RU2799973C1 - Vector autonomous recorder - Google Patents

Abstract

FIELD: measuring technology and hydrophysics.

SUBSTANCE: vector autonomous recorder comprises a frame, a core made of soft magnetic material, a spherical body of the vector recorder, an annular elastic caging element, an electronic unit, batteries, a piezoelectric sensor, a hydrophone, a temperature sensor, a pressure sensor, an electric coil of the retention system, a high-frequency electric coil of an induction position sensor, wiring boards of the electronic unit, magnetic field sensor.

EFFECT: simplification of the design, an increase in the reliability of the device, an expansion of the recorded parameters.

2 cl, 2 dwg

Description

The invention relates to measuring technology and hydrophysics and is intended for measuring a number of parameters of the physical fields of the ocean, namely: a hydroacoustic field, including scalar pressure and an oscillatory velocity vector, an environmental current velocity vector, ambient temperature and pressure.

To solve applied and fundamental problems of oceanology and hydroacoustics, various sensors and meters of physical fields are known, among which are sensors of hydroacoustic fields - combined hydroacoustic receivers, temperature sensors and current velocity meters and environmental pressure sensors at the point where the sensors are located to calculate the depth at which the sensors are placed

As temperature sensors, for example, commercially available semiconductor sensors with a digital output are used, which can be directly connected to information recording systems based on microprocessors. Pressure sensors are installed, for example, analog, commercially available, while the output of the sensor is connected to the ADC, which is part of the information recording system based on a microprocessor.

Current meters are widely represented by numerous commercially available designs. According to their design features, these devices can be divided into two types: vector and component. Vector devices have separate sensors for the speed and direction of currents (VMM turntables, such as Ekman-Merz, BPV, DISK, Potok, Vector. Component devices have sensors for the current velocity components and sensors for the position of the device body relative to the magnetic meridian (ACITT) (V.P. Korovin, V.M. Timets, “Methods and means of hydrometeorological measurements (Oceanographic works)”, S-P., Gidrometeoizdat, 2 000). According to the measurements of the components of the current velocity and the position of the device, all the necessary parameters of the currents are calculated on a computer: the module, the direction of the projection on the parallel and the meridian. Acoustic current velocity meters are also known, based on measuring the Doppler frequency shift of the emitted signal reflected from the inhomogeneities of the medium.

Structurally, the current meters are hermetically sealed housings that house electronic equipment and sensors placed in the environment, for example, spinner type, which are rotors with blades rotating under the action of a moving fluid flow, the useful signal of which is the rotor speed proportional to the speed of the moving fluid flow. Acoustic meters also contain a sealed housing with electronic equipment, on which emitters and receivers of an acoustic signal are placed.

It should be noted that spinner current meters are characterized by reduced reliability associated with the presence of a mechanical system with a rotating element due to the possibility of contamination and low sensitivity due to the presence of friction in the spinner bearings; acoustic meters stop working in the aquatic environment in the absence of elements that reflect the emitted signal (air bubbles, various suspensions - sand, plankton).

Combined hydroacoustic receivers (CHRs) are known and widely used in hydroacoustics. The receivers contain an acoustic pressure channel and three orthogonal channels for determining the vibrational velocity vector. All channels have a single phase center located in the geometric center of the vector receiver housing, which, as a rule, has a spherical shape. The receivers are equipped with power supply and information transmission systems. In addition, the receiver is equipped with a system that holds it in a certain position (clause RF No. 2569201 C1).

QGP allow one to obtain additional information about hydroacoustic fields due to the fact that they determine not only the scalar pressure in the acoustic wave field, but also the vibrational velocity vector. This approach, in addition to determining the direction of arrival of acoustic oscillations in the operating frequency range, makes it possible to calculate the characteristics of the power flow, due to which an advantage can be obtained in direction finding of noise in an isotropic sea noise field. The main problems that worsen the performance of receivers are vibration interference that occurs for various reasons and is transmitted to the receiver housing due to the mechanical connection between the receiver and suspension elements and the presence of cables (cable) for supplying power and / or outputting useful information. For the same reasons, due to the penetration of acoustic vibrations on the receiver housing, again through the suspension elements and the supply cables, the directivity characteristic is distorted. In addition, there are difficulties in providing such a low resonant frequency of the elastic suspension that it is outside the operating range. It should be noted that many tasks of hydroacoustics require an expansion of the operating range, which is carried out by reducing the minimum operating frequency, which is associated both with the conditions of sound propagation in the ocean and with the features of the objects that emit this sound and are the subject of research.

