RU2411476C1 - Method of determining liquid or gas leakage point in underground pipeline and device for realising said method - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: device has a synchroniser 1, transmitters 2.1-2.4, antenna switches 3.1-3.4, transceiving antennae 4.1-4.4, receivers 5.1-5.4, processing units 6.1-6.4, field of vision switch 7, strobe pulse generator 8, indicator 9, thermal image sensor 10, television sensor 11, receiving unit 12, receiving antenna 13, motor 14, reference generator 15, first heterodyne frequency synthesiser 16, first intermediate frequency amplifiers 18, 26-29, second heterodyne 19, mixers 17, 20, 22-25, second intermediate frequency amplifier 21, multipliers 30-33, 38, 40, narrow band-pass filters 34-37, 42, 44, delay lines 39, 41, phase detectors 43, 45, phase metres 46-49, correlator 50, controlled delay unit 51, multiplier 52, low-pass filter 53, optimal control 54, range indicator 55, recording and analysis unit 56. The transceiving antennae 4.1-4.4 are placed on ends of helicopter main rotor blades. The receiving antenna 13 is placed over the rotor head of the helicopter. The motor 14 is kinematically linked to the helicopter rotor and reference generator 15.

EFFECT: high accuracy of determining route of a main pipeline and distance to the pipeline.

1 tbl, 2 dwg

Description

The proposed method and device relate to a control and measuring technique designed to control the tightness of gas-oil-containing equipment, and more particularly to a technique for remote determination of the leakage of liquid or gas from a main pipeline located in a trench under the ground.

Known methods and devices for determining the location of a leak of liquid or gas from pipelines (ed. Certificate of the USSR No. 934.269, 1.216.551, 1.283.566, 1.610.347, 1.657.988, 1.672.105, 1.679.232, 1.705.709, 1.733.837, 1.777.014, 1.778.597, 1.812.386; RF patents Nos. 2.135.887, 2.138.037, 2.231.037; US patents Nos. 4.289.019, 4.570.477, 5.038.614; UK patent No. 1.349.129; French patent No. 2,498.325; Japanese patents No. 59-38.537, 60-24.900, 63-22.531; Pipeline transport of liquid and gas. M., 1993 and others).

Of the known methods and devices closest to the proposed are the "Method of determining the place of leakage of liquid or gas from the pipeline located in the ground, and a device for its implementation" (RF patent No. 2.231.037, G01M 3/22, 2002), which are selected as prototypes.

Known technical solutions provide remote location of a leak of liquid or gas from a buried trunk pipeline. At the same time, a pipeline route is surveyed by radar to determine where it lies. At the same time, the pipeline is scanned with aligned thermal imaging and television sensors and digital signal processing of the sensors is carried out jointly.

A disadvantage of the known technical solutions is the low accuracy of determining the path of the main pipeline. This is because the azimuth α, elevation angle β, and distance D to the path of the main pipeline are not determined.

An object of the invention is to increase the accuracy of determining the path of the main pipeline by measuring the azimuth, elevation and distance to the path of the main pipeline.

The problem is solved in that the method of determining the place of leakage of liquid or gas from a pipeline located in the ground, consisting, in accordance with the closest analogue, in the survey of the pipeline by a locator by flying around a low-altitude aircraft, while scanning the pipeline using aligned thermal imaging and television sensors and joint digital filtering the signals of radars, thermal imaging and television sensors, while four radars are used as a locator of different wavelengths, the transceiver antennas of the four radars are placed at the ends of the rotor blades of the helicopter, the signals received by them are processed according to the aperture synthesis algorithm, and the place of leakage of liquid or gas from the pipeline is judged by the local temperature decrease recorded by the thermal imaging sensor and the information received by radars and by a television sensor, the depth of the pipeline is judged by the color of its image on the indicator screen, differs from the closest analogue in that I use one measuring and four direction finding channels located in the azimuthal and elevation planes, two on each plane, in each channel, the frequency signals reflected from the pipeline are converted using the frequency synthesizer of the first local oscillator, the voltages of the first intermediate frequency are extracted, the voltage of the first the intermediate frequency of the measuring channel using the frequency of the second local oscillator, isolate the voltage of the second intermediate frequency, multiply it with the voltage of the first intermediate frequency of direction finding channels, harmonic oscillations at the frequency of the second local oscillator are extracted from the received voltages while maintaining phase relationships, the harmonic oscillations of two direction finding channels are multiplied in each plane, harmonic oscillations are distinguished at the rotor rotor speed of the helicopter, they are compared with the reference voltage and accurately , but ambiguously measure the azimuth and elevation of the route of the main pipeline, at the same time carry out autocorrelation processing harmonic oscillations allocated in another direction-finding channel of each plane and roughly but unequivocally measure the azimuth and elevation angle of the trunk pipeline, decreasing the phase modulation index without decreasing the R / λ ratio, where R is the radius of the circle on which the transceiver antennas are located, λ is the wavelength, the probe signal of the first transmitter is multiplied with the reflected signal received by the antenna of the measuring channel and passed through the adjustable delay unit, low-frequency thus forming the correlation function R (τ), where τ is the current time delay, the correlation function is maintained at the maximum level by changing the delay, the time delay τ _s between the probing and reflected signals is fixed, and the distance to the path of the main pipeline is determined by its value, the receiving antenna of the measuring channel is placed above the rotor hub of the helicopter.

