RU2353925C1 - Device for contactless high-precision measurement of object physical and technical parameters - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: device for contactless measurement of physical and technical parameters of object comprises body with inlet and outlet for running liquid and contains high-frequency ultrasonic radiator including buffer rod and piezoelectric plate fixed on it with electrodes for connection to external high-frequency generator. Device comprises acoustic lens installed in body and arranged with the possibility of displacement along its axis for focusing of sonic signal in object, acoustooptical shaper of optical image of sonic signals with two acoustooptical channels, measurer of acoustic lens displacement, computer.

EFFECT: expansion of functional resources.

15 cl, 8 dwg

Description

The invention relates to measuring technique and can be used in mechanical engineering for non-contact, high-precision measurement of linear displacements, tilt angle, profile and surface vibration of the objects under study and flaw detection of their material. The invention can also be used in medical equipment, in particular in tomographic equipment.

Optical double-beam and multi-beam Michelson-type interferometers with parallel light beams in the working and reference optical channels are known for non-contact measurement of the linear displacement and surface profile of an object with an accuracy of 0.05 μm (Kolomiytsov Yu.V. Interferometers: fundamentals of engineering theory and application. - L.: Mechanical Engineering, 1976).

Their disadvantage is the requirement that the surface roughness of the object be less than 0.01 μm and not be covered with a film of light-scattering or light-absorbing material. Also, with their help it is impossible to measure the parameters of an object with an angle of inclination of the surface relative to the axis of the working channel for more than 20 seconds. In this case, the interference pattern cannot be processed, because it changes even with a slight plane-parallel displacement or rotation of the object. For these reasons, these optical interferometers have highly specialized applications.

For non-contact measurement of object parameters with a surface roughness of more than 0.1 μm, as well as for flaw detection of optically opaque materials, acoustic devices such as sonar detectors, flaw detectors, tomographs are used (Bergman L. Ultrasound and its application in science and technology. - M .: IL, 1957 ) In these devices, the distance to the object under study is defined as the product of a given speed of sound in the medium by half the propagation time of sound to the object and vice versa. This time is determined by measuring the time interval between sending and receiving a pulsed sound signal or a difference frequency between the moments of sending and receiving a continuously emitted sound signal with a ramp.

In high-precision acoustic devices for measuring linear displacements with an accuracy of 1.0 μm, you can use the pulse-phase method used to measure the speed of sound in a solid or liquid medium (Kolesnikov A.E. Ultrasonic measurements. - M .: ed. Standartov, 1970 , p. 62-70). The basis of this method is the principle of antiphase superposition of two ultrasound pulses traveling towards the buffer rod in the ultrasound source after they are reflected from an object located at a fixed distance from the buffer rod. The combination of pulses in space and time is carried out by precision control of the moments of their excitation in the ultrasound source. In this case, by the time of their application, the first pulse should be reflected twice from the object and once from the end of the buffer rod, and the second pulse should be reflected once from the object.

To ensure high accuracy of combining ultrasonic pulses, it is necessary that they propagate with a plane wave front in the space between the buffer rod and the object. This is prevented by the phenomena of diffraction and scattering of ultrasonic waves. Because of this, the design and parameters of the ultrasound source, including the piezocrystal plate and the buffer rod, must satisfy very stringent conditions: the piezoelectric and elastic properties of the piezocrystal plate must be very uniform, its surface cleanliness is not lower than grade 12, transverse dimensions are not less than 25 lengths Λ waves of ultrasound with non-parallel work surfaces not more than 10 seconds. The transverse dimensions of the buffer rod should be at least 40 Λ, the length of the buffer rod should ensure the attenuation of echo pulses repeatedly reflected from its ends by the moment of excitation of the next pulse in it, the parallelism of the ends of the buffer rod, and also of the reflecting surface of the object under study, should not exceed 20-30 seconds . When using degassed, distilled water as a sound-conducting medium, the frequency of the emitted sound signal should be in the range of 1-60 MHz, and the power level should not exceed 0.25 W / cm ² so that sound attenuation under the influence of nonlinear effects does not occur and liquid cavitation does not occur . The sound signal should be in the form of short, rectangular pulses with a repetition rate of 50-100 Hz, so that all echo pulses are attenuated by the time the next series of pulses are excited in the piezocrystal.

This measurement method is used in the invention to determine the distance to the test object, but its main disadvantages are eliminated.

Similar requirements are imposed on the design and operating parameters of accurate ultrasonic flaw detectors and tomographs operating on the principles of transmission and reflected pulses. But even if all the requirements are met, the resolution of the flaw detectors when small objects with a large curvature of the surface, such as metal balls and wires in plastic and liquid, are detected in an opaque medium, does not exceed 0.1 mm ² due to their strong scattering effect. In ultrasound tomographs, the resolution for ultrasound imaging of the soft tissues of the body is much less than in flaw detectors. This is due to the fact that heterogeneities in the tissues of the body differ little in density and speed of sound, although they may have a large surface curvature. For example, blood capillaries, lymphatic ducts and glands in the skin, muscles and internal organs. In this case, the ultrasound probe should be oriented strictly perpendicular to the skin and come into contact with it through a layer of oil or petroleum jelly. When the probe moves over the skin, air must not enter between them, because the air gap with a thickness of even 0.001 mm does not transmit ultrasonic waves. Therefore, tomographs use slow and complex mechanical scanning systems, and the computing device uses complex algorithms for layer-by-layer construction of a two-dimensional image of tissues using statistical methods for processing echograms and spatial coordinates. Despite this, modern tomographs obtain rather rough images of body tissues (see, for example, patent RU 2203622 C2, 09/20/2000, IPC A61B 8/14).

The use of the proposed device in flaw detectors and tomographs eliminates their main disadvantages.

Note that the requirement that the source and receiver of ultrasound be located together with the object in the volume of liquid or mounted on the surface of the object using a film of viscous liquid to ensure acoustic contact between them is a serious drawback of acoustic devices. Due to the above main disadvantages, known acoustic measuring devices have highly specialized applications and do not provide high accuracy.

Most of the stringent requirements for the design and parameters of acoustic and optical measuring devices can be eliminated if, firstly, the beam of sound or light waves is focused to a point on the surface (or inside) of the object under study using an appropriate lens. Due to the amplification of these waves in amplitude in the focus region, as well as the fact that they have a flat front in the center of this region, the influence of diffraction phenomena on the amplitude and phase of the reflected wave is significantly reduced due to the scattering effect of roughness and curvilinearity of the surface of the object. In addition, if sound or light waves, before the lens travels, move with a flat front parallel to its axis, then after reflection from the surface of the object, these waves, passing the lens in the opposite direction, move again with a flat front parallel to its axis. This is also done when the surface of the object is located at a small angle to the incident wave. Secondly, if between the measured device and the object the propagation of sound or light waves is carried out through a flowing liquid, characterized by a slight absorption of these waves and having a low cost, then the measurement of physical and technical parameters can be made both of a stationary and a moving object. Moreover, the radiation and reception of these waves can be produced at a sufficiently large angle to the surface of the object. Thirdly, if in an acoustic device instead of a piezoelectric receiver of ultrasonic waves we use an acousto-optic system that forms the optical image of the sound beam (Balakshy V.I., Parygin V.N., Chirkov L.E. Physical foundations of acousto-optics. - M .: Radio and communication, 1985), then it is possible to implement observation of interference and measurement of spatial parameters of at least two spatially separated sound beams using simpler but more accurate means. In this case, it is also possible to increase the sensitivity and expand the dynamic range of measurement of the reflected sound signal. Fourthly, if to measure the displacement of functional units and elements, such as acoustic and optical lenses, instead of contact mechanical indicators, we use a non-contact optical measuring system of white light (Foteva II and others. Measurement of the thickness of semiconductor films by the interferometric method. - "OMP ”, 1975, No. 1, p. 62), it is possible to significantly improve the accuracy, reliability and performance of the measurement data.

Known devices and methods in which an acousto-optical system is used to measure the physical and technical parameters of an object. For example, there is a method of optical control of surface roughness by analyzing the dependence of light intensity on its scattering angle by the surface of an object, which is based on the effect of angular selection of the intensity of a diaphragmed light beam when a diverging light beam is transmitted through a sound wave traveling in an active acousto-optic medium (patent RU No. 2217696 C2 , 2002, IPC G01B 11/30).

Known devices and methods in which to measure the physical and technical parameters of an object, an optical white light measuring system is used. For example, this system is used in a contact optical device for precision measurement of the dimensions of parts (AS USSR No. 1052856 A, 1982, IPC G01B 11/02).

To conduct non-contact high-precision measurements of the linear displacement of the object, as well as its surface profile with a roughness of less than 0.01 μm, the proposed measuring device includes the main elements of a two-beam optical interferometer of the Zakharyevsky-Miro type, which uses focusing of the light beam in the working and reference channels (Vasiliev V .N., Gurov IP Computer processing of signals as applied to interferometric systems. - SPb .: BHV - St. Petersburg, 1998. p. 80). The interferometer contains a monochromatic, coherent light source, including a light emitter and a collimator in the form of a lens, forming the emitter light into a parallel light beam, a first beam splitter located at the intersection of the optical axis of the device and the collimator axis at an angle of 45 ° to them, a focusing lens mounted on the optical axis of the device between the beam splitting mirror and the object, the second beam splitting mirror mounted on the optical axis of the device at an angle of 45 ° between the focusing lens and the object ohm, which directs part of the light flux to a reference mirror located on an axis intersecting perpendicularly to the optical axis of the device, a photocell array mounted on the optical axis of the device in front of the first beam splitting mirror. The working and reference light beams reflected from the surface of the object and the reference mirror interfere on the surface of the matrix of photocells. A computing device is connected to the matrix of photocells, with the help of which the geometric parameters of the surface of the investigated object are determined in the vicinity of the focal point. This interferometer allows high-precision measurements of the geometric parameters of an object with a flat surface.

The disadvantages are the requirements that, firstly, the angle between the light beam incident on the surface of the test object and the light beam reflected from the object does not exceed 30 seconds, because the reference mirror is flat and motionless. Secondly, the focus on the surface of the object under study is adjusted by linearly moving the object along the optical axis of the device, because the focusing lens and the reference mirror are motionless. To control the movement, a measuring device, for example, a contact type, is used, which provides less accuracy compared to an interferometer. In the claimed invention, these disadvantages are eliminated.