Combined receivers are known, in which, to reduce the impact on the receiver of vibrations, systems are used that hold the receiver in a certain position using elastic threads. For example, a CHP is proposed in which a two-link suspension system is used, in which the combined receiver is installed in a sound-transparent frame, which, in turn, is attached to the body through a tensioner, to which the combined receiver is also attached by means of a restrictive thread. Fastening is carried out by means of longs made of elastic and restrictive threads, for example, rubber and Kevlar threads (p. RF No. 106880).

It should be noted that the CHP suspension systems, including elastic and restrictive threads, as well as electrical cables that serve to supply power and connect sensors to the information transmission/accumulation system, degrade the CHP characteristics, distorting the directional characteristic; It should also be noted that sealed containers with electronic units and batteries located in the immediate vicinity of the receiver housing have numerous intrinsic mechanical resonances, which distorts the acoustic field acting on the QGP, causing additional measurement errors.

Closest to the claimed is a combined hydroacoustic receiver (p. RF No. 2577421 C1), containing a body with a load located in the center of the body, a hydrophone channel, three vector channels installed centrally symmetrically between the body and the load, an electronic unit for converting acoustic vibrations, a system for fixing the body in a certain position, equipped with power supply and information transmission systems. The body fixation system is made in the form of a rigid frame, equipped with a non-contact body suspension system, consisting of position sensors placed around the body and permanent magnets installed inside the body, as well as electromagnets placed on the frame, and an electronic system for adjusting the current in the electromagnets. Power supply and information transmission systems are made remote. The information transmission system includes a transmitting part located in the housing and connected to an electronic unit for converting acoustic vibrations, and a receiving part associated with it, mounted on a frame and connected to an electronic unit for converting received signals, storing and / or transmitting information. a circuit or a coil with a magnetic circuit separated from the magnetic circuit of the transmitting part by a gap that provides the possibility of oscillatory movement of the hollow body.

However, the functionality of the receiver is reduced due to the registration of only vector-scalar measurements of the parameters of the hydroacoustic fields of the ocean, the design of the device is rather complicated and not sufficiently accurate due to the use of elastic longs, fastening threads and electric cables, as well as a closely spaced sealed container with batteries and an information recording system, which distorts the acoustic field near the device.

The claimed invention is directed to the development of the design of the receiver, providing the expansion of functionality, simplifying the design and reducing the cost, improving the performance of the combined receiver, eliminating the distortion of the acoustic field and the information recording system.

The technical result of the proposed solution is the possibility of simultaneously obtaining data on the scalar pressure in the acoustic field, the acoustic field oscillatory velocity vector, the current velocity vector, ambient temperature and pressure (depth of immersion), as well as improving the shape of the CGP directivity characteristic, increased reliability of the device, as a current velocity vector meter, due to the absence of moving parts, simplifying the design and cost.

The inventive autonomous vector recorder includes a non-metallic frame in the form of two perpendicularly intersecting rings with six cores of magnetically soft iron fixed at the intersection points, a spherical sealed split case of zero buoyancy placed inside the frame made of a non-magnetic and non-conductive material, with cage elements installed on the surface, separated from the frame by gaps, in the center of the case there is an electronic unit with batteries connected to the case by means of six pins, which is simultaneously an inert mass ezoelectric sensors located along the axes of an orthogonal coordinate system, the center of which coincides with the geometric center of the spherical body, and forming, together with the inert mass of the electronic unit, a three-coordinate accelerometer, a magnetic field sensor is installed inside the body, four hydrophones, a temperature sensor, an ambient pressure sensor are symmetrically installed on the outer surface of the body, and six electric coils of the retention system are installed opposite the cores, inside which are located high-frequency electric coils of induction position sensors, while high-frequency electric coils, accelerometers, hydrophones and temperature and pressure sensors are connected to ADCs located on the wiring boards of the electronic unit, electric coils are connected to the power elements of the electronic unit, and the magnetic field sensor is connected to the ADC of the electronic unit equipped with an information storage system.

The storage system may be implemented on an SD card, for example.