The problem is solved in that a device for determining the place of leakage of liquid or gas from a pipeline located in the ground, containing, in accordance with the closest analogue, four paths, each of which consists of a transmitter, an antenna switch connected in series to the synchronizer output, the second input of which is connected with the output of the field of view switch, and the input-output connected to the transceiver antenna, the receiver, the second input of which is connected to the output of the strobe pulse generator, and the processing unit, the second in One of which is connected to the output of the synchronizer, and the output is connected to a four-color indicator, the control input of which is connected to the output of the synchronizer, as well as a receiving unit, the corresponding inputs of which are connected to the outputs of the antenna switches, thermal and television sensors, the second inputs of which are connected to the output of the synchronizer, and the outputs are connected to the receiving unit, the transceiver antennas are located at the ends of the rotor blades of the helicopter, differs from the closest analogue in that it is equipped with an engine, supports a generator, a correlator, a measuring channel, four direction finding channels and a recording and analysis unit, the measuring channel consisting of a series-connected receiving antenna, a first mixer, the second input of which is connected to the output of the frequency synthesizer of the first local oscillator, the amplifier of the first intermediate frequency, the second mixer, and the second the input of which is connected to the output of the second local oscillator, and the amplifier of the second intermediate frequency, each direction-finding channel consists of series-connected to the output mixer antenna switch, the second input of which is connected to the output of the frequency synthesizer of the first local oscillator, the amplifier of the first intermediate frequency, multiplier, the second input of which is connected to the output of the amplifier of the second intermediate frequency of the measuring channel, and the narrow-band filter, the fifth multiplier is connected in series to the output of the first narrow-band filter, the second the input of which is connected to the output of the second narrow-band filter, the third narrow-band filter and the first phase meter, to the output of the second narrow-band fil The first delay line is connected in series, 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 is connected in series to the output of the fourth narrow-band filter, the second input of which is connected to the output of the fifth narrow-band filter, the sixth narrow-band filter, and the third a phase meter, a second delay line, a second phase detector, the second input of which is connected to the output of the fifth, is sequentially connected to the output of the fifth narrow-band filter bandpass filter, and the fourth phase meter, the second inputs of the phase meters are connected to the output of the reference generator, and the outputs are connected to the first, second, third and fourth inputs of the recording and analysis unit, respectively, the fifth input of which is connected to the output of the receiving unit, the correlator is made in the form of series-connected to the output of the receiving antenna of the adjustable delay unit, the seventh multiplier, the second input of which is connected to the output of the first transmitter, low-pass filter and extreme controller, the output of which is one with the second input of the adjustable delay unit, a second output of which is connected via a pointer range to the sixth entry registration unit and analyzes the receiving antenna positioned above the helicopter rotor hub, the engine is kinematically connected to a helicopter rotor and the reference generator.

The structural diagram of a device that implements the proposed method is presented in figure 1. The relative position of the pipeline, transceiver antennas 4.1-4.4 and receiving antenna 13 is shown in figure 2. The penetration characteristics of radio waves of various lengths are depicted in figure 3.

The device contains four paths, four direction finding channels (two on each plane), one measuring channel, a synchronizer 1, a correlator 50, a recording and analysis unit 55.