By the totality of common features, the closest analogue (prototype) of the claimed invention is an acoustic device for flaw detection of sheet materials using translucent sound pulses (Bergman L. Ultrasound and its use in science and technology. - M .: IL, 1957). In this device, the emitter and the ultrasound receiver have the same design. In their case in the form of a metal pipe there is an input and output for flowing fluid, a high-frequency piezoelectric transducer in the form of a quartz plate mounted on the end of the buffer rod. An alternating voltage from an external generator is connected to the electrodes on the quartz plate. In the receiver, the alternating voltage removed from the quartz plate is supplied to an external indicator. An object in the form of sheet material is located between the terminals for the flowing fluid of the emitter and receiver. Ultrasonic communication between them is through a flowing fluid. To eliminate the effect of a standing sound wave in the generator in the space between the buffer rod and the object, an alternating voltage with a frequency of 1 MHz is modulated in amplitude with a frequency of 100 Hz.

The disadvantage of this flaw detector is a small resolution not exceeding 5 mm ² , because it operates in transmission pulses with a relatively low carrier frequency and there is no focusing of the ultrasonic beam. In principle, using this device it is possible to measure the linear displacements of an object, using, for example, the pulse-phase method described above for measuring the time it takes for a sound to travel from a source to an object. But in this case, the design and operating parameters of the device must impose the stringent requirements described above. These disadvantages are eliminated in the claimed invention.

The objective of the invention is to provide a device for non-contact high-precision measurement of a complex of physical and technical parameters of the studied object.

The technical result is the ability to measure with a single device the linear movement of an object, its angle of inclination, roughness and surface vibration, as well as an echographic visualization of the structure of its material based on the interference of an ultrasonic and light signal.

The problem is solved in that the inventive device, comprising a housing with an input and output for flowing fluid and a high-frequency ultrasonic emitter located in it, including a buffer rod and a piezoelectric plate with electrodes fixed to it for connection to an external high-frequency generator, additionally contains an acoustic solution according to the technical solution a lens located in the housing and configured to move along its axis to focus the sound signal on the object, acoustics an optic shaper of an optical image of sound signals with two acousto-optical channels, an acoustic lens displacement meter, a computing device, and the acousto-optical shaper of an optical image of sound signals includes a monochromatic coherent radiation source, the first optical system consisting of lenses and mirrors for generating working light beams in the acousto-optical channels in which the axes are located in the same plane perpendicular to each other and pass between the buffer rod and an acoustic lens through the region of propagation of sound signals to generate diaphragmed light beams, a second optical system consisting of mirrors for separating diaphragmed light beams of the working light beam in each acousto-optic channel into first and second diaphragmed light fluxes, spherical lenses for integrating each first diaphragmed light beam focal points and cylindrical lenses for integrating every second diaphragmed light flux into piecewise lines, photodetectors installed behind spherical and cylindrical lenses, respectively, while photodetectors and an acoustic lens displacement meter are connected to a computing device, and the body volume is divided into two isolated cavities, the first of which is located between the buffer rod and the acoustic lens, and the second between an acoustic lens and an outlet for flowing fluid, while the first cavity is designed to fill with liquid with a high coefficient of acousto-optical quality, and the second I fill flow fluid.

Due to these differences, using the proposed device, you can measure the distance to the object not only when the sound pulse is reflected from the object in the same direction in which it fell on it, but also when it is reflected at an angle. This possibility is realized by focusing the sound waves on the surface of the object, which uses a moving acoustic lens in the form of a spherical shell located between the buffer rod and the outlet for flowing fluid. In a fluid filling an acoustic lens, sound pulses move with a flat front parallel to its axis both towards the object and when reflected from it, including the case when sound is reflected from the object at an angle. But in this case, the density waves of the direct and reflected sound impulses overlap each other only partially, due to which it is impossible to combine them simultaneously in time and space.

The invention combines both the time and space of their optical images formed using the Riemann-Nat acousto-optical diffraction phenomenon (Balakshy V.I., Parygin V.N., Chirkov L.E. Physical foundations of acousto-optics. - M .: Radio and communication, 1985). For this, an acousto-optic system containing two acousto-optic channels is introduced between the acoustic lens and the buffer rod. In this acousto-optic system, the radiation of a monochromatic coherent light source, using the first optical system consisting of lenses and mirrors, is directed into both acousto-optical channels in the form of tape working light beams, which are then passed through a liquid filling the space between the acoustic lens and the buffer rod. Both acousto-optical channels are located in the same plane perpendicular to each other, as well as perpendicular to the axis of the acoustic lens, and pass through the region of propagation of sound signals. In this region, as a result of the acousto-optical interaction of sound waves and light, diaphragmed light beams are generated in each acousto-optic channel, the amplitude and phase of the light field of which describe the amplitude-phase characteristics of the sound wave. The invention uses first-order diaphragmed beams.

To observe in each acousto-optic channel the interference and spatial position of diaphragmed light beams carrying an optical image of direct and reflected sound beams, a second optical system is used that contains mirrors for dividing diaphragmed beams of the working light beam in each acousto-optic channel into two light fluxes. The first light flux is used to observe the interference of optical images of sound waves using the Fraunhofer diffraction phenomenon, for which spherical optical lenses are used. Lenses integrate the light fields of first-order diaphragmed beams at the secondary focal points at which the photodetectors are located. With their help, the moment in time is determined in both acousto-optical channels when, as a result of interference, the optical images of the incident and reflected sound pulses from the object are suppressed. The second luminous flux is used to register the spatial position of the sound beams relative to the axis of the acoustic lens. For this, this light flux is focused by cylindrical optical lenses in side focal lines along which the photodetector lines are located. Using the lines of photodetectors in both acousto-optical channels, data are displayed on the transverse dimensions of the optical images of sound beams and the distance between their axes in two perpendicular directions. The number of photodiodes in the rulers is selected from the condition of achieving maximum accuracy in determining the size of the optical images of sound beams.

In the invention, in order to use the pulse-phase method of measuring the distance to the object, it is necessary to have data on the distance between the acoustic lens and the buffer rod. To determine this distance with high accuracy, the known method is used in the invention (Foteva II, et al. Measurement of the thickness of semiconductor films by the interferometric method. - “OMP”, 1975, No. 1, p. 62), based on the resonant passage of white light through Sequentially located reference and working Fabry-Perot interferometers. For this, it is necessary that the main maximum of the white light spectrogram formed in the Fabry-Perot interferometer coincides with the main or first secondary maximum of the white light spectrogram formed in the Fabry-Perot reference interferometer. These conditions are satisfied when the reference and working Fabry-Perot interferometers are filled with the same optical medium and when the distance between the beam-splitting mirrors in the reference Fabry-Perot interferometer is equal to or twice the distance between the beam-splitting mirrors in the working Fabry-Perot interferometer.

This method of determining the distance between the acoustic lens and the buffer rod is used in the first white light measurement system. In the working interferometer of this measuring system, a movable mirror is mounted on an acoustic lens. The distance between the mirrors in a working interferometer is measured in two stages. First, the distance between the mirrors of the reference interferometer changes to a value equal to the distance between the mirrors in the working interferometer, which is fixed at the moment of combining the main maxima of the white light spectrograms formed in the reference and working interferometers. Then, the distance between the mirrors of the reference interferometer is doubled, which is fixed at the moment of combining the first side maximum of the white light spectrogram formed in the reference interferometer with the main maximum of the white light spectrogram formed in the working interferometer. At the same time, the number of beating half-waves arising from the interference of light in a Fabry-Perot measuring light interferometer is calculated, because the distance between its mirrors is changed synchronously with the change in the distance L _op between the mirrors of the reference white light interferometer. Due to this, the distance between the mirrors in the reference interferometer is L _op = n λ / 2, where n is the number of beating half-waves in the Fabry-Perot monochromatic light measuring interferometer.

The computing device processes data from photodetectors at the output of a working white light interferometer and a monochromatic light measuring interferometer, as well as data from photodetector lines in an acousto-optic system for generating an optical image of a sound beam. According to the results of processing, the distance between the acoustic lens and the surface of the object under study is determined, as well as the angle of inclination of the surface of the object relative to the direction of the sound beam incident on it.

In the proposed device, it is possible to dynamically scan in two perpendicular directions the radiation and reception of ultrasonic waves, which significantly expands the possibilities when measuring the geometric parameters of an object and flaw detection of its material, as well as when used in medical tomographs for ultrasound imaging of body tissues. For this purpose, an acoustic mirror located between the acoustic lens and the outlet for the flowing fluid is introduced into the device in the second cavity of the housing. A mirror can swing around two mutually perpendicular axes: the first axis of rotation coincides with the axis of the acoustic focusing lens, and the second axis of rotation is perpendicular to the first axis.

The proposed device allows through a stream of flowing liquid to measure the frequency and amplitude of vibration of the surface of the object. Using a high-frequency ultrasound source operating in the range 1-60 MHz, the measurement data can be carried out in two ways. The first method consists in measuring the time it takes for the sound to travel from the acoustic lens to the object and vice versa using the pulse-phase method described above, because this time varies in time with the vibration frequency and depends on its amplitude. This method is applicable for measuring low frequency vibrations. The second method consists in measuring the frequency spectrum of the beats during interference of the reflected and emitted sound signals, because due to the Doppler effect, the frequency of the reflected signal is shifted relative to the frequency of the emitted signal by the vibration frequency. This method is applicable for measuring high frequency vibrations. In both cases, an acousto-optical system is used to transform the amplitude-phase parameters of the sound beams into the amplitude-phase parameters of the diaphragmed light beams.

However, when the surface roughness of the object is more than Λ / 8, intense scattering of the reflected sound signal occurs, which greatly affects the accuracy of the measurement of vibration parameters. Therefore, these measurements in the invention are carried out at lower sound frequencies, because In this case, Λ is much larger than the roughness, and, moreover, in the flowing fluid, it is not longitudinal waves that begin to propagate, but bulk sound waves that effectively transmit low-frequency vibration. However, at these frequencies, the focusing properties of the acoustic lens and the guiding properties of the acoustic mirror are lost. Therefore, in the proposed device in the second cavity of the housing between the acoustic mirror and the outlet of the flowing fluid introduced low-frequency sound emitter-receiver, operating in the range from units of Hz to 100 kHz. This sound emitter-receiver can be made of highly efficient piezoelectric material in the form of a plate, cylinder or focusing mirror, in the center of which there is a hole. The size of the hole allows the passage of high-frequency sound waves both towards the object and reflected from it. The low-frequency sound emitter-receiver is connected through a switch to a sound generator and an indicator.

