RU2137153C1 - Device measuring parameters of seas - Google Patents

Abstract

FIELD: navigation, measurement of parameters of seas with use of influence meters. SUBSTANCE: device measuring parameters of seas has antenna, transceiver, Doppler frequency meter, speed measuring unit, computer of wave height and wave phase speed, computer, circuit determining fluctuation component of speed, unit determining direction of wave arrival, computer of wave striking angle, measurement module and correction unit. EFFECT: improved measurement accuracy. 14 dwg

Description

 The invention relates to the field of navigation, and more particularly to the measurement of wave parameters by means of devices that are electronic non-contact meters.

 Known devices (A.A. Zagorodnikov. Radar imaging of sea waves. L., Gidrometeoizdat, 1978, pp. 141-158) contain a coherent radar receiver and transmitter, a gating device, a Doppler frequency receiving circuit, a frequency meter, a memory device, a correction filter, and spectrum analyzer. The principle of operation of which is to irradiate the sea surface with electromagnetic waves, receive reflected signals, isolate a signal with a given fixed range, measure the Doppler frequency, convert the Doppler frequency to voltage, fix this voltage in a storage device and then pass through a correction filter to a spectrum analyzer.

 A significant drawback of these devices is the long measurement period of about 20 minutes, which may be unacceptable for the rapid acquisition of wave data, as well as the need to fix the irradiated sea area allows you to actually use these devices only from helicopters or other aircraft with a hanging mode. The accuracy of measurement of these devices is low, which requires several series of measurements.

 There is also known a device - a prototype described in the article: "Determination of wave parameters by a combined system for measuring the speed of a vessel and wave height" (Vanaev A.P., Chernyavets V.V. - Shipbuilding N 8-9, 1993, pp. 6-8), consisting of an antenna, a transceiver, a height measuring unit, a Doppler frequency meter, a speed measuring unit, a wave height calculator and a phase wave velocity, a calculator, a device for determining the direction of arrival of the waves, a circuit for determining the fluctuation component of speed, a calculator of the angle of encounter with the wave, allowing perativno measure parameters of excitement not only with aircraft having a hover, but also on board all mobile offshore facilities.

 The prototype compares favorably with its counterparts, however, it measures the relative height determined by the difference between the current side height and elevation of the wave profile, which significantly impedes the accuracy of the measurement of wave parameters. The accuracy of the measurement of this device is influenced by external disturbances caused by the rolling of the vessel.

 The purpose of this proposal is to increase the accuracy of measuring the parameters of the waves.

 This goal is achieved by the fact that in a device consisting of an antenna, a transceiver, a Doppler frequency meter, a speed measuring unit, a wave height and phase wave velocity calculator, a computer, a scheme for determining the fluctuation component of speed, a device for determining the direction of arrival of waves, a computer for meeting the angle of a wave in which the antenna is connected by an input and an output to the input and output of a transceiver, which is connected by two outputs to two inputs of a height measuring unit, which is connected by two outputs to the calculator and the same outputs are connected to two inputs of the calculator of wave height and phase velocity of the waves and two more outputs are connected to a device for determining the direction of arrival of the waves, the output of which is connected to the input of the calculator of the angle of encounter with the wave, the other two inputs of which are connected respectively to the outputs of the calculator, calculator of wave height and phase velocity of the waves and two more inputs of the device for determining the direction of arrival of the waves are connected to two outputs of the circuit for determining the fluctuation component of the velocity, which two inputs are connected to two outputs of the speed measuring unit and two more inputs are connected to two outputs of the Doppler frequency meter, which is connected by these outputs to two inputs of the speed measuring unit, and a Doppler frequency meter is connected by two inputs to two more outputs of the transceiver and a correction unit, which is respectively connected by its inputs to the outputs of a wave height and phase wave velocity calculator, a wave angle calculator, a speed measuring unit, and two the outputs of the measuring module, which is connected by an input to the output of the speed measuring unit, which is connected by two more inputs to the same outputs of the transceiver as the Doppler frequency meter, and the output of the correction unit is the output of the device.

 A block diagram of the proposed device is presented in the drawing (Fig. 1): antenna 1, transceiver 2, height measurement unit 3, Doppler frequency meter 4, speed measurement unit 5, wave height and phase wave velocity calculator 6, calculator 7, device for determining directions of arrival of waves 8, a scheme for determining the fluctuation component of speed 9, a calculator of the angle of encounter with wave 10, a measuring module 11, an interface unit 12.

Antenna 1 is a slotted waveguide antenna with a working opening of 325 x 310 mm, formed by the 29th radiating aluminum waveguides with inclined slots on a narrow wall. The power of the emitting waveguides is carried out by two transverse waveguides with slots and provides four radiation beams from a single aperture with a beam width of 4 ^o , 5. The antenna also includes a waveguide path with a circulator, load elements.