Each path contains a transmitter 2.1 (2.2, 2.3, 2.4), an antenna switch 3.1 (3.2, 3.3, 3.4) connected in series to the output of the synchronizer 1, the second input of which is connected to the output of the field of view switch 7, and the input-output is connected to the transceiver antenna 4.1 (4.2, 4.3, 4.4), the receiver 5.1 (5.2, 5.3, 5.4), the second input of which is connected to the output of the strobe-pulse generator 8 and the processing unit 6.1 (6.2, 6.3, 6.4), the second input of which is connected to the output of the synchronizer 1, and the output is connected to the corresponding input of the four-color indicator 9, the control input of which connected to the output of the synchronizer 1. The outputs of the antenna switch 3.1 (3.2, 3.3, 3.4), the thermal imaging sensor 10 and the television sensor 11 are connected to the corresponding inputs of the receiving unit 12, the output of which is connected to the fifth input of the recording and analysis unit 56. The control inputs of the thermal imaging sensor 10, the television sensor 11 and the receiving unit 12 are connected to the output of the synchronizer 1.

The measuring channel contains a receiving antenna 13 connected in series, a first mixer 17, the second input of which is connected to the output of the frequency synthesizer 16 of the first local oscillator, an amplifier 18 of the first intermediate frequency, a second mixer 20, the second input of which is connected to the output of the second local oscillator 19, and the amplifier 21 of the second intermediate frequency.

Each direction finding channel contains a mixer 22 (23, 24, 25) connected in series to the output of the antenna switch 3.1 (3.2, 3.3, 3.4), the second input of which is connected to the output of the frequency synthesizer 16 of the first local oscillator, and the amplifier 26 (27, 28, 29) of the first intermediate frequency, multiplier 30 (31, 32, 33) and narrow-band filter 34 (35, 36, 37). The fifth 38 (sixth 40) multiplier is connected in series to the output of the first 34 (fourth 36) narrow-band filter, the second input of which is connected to the output of the second 35 (fifth 37) narrow-band filter, the third 42 (sixth 44) narrow-band filter and the first 46 (third 48) phase meter. The output of the second 35 (fifth 37) narrow-band filter is connected in series to the first 39 (second 41) delay line, the first 43 (second 45) phase detector, the second input of which is connected to the output of the second 35 (fifth 37) narrow-band filter, and the second (fourth) phasometer 47 (49). The second inputs of the phase meters 46, 47, 48 and 49 are connected to the output of the reference generator 15, and the outputs are connected to the corresponding inputs of the block 56 registration and analysis.

The correlator 50 is made in the form of series-connected to the output of the receiving antenna 13 of the adjustable delay unit 51, the seventh multiplier 52, the second input of which is connected to the output of the first transmitter 2.1, a low-pass filter 53 and an extreme controller 54, the output of which is connected to the second input of the block 51 adjustable delay, the second output of which through the range indicator 55 is connected to the sixth input of the recording and analysis unit 56.

Transceiver antennas 4.1, 4.2, 4.3 and 4.4 are located at the ends of the rotor blades of the helicopter. The receiving antenna 13 is located above the hub of the helicopter propeller. The engine 14 is kinematically connected with the helicopter propeller and the reference generator 15.

The proposed method for determining the place of leakage of liquid or gas from the main pressure pipe is as follows.

On a low-altitude aircraft, such as a helicopter, four radars, four direction finders, a measuring channel, a thermal imaging and television devices, and a digital filtering block for signals from a thermal, television, and radar device are located.

When flying over the main pipeline, located in the ground, on a low-altitude aircraft produced:

- overview of the pipeline with four radars with λ ₁ = 5 m, λ ₂ = 1 m, λ ₃ = 0.6 m and λ ₄ = 0.003 m, to determine the location of the pipeline (pipeline route);

- direction finding of signals reflected from the pipeline and measuring the distance to the pipeline to more accurately determine the location of the pipeline (pipeline route);

- time-synchronized observation of the space above the pipeline route with aligned thermal imaging and television devices;

- joint digital filtering of signals from radar, thermal imaging and television devices, which allows you to determine the profile of the pipeline and highlight heat spots on the ground along the pipeline in the place of leakage from it.

The basis of the proposed method is the principle of joint logical processing of signals, aligned and synchronously operating information thermal, television and radar channels.

The radar channel provides an accurate determination of the location of the pipeline (pipeline route).