With the help of a low-frequency sound emitter-receiver, if necessary, cavitation of a flowing liquid, for example water, can be realized. In particular, in the joint operation of high-frequency and low-frequency emitters under the influence of sound waves of low and high frequency, it is possible to realize stimulated cavitation of flowing fluid in the focus area of an acoustic lens in the immediate vicinity of the surface of the object. The resulting gas and vacuum bubbles, filling the space between the roughnesses of the surface of the object, as it were, will level it and thereby reduce the scattering of the reflected high-frequency sound signal. Due to this, it is possible to carry out accurate measurements of the dimensions of the object even with a surface roughness of more than Λ / 8.

Used in the invention, an acoustic method for measuring the linear displacements of an object is used when the surface roughness is more than 0.1 μm. When the roughness is less than 0.1 μm and you need to accurately analyze the surface profile of the object, including the case when the surface is at an angle to the incident light beam, the proposed device uses a more accurate optical measurement method. It is based on the interference of two monochromatic light beams, one of which focuses on the surface of the object under study, and the other on the supporting surface. In this case, the supporting surface is located at that distance and with the same angle of inclination as the investigated surface of the object. To implement this method of measurement, the proposed device contains a measuring optical system such as a Zakharyevsky-Miro interferometer (Vasiliev V.N., Gurov I.P. Computer signal processing as applied to interferometric systems. - SPb .: BHV - St. Petersburg, 1998, p. .80). This measuring optical system includes a first beam splitting mirror and a matrix of photocells located outside the housing, a second beam splitting mirror and a supporting mirror located in the second cavity of the housing in the flowing fluid, an optical focusing system built into the wall of the second cavity of the housing. In this case, the first and second beam splitting mirrors and the optical focusing system located between them form a working optical channel, the axis of which passes through the acoustic mirror and the outlet for flowing fluid, in which these mirrors are installed at an angle of 45 ° to the axis. The second beam splitting mirror and the reference mirror form a reference optical channel, the axis of which is perpendicular to the axis of the working optical channel. Since the working and reference optical channels are located in the flowing fluid, they provide the same conditions for the propagation of light beams. The second beam splitting mirror, the reference mirror and the optical focusing system are movable. The ability to move the optical focusing system along the axis of the working optical channel provides optical focus adjustment on the surface of the object or inside it when the material is optically transparent. The second beam splitting mirror has three sections on the surface with a transparent, beam splitting and mirror coating. The ability to move this mirror perpendicular to the axis of the working optical channel provides discrete switching of its reflection coefficient. The reference mirror is arranged to move along the axis of the reference optical channel, rotate around this axis, and also rotate around an axis perpendicular to the axis of the reference optical channel. Due to this, the surface of the reference mirror can be positioned at the same distance and with the same angle of inclination as the surface of the object. Since the acoustic mirror is located on the axis of the working optical channel, it is made of optically transparent material so that light passes through it.

The radiation of the monochromatic light source is directed through the working optical channel to the object under study, and through the reference optical channel to the reference mirror. Light beams reflected from the object and the reference mirror interfere on the surface of the second beam splitter mirror, and then are directed by the first beam splitter mirror to a two-dimensional matrix of photocells connected to the computing device.

The measurement of the displacement of the optical focusing system is carried out using the second white light measuring system introduced into the device. For this, a movable beam splitting mirror as part of the working white light interferometer of this measuring system is mounted on an optical focusing system. The principle of operation of this measuring system of white light is discussed above.

A prerequisite for accurate measurement of the microprofile of an object’s surface by the interference of two monochromatic light beams reflected from focal points on the surface of an object and a reference mirror is the requirement that the light path lengths along the reference and working optical channels be equal. The measurement of the light path length along these channels is carried out using the third white light measuring system introduced into the device. In the working white light interferometer of this measuring system, the surface of the object and the reference mirror are alternately used as a mirror. To switch the light to the reference or working optical channel, a second beam splitting mirror is used, which has the properties of a mirror with a discretely changing reflection coefficient, which can be moved across the working optical axis.

If an acoustic mirror is used as the second beam splitting mirror, then the axis of the reference channel coincides with the axis of the acoustic lens. In this case, the acoustic mirror has three sections on the surface with a transparent, reflective and beam splitting coating, i.e. acts as a mirror with a discretely changing reflection coefficient. The combination of these sections with the working optical channel is made by moving the acoustic mirror along its second axis of rotation.

When white light is transmitted through the working optical channel, either a transparent portion or a coated portion in the form of a reflecting mirror is mounted on the second beam splitting mirror. In the first case, the light path in the working optical channel is measured. To this end, in the third white light measuring system, the corresponding maxima of the white light spectrograms of the reference and working white light interferometers are sequentially combined, in which in this case the object surface is used as one of the mirrors. In the second case, the light path in the reference optical channel is measured. Then, in the working white light interferometer, a reference mirror is used as one of the mirrors. In both cases, to measure the length of the light simultaneously with the combination of the corresponding maximums of the white light spectrograms, the number of beating half-waves is calculated in a monochromatic light measuring interferometer located in the third white light measuring system, which synchronously moves with the reference white light interferometer of this measuring system.

If the surface of the object is located at an angle to the axis of the working optical channel, it is necessary to satisfy the condition of equal angles determining the inclination of the reference mirror to the axis of the reference optical channel and the inclination of the surface of the object to the axis of the working optical channel, which is achieved due to the movement and rotation of the reference mirror.

In the invention, using the optical interference method, it is possible to accurately measure the geometric parameters of the surface of an object if its roughness is more than 0.05 μm, as well as when the surface of the object is covered with a film of light-scattering or light-absorbing material. A film of light-scattering or light-absorbing material, for example, oil, can be removed or thinned to a size smaller than λ / 4 during the measurement using a jet of flowing liquid, into which, if necessary, active additives, for example, alkali, acid, salt, are introduced. To enhance their effect, the phenomenon of cavitation of a liquid under the action of ultrasonic waves excited by a low-frequency sound emitter can be used. To reduce the scattering effect of roughness, the space between microroughnesses in the surface of an object can be temporarily filled with an electrically conductive material. For this, a suspension of electrically conductive particles, for example, metal or graphite nanoparticles, is introduced into the flowing fluid. In this case, the acoustic lens and the focusing optical system are focused at one point on the surface of the object. Then, under the influence of low and high frequency sound due to stimulated cavitation of the liquid, gas and vacuum bubbles are formed in the region of the focal point, which capture the electrically conductive particles. Gas and vacuum bubbles with nanoparticles under the action of radiation pressure forces are concentrated in the region of the minima of the vibrational velocity of the sound wave located between the surface roughness. Due to this, the concentration of nanoparticles increases between roughnesses. Thereby, the scattering of both white and monochromatic light reflected from a rough surface is reduced.

The functionality of the proposed device allows it to be effectively used in medical acoustic tomographs as an ultrasound probe. With its help, it is possible to realize amplification of sound waves in amplitude within the body in the focus area, which can significantly increase the resolution during echographic visualization of body tissues. It is possible to move the focus region over wide limits due to the movement of the acoustic lens along its axis and the swing of the acoustic mirror around two mutually perpendicular axes. The ability to transmit sound waves to the surface of the body through running water, which has wave impedance comparable to the wave impedances of various types of tissues, allows the ultrasound probe to quickly move over the skin of the body and position it at a sufficiently large angle to it. This ensures a minimum reflection of sound from the skin. A significant increase in the resolution and speed of ultrasound imaging of the soft tissues of the body can be achieved by using two-dimensional matrices from the proposed devices, because in this case, each device can be installed not only vertically to the surface of the investigated object, but also at a certain angle to it, and receive an echo signal caused by radiation from other devices.

To reduce the flow rate of the fluid in the proposed measuring device, a cuff is used, in which the casing is made in the form of a pipe made of an elastic material that absorbs sound. The cuff is mounted on the outlet for the flowing fluid. To ensure a minimum gap between the end surface of the cuff and the object and, at the same time, be able to change the angle of emission or reception of sound or light relative to the surface of the object, part of the cuff body is corrugated. For the same purpose, the end surface of the cuff in contact with the object has a shape corresponding to the shape of the surface of the studied object. Also, the contacting end face of the cuff can be a brush made of elastic pins or vacuum suction cups connected through pneumatic channels in the walls of the cuff body to the pump nozzle.

The claimed invention is illustrated by drawings.

Figure 1 shows a design variant of the proposed device, in which non-contact measurement of the geometric parameters of the object and flaw detection of the material is carried out using ultrasound.

Figure 2 and figure 3 schematically shows an acousto-optical system that forms optical images of sound beams in two mutually perpendicular acousto-optical channels. The notation is introduced here: a is the cross section of the sound beam incident on the object and b is the cross section of the sound beam reflected from the object.

Figure 4 shows a design variant of the proposed device, in which non-contact measurement of the geometric parameters of the object and flaw detection of the material are carried out using ultrasonic and light signals.

Figure 5 shows a variant of the design of the cuff, in which the contacting end surface has a brush of elastic pins.

Figure 6 shows an embodiment of the design of the cuff, in which the contacting end surface has vacuum suction cups.

Figure 7 schematically shows plots of changes in the intensity of light signals at the output of monochromatic and white light channels in the process of changing the distance between the mirrors of the reference white Fabry-Perot interferometer, where the notation is introduced: f is the main maximum of white light, s is the first secondary maximum of white light.

Fig. 8 shows the paths of the propagation path of sound beams for the case when the surface of the object is located at an angle α / 2 to the incident sound beam, where are indicated: a - the path of the sound beam incident on the object, b - the path of the path from the sound beam object, s - the area of interaction of sound and light beams.