 The transceiver 2 (Fig. 2) consists of an ultrahigh frequency generator 13, a filter resonator 14, a diode mixer 15, an amplifier 16, a block for automatically adjusting the zone of the generator 17, modulator 18, and a synchronous detector 19.

 The height measurement unit 3 (Fig. 3) consists of a setup circuit for the initial height 20, an integrator 21, and a voltage-code converter 22.

 The Doppler frequency meter 4 (Fig. 4) consists of a block of Doppler frequency filters 23, a block of formers 24, a controversial frequency circuit 25, a switching circuit 26, an electronic adder of Doppler frequencies 27, an output divider block 28.

 The speed measuring unit (Fig. 5) consists of an inverter 29, a differentiating circuit 30, a shaper 31, two triggers 32, 33, an adder 34, an amplifier 35.

 The calculator of the wave height and phase velocity of the waves 6 (Fig. 6) consists of a circuit for isolating the fluctuation component 36, a rectification circuit 37, an amplifier-limiter 38, an integrator 39, a voltage-to-code converter 40.

 The calculator 7 (Fig. 7) consists of an integrator 41, including an AND 42 circuit, an integrator 43, a threshold device 44, a sign extraction circuit 45, including an adder 46, a threshold device 47, and an angle transformer 48, including a character entry circuit in code 49 and a circuit sign calculation 50.

 A device for determining the direction of arrival of waves 8 (Fig. 8) consists of a circuit 51 and an adder 52, an analog-to-digital converter 53, a divider 54, a multiplier 55, and a functional calculator 56.

 The circuit for determining the fluctuation component of speed 9 (Fig. 9) consists of a frequency-voltage converter 57, a circuit for isolating the fluctuation component 58, and an amplifier-limiter 59.

 The calculator of the angle of encounter with wave 10 (Fig. 10) consists of an inverter of sign 60, a switching circuit 61, an adder 62, a subtractor 63.

 Analogues of blocks 1-10 are the devices described in the book. Kolchinsky V.E., Konstantinovsky M.I. Doppler devices and navigation systems. M., Soviet Radio, 1975, and also in the application N 93-026874 (09) 027093 dated 05/19/93 and copyright certificates NN 296711 - 1989, 326577 - 1991, 198466 - 1989.

 The measuring module 11 consists of a newmeter and an analog-to-digital Converter. The newmeter is described in book. V.D. Andreev. Theory of inertial navigation. M., Science, 1966, 580 p. - with. 16-21.

 The analog-to-digital converter (Fig. 11) is an integrating converter in which the synchronization and control circuit associated with the output of the second comparator controls the integration cycles. In the first cycle, the input signal (upper switch position) is integrated over a fixed time interval determined by the synchronization and control circuit. In the second cycle (lower position of the switch), the voltage signal is supplied to the integrator input. The integration time in the second cycle is variable and is determined by the moment the output voltage of the integrator is equal to zero. Analogs are described in the book. Yu.M. Smirnov, G.I. Vorobiev. Specialized computers. M., Higher School, 1989-144 p., P. 72-87.

 Correction block 12 (Fig. 12) consists of a switch 64, an electronic adder 65, a microprocessor 66, a frequency-to-code converter 67, a voltage-to-code converter 68, a comparison circuit 69, and an output block 70.

 Microprocessor 66 is assembled on the basis of the BIS K1804 kit (The BIS K1804 kit in processors and controllers) V.M. Meshcheryakov, I.E. Lobov, S.S. Glebov et al. - Ed. B. B. Smolova / M.,: Radio and communications, 1990 - 256 p.).

 The device operates as follows. The generator of microwave oscillations 13 through the circulator in the antenna 1; in valve mode, it is loaded onto filter zoning 14, which serves to automatically adjust the generator zone and temperature stabilization. The frequency modulation of the generator is carried out by the APSG unit 17. The signal emitted by antenna 1 is reflected from the underlying sea surface and, after reception by the same antenna, is sent through a circulator to a diode mixer 15, which uses a detector section based on a Schottky diode with low noise.

 After conversion with a part of the emitted signal, the magnitude of which is regulated by a special screw, the received signal (first harmonic) is filtered and amplified in block 16, the tuning frequency of which is equal to the modulation frequency, the band is the doubled band of the spectrum at the maximum speed of the vessel. The signal from the output bl. 16 arrives at the synchronous detector 19. After synchronous detection with a modulating signal, an alternating voltage is emitted by the Doppler frequency.