The pulses generated in synchronizer 1 trigger four transmitters 2.1-2.4 and control the operation of four signal processing units 6.1-6.4. The pulses of the synchronizer 1 also control the operation of the generator 8 strobe pulses, color indicator 9, thermal imaging 10 and television 11 sensors and the receiving unit 12. The duration and position in time of the strobe pulse determine the position and extent of the observed element of the earth's surface in range. This pulse is fed to the processing units.

Each transmitter operates at its own wavelength, which determines the depth of penetration of electromagnetic radiation under the underlying surface of the earth (table).

The probe pulses from the transmitters 2.1-2.4 through the antenna switches 3.1-3.4 arrive at their antennas 4.1-4.4, each of which is located at the end of the rotor blade of the helicopter (figure 2).

Each antenna, located at the end of the rotating blade, is connected to its transmitter and receiver only at the moment of passing a certain predetermined field of view. This is done using the switch 7 of the field of view, which is an electrical contact made in the form of four brushes located under the corresponding blades, moving during rotation along a stationary conductive segment, which, in turn, can be installed in a fixed position around the axis of the screw. Each transmitter and receiver are connected to the antenna only during the passage of the corresponding brush in the segment. The position of the segment determines the position of the viewing sector in space. It is ensured in such a way that either transceiver antennas 4.1 and 4.2 or transceiver antennas 4.3 and 4.4 are simultaneously involved in the operation.

From antennas 4.1-4.4, signals are emitted in the direction of the underlying surface.

The signals reflected from the pipeline are received by antennas 13, 4.1, 4.2, 4.3 and 4.4:

U ₁ (t) = υ ₁ * Cos [(ω _{1 ±} Δω) t + φ ₁ ],

U ₂ (t) = υ ₂ * Cos [(ω _{1 ±} Δω) t + 2π * R / λ ₁ * Cos (Ω-α)],

U ₃ (t) = υ ₃ * Cos [(ω _{2 ±} Δω) t-2π * R / λ ₂ * Cos (Ω-α)],

U ₄ (t) = υ ₄ * Cos [(ω _{3 ±} Δω) t + 2π * R / λ ₃ * Cos (Ω-β)],

U ₅ (t) = υ ₅ * Cos [(ω _{4 ±} Δω) t-2π * R / λ ₄ * Cos (Ω-β)], 0≤t≤T _C ,

where υ ₁ h ÷ υ ₅ , ω ₁ ÷ ω ₄ , φ ₁ , T _C are the amplitudes, carrier frequencies, the initial phase and the duration of the signals;

± Δω is the instability of the carrier frequencies of the signals due to various destabilizing factors;

R is the radius of the circle on which the transceiver antennas are located 4.1-4.4;

λ ₁ , λ ₂ , λ ₃ , λ ₄ - wavelength;

Ω = 2π * R is the rotation speed of the transceiver antennas 4.1-4.4 around the receiving antenna 13 (rotational speed of the helicopter rotor);

α, β - azimuth and elevation of the pipeline route,

and they come directly and through antenna switches 3.1-3.4 to the first inputs of mixers 17, 22, 23, 24 and 25, receivers 5.1-5.4, and then processing units 6.1-6.4, in which the received signals are processed using the aperture synthesis algorithm. In the same blocks, the effect of changing the distance from the antenna to the pipeline, caused by the movement of the antennas around the circumference during the synthesis process, is taken into account. In blocks 6.1-6.4, signals are processed that are received only from a certain distance section, the position and extent of which is determined by the gating pulse supplied from the generator 7. From processing blocks 6.1-6.4, the signals are sent to indicator 9 with a color image, and the signals from each processing block correspond to image in a specific color.

The second inputs of the mixers 17, 22, 23, 24 and 25 are supplied with the voltage of the synthesizer 16 frequencies of the first local oscillator

U _Гi (t) = υ _Гi * Cos (ω _Гi t + φ _Гi ), 0≤t≤T _Гi ,

where i = 1, 2, 3, 4.