The positions in the figures indicate: 1 - ultrasonic piezoelectric emitter; 2 - buffer rod; 3 - high-frequency generator; 4 - input fluid flow; 5 - flowing fluid filling the second cavity of the housing; 6 - the investigated object; 5 - output fluid flow; 8 - an acoustic lens; 9 - corrugated shell of the first cavity of the body; 10 - liquid filling the first cavity of the housing; 11 - thermostat tank; 12 - piston, providing a change in the volume of the tank of the thermostat; 13 - acoustic mirror; 14 - low-frequency piezoelectric emitter-receiver; 15 is a device comprising a switch, a low-frequency sound generator and an indicator; 16 - coherent monochromatic light source; 17, 18 - beam splitting mirrors; 19, 20 - reflecting mirrors; 21, 22 - diaphragms; 23, 24 is a schematic representation of the optical axes of acousto-optical channels; 25, 26 - spherical optical lenses; 27, 28 - line of photodetectors installed at the focal points of spherical optical lenses; 29 - beam-splitting mirrors in each acousto-optical channel directing the first diaphragmed light fluxes to spherical optical lenses; 30 — a reflecting mirror in each acousto-optical channel directing the second diaphragmed light fluxes to cylindrical optical lenses; 31, 32 - cylindrical optical lenses; 33, 34 - line of photodetectors installed in the focal lines of cylindrical optical lenses; 35 is a mirror directing the light of a coherent monochromatic source into a channel of monochromatic light; 36 - a source of white light; 37, 38 - movable and fixed beam splitting mirrors of a measuring interferometer of monochromatic light Fabry-Perot of the first measuring white light system, respectively; 39 is a mirror directing light from a measuring Faber-Perot monochromatic light interferometer of the first white light measuring system to a photodetector; 40 - photodetector, recording the optical signal at the output of the measuring interferometer of monochromatic light Fabry-Perot; 41, 42 - movable and stationary beam splitting mirrors of the reference white light interferometer Fabry-Perot, respectively, of the first measuring white light system; 43 - a movable beam splitting mirror of a working white light interferometer Fabry-Perot of the first measuring white light system mounted on an acoustic lens; 44 - an auxiliary mirror of the working white light interferometer Fabry-Perot of the first measuring white light system; 45 is a photodetector detecting an optical signal at the output of a working white light interferometer Fabry-Perot of the first measuring white light system; 46 - computing device; 47 - the first beam splitting mirror in the working optical channel; 48 - optical focusing system; 49 - corrugated shell of the second cavity of the housing on which the optical focusing system is installed; 50 - reference mirror in the reference optical channel; 51 — a beam splitting mirror directing the light of a monochromatic source into a working optical channel; 52, 53 - beam splitting mirrors of the reference white light interferometer of the second white light measuring system; 54 is a movable beam splitting mirror of a working white light interferometer of a second white light measuring system mounted on an optical focusing system; 55, 56 - mirrors directing the radiation of a white light source into the second measuring system of white light; 57 is a mirror directing radiation from a working white light interferometer of the second measuring white light system to a photodetector; 58 is a photodetector registering an optical signal at the output of a working white light interferometer of a second white light measuring system; 59, 60, 61 — beam-splitting mirrors of the moving unit included in the working white light interferometer of the third measuring white light system; 62 - matrix photodetector; 63 - corrugated part of the cuff body; 64 - brush elastic pins on the end surface of the cuff body in contact with the test object; 65 - vacuum suction cups on the end surface of the cuff body in contact with the test object; 66 - pneumatic channels in the walls of the cuff; 67 - pumping nozzle.

The design variant of the device shown in Fig. 1 comprises an ultrasonic piezoelectric emitter 1 mounted on the end of the buffer rod 2. An alternating voltage from the high-frequency generator 3 operating in the range of 1-60 GHz is supplied to the electrodes of the ultrasonic piezoelectric emitter 1. An input 4 of flowing fluid 5, for example, water, which flows to the surface of the test object 6 through the outlet of flowing fluid 7, is located in the device’s body. Sound waves emitted from the ultrasonic emitter 1 propagate through the flowing fluid 5 to the surface of the object 6. Sound waves propagating in the fluid 5 are focused a liquid acoustic lens in the form of a spherical shell 8 of radius R _LV . The space bounded by the shell 8 and the buffer rod 2, and in the transverse direction by the corrugated shell 9, is filled with a liquid 10, which has a lower sound velocity than the flowing liquid 5, and has a high coefficient of acousto-optical quality. Ethanol and propyl iodide, for example, have such properties. The focusing shell 8, mounted on the corrugated shell 9, can move along its axis using a precision motor (not shown in figure 1). The change in the volume of liquid 10 associated with the movement of the shell 8 is compensated by a corresponding change in the volume of the tank of the thermostat 11, for example, by moving the piston 12. The temperature of the liquids 5 and 10 is measured using temperature sensors (not shown in FIG. 1) so that the density change can be accurately determined and the speed of sound in these fluids versus temperature. To change the direction of emission and reception of ultrasonic waves, an acoustic mirror 13 is used, formed by two parallel plates with a thin air gap between them. The acoustic mirror 13 is located at the intersection of the axis of the acoustic lens 8 and the axis perpendicular to it and passing through the center of the hole in the outlet of the flowing fluid 7. The acoustic mirror 13 can swing around two axes using precision motors (not shown in FIG. 1). The first axis of rotation coincides with either the axis of the acoustic mirror 8 or with the axis passing through the center of the hole in the outlet of the flowing fluid 7. The second axis of rotation is perpendicular to the first axis.

The low-frequency piezoelectric emitter-primer 14 is used to measure the frequency and amplitude of low-frequency vibrations of the surface of the object 6 propagating through the flowing fluid 5 in the form of volumetric sound waves, as well as to create cavitation of the flowing fluid 5 in the focus area of the acoustic lens 8. The emitter 14 is located on the acoustic axis between the acoustic mirror 13 and the hole in the outlet of the flowing fluid 7. It can be made in the form of a plate, cylinder or focusing mirror, in the center of which there is a hole term. The size of the hole allows the passage of high-frequency sound beams emitted from the acoustic lens 8 or reflected from the object 6, and the external size of the emitter and the type of piezoelectric material are selected from the requirement of its effective operation in the range of 10-500 kHz. The emitter 14 is connected to a device including a switch, a low-frequency sound generator and an indicator 15.

To create optical images of direct and reflected sound beams, an acousto-optical system is used, which forms the optical image of sound beams. The given design variant of this system includes a monochromatic coherent light source 16, beam splitting mirrors 17 and 18, reflecting mirrors 19, 20 and apertures 21, 22 (these mirrors are not shown in FIG. 2 and FIG. 3). Using these optical elements, two tape light beams are formed in two acousto-optical channels 23 and 24, which are transmitted through the liquid 10 in the same plane perpendicular to each other and also perpendicular to the acoustic axis of the acoustic lens 8. For this, the mirrors 17 and 18 are located on a common optical axis, located at an angle of 45 ° and rotated around the axis relative to each other at an angle of 90 °. The propagation direction of one of the light beams is changed through an angle of 180 ° using mirrors 19 and 20. In each acousto-optical channel, part of the luminous flux of the diaphragmed light beams reflecting the optical image of the sound beams is guided through beam-splitting mirrors 29, and then is integrated by spherical optical lenses 25, 26 At the side focal points of these lenses, photodetector arrays 27, 28 are installed (see FIGS. 2-3), which display the interference of optical images of sound beams in the form of an electric signal. In order for the photodetectors 27, 28 to be aligned with the light spots of the diaphragmed beams, the photodiodes in them are arranged with a step of λF _{1 1} / Λ _л , where F _{1 1} is the focal length of the lenses 25, 26. To register the spatial position of the sound beams relative to the axis of the acoustic lens 8 in both acousto-optical channels, the second part of the luminous flux of the diaphragmed beams is guided by beam splitting 29 and reflecting 30 mirrors through cylindrical optical lenses 31, 32 to the lines of photodetectors 33, 34. The number of lines 33 and 34 corresponds to the number analyzed diaphragmed beams, and the number of photodiodes in these lines is selected from the condition of achieving maximum accuracy when determining the size of the optical images of sound beams. In order for the photodetector arrays 33, 34 to be aligned with the light spots of the diaphragmed beams, they are arranged in increments of λF _lo2 / Λ _g , where F _lo2 is the focal length of the lenses 31, 32.

The exact determination of the distance between the focusing shell 8 and the buffer rod 2 is carried out in the white light interference measuring system by combining the corresponding maxima of the white light spectrograms after passing two Fabry-Perot interferometers in series. This optical system includes a monochromatic light channel into which the light of the monochromatic coherent source 16 is directed using, for example, beam splitting mirrors 17, 35, and a white light channel into which the light of the white light source 36 is directed. The monochromatic light channel forms a Fabry monochromatic light measuring interferometer A pen that includes a movable beam splitter mirror 37 and a stationary beam splitter mirror 38. From a Fabry-Perot monochromatic light interferometer, a beam of light using a mirror 39 into a photodetector 40 connected to a computing device 46. Thus, in this interferometer, the distance between the mirrors 37, 38 is determined with an accuracy of λ / 2. In the white light channel, the light beam is directed to a reference white light interferometer formed by a movable beam splitter a mirror 41 and a stationary beam-splitting mirror 42. After multiple reflection from the mirrors 41, 42, a beam of white light is directed through a beam-splitting mirror 42 into a working white light interferometer formed by a stationary a beam splitting mirror 42 and a moving beam splitting mirror 43 mounted on an acoustic lens 8. Between the mirrors 42 and 43, white light changes the direction of propagation using, for example, an auxiliary reflecting mirror 44. The moving mirror 37 and the moving mirror 41 are located in the moving block and are mechanically connected therefore, they move synchronously using a precision motor (not shown in FIG. 1). Thus, the mirrors 41, 42 and 42, 43 form two Fabry-Perot interferometers mounted in series in the white light channel. The spectrogram of the initial white light is formed between the mirrors 41 and 42. When, as a result of the movement of the mirrors 41 and 43, the lengths of the white light paths between the mirrors of the first and second white light interferometers become the same, the same white light spectrograms are formed in them. In this case, the white light beam passes through the mirror 43 and enters the photodetector 45 connected to the computing device 46. In the computing device 46, the data from the photodetectors 40, 45 and the lines of the photodetectors 27, 28 and 33, 34 are jointly processed. As a result of calculations with up to λ / 2, the distance between the buffer rod 2 and the acoustic mirror 8 is determined, and the moment of mutual cancellation of the direct and reflected sound pulses and their spatial position are also determined. According to these data, the linear movement of the object 6 and the angle of inclination of its surface relative to the direction of propagation of the sound pulses incident on it are calculated. In the same way, the dimensions and position of the defect in the material of the object 6 are determined.

Depicted in figure 4, the proposed device is designed for non-contact measurement of physico-technical parameters of the object using the interference of ultrasound and light. It includes elements of the device of figure 1. The following elements are introduced to perform measurements using two-beam interference of monochromatic light beams focused on the surface of the object and the reference mirror.