 In the transceiver 2 uses the frequency manipulation mode described in the book. Varkatapyan A.G., Korshunov G.I., Nadelyaev M.A. and others. Automation of control of the parameters of the aquatic environment. - L .: Shipbuilding, 1988, 232 p.

From block 2, the signals are sent to blocks 3 and 4, in block 4 the following functions are provided:
- filtering Doppler signals;
- amplification of Doppler signals;
- transformation of the shape of the Doppler signals from a sinusoidal shape to a rectangular one.

 Low-pass filters are analog active filters that pass iron signals in the frequency range from 0 to 6500 Hz. The main interference is at a frequency of 20 kHz, at which the power voltage converter operates, 75 and 100 kHz - at the frequencies of the modulation of the microwave signal.

 Shapes of the waveform convert Doppler signals of a sinusoidal shape, varying in amplitude and frequency, and signals of a rectangular shape with a constant amplitude and a constant pulse duration equal to the minimum period of the useful signal. During a long pulse, the shaper is not sensitive to input signals. Thus, additional filtering of the useful signal from interference caused by vibration of the transceiver housing occurs. These interference are critical at small amplitudes of the Doppler signal, with a weak reflected signal of microwave energy, i.e. with a small signal to noise ratio. Since during the reference period the Doppler signals pass two transitions through the zero state, the frequency of the rectangular pulses at the output of the driver is twice as high as the input Doppler signal.

 The reference frequency circuit 25 contains a 200 kHz crystal oscillator, a reference pulse signal distributor, and a frequency divider. A reference time interval of 0.25 s is formed on the frequency divider. The reference pulse signal distributor comprises synchronization devices in an amount corresponding to the number of rays generated by the antenna. Each synchronization device, which is a logical trigger ring, designed to synchronize the reference frequency of the pulse sequences of the Doppler signal. For each synchronization device, the reference frequency obtained at the reference signal distributor is applied, the pulses of which are spaced in time. Thus, the time diversity of the Doppler pulsed signals from each beam occurs.

 Bl signals 4 arrive at bl. 5, where pulse sequences are formed with frequencies proportional to the longitudinal and transverse components of the speed of movement. The Doppler signal coming from the transceiver 2 to determine the sign of movement is also used as input information. Since two identical Doppler signals with a phase shift between them are received for each beam after demodulation, taking one of them as a reference signal, we determine the phase sign of the other signal, which characterizes the sign of the direction of movement of the vessel.

где Δf - девиация частоты;
T_Δf - период модуляции.On bl. 3 s bl. 2, the difference frequency signal F _p (t) = f ₁ (t) -f ₂ (t) (instantaneous frequency of the converted signal) is supplied, which carries information on the shift τ of the laws of change in the frequency of the studied f ₁ and received f ₂ signals

where Δf is the frequency deviation;
T _Δf is the modulation period.

коэффициент пропорциональности.In bl. 3 when measuring the height of movement from the antenna to the underlying surface, its proportional relationship with the difference frequency is used
H = ΔtF _p ,
Where

coefficient of proportionality.

Determination of the value of F _p with bl. 3 reduces to counting the number of pulses (for example, positive half-waves of the difference frequency signal) for the modulation period.

где Ω_1,2(t) - доплеровские частоты;
K_1,2 - волновые числа;
R - наклонная дальность.When emitting alternately with the frequency of the manipulation of two signals
f _1,2 (t) = E _m1,2 cos (ω _1,2 + φ _1,2 ),
where E _m1,2 , ω _1,2 + φ _1,2 - amplitude, frequency and phase, respectively, the received signals have the form:

where Ω _1,2 (t) are the Doppler frequencies;
K _1,2 - wave numbers;
R is the slant range.

Постоянная составляющая (Δφ) пропорциональна средней дальности до поверхности, а переменная ее профиль, причем размах переменной составляющей

пропорциональна высоте волны, т.е. для выделения высоты волны необходимо измерить разность фаз с выделением из результата флюктуационной составляющей, что производится в бл. 6.The phase difference is more convenient to measure for voltages having a low frequency, such as Doppler. Such signals are formed by shifting the received signal with part of the emitted:
f _1,2 (t) = E _mcm • 2cos (Ω _1,2 (t) ± 2K _1,2 R).
In this case, the phase difference for K ₁ <K ₂ is

The constant component (Δφ) is proportional to the average distance to the surface, and the variable is its profile, and the amplitude of the variable component

proportional to the height of the wave, i.e. to highlight the wave height, it is necessary to measure the phase difference with the allocation of the fluctuation component from the result, which is done in bl. 6.

 In the calculator 7, the measurement of τ. In bl. 9, the voltage of the Doppler frequency is converted into a sequence of pulses with a repetition rate equal to the Doppler frequency and matching of this sequence, but with a variable time constant, which is necessary for more efficient matching of Doppler frequency fluctuations caused by the random nature of the received signal and the isolation of fluctuations caused by the wave.