At the output of the mixers 17, 22-25, voltage of combination frequencies are formed. Amplifiers 18, 26-29 are allocated the voltage of the first intermediate frequency:

U _PR1 (t) = υ _CR1 * Cos [(ω _{CR1 ±} Δω) t + φ _CR1 ],

U _PR2 (t) = υ _pr1 * Cos [(ω _{pr1 ±} Δω) t + 2π * R / λ * Cos (Ω-α)],

U _PR3 (t) = υ _pr2 * Cos [(ω _{pr1 ±} Δω) t + 2π * R / λ * Cos (Ω-α)],

U _PR4 (t) = υ _pr3 * Cos [(ω _{pr1 ±} Δω) t + 2π * R / λ * Cos (Ω-β)],

U _PR5 (t) = υ _CR4 * Cos [(ω _{CR1 ±} Δω) t + 2π * R / λ * Cos (Ω-β)], 0≤t≤T _C ,

where υ _pr1 = 1 / 2υ ₁ * υ _g1 ;

υ _pr2 = 1 / 2υ ₂ * υ _g1 ;

_PR3 υ = 1 / 2υ ₃ * υ _r2;

υ _pr4 = 1 / 2υ ₄ * υ _g3 ;

υ _pr5 = 1 / 2υ ₅ * υ _g4 ;

_pr1 ω = ω ₁ -ω _d1 = ω _z2 -ω ₂ = ω ₃ = ω -ω _{z3 z4} -ω ₄ - intermediate (difference) frequency;

φ _pr1 = φ ₁ -φ _g1 .

The signs “+” and “-” in front of the values 2π * R / λ * Cos (Ω-α) and 2π * R / λ * Cos (Ω-β) correspond to diametrically opposite locations of the transceiver antennas 4.1 and 4.2, 4.3 and 4.4 at the ends the rotor blades of the helicopter relative to the receiving antenna 13 located above the rotor hub of the helicopter.

The voltage U _PR1 (t) from the output of the amplifier 18 of the first intermediate frequency is supplied to the first input of the mixer 20, the second input of which is supplied with the voltage of the second local oscillator 19 with a stable frequency ω _g5

U _Г5 (t) = υ _г5 * Cos (ω _г5 + φ _г5 ).

At the output of the mixer 20, voltages of combination frequencies are generated. The amplifier 21 is allocated the voltage of the second intermediate frequency

U _PR6 (t) = υ _CR6 * Cos [(ω _{CR2 ±} Δω) t + φ _CR6 ],

where υ _pr6 = 1 / 2υ _pr1 * υ _g5 ;

ω _pr2 = ω _{pr1 -ω g5} is the second intermediate frequency;

φ _pr6 = φ _pr1 -φ _g5 ,

which is supplied to the second inputs of the multipliers 30-33, the first inputs of which are supplied with voltage U _PR2 (t), U _PR3 (t), U _PR4 (t) and U _PR5 (t) from the outputs of amplifiers 26-29 of the first intermediate frequency, respectively.

At the outputs of multipliers 30-33, phase-modulated (FM) voltages are formed at a stable frequency ω _{g5 of the} second local oscillator 19:

U ₆ (t) = υ ₆ * Cos [(ω _g5 t + φ _g5 + 2π * R / λ * Cos (Ω-α)],

U ₇ (t) = υ ₇ * Cos [(ω _g5 t + φ _g5 -2π * R / λ * Cos (Ω-α)],

U ₈ (t) = υ ₈ * Cos [(ω _g5 t + φ _g5 + 2π * R / λ * Cos (Ω-β)],

U ₉ (t) = υ ₈ * Cos [(ω _g5 t + φ _g5 -2π * R / λ * Cos (Ω-β)], 0≤t≤T _C ,

where υ ₆ = 1 / 2υ _pr6 * υ _pr1 ;

υ ₇ = 1 / 2υ _pr6 * υ _pr2 ;

υ ₈ = 1 / 2υ _pr6 * υ _pr3 ;

υ ₉ = 1 / 2υ _pr6 * υ _pr4 ;

which are allocated by narrow-band filters 34-37 with a tuning frequency of ω _n = ω _g5 .

Therefore, useful information about the azimuth α and the elevation angle β of the pipeline path is transferred to the stable frequency ω _{g5 of the} second local oscillator 19. Therefore, the frequency instability ± Δω caused by various destabilizing factors does not affect the direction finding result, thereby increasing the accuracy of determining the location of the pipeline.

Moreover, the value Δφ _m = 2π * R / λ, which is part of these oscillations and is called the phase modulation index, characterizes the maximum value of the phase deviation of the reflected signals received by the rotating transceiver antennas 4.1 and 4.2, 4.3 and 4.4 relative to the phase of the signal received by the stationary antenna 13.