Along the axis of the working optical channel, the first beam splitting mirror 47 and the optical focusing system 48, which is installed in the corrugated shell 49, are arranged in series. Thanks to the corrugation on the shell 49, the focusing system 48 can move along the main optical axis using a precision motor (not shown in Fig. 4) . This ensures the adjustment of its optical focus on the surface of the studied object 6. Behind the optical focusing system 48 there is a mirror with a discretely varying light reflection coefficient 13. In the device of Fig. 4, an acoustic mirror made of optically transparent material is used on this surface, on the surface of which there is Three sections with a transparent, beam-splitting and reflective coating. Next is a low-frequency sound emitter-receiver 14 connected to a device 15, including a switch, a generator and an indicator. Sound and light beams propagate through the hole 7 through the flowing fluid 5 to the surface of the test object 6. In the reference optical channel, the axis of which passes through the center of the mirror 13 and coincides with the axis of the acoustic mirror 8, there is a reference mirror 50, which can rotate around the axis reference optical channel, move along it, and also rotate around an axis perpendicular to the axis of the reference optical channel. A beam of monochromatic light from a source 16 is guided along the working optical channel through a beam-splitting mirror 51. The mirror 51 is mounted in a movable unit, which introduces this mirror into the working optical channel when measuring the surface parameters of object 6 in an interference manner. Reflected from the object 6 and the reference mirror 50, beams of monochromatic light using a mirror 13, an optical focusing system 48 and a first beam splitter mirror 47 are sent to a matrix photodetector 62 connected to the computing device 46.

To measure with high accuracy the movement of the focusing optical system 48, a second white light measuring system is used. In the device of FIG. 4, this system comprises a monochromatic light measuring interferometer containing the same optical elements — mirrors 35, 37, 38, 39 and a photodetector 40, as in the device of FIG. 1. In the second white light measuring system, the reference white light interferometer includes beam splitting mirrors 52 and 53, and the working white light interferometer includes beam splitting mirrors 53 and 54. Moreover, the mirror 54 is mounted on the optical focusing system 48. The white light of source 36 is directed to the second white light measuring system through a beam splitting mirror 55 and a reflecting mirror 56, and the output of white light is directed by a mirror 57 to a photodetector 58 connected to a computing device 46.

To measure the distance to object 6 with high accuracy, a third white light measuring system is used. This system uses a monochromatic light measuring interferometer (mirrors 35, 37, 38, 39 and a photodetector 40) and a white light reference interferometer (mirrors 51 and 52) used in the second white light measuring system. In the third measuring system, the working white light interferometer is formed by optical elements, either a mirror 59, a transparent coating on the mirror 13, the surface of the object 6, or a mirror 59, a reflective coating on the mirror 13, a reference mirror 50. The white light of the source 36 is directed from the reference white light interferometer ( mirrors 52 and 53) into the working white light interferometer through the movable block of mirrors 59, 60, 61. The output of white light through the mirror 61 and the first beam splitting mirror 47 is directed to the photodetector array 62 connected to ychislitelnomu device 46.

Figure 5 and figure 6 shows the design options of the cuffs, designed to reduce the flow rate of flowing fluid in the proposed device. The cuff body is made in the form of a pipe made of an elastic material, such as rubber. In this case, the body part is corrugated 63. The end surface of the cuff body in contact with the test object may have a shape corresponding to the shape of the surface of the object. This surface is provided with a brush of elastic pins 64 (Fig. 5) or vacuum suction cups 65 (Fig. 6), connected through pneumatic channels 66 in the walls of the cuff body to a pump nozzle 67, which is connected to an air pump (not shown in Fig. 6). Cuffs are installed on terminal 7 for flowing fluid.

The proposed device operates as follows.

When measuring the linear displacement of the test object by the acoustic method, the design of the acousto-optical device shown in Fig. 1 is applied. The measurement is carried out by the method of combining in time and in space the amplitude-phase characteristics of two sequentially emitted sound pulses traveling in one direction by precision control of their amplitude and the moment of radiation in the ultrasound source. Moreover, by the time of combining, the first pulse of sound should once reflected from the object and source of ultrasound, and the second should only be emitted from the sound source.

In this device, the generator 3 generates high-frequency electrical oscillations in the range of 1-60 MHz at frequencies Ω = n ω, which are multiples of the frequency ω, where n = 1, 2, 3, 4, 5, in the form of short, rectangular pulses, the amplitude and time interval between which are regulated with high accuracy. The frequency ω is determined by the dimensions of the plate of the ultrasonic piezoelectric emitter 1. The choice of the working frequency Ω is determined by the roughness of the surface of the object 6 and the required measurement accuracy (the higher the generated frequency, the higher the measurement accuracy; the lower the generated frequency, the greater the roughness can measure the geometric parameters of the object). High-frequency electrical vibrations are supplied to the electrodes of the piezoelectric emitter 1, in which they are converted into longitudinal mechanical vibrations of the piezoelectric plate. As the material of the piezoelectric plate, it is advisable to use lithium niobate (LiNbO ₃ ), which works well at ultrasonic frequencies from 0.5 MHz to 150 MHz. The sound pulse emitted by the plate 1 in the form of a plane, longitudinal wave propagates along the axis of the buffer rod 2. From the end of the buffer rod 2, the sound pulse is radiated into the liquid 10 filling the space of the focusing acoustic lens. The optimal conditions for the passage of sound from the rod into the liquid 10, as well as to reflect the sound incident on the rod, are provided when the reflection coefficient of sound power is about 0.5 (Kanevsky I.N. Focusing of sound and ultrasonic waves. - M .: 1977) . This condition is achieved when using a two-layer buffer rod, consisting, for example, of sequentially located plates of quartz and polystyrene. In the liquid 10, the sound pulse propagates in the form of a plane, longitudinal wave to the focusing shell of the acoustic lens 8. Behind the shell 8, the sound pulse passes into the flowing fluid 5. The flat front of the longitudinal sound wave is converted to a spherical front due to the refractive action of the focusing shell 8. For this requires that the sound velocity c in the fluid _YF 10 is less than the velocity of sound in the fluid with _GERD 5, spherical shell 8 and the radius R _{of LV} facing its convexity toward the liquid 5. Through this ƃ pulse is focused at a focal point located on the shell 8 in the region F _LV (Kanevskii IN Focusing sonic and ultrasonic waves -. M .: 1977)

The size of the focus area in the transverse (ΔF _false ) _⊥ and longitudinal (ΔF _false ) _|| directions equals

where Λ _lpr = Ω / s _lpr is the wavelength of sound in the fluid 5, characterized by the density ρ _lpr , d _p is the transverse size of the sound beam emitted from the buffer rod 2.

In order for the reflection of sound from the cladding 8 to be minimal and, therefore, the diffraction distortions of the sound wave front to be minimal, the conditions

where ρ _JL - liquid density 10; c _about - the speed of sound in the material of the shell 8 with a thickness of d _about , G _l - the reflection coefficient of sound from the surface of the shell 8. In this case, liquids 5 and 10 should minimize sound absorption at operating frequencies. These conditions are met by water used as flowing fluid 5, and ethyl or methyl alcohol or propyl iodide, used as fluid 10. As the material of the focusing shell 8, for example, plexiglass or polystyrene can be used.

A spherical sound wave propagates in the fluid 5 to the surface of the acoustic mirror 13, which directs the sound wave through the hole in the low-frequency sound emitter 14 into the hole in the outlet 7 for flowing fluid 5. The mirror 13 forms two parallel plates with a thin air gap between them. As the material of the plates, you can use aluminum, quartz or sapphire. Behind the hole in the outlet of the flowing fluid 7, a pulse of sound travels along the stream of flowing fluid 5 to the surface of the object 6. Moreover, it focuses in the region with transverse dimensions defined by expressions (2). To ensure focusing of sound on the surface of the object 6, the focusing shell 8 of the acoustic lens is moved along its axis using a precision motor (not shown in Fig. 1). The change in the volume of liquid 10 associated with the movement of the shell 8 is compensated by a corresponding change in the volume of the tank of the liquid thermostat 11 by moving the piston 12. The corrugated shell 9 prevents the mixing of liquids 5 and 10 during the movement of the shell 8.

To more accurately set the sound focus at a given point on the surface of the object 6 with the help of an acoustic mirror 13, the direction of emission and reception of ultrasonic waves is changed to some extent. This is done by rotating the mirror 13 around its first axis of rotation, coinciding with the axis of the acoustic lens 8, and a second axis of rotation perpendicular to the first axis. The rotation of the mirror 13 on both axes is provided by precision engines (not shown in FIG. 1).

If the sound pulse falls onto the surface of the object 6 vertically, then the reflected sound pulse returns to the buffer rod 2 along the same path. Reflecting from it, it again goes towards the object 6 along the same path. When taking measurements at the moment of reflection of the first pulse, a second pulse is emitted from the buffer rod 2. Moreover, in the generator 3, the amplitude and the moment of its radiation are precisely controlled from the ultrasound source 1. Since both pulses in liquid 10 move along the same trajectory with a flat front of the sound wave, they completely overlap each other, interfere in antiphase and suppress each other in this way.

In the case when the surface of the object 6 is located at an angle to the direction of propagation of the sound pulse incident on it, the reflected pulse returns to the buffer rod 2 along a different path. But even in this case, the sound wave moves in the liquid 10 with a flat front parallel to the axis of the acoustic lens 8. However, the first pulse reflected from the buffer rod 2 and the second pulse emitted from it overlap each other only partially. But they may not overlap if their transverse dimensions are small.