On FIG. 1 shows a diagram of the proposed registrar, where 1 is a frame; 2 - core made of soft magnetic material; 3 - spherical body of the vector recorder; 4 - annular elastic arresting element; 5 - electronic unit; 6 - batteries (batteries), 7 - piezoelectric sensor; 8 - hydrophone; 9 - temperature sensor; 10- pressure sensor; 11 - electric coil of the retention system; 12 - high-frequency electric coil of the induction position sensor; 13 - wiring boards of the electronic unit; 14 - magnetic field sensor.

On FIG. 2 shows the appearance of the recorder.

The vector autonomous recorder is designed to work as part of a bottom station, to the structure of which it is docked using frame fasteners (not shown in the figures). The annular elastic retaining elements 4, fixed on the spherical body 3, are separated from the structure of the frame 1 by gaps, which ensures free movement of the body 3 relative to the frame 1 within these gaps. The dimensions of the housing 3 are chosen so that, with the available mass of the housing 3, together with all the devices installed inside and outside the housing 3, the average density of the housing 3 is approximately equal to the density of water. The frame, made of a non-magnetic and non-conductive material, such as plastic, acrylic polymer, has six built-in cores 2 made of soft magnetic iron, isolated from water to prevent corrosion. Opposite the cores 2 of the frame 1, there are electric coils 11 of the retention system, during the flow of current through which magnetic interaction forces arise, attracting the coils 11 to the cores 2. Inside the coils 11, coaxially with them, there are high-frequency electric coils 12 of induction position sensors, through which an alternating electric current of high frequency flows, while the inductive resistance of the coil 12 depends on the inductance of the coil, which depends on the distance between the coil 12 and core 2. On the wiring boards 13 of the electronic unit 5, a servo system is assembled that regulates the current of the electric coils 11 so that the inductive resistances of the coils 12, depending on the distances between the coils 12 and the cores 2, are all the same, which ensures that the body 3 is held in the geometric center of the frame 1, while the annular elastic cage elements 4, mounted on the spherical body 3, will not touch the frame , providing body 3 freedom of movement within the gaps. In this case, the body 3 gets the opportunity to oscillate under the influence of an acoustic wave, the amplitude of which, with an average density of the body 3, equal to the density of water, is equal to the amplitude of the oscillations of fluid particles in the field of an acoustic wave [Vector-phase methods in acoustics / V.A. Gordienko, V.I. Ilyichev, L.N. Zakharov. - M.: Nauka, 1989, -223s]

Due to the fact that the electronic unit 5 is unfastened inside the housing 3 by means of piezoelectric sensors 7, the inertia forces of the electronic unit that occur during vibrations of the housing 3 load the piezoelectric sensors, causing the appearance of electrical voltage on their electrodes, which is fed through electrical wires to the receiving path for recording acoustic signals, located on the wiring boards and containing amplifiers (if necessary), a multichannel ADC connected to the processor of the electronic unit, and a recording/storage system information, for example, on an SD card. It should be noted that the signals of the piezoelectric sensors are proportional to the vibrational acceleration acting on the housing 3, therefore, to obtain the vibrational velocity components, the digitized signals of the sensors 7 must be integrated in the processor. Similarly, with the exception of the integration procedure, hydrophone signals are input to the processor with the help of amplifiers and a multichannel ADC, where the signals from all hydrophones are summed with subsequent recording on an SD card. Also, with the help of amplifiers, an ADC and a processor, the signals of temperature sensor 9 and pressure sensor 10 are recorded on the SD card.

In the presence of a flow, there is a flow flowing onto the body 3 with a velocity vector V, which can be represented as projections of the velocity vector on the axes of the coordinate system Vx, Vy, Vz. In this case, the projections of the velocity vector will exert a force effect on the body, the force vector of which F can also be represented by projections on the axes of the coordinate system Fx, Fy, Fz. In the general case, the force of the flow on a spherical body in the flow can be represented as

Where

F - force, ρ - liquid density, Cx - coefficient of hydrodynamic resistance of a spherical body, Sm - midsection area of a spherical body, V - flow velocity.

Obviously, under the action of the force F, the spherical body 3 will tend to shift relative to the frame 1 in the direction of flow, which will cause a change in the distances between the high-frequency coils 12 and the cores of the frame 2, which will cause the tracking system of the electronic unit to work, which will change the current flowing in the coils 11 of the retention system so that the distances between the high-frequency coils 12 and the cores 2 remain the same. In this case, there is a dependence between the difference of currents ΔI flowing in the coils 11 lying on the same axis of the coordinate system and the component of the force vector F acting on the body 3 from the side of the flow along the same axis of the coordinate system:

Where

ΔI is the difference between the currents flowing through the coils, F _i is the projection of the force vector of the current flow acting on the spherical body 3 on the considered axis of the coordinate system, k is a coefficient depending, in the general case, on the geometric and electrical parameters of the coil, the geometry and magnetic permeability of the core, the dimensions of the body and the gap between the coil 11 and the core 2.