The direction-finding device 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 difference exceeds 2π, i.e. there is an ambiguity in the reading of the angles α and β.

Therefore, for R / λ> 1/2, the ambiguity of the reference angles α and β occurs. 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 values of R / λ due to design considerations.

At the output of the multipliers 38 and 40, harmonic voltages are formed:

U ₁₀ (t) = υ ₁₀ * Cos (Ω-α),

U ₁₁ (t) = υ ₁₁ * Cos (Ω-β), 0≤t≤T _C ,

where υ ₁₀ = 1 / 2υ ₆ * υ ₇ ;

υ ₁₁ = 1 / 2υ ₈ * υ ₉ ,

with phase modulation index

Δφ _m1 = 2π * R ₁ / λ, R ₁ = 2R,

which are allocated by narrow-band filters 42, 44 and are supplied to the first inputs of the phase meters 46 and 48, the second inputs of which are supplied with the voltage of the reference oscillator 15

U _O (t) = υ _o * CosΩt.

Phasometers 46 and 48 provide an accurate but ambiguous measurement of the angular coordinates α and β.

To eliminate the ambiguity in reading the angles α and β, it is necessary to reduce the phase modulation index without decreasing the R / λ ratio. This is achieved by using autocorrelators consisting of a delay line 39 (41) and a phase detector 43 (45), which is equivalent to reducing the phase modulation index to

Δφ _m2 = 2π * d ₁ / λ, where d ₁ <R.

Phasometers 47 and 49 in this case provide a rough but unambiguous measurement of the angles α and β.

At the same time, the probing signal of the first transmitter 2.1 is supplied to the first input of the seventh multiplier 52, the second input of which is supplied with a reflected signal from the output of the receiving antenna 13 through the adjustable delay unit 51. The voltage obtained at the output of the multiplier 52 is passed through a low-pass filter 53, at the output of which a correlation function R (τ) is formed. The extreme controller 54, designed to maintain the maximum value of the correlation function R (τ) and connected to the output of the low-pass filter 53, acts on the adjustable delay unit 51 and maintains the delay τ introduced by it equal to τ _s (τ = τ _s ), which corresponds to the maximum value correlation function R (τ _s ). The range indicator 55, connected with the controlled delay unit 51, allows you to directly read the measured value of the range to the main pipeline

D = s * τ _s / 2,

where c is the propagation velocity of radio waves.

Therefore, the task of measuring the range D is reduced to measuring the time delay τ _{s of the} reflected signal relative to the probing one.

The measured values of α, β and D are recorded by the block 56 registration and analysis.

The thermal imaging channel allows you to record a direct physical sign of gas leakage from a buried gas pipeline in the form of a local decrease in temperature (negative thermal contrast on the surface of the gas pipeline coating in the leak area) due to the throttle effect when gas flows from the gas pipeline. In this case, the possible surface thermal contrasts in the leak area, according to available experimental and calculated data, are up to 8-10 ° C, which significantly exceeds the threshold characteristics of the sensitivity of thermal imaging devices (0.5-1.0 ° C) and, accordingly, can be detected by measurements . However, the efficient allocation of a leak site by this direct physical feature is difficult due to the presence of a natural inhomogeneity of the temperature field.

In the areas where the pipeline occurs, the values of random temperature contrasts caused by a number of factors: the nature of the coating and soil structure, time of day, year, weather conditions - can be comparable or even exceed the values of the identified local temperature contrasts in the leak area. Accordingly, to increase the reliability of leak detection, it is proposed to use information from additional channels: radar and television, which allow one to identify indirect features, the combination of which with the measurement of a direct sign (negative thermal contrast) significantly reduces the likelihood of erroneous identification (false alarm).

So, the radar channel, highlighting the geometric location of the metal pipeline on the ground by contrasts of the radar signals at four frequencies and determining the azimuth α, elevation angle β and the distance D to the main pipeline, thereby forms an indirect logical sign of the possible location of the leak, namely only in the area the location of the pipeline.