Therefore, in the invention, instead of combining sound pulses simultaneously in time and space, as in the known method (Kolesnikov AE Ultrasonic measurements. - M .: ed. Standartov, 1970, pp. 62-70), the combination of optical images of sound pulses is used. For this, the phenomenon of transformation of the amplitude-phase parameters of the sound beam into the amplitude-phase parameters of diaphragmed tape light beams is used. Diaphragmed light beams are generated when a tape beam of monochromatic coherent light passes through a liquid parallel to the front of the sound wave. This phenomenon is called acousto-optical Riemann-Nat diffraction. The invention uses first-order diaphragmed light beams (m = ± 1), because their amplitude and phase are proportional to the integral value of the amplitude and phase of the sound wave in the direction of passage of the tape light beam. The diaphragmed beams are emitted in the form of tape light beams at an angle θ = ± λ / Λ to the incident light beam, where λ and Λ are the wavelengths of light and sound, respectively. When using water as a flowing fluid 5 having n _zpr = 1.33, with _zpr = 1.49 · 10 ³ m / s, ρ _zpr = 1.0 g / cm ³ , it is advisable to use liquid to fill the volume of acoustic lens 8 10, characterized by low sound loss and a wave impedance value of ρ _j · s _jl at frequencies of 1-60 MHz, comparable with the wave impedance of water, as well as a high relative coefficient of acousto-optical quality M (coefficient M is determined relative to the coefficient of acousto-optical quality of quartz). Such requirements are satisfied, for example, ethyl alcohol with M = 415, n _jl = 1.37, c _jl = 1.15 · 10 ³ m / s, ρ _jl = 0.79 g / cm ³ and iodide propyl with M = 1240 , n _LC = 1.51, c _LC = 0.93 · 10 ³ m / s, ρ _LC = 0.84 g / cm ³ . Note that the use of iodide propyl in the acousto-optical system allows us to realize the dynamic sensitivity range of the proposed device above 80 dB. Therefore, the use in the device of the inverse transformation of sound energy into electrical energy using piezoelectric 1 can only be considered as an auxiliary tool, because the dynamic sensitivity range implemented in this case does not exceed 40 dB.

As an example illustrating the measurement method proposed in the invention, we consider the case when two sound beams having a square section d _p × d _p propagate in the liquid 10 in the same direction parallel to the axis of the acoustic lens 8 (along the x coordinate) (see also FIG. 2 and 3). The axis of the first sound beam coincides with the axis of the acoustic lens 8, and the axis of the second sound beam is shifted by d _z in the propagation direction (along the z coordinate) of the incident light beam incident on the sound beams and by d _y in the transverse direction (along the y coordinate). For the first sound beam, the initial phase of the sound wave is ψ ₀₁ , and for the second - ψ ₀₂ . A beam of light hits the sound beams parallel to the front of their density wave. According to (Balakshiy V.I., Parygin V.N., Chirkov L.E. Physical foundations of acousto-optics. - M .: Radio and communications, 1985) its field has the form E _E (x, y, z) = E _E0 exp {j [v · tk · z]}, where k = 2π / λ, | x | ≤Δ _E / 2, | y | ≤L _E / 2 for L _E > Max2 (d _p + | d _y |). The field of the light beam passing through the sound beams has the form E _E (x, y, z) = E _Е0 exp {j [ν · tk · z-ψ (t, x, y, z)]}, where Ψ is the phase light field. Phase Ψ is determined by a change in the refractive index of the liquid n _jins within the front of the sound wave. For the case when the wavefront of one sound beam partially overlaps with the wavefront of another beam, the phase Ψ in the plane z ₀ = d _p + d _{z is} described by the expression

Here, for the portion of the wave front of the first sound beam that does not overlap with the wave front of the second sound beam, i.e. when - d _p / 2≤y ₀ ≤d _y -d _p / 2, we have

for the section of the wave front of the second sound beam that does not overlap with the wave front of the first sound beam, i.e. when d _p / 2≤y ₀ ≤d _y + d _p / 2, we have

and for sections of the front of sound waves of the first and second beams superimposed on each other, i.e. when d _y -d _p / 2≤y ₀ ≤d _p / 2, we have

In this case, in the plane z ₀ = d _p + d _{z the} field of diaphragmed light beams of the mth order is given by the expression

where J _m (μ) is the Bessel function of the first kind, Δ _{Ex (m)} = Δ _Ex + mλ (d _p + | d _z |) / Λ _l is the width of the m-th diaphragmed light beam, - Δ _{Ex (m)} / 2≤x ₀ ≤Δ _{Ex (m)} / 2, K = 2π / Λ _l .

It follows from (5) - (10) that the distribution of the amplitude and phase of light in diffraction light beams, primarily of the first order, reflects the distribution of the amplitude and phase of density waves in sound beams. Moreover, this display occurs only in the direction transverse to the direction of light propagation (in this case, along the y axis).

, описываемое (10), совпадает с передней фокальной плоскостью круглой тонкой линзы, а пространственно-спектральное изображение поля диафрагмированных световых пучков U(x, у) формируется в задней фокальной плоскости линзы z=2F_л+z₀. Если воспользоваться формулой Френеля и передаточной функцией тонкой сферической оптической линзы, то поля диафрагмированных световых пучков в передней и задней фокальных плоскостях этой линзы связываются функцией видаThe case of interest to us — the spatial spectral mapping of the interference of density waves of two sound beams that do not overlap each other (for d _z > d _p and d _y > d _p ) —we obtain if we pass the diaphragmed beams through an optical focusing spherical lens. We assume that the plane z ₀ = (d _p + d _z ), in which the field of diaphragmed light beams is formed

described by (10) coincides with the front focal plane of a circular thin lens, and a spatially spectral image of the field of diaphragmed light beams U (x, y) is formed in the rear focal plane of the lens z = 2F _l + z ₀ . If we use the Fresnel formula and the transfer function of a thin spherical optical lens, then the fields of diaphragmed light beams in the front and rear focal planes of this lens are connected by a function of the form

Substituting (10) into (11), for the case of interest to us, we have

where the notation is used: sinc ζ = (sinζ) / ζ.

It follows from (12) that the field intensity maxima of the diaphragmed light beams are located at the side focal points of the optical lens along a line parallel to the axis of the acoustic lens (x axis), in the form of luminous spots of a rectangular shape. Spot centers are at points

and their transverse dimensions σ _{Fу (m)} (along the y axis) and σ _{Fx (m)} (along the x axis) are equal

So that the field spots of diaphragmed beams with adjacent indices m, for example m = 0 and m = ± 1, do not overlap each other, it is necessary to have Δ _Ex > Λ _l / 2.

To process information on the optical display of the interference of two sound beams in a computing device, it is necessary to measure the light intensity in the spots of diaphragmed beams, preferably with an index m = ± 1, measure using a photodetector, the current in which i _{d is} proportional

where δ _d × δ _d is the transverse size of the photodetector, satisfying δ _d << σ _{Fу (m)} and δ _d << σ _{Fх (m)} . Using (12) and taking into account sinc (πd _п δ _d / λF _l ) ≈sinc (πΔ _Ex δ _d / λF _l ) ≈1, we have

By choosing the optimal operating parameters and dimensions of the structural elements of the proposed device, it is possible to provide sinc (πd _y δ _d / λF _l ) ≈1. Then, when two conditions are satisfied: μ ₁ = μ ₂ is the equality of the amplitudes of the sound waves for both sound pulses and ψ ₀₂ -ψ ₀₁ = π is the antiphase superposition of their optical images, it follows from (15) that i _d = 0. Thus, the required technical problem has been solved - observation of the interference of two sound beams by means of the interference of their optical images both when the sound beams overlap in space (d _y = 0) and when they do not overlap in space on a friend (d _y ≠ 0).

To register the spatial position of sound beams relative to the axis of the acoustic lens, diaphragmed beams must be passed through cylindrical optical lenses. Using the transfer function of a thin cylindrical lens, the fields of diaphragmed light beams in the front and rear focal planes of this lens are connected by a function of the form

Substituting (16) into (17), we have

Where

In order to process the optical display of the spatial position of two sound beams in an optical display device, it is necessary to distribute the light intensity of diaphragmed beams with index m = ± 1 along the focal lines of a cylindrical lens using a photodetector whose current i _d , according to (15), is proportional

Thus, the required technical problem has been solved - the observation of the optical display of the spatial position of two sound beams both in the case when the sound beams overlap in space (d _y = 0) and in the case when they do not overlap in space ( d _y ≠ 0).

To create optical images of direct and reflected sound beams, an acousto-optical system for forming optical images of sound beams is used. This system works as follows. The light of a monochromatic coherent source 16 with the help of beam splitting mirrors 17, 18 and reflecting mirrors 19, 20 is divided into two beams of light, which diaphragms 21, 22 are formed in the form of two tape light beams. These light beams are passed through a liquid 10 through two acousto-optical channels 23 and 24 located in the same plane perpendicular to each other and also perpendicular to the axis of the acoustic lens 8. For this, the mirrors 17 and 18 located on a common optical axis are rotated relative to each other 90 °, and using mirrors 19 and 20, the direction of propagation of one of the light beams is rotated through an angle of 180 °.

In each acousto-optical channel 23, 24, a part of the luminous flux of the diaphragmed light beams is directed through beam-splitting mirrors 29 to integrating spherical optical lenses 25 or 26. The photodetector lines 27 and 28 installed in the side focal points of these lenses (see Fig. 2 and Fig. 3) perceive optical signals that display interference about the optical images of sound beams. In order for the photodetectors 27, 28 to display the light spots of the first-order diaphragmed beams when the generator 3 is operating at frequencies Ω = n ω that are multiples of the frequency ω, the photodiodes in them are arranged with a step of nλF _{л 1} / Λ _{0 ж} , where F _{1 1} is the focal length of the lenses 25, 26, Λ _awl - the sound wavelength at the frequency ω.

The necessary data on the spatial position of the sound beams relative to the axis of the acoustic lens 8 are recorded in both acousto-optical channels 23, 24 using cylindrical optical lenses 31, 32. For this, the second part of the light flux of the diaphragmed beams is directed to these lenses through beam-splitting 29 and reflecting 30 mirrors. The diaphragmed light beams are focused in cylindrical lenses 31, 32 in their focal lines. The distribution of light intensity along the focal lines is perceived by the corresponding lines of photodetectors 33, 34. The number of lines 33 and 34 in accordance with the number of diaphragmed beams analyzed is 2n. In order for the lines 33, 34 to be aligned with the light spots of the diaphragmed beams, they are arranged with a step of nλF _lo2 / Λ _0l , where F _Lo2 is the focal length of the lenses 31, 32. The number of photodiodes in the lines 33, 34 is selected from the condition of achieving maximum accuracy when determining sizes optical images of sound beams. It is limited by existing technological capabilities when creating lines of photodiodes with a minimum pixel resolution. Currently, a pixel resolution of 5 μm is obtained.

When measuring the linear displacement of object 6, the data required in this case about the distance between the focusing shell 8 and the buffer rod 2 are determined with high accuracy using a white light measuring system. The monochromatic light measuring interferometer formed by the beam splitting mirrors 37, 38 included in this system, as well as the reference white light interferometer formed by the beam splitting mirrors 41, 42, and the working white light interferometer formed by the beam splitting mirrors 42, 43, are located in the same optical environment, for example in the air. Moreover, the distance between the mirrors 37, 38 is always equal to the distance between the mirrors 41, 42, because the mirrors 37 and 41, which are part of the movable unit, move synchronously. The distance L _SL between the shell 8 and the buffer rod 2 is associated with the distance L _pp between the mirrors 42, 43 in the working white light interferometer through the proportionality coefficient k determined by the design parameters of the device, i.e.

