

;

from which the low-pass voltage is allocated by the low-pass filter 57

u _H (t) = U _H φ _k (t),

proportional to the modulating code M (t), which is fixed by the registration unit 58 and simultaneously enters the second input of the multiplier 54, at the output of which a reference voltage is generated

u ₀ (t) = U ₀ cos [(ω _ol ± Δω) t + φ _ol ] + U ₀₁ cos [(ω _ol + Δω) t + 2φ _k (t) + φ _ol ] =

= 2U ₀₁ cos [(ω _ol ± Δω) t + φ _ol ] = U ₀ cos [(ω _ol ± Δω) t + φ _ol ],

; U₀=2U₀₁.Where

; U ₀ = 2U ₀₁ .

It should be noted that the demodulator 53 QPSK signals operates in two modes: transient and stationary. The transition mode corresponds to the moment the device is turned on, when many harmonic oscillations are formed on nonlinear elements, among which there will be harmonic oscillation at an intermediate frequency ω, _etc. This oscillation falls into the passband of the narrow-band filter 56 and enters the second input of the multiplier 55. From this moment, the demodulator 53 goes into the stationary mode of operation, which is described above.

The voltage u _pr (t) from the output of the amplifier 52 is simultaneously supplied to the second inputs of the multipliers 59, 60, 61 and 62 of direction finding channels, the first inputs of which receive signals u ₂ (t), u ₃ (t), u ₄ (t), u ₅ (t), respectively. At the output of the multipliers 59, 60, 61 and 62, phase-modulated (FM) voltages are formed at a stable frequency ω _{G of the} local oscillator 50:

Where

which are distinguished by narrow-band filters 63, 64, 65 and 66 with a tuning frequency of ω _n = ω _g .

и

соответствуют диаметрально противоположным расположениям антенн 39 и 40, 41 и 42 на концах лопастей несущего винта вертолета относительно приемной антенны 38, размещенной над втулкой винта вертолета.The signs "+" and "-" in front of the quantities

and

correspond to diametrically opposite locations of the antennas 39 and 40, 41 and 42 at the ends of the rotor blades of the helicopter relative to the receiving antenna 38 located above the rotor hub of the helicopter.

, входящая в состав указанных колебаний и называемая индексом фазовой модуляции, характеризует максимальное значение отклонения фазы сигналов, принимаемых вращающими антеннами 39, 40, 41 и 42 относительно фазы сигнала, принимаемого неподвижной антенной 38.Consequently, useful information about the azimuth α and elevation angle β are transferred to the stable frequency ω _{g of the} local oscillator 50. Therefore, the instability ± Δω of the carrier frequency caused by various destabilizing factors and the type of modulation (manipulation) of the received signals do not affect the direction finding result, thereby increasing the accuracy determining the location of the black box and the plane that crashed. Moreover, the value

, which is part of these oscillations and called the phase modulation index, characterizes the maximum value of the phase deviation of the signals received by the rotating antennas 39, 40, 41 and 42 relative to the phase of the signal received by the stationary antenna 38.

The direction finder is the more sensitive to changes in the angles α and β, the larger the relative size of the measuring base R / λ. However, with increasing R / λ, the values of the angular coordinates α and β decrease at which the phase differences exceed 2π, i.e. there is an ambiguity in the reading of the angles α and β.

наступает неоднозначность отсчета углов α и β.Therefore, for

there is an ambiguity in the reading of the angles α and β.

The elimination of this ambiguity by reducing the R / λ ratio usually does not justify itself, since the main advantage of a wide-base system is lost. In addition, in the range of meter and especially decimeter waves, it is often not possible to take small R / λ values due to design considerations.

To increase the accuracy of direction finding of the "black box" in the horizontal (azimuthal) and vertical (elevation) planes, the receiving antennas 39 and 40, 41 and 42 are located at the ends of the rotor blades of the helicopter. Mixing signals from two diametrically opposite receiving antennas 39 and 40, 41 and 42 located at the same distance R from the rotor axis of the rotor causes phase modulation similar to that obtained with two receiving antennas rotating in a circle, whose radius R ₁ is twice more (R ₁ = 2R).

Indeed, at the output of multipliers 67 and 69, harmonic voltages are formed:

u ₁₀ (t) = U ₁₀ cos (Ω-α) t,

u ₁₁ (t) = U _ll cos (Ω-β) t,

Where

with phase modulation index

, где R₁=2R,

where R ₁ = 2R,

which are allocated by narrow-band filters 71 and 73, respectively, and are supplied to the first inputs of the phase meters 75 and 77, the second inputs of which are supplied with the voltage of the reference oscillator 49

u _Ω (t) = U _Ω cosΩt.