The television channel, highlighting the field of contrasts, the primary cause of which is the presence of an external source of illumination (the sun), also allows you to form indirect logical signs of a leak, i.e. an internal source of negative thermal contrast, not related to external illumination, due to a joint assessment of the size of the texture of the sign of the contrast formations of the television and thermal imaging frames, taking into account the lighting conditions (illumination, weather conditions, etc.).

Thus, a joint logical analysis (filtering) of the signals of a multichannel system that measures the direct sign (thermal contrast) and indirect signs (contrasts of the reflected radiation from external sources of illumination of the visible and radio bands) can significantly increase the efficiency of leak detection compared to a single-channel method, for example, thermal imaging or spectral analysis of the absorption of gas products on the ground.

The use of four radars with λ ₁ = 5 m, λ ₂ = 1 m, λ ₃ = 0.6 m and λ ₄ = 0.003 m in the proposed method is due to the need, on the one hand, to ensure that it is possible to obtain reflected signals from the pipeline, buried in the trench by 1.5-2.0 m, on the other hand, localization of the location of the pipeline according to the measurement results with errors for greater reliability and accuracy of the allocation of an indirect sign.

The assessment showed that the use of shorter-wavelength radio emission does not provide the location of the main pipeline with the required depths (1.5-2 m). On the other hand, a location with a longer wavelength range (tens of meters or more), ensuring the passage of the signal to the required depth of the pipeline, has unsatisfactory indicators for signal direction finding accuracy (within tens of degrees).

It is also unsatisfactory for the proposed method for operational control of a leak by, for example, helicopter flying and using the well-known method of localizing metal pipelines by distortions of the geomagnetic field (magnetometric method). Given the high flight altitudes acceptable from safety conditions at least 50-100 m, the presence of a significant interfering metal mass in the measurement zone (helicopter body), the allocation of geomagnetic field distortions caused by the presence of the mass of the pipeline is difficult to apparatus. Moreover, the accuracy of direction finding by the magnetometric method does not exceed 20-30 °, which significantly reduces the value of the measured indirect feature.

A radar channel with synthesized equipment and antennas located at the ends of rotating rotor blades and operating at different frequencies allows one to more accurately and accurately identify an indirect feature necessary to detect the location of a leak of liquid or gas from a pipeline in the ground.

Thus, the proposed method and device in comparison with prototypes and other technical solutions of a similar purpose provide increased accuracy in determining the route of occurrence of the main pipeline. This is achieved by accurately and unambiguously measuring the azimuth, elevation angle and distance to the occurrence path of the main pipeline. Moreover, an accurate and unambiguous measurement of the azimuth and elevation angle of the main pipeline is provided by the phase method of direction finding of signals reflected from the pipeline. And the measurement of the distance to the main pipeline is achieved by correlation processing of the probing and reflected signals.

Accurate and unambiguous measurement of angular coordinates and range can significantly increase the accuracy of determining the path of the main pipeline and, therefore, allows you to very accurately and accurately identify the indirect sign necessary to detect the location of leakage of liquid or gas from the main pipeline in the ground.

Table A method for determining the location of a leak of liquid or gas from a pipeline in the ground, and a device for its implementation Radio wave penetration characteristics Front view Wavelength, m Attenuation coefficient, dB / m Penetration depth when attenuating power 100 times, m Frozen soil one 4.2 4,5 Dry soil 5 0.8 25 Quartz sand 0.003 2.0 10 Sandy soil with humidity: 3% 0.003 0.5 0,07 0.6 3 6.7 12% 0.003 1100 0.02 0.6 12 1,6 Clay soil with moisture: 3% 0.003 300 0,07 0.6 fourteen 1.4 12% 0.003 1400 0.014 0.6 fifty 0.4

Claims (2)