The measuring system of white light works as follows. In the initial state, the distance between the mirrors 37 and 38, equal to the distance L _op between the mirrors 41 and 42, is set to a minimum. After that, the focusing shell 8 is moved to a position that provides focusing of the sound pulses on the surface of the object 6. This moment is fixed in both acousto-optical channels 23, 24 at the minimum transverse size of the optical image of the sound pulse reflected from the object 6 using the lines of the photodiodes 31 and 32. This information is transmitted from the photodiodes to the computing device 46 for further processing.

Since, in this case, the optical path lengths of the white light beam between the reference mirrors 41, 42 and the working white interferometers mirrors 42, 43 are not the same, different spectra of white light are formed in these resonators due to multiple reflections. Because of this, white light does not exit through the mirror 43. The movable block of the mirrors 37 and 41 is moved until the distance between the mirrors 41, 42 in the reference interferometer becomes equal to the distance between the mirrors 42, 43 in the working white light interferometer. Since the optical paths of white light in these interferometers become the same, the spectrograms of white light beams formed in them will be the same. Due to this, a white light beam exits through the mirror 43 and enters the photodetector 45, the electric signal from which enters the computing device 46. Thus, in this device, the starting point of the distance between the focusing shell 8 and the buffer rod 2 is noted (see Fig. 7 ) The movable block of mirrors 37, 41 continues to move in the same direction until the distance L _op between the mirrors 41, 42 in the reference white light interferometer becomes equal to twice the distance between the mirrors 42, 43 in the working white light interferometer, i.e. L _op = 2 L _pp . At this moment, between the mirrors 42, 43 the first side maximum spectrum of white light is formed (see Fig. 7).

In the movable unit, when moving the mirror 41 in the reference white light interferometer, the mirror 37 in the measuring interferometer of monochromatic light moves synchronously. In it, due to the multipath interference of a monochromatic light beam, periodically, in accordance with a change in the distance between the mirrors by λ / 2, monochromatic light through the mirror 38 enters the photodetector 40. Therefore, synchronously with the movement of the mirrors 37 and 41 between the start and end points to the computational device 46 receives n ₀ electric pulses from the photodetector 40. As a result, in the device 46, up to λ / 2 is determined by the change in the distance between the mirrors 41 and 42 and thereby determines the magnitude ne emescheniya envelope 8 focusing the acoustic mirror. This calculation is carried out according to the formula

Processing in the computing device 46 the data obtained from the photodetectors 24, 25 and 30, 31 on the interference of the optical images of sound beams and their spatial position allows, together with the calculation data according to (22), to calculate the linear displacement and angle α / 2 of the inclination of the surface of the object 6 (see Fig. 8).

When deriving the calculation formula, the condition

where L _BSL is the sound path between the top of the focusing shell 8 and the end of the buffer rod 2, determined by the formula (22); L _lop - the sound path from the top of the focusing shell 8 to the surface of the object 6; L _loo - the sound path from the surface of the object 6 to the refraction point of the reflected sound beam on the focusing shell 8; T is the time interval corresponding to the moment of suppression of two sound pulses traveling in one direction by changing the amplitude and the time interval between the pulses of high-frequency oscillations in the generator, while at this time the first sound pulse reflected once from object 6 and buffer rod 2, and the second pulse radiated from buffer rod 2; p = s _zl / s _zpr ; ΔL _l is the sound path between the vertex and the plane intersecting the focusing shell 8 at the refraction point of the reflected sound beam, determined by the formula

Given that

,

,

the calculation of L _lop value is carried out according to the formula

Where

The calculation of the angle α is carried out according to the formula

In expressions (25), (26), the accuracy of the job L _LFL is λ / 2, the accuracy of the job Δd _p , limited by the pixel resolution of the photodetector lines 33, 34, is ~ 10 ^-4 . Therefore, the error in calculating the value of L _lop is determined by the accuracy of setting the value of T, which is determined by the hardware capabilities of measuring time intervals. Currently, using modern logical elements of computer technology, it is quite achievable to determine the value of T with an accuracy of 10 ^-9 sec.

The linear displacement and the angle of the object are measured optically using the device shown in Fig. 4. In this device, the measurement is carried out by the method of interference of two monochromatic light beams, one of which is focused in the working optical channel on the surface of the test object 6, and the other in the reference optical channel on the surface of the reference mirror 50. The operation of the proposed device begins with the second measuring white light systems. For this, the mirrors 59, 60 and 61, located in the movable unit of the third measuring white light system, are displayed outside the working optical channel, as well as outside the second working multi-beam white light interferometer (mirrors 53, 54). The minimum distance between the mirrors 37 and 38 is set in the measuring interferometer of monochromatic light. At the same time, the minimum distances equal to the minimum distance between the mirrors 37, 38 are established between the mirrors 52, 53 in the second reference white light interferometer and between the mirrors 53, 54 in the second working white light interferometer, because they synchronously move with the mirrors 37, 38. B In this case, the optical path lengths of the white light beams between the mirrors 52, 53 and 53, 54 are the same, therefore, the same white light spectrograms are formed between them. By virtue of this, white light exits through the mirror 54 and, reflected from the mirror 57, enters the photodetector 58 connected to the computing device 46. This marks the starting point in the procedure for moving the optical focusing system 49.

Then, the optical focus is adjusted on the surface of the object 6 using monochromatic light. On the second beam splitting mirror 13 (playing the role of an optical mirror with a discretely changing light reflection coefficient), a portion with a transparent coating is installed. A movable mirror 51 is introduced into the working optical channel. Then the radiation of the monochromatic source 16 is directed through the mirrors 17 and 51 to the working optical channel. The monochromatic light beam passes through the first beam splitter mirror 47, the optical focusing system 49 and the transparent portion of the second beam splitter mirror 13 to the surface of the object 6 and, reflected from it, passes in the opposite direction to the mirror 47, which directs the reflected light beam to the matrix photodetector 62. B a computing device 46 connected to the matrix 62, fixes the position and the transverse size of the light spot of the light beam reflected from the object 6.

After that, the optical focusing system 49 is moved along the axis of the working optical channel until the transverse size of the light spot of the light beam reflected from the object 6 becomes minimal on the matrix photodetector 62. This corresponds to setting the focus of the focusing system 49 on the surface of the object 6.

In the next operation, the reference mirror 50 is pre-installed in the working position. For this, a mirror-coated area is installed on the second beam splitter mirror 13. In this case, the monochromatic light beam passes through the first beam splitter mirror 47, the optical focusing system 49, and, reflected from the mirror 13, passes to the mirror 50. Having reflected from it, passes in the opposite direction to the mirror 47, which directs the reflected light beam to the photodetector 62 By movements of the mirror 50 by moving along the axis of the reference optical channel and rotation around this axis, light spots of light beams reflected from the surface of the object 6 and from the mirror 50 are combined, and then they are reduced operechny spot size of the light beam reflected from the mirror 50. This is performed automatically by the calculation unit 46 connected to the photodetector matrix 62 and controls the operation of the respective motors.

In the next series of operations, firstly, the measurement of the displacement of the optical focusing system 49 is performed. Secondly, the measurement of the optical path length of white light between the input point and the output point on the beam splitter mirror 59 for the light beam reflected from object 6 and for the beam light reflected from the mirror 50. Thirdly, the mirror 50 is installed in the final working position due to additional movements. This corresponds to the equality of the lengths of the optical path of white light between the input point and the output point on the mirror 59 for the beam of light reflected from the object 6 and for the beam of light reflected from the mirror 50. To this end, the movable mirror 51 is removed from the working optical channel. The movable mirror 52 in the second reference white light interferometer synchronously moves until the same white light spectrograms are formed between its mirrors 52 and 53 and the mirrors 53 and 54 of the second working white light interferometer. Then the white light beam again exits through the mirror 54 and, reflected from the mirror 57, enters the photodetector 58. Since the movable mirror 37 in the measuring interferometer of monochromatic light synchronously moves with the mirror 52, pulsed electrical signals are received simultaneously from the mirrors from the computing device 46 with the mirrors moving photodetector 40. As a result, a change in the distance between the mirrors 53 and 54 is determined in the device 46 with an accuracy of λ / 2, and thereby the amount of displacement of the optical focusing system 49 is determined.

At the next stage, the mirrors 59 and 61 of the movable unit are introduced into the working optical channel, the mirror 60 of this unit is inserted between the mirrors 53, 54 in the second working white light interferometer. To measure the length of the optical path between the input point and the output point on the mirror 59 for a beam of light reflected from the object 6, a section with a transparent coating is installed on the second beam splitting mirror 13. The mirror 52 is set to its initial state, corresponding to the minimum distance between the mirrors 52 and 53. Then, the mirror 52 moves synchronously with the mirror 37 until the same spectrograms of white are formed between its mirrors 52, 53, and also between the mirror 59 and the surface of the object 6 Sveta. In this case, the white light beam exits through the mirror 59 and through the beam splitting mirror 61, reflected from the mirror 47, enters the matrix photodetector 62. Since the mirror 37 moves synchronously with the mirror 52, the desired optical length is determined in the device 46 with an accuracy of λ / 2 trajectories.

To measure the length of the optical path between the input point and the output point on the mirror 59 for a beam of light reflected from the reference mirror 50, a portion with a reflective coating is installed on the second beam splitting mirror 13. The mirror 52 is set to its original state, and then it and the mirror 37 move synchronously until the same white light spectrograms are formed between its mirrors 52, 53, and also between the mirror 59 and the mirror 50. In this case, the white light beam exits through the mirror 59 and through the beam splitting mirror 61, reflected from the mirror 47, enters the matrix photodetector 62. Since the mirror 37 moves synchronously with the mirror 52, the desired optical length is determined in the device 46 with an accuracy of λ / 2 trajectories.

If the lengths of the optical path between the input point and the output point on the mirror 59 for the light beams reflected from the mirror 50 and from the object 6 do not coincide, then this equality is achieved by additional motions of the mirror 50.