Phasometers 75 and 77 provide accurate but ambiguous measurements of the angular coordinates α and β of the black box.

To eliminate the ambiguity in reading the angles α and β, it is necessary to reduce the phase modulation index without decreasing R / λ. This is achieved by using autocorrelators consisting of delay lines 68 and 70 and phase detectors 72 and 74, which is equivalent to reducing the phase modulation index to

where d ₁ <R.

At the output of the autocorrelators, voltages are formed:

u ₁₂ (t) = U ₁₂ cos (Ω-α) t,

u ₁₃ (t) = U ₁₃ cos (Ω-β) t

with the phase modulation index Δφ _m2 , which are supplied to the first inputs of the phase meters 76 and 78, the second inputs of which are supplied with the voltage u _Ω (t) of the reference oscillator 49. The phase meters 76 and 78 provide rough but unambiguous measurements of the angular coordinates α and β of the black box "

Having determined the flight altitude h of the helicopter using the onboard altimeter and measuring the angular coordinates α and β of the black box, the helicopter crew determines the location of the black box and the plane that crashed.

Thus, the proposed system in comparison with the base object and other technical solutions of a similar purpose provides the ability to quickly and accurately detect the black box, and therefore the crash site of the aircraft. This is achieved by using a search instrument (direction finding) on board the helicopter and complex PSK signals. At the same time, the presence of a rotary rotor of the helicopter, at the ends of the blades of which receiving antennas are located, is used for accurate and unambiguous direction finding of the "black box".

The applied complex QPSK signals have high energy and structural secrecy.

The energy secrecy of these signals is due to their high compressibility in time or in the spectrum with optimal processing, which reduces the instantaneous radiated power. As a result of this, the complex QPSK signal used at the receiving point may be masked by noise and interference. Moreover, the energy of a complex QPSK signal is by no means small; it is simply distributed over the time-frequency domain so that at each point of 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.

These signals allow the use of structural selection. This means that it becomes possible to distinguish complex QPSK signals from other signals and interference operating in the same frequency band and at the same time intervals. This feature is realized by convolution of the spectrum of complex PSK signals.

For the synchronous detection of complex PSK signals, a universal demodulator is used, free of the phenomenon of “reverse operation”, which is inherent in all known PSK signal demodulators (A. A. Pistolkors, V. I. Siforov, D. F. Kostas, E. Travina. BUT.).

Claims (1)

A system for determining the scene of an airplane crash, containing a “black box” with an alarm system that is thrown out of the compartment with a parachute and lands or is brought down on the sea surface, emitting electromagnetic waves and sound signals, the “black box” is placed in the tail section the plane and is automatically thrown out, while during the opening of the parachute the crane opens and through the air pipe from the compressed air chamber air enters the rubber chamber, which is inflated and turns electromagnetic waves and sound signals are also emitted at a depth, characterized in that it is equipped with a search instrument placed on board the helicopter and consisting of a measuring and four direction finding channels, the measuring channel containing a receiving antenna, high-frequency amplifier, mixer, the second input of which is connected to the output of the local oscillator, an intermediate frequency amplifier, the first multiplier, the second input of which is connected to the output a low-pass filter house, a narrow-band filter, a second multiplier, the second input of which is connected to the output of the intermediate-frequency amplifier, a low-pass filter and a registration unit, each direction finding channel contains a receiving antenna, a high-frequency amplifier, a multiplier, the second input of which is connected to the output of the amplifier the intermediate frequency, and a narrow-band filter, to the output of the first narrow-band filter, a fifth multiplier is connected in series, the second input of which is connected to the output of the second of the first narrow-band filter, the fifth narrow-band filter and the first phase meter, the first delay line, the first phase detector, the second input of which is connected to the output of the second narrow-band filter, and the second phase meter, the sixth multiplier are connected in series to the output of the second narrow-band filter, to the output of the second narrow-band filter, whose second input is connected to the output of the fourth narrow-band filter, the sixth narrow-band filter and the third phase meter, to the output of the fourth narrow-band filter the second delay line, the second phase detector, the second input of which is connected to the output of the fourth narrow-band filter, and the fourth phase meter, the second inputs of the phase meters are connected to the output of the reference generator, the receiving antenna of the measuring channel is located above the helicopter rotor hub, the receiving antennas of direction finding channels are placed at the ends helicopter rotor blades, the engine is kinematically connected with the helicopter rotor and the reference generator.

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