1. A method for determining the location of a leak of liquid or gas from a pipeline located in the ground, which consists in viewing the pipeline with a locator by flying around a low-altitude aircraft, scanning the pipeline simultaneously with aligned thermal and television sensors and joint digital filtering of radar signals, thermal and television sensors, Four radars of different wavelengths are used as a locator, and transceiver antennas of four radars of size they are located at the ends of the rotor blades of the helicopter, the signals received by them are processed using the synthesized aperture algorithm, and the place of leakage of liquid or gas from the pipeline is judged by the local temperature drop recorded by the thermal imaging sensor, and the information received by radars and a television sensor, the depth of the pipeline is judged by the color of its image on the indicator screen, characterized in that they use one measuring and four direction finding channels located in azimuth and angle frequency planes using the frequency synthesizer of the first local oscillator, isolate the voltage of the first intermediate frequency, re-convert the voltage of the first intermediate frequency of the measuring channel using the frequency of the second local oscillator, isolate the voltage the second intermediate frequency, multiply it with the voltages of the first intermediate frequency direction finding channels, isolated from the obtained stresses ha mono oscillations at the frequency of the second local oscillator while maintaining phase relationships, in each plane multiply the harmonic oscillations of the two direction finding channels with each other, emit harmonic oscillations at the rotational speed of the rotor of the helicopter, compare them with the reference voltage and accurately, but ambiguously, measure the azimuth and elevation angle of the path bedding of the main pipeline, simultaneously carry out autocorrelation processing of harmonic oscillations allocated in another direction finding channel of each flat In addition, roughly and unequivocally, they measure the azimuth and elevation angle of the trunk pipeline, decreasing the phase modulation index without decreasing the R / λ ratio, where R is the radius of the circle on which the transceiver antennas are located, λ is the wavelength probing signal of the first transmitter multiplied with the reflected signal received by the antenna of the measuring channel and passed through the adjustable delay unit, a low-frequency voltage is extracted, thereby forming a correlation function R (τ), where τ is the current time delay, from eneniem support delay correlation function at a maximum, fixed time delay τ _of between excitation and reflected signals and its value range to determine the occurrence of the track of the main pipeline, the receiving antenna of the measuring channel is placed above the helicopter main rotor hub. 2. A device for determining the place of leakage of liquid or gas from a pipeline located in the ground, containing four paths, each of which consists of a series-connected to the output of the transmitter synchronizer, an antenna switch, the second input of which is connected to the output of the field of view switch, and the input-output is connected with a transceiver antenna, a receiver, the second input of which is connected to the output of the strobe pulse generator, and a processing unit, the second input of which is connected to the output of the synchronizer, and the output is connected to four a color indicator, the control input of which is connected to the output of the synchronizer, as well as a receiving unit, the corresponding inputs of which are connected to the outputs of the antenna switches, thermal imaging and television sensors, the second inputs of which are connected to the output of the synchronizer, and the outputs are connected to the receiving unit, the transmitter-receiver antennas are located at the ends rotor blades of a helicopter, characterized in that it is equipped with an engine, a reference generator, a correlator, a measuring channel, four direction finding channels and bl registration and analysis, and the measuring channel consists of a series-connected receiving antenna, the first mixer, the second input of which is connected to the output of the frequency synthesizer of the first local oscillator, the amplifier of the first intermediate frequency, the second mixer, the second input of which is connected to the output of the second local oscillator, and the second intermediate amplifier frequency, each direction finding channel consists of a series-connected to the output of the antenna switch of the mixer, the second input of which is connected to the output of the synthesizer the first local oscillator, the amplifier of the first intermediate frequency, the multiplier, the second input of which is connected to the output of the amplifier of the second intermediate frequency of the measuring channel, and the narrow-band filter, the fifth multiplier is connected in series to the output of the first narrow-band filter, the second input of which is connected to the output of the second narrow-band filter, the third narrow-band filter and first phase meter; the first delay line, the first phase detector, and the second input are connected in series to the output of the second narrow-band filter which is connected to the output of the second narrow-band filter, and the second phase meter, the sixth multiplier is connected in series to the output of the fourth narrow-band filter, the second input of which is connected to the output of the fifth narrow-band filter, the sixth narrow-band filter and the third phase meter, the second delay line is connected in series to the output of the fifth narrow-band filter, the second phase detector, the second input of which is connected to the output of the fifth narrow-band filter, and the fourth phase meter, the second inputs of the phase meters are connected to the op generator, and the outputs are connected to the first, second, third and fourth inputs of the recording and analysis unit, respectively, the fifth input of which is connected to the output of the receiving unit, the correlator is made in the form of series-connected to the output of the receiving antenna of the adjustable delay unit, the seventh multiplier, the second input of which connected to the output of the first transmitter, low-pass filter and extreme controller, the output of which is connected to the second input of the adjustable delay unit, the second output of which is through a pointer alnosti connected to the sixth entry registration and analysis unit, the receiving antenna is located on a helicopter rotor hub, the engine is kinematically connected to a helicopter rotor and the reference generator.

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