Thus, by measuring the values of the currents flowing in the coils 11 of the containment system and entering, for example, using a multichannel ADC, the measured values into the processor of the electronic unit, by further processing the obtained values in the processor, taking into account formulas (1) and (2), we obtain by calculation the values of the projections of the flow velocity on the axes of the coordinate system Vx, Vy, Vz, which are recorded on the SD card.

Measurements of the oscillatory velocity vector and the flow velocity vector in the vast majority of cases require binding the orientation of the meter to the geographic coordinate system, for which the vector autonomous recorder is equipped with a magnetic field sensor 14, located inside the spherical body 3. Thus, the operation of the body 3 retention system in the geometric center of the frame 1 is based on the interaction of the magnetic fields of the coils 11 with the cores 2, these magnetic fields will cause errors in determining the Earth's magnetic field vector by the magnetic field sensor 14. In order to exclude the influence of the operation of the containment system on the determination of the orientation of the device, the measurement of the Earth's magnetic field vector is performed for a short period of time before starting work with the hold system turned off, for which the timer of the processor responsible for ensuring the operation of the device is used. For this, a software delay for turning on the vector meter systems is provided, counted using a timer.

It should be noted that the CGP flows in the flow are affected by turbulent vortices that break off the receiver body during the flow, which manifests itself in the appearance of so-called pseudosonic noise. To combat this phenomenon, sound-transparent fairings are used, which reduce the speed of the flow flowing onto the receiver body; it is noted, however, that the use of fairings significantly worsens the directivity characteristic of the CHP; moreover, in this case, the use of a fairing that reduces the speed of the flow flowing onto the CGP body is generally unacceptable, since the effect of the flow on the body is used to determine the flow velocity. Therefore, if the operating range of the QGP lies in the area of existence of pseudosonic interference, it is possible to propose the use of several autonomous vector recorders located close to each other with subsequent joint signal processing, while the acoustic signals recorded by the recorders turn out to be correlated, and the pseudosonic interference signals are uncorrelated, which makes it possible, by processing the received signals, to get rid of the above-mentioned interference. An additional advantage of this approach is the possibility of forming a vector-phase antenna from several QGPs, which expands the possibilities for studying ocean acoustic fields.

The body of the recorder is made detachable and connected, for example, with screws, for battery replacement, repair, or periodic removal of memory cards.

Thus, the vector autonomous recorder of the physical fields of the ocean has a simpler and lighter design of lower cost, which allows solving a wider range of problems in oceanological research compared to the known ones, due to the expansion of the recorded parameters: temperature, pressure (depth), orientation relative to the magnetic pole, current velocity vector, oscillatory velocity vector and scalar pressure of the acoustic field; increasing the accuracy of measurements due to the absence of any hermetic volumes in the immediate vicinity of the spherical body that distort the acoustic field; the proposed system for transmitting information, in which the batteries and the system for recording the information received are placed directly inside the spherical body.

Claims (2)

1. Vector autonomous recorder, including a non-metallic frame in the form of two perpendicularly intersecting rings with six cores of magnetically soft iron fixed at the intersection points, a spherical sealed split case of zero buoyancy placed inside the frame made of a non-magnetic and non-electrically conductive material, with cage elements installed on its surface, separated from the frame by gaps, an electronic unit with batteries located in the center of the case, connected to the case by means of six piezoelectric sensors located along the axes of the orthogonal coordinate system, the center of which coincides with the geometric center of the spherical body, and forming, together with the inertial mass of the electronic unit, a three-coordinate accelerometer, a magnetic field sensor is installed inside the body, and four hydrophones, a temperature sensor and an ambient pressure sensor are symmetrically installed on the outer surface of the body; lerometers, hydrophones and temperature and pressure sensors are connected to ADCs located on the wiring boards of the electronic unit, electric coils are connected to the power elements of the electronic unit, and the magnetic field sensor is connected to the ADC of the electronic unit equipped with a data storage system. 2. Vector autonomous recorder according to claim 1, characterized in that the data storage system is made on an SD card.