 The speed and altitude signals are sent to block 8, where the angle of arrival of the wave for each pair of rays is determined in accordance with the algorithms described in the prototype. Signals from bl. 6, 7, 8 are served on bl. 10, where the angles obtained are reduced to the diametrical plane of the vessel.

 Bl 11 provides a measurement of the proper vertical movements of the object, signals about which are digitally fed to bl. 12.

Структурная схема, поясняющая решение задачи очищения сигналов от помех, вызванных шумами измерения приведена на фиг. 14, где h(t) и ζ(t) измеряемые абсолютная высота движения и высота профиля волн; h'(t) и ζ(t) оценки этих величин: l₁(t)= h(t)-h'(t) и l₂(t)= (t)-'(t) - ошибки измерений; V₀₁(t) и V₀₂(t) - погрешности измерения бл. 2 и 11; W_1A(S) и W_A1(S) известные передаточные функции бл. 2 и 11; W_1,2,3(S) искомые передаточные функции каналов очищения сигналов в бл. 12.Since the measurement channels are not narrow-band, the output bl. 5, 6, 7, 11, the signals contain spectral components distorted by the measurement noise. To clear these signals from interference, bl. 12 which provides a solution to the transfer functions of the form (Fig. 13)

A block diagram explaining the solution to the problem of clearing signals from interference caused by measurement noise is shown in FIG. 14, where h (t) and ζ (t) are the measured absolute height of movement and the height of the wave profile; h '(t) and ζ (t) are the estimates of these quantities: l ₁ (t) = h (t) -h' (t) and l ₂ (t) = (t) - '(t) are the measurement errors; V ₀₁ (t) and V ₀₂ (t) - measurement errors bl. 2 and 11; W _1A (S) and W _A1 (S) are known transfer functions of bl. 2 and 11; W _1,2,3 (S) the desired transfer functions of the signal purification channels in bl. 12.

что значительно выше, чем у аналогов и прототипа: 0,031 < 0,2 м при волнении моря около 6 баллов по шкале Гугмо.The introduction of new elements distinguishes the proposed device from analogues and prototypes, because a complete set of spectral components of the measured parameters is provided in the form most cleared of interference, which ensures high accuracy and inertia of measurements. An assessment of the accuracy of measurement by the proposed device showed that at h _3% = 4 m (incomplete six-wave excitement), φ = 45 ^° , Δf = 0.01 Hz and the characteristic velocity of high-speed moving objects (for example, ekranoplan) V = 150 m / with the rms value of the measurement error is:

which is significantly higher than that of analogues and prototype: 0.031 <0.2 m with sea waves of about 6 points on the Gugmo scale.

 Sea waves are the most significant disturbing factor for the vast majority of ships and non-displacement marine vehicles (hydrofoils or air cushions, ekranoplanes; seaplanes and sea helicopters during takeoff and landing), as control objects. Its influence leads to the appearance of undesirable oscillatory movements, worsening the functional efficiency, safety and comfort of using such devices in comparison with the case of a calm sea. Using the proposed device will allow the adaptation of the control loop and the characteristics of sea waves.

Claims (1)

 A device for measuring wave parameters, consisting of an antenna, a transceiver, a Doppler frequency meter, a speed measuring unit, a wave height and phase wave velocity calculator, a calculator, a fluctuation velocity component determination circuit, a device for determining a wave arrival direction, a wave angle calculator in which the antenna input and output is connected to the input and output of the transceiver, which is connected by two outputs to two inputs of a height measuring unit, which is connected to the body and the same outputs are connected to two inputs of the calculator of wave height and phase velocity of the waves and two more outputs are connected to a device for determining the direction of arrival of the waves, the output of which is connected to the input of the calculator of the angle of encounter with the wave, the other two inputs of which are connected respectively to the outputs of the calculator, a wave height and phase wave velocity calculator and two more inputs of the device for determining the direction of arrival of the waves are connected to two outputs of the circuit for determining the fluctuation component of the velocity, which it has two inputs connected to two outputs of a speed measuring unit and two more inputs connected to two outputs of a Doppler frequency meter, which is connected by these outputs to two inputs of a speed measurement unit, and a Doppler frequency meter by two inputs is connected to two more outputs of a transceiver, characterized in that a measuring module and a correction unit are introduced, which are respectively connected by their inputs to the outputs of the wave height and phase wave velocity calculator, the wave angle calculator, and the measurement unit speed measuring module and two outputs, which is input connected to the output of speed measurement block which has two inputs connected to the outputs of the same transceiver as the Doppler frequency meter, and the output correction unit is an output device.

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