Upon completion of the measurement data, an operation is performed to measure the surface profile of the object 6. For this, a section with a beam splitting coating is installed on the second beam splitting mirror 13. A movable mirror 51 is introduced into the working optical channel, and the radiation of the monochromatic source 16 is directed through the mirrors 17 and 51 into this channel. The monochromatic light beam passes through the first beam splitter mirror 47, the optical focusing system 49 and the beam splitter section of the mirror 13 to the surface of the object 6 and passes in the opposite direction to the mirror 47, which directs the reflected light beam to the matrix photodetector 62. At the same time, part of the light flux reflected from the mirror 13 passes to the reference mirror 50, and then passes in the opposite direction to the mirror 47, which directs the reflected light beam to the array photodetector 62. On the array photodetector 62 the two beams of light interfere. In the computing device 46, the interference pattern is fixed, according to which the geometric parameters are calculated for the surface profile of the object 6 in accordance with the working methods (Vasiliev V.N., Gurov I.P. Computer signal processing as applied to interferometric systems. - SPb .: BHV - St. Petersburg, 1998). The same device also calculates the distance from the focusing optical system 48 to the object 6 and the angle α / 2 of the inclination of the surface of the object relative to the axis of the working optical channel.

For the case when a glass spherical lens of radius R _l with a refractive index of glass n _{l is} used as the focusing optical system 48, the following condition was used to derive the calculation formula

where ΔL _LZ - light path between the top casing 8 and the focusing mirror 59, defined by the formula (22); L _lop - the light path from the top of the focusing lens 48 to the surface of the object 6; L _loo - the light path from the surface of the object 6 to the refraction point of the reflected sound beam on the surface of the focusing lens 8; L _loo - the light path between the mirrors 52, 53; p = n _lpr / n _l ; ΔL _l - the light path between the apex of the lens 48 and the plane crossing its surface at the point of refraction of the reflected light beam, determined by the formula

Given that

,

,

the calculation of L _lop value is carried out according to the formula

Where

In the expressions (25), (26) the precision reference ΔL _LZ is λ / 2; the accuracy of the job L _op is λ / 2; the accuracy of the task Δd _p , limited by the pixel resolution of the matrix of photo receivers 62, is ~ 10 ^-4 . Therefore, the error in calculating the value of L _Lop is ~ λ / 2.

Flaw detection of cracks, voids and seals in the optically opaque material of the object under study can be carried out using the devices in figure 1 and figure 4. For this, the same principles of work and methods are used as when measuring linear displacements. The only difference is that the sound beam is focused inside the material of the object. If one device is used, then the flaw detector is carried out in the mode of reflected sound pulses. If two or more devices are used, then the flaw detection can be carried out simultaneously in the modes of translucent and reflected sound pulses. But when using reflected pulses, greater sensitivity is achieved, which allows you to detect defects that reflect only 5% of sound energy. The ability to use high frequencies, 1-60 MHz, provides a resolution of up to 0.1 mm ² .

Great opportunities in the study of the configurations of several internal defects or in the construction of two-dimensional images of the cross sections of object 6 appear when using a complex of several proposed devices operating at different frequencies, each of which can simultaneously operate at several multiple frequencies. Due to the transmission of sound to the object through a stream of flowing fluid 5, they can be located at different points of the object 6 at different angles to its surface. In this case, you can use the scanning direction of propagation of sound pulses using a movable acoustic mirror 13. These technical capabilities allow the use of modern computational methods for processing complex signals, which eliminate the influence of spurious echo pulses, the manifestation of refraction during the propagation of sound in the material of an object, and device-dependent ultrasonic distortions signal. This is especially important when using the proposed device in medical ultrasound tomographs both for the study of soft tissues of the body, and for the early diagnosis of diseases of the brain.

Using the proposed device in figure 1 and figure 4, you can measure the frequency and amplitude of vibration of the surface of the object. Using a high-frequency sound source 1, the measurement data is carried out through a stream of flowing fluid 5 in two ways. The first method consists in measuring the propagation time of sound between the object 6 and the acoustic focusing lens 8. In this case, using the acousto-optic system that generates optical images of sound beams, the moments of propagation of the emitted and reflected sound pulses are recorded in the computing device 46, according to which spectral analysis of vibration is performed . The repetition rate of sound pulses should be significantly higher than the vibration frequency, but in this case, in the intervals between two emitted pulses, conditions should be provided for the attenuation of reflected pulses, in particular from buffer rod 2. To increase the resolution of the spectral analysis of vibrations, the second method is used, which consists in measuring the spectrum beat frequencies during interference of reflected and emitted sound signals using an acousto-optical system. These beats occur due to the Doppler frequency shift of the reflected signal relative to the frequency of the emitted signal, equal to the vibration frequency.

At large roughnesses of the surface of the object due to scattering of the reflected sound signal, measurements are carried out at lower sound frequencies, 10-500 kHz, using a low-frequency sound emitter-receiver 14, which accepts both longitudinal and volume sound waves that effectively transmit low-frequency vibration of the surface of the object 6. For the manufacture of the emitter / receiver, you can use high-performance piezoelectrics, for example, piezoceramics from barium titanate (BaTiO ₃ ). Measurements can be carried out continuously during operation of the generator in the device 15 with a linear change in frequency. In this case, the vibration parameters are transmitted through the switch and the indicator in the device 15 to the computing device 46 in the form of beats arising due to the Doppler frequency shift between the emitted and reflected signals.

When measuring physical and technical parameters of a stationary or inactive object in the proposed device to reduce the flow rate of the flowing fluid 5, cuffs are used, which are installed on the output 7 for the flowing fluid 5 (FIG. 5 and FIG. 6). For example, a cuff having vacuum suction cups on the contact end surface of the housing (Fig. 6) works as follows. A cuff is selected, the contacting surface of which has a shape corresponding to the shape of the surface of the object 6. The cuff is mounted on terminal 7, and the pump is connected to the nozzle 67 through a hose. The cuff is pressed against the surface of the object 6, and the pump is turned on. After suctioning the cuff, the measuring device is installed at the required angle to the surface of the object 6 due to the action of the corrugation 63, and then flowing liquid 5 is fed into it through the inlet 4.

Claims (15)

1. A device for non-contact measurement of the physical and technical parameters of an object, comprising a housing with an input and output for flowing liquid and a high-frequency ultrasonic emitter located in it, including a buffer rod and a piezoelectric plate with electrodes fixed to it for connecting to an external high-frequency generator, characterized in that it contains an acoustic lens located in the housing and configured to move along its axis to focus the sound signal on the object, an akus an optical optic shaper of an optical image of sound signals with two acousto-optic channels, an acoustic lens displacement meter, a computing device, while an acousto-optical shaper of an optical image of sound signals includes a monochromatic coherent radiation source, the first optical system consisting of lenses and mirrors for generating working light beams in the acousto-optical channels in which the axes are located in the same plane perpendicular to each other and pass between the buffer it and an acoustic lens through the region of propagation of sound signals to generate diaphragmed light beams, a second optical system consisting of mirrors for separating diaphragmed light beams of the working light beam in each acousto-optic channel into first and second diaphragmed light streams, spherical lenses for integrating each first diaphragmed light beam focal points and cylindrical lenses to integrate every second diaphragmed light flux into okusnye lines, photodetectors installed behind spherical and cylindrical lenses, respectively, while photodetectors and an acoustic lens displacement meter are connected to a computing device, and the body volume is divided into two isolated cavities, the first of which is located between the buffer rod and the acoustic lens, and the second between an acoustic lens and an outlet for flowing fluid, while the first cavity is designed to fill with liquid with a high coefficient of acousto-optical quality, and the second To fill fluid flow. 2. The device according to claim 1, characterized in that the acoustic lens displacement meter is a first white light measuring system including a monochromatic light channel with a monochromatic coherent light source and a Fabry-Perot measuring monochromatic light interferometer, in which at least one of beam-splitting mirrors is made movable, and the white light channel with a white coherent light source and white and working reference interferometers installed in series along the channel about Fabry-Perot light, in which at least one of the beam splitting mirrors is movable, while the moving beam splitting mirror of the working white light interferometer is mounted on an acoustic lens, and the moving mirrors in the reference white light interferometer and in the measuring monochromatic light interferometer are made with the possibility of synchronous movement. 3. The device according to claim 1, characterized in that it contains an acoustic mirror for changing the direction of the sound signal located in the second cavity of the housing on the axis of the acoustic lens and made to rotate around two axes, the first of which is the axis of the acoustic lens, and the second axis perpendicular to the first. 4. The device according to claim 1, characterized in that it contains a low-frequency sound emitter-receiver, made in the form of a plate or cylinder or a focusing mirror with a hole in the center and with electrodes for connection with a generator or indicator, while the low-frequency sound emitter-receiver is located in the second cavity of the housing on the propagation path of the sound signal before the output for the flowing fluid. 5. The device according to claim 3, characterized in that it contains a measuring optical system such as a Zakharyevsky-Miro interferometer, comprising a first beam splitter mirror and a photocell array located outside the housing, a second beam splitter mirror and a reference mirror located in the second cavity of the housing, optical focusing a system integrated into the wall wall of the second cavity, the first and second beam splitting mirrors and the optical focusing system located between them form a working optical the axis, the axis of which passes through the acoustic mirror and the outlet for flowing fluid, while the mirrors are mounted at an angle of 45 ° to the axis of the working optical channel, and the second beam splitting mirror and the reference mirror form a reference optical channel, the axis of which is perpendicular to the axis of the working optical channel, The acoustic mirror is made of optically transparent material. 6. The device according to claim 5, characterized in that the second beam splitting mirror, the reference mirror and the optical focusing system are movable, while the optical focusing system is movable along the axis of the working optical channel, the second beam splitting mirror has three sections with a transparent surface , with a beam splitting and mirror coating and is made with the ability to move perpendicular to the axis of the working optical channel to provide discrete switching of its reflection coefficient and the reference mirror is made with the possibility of movement along the axis of the reference optical channel, rotation around this axis, as well as rotation around an axis perpendicular to the axis of the reference optical channel. 7. The device according to claim 5, characterized in that the working optical channel is connected to a source of monochromatic coherent light of an acousto-optic shaper of an optical image of sound signals or provided with a separate source of monochromatic coherent light. 8. The device according to claim 5, characterized in that an acoustic mirror is used as the second beam splitting mirror. 9. The device according to claim 6, characterized in that it contains a second measuring system of white light for measuring the movement of the focusing optical system, comprising a channel of monochromatic light with a source of monochromatic coherent light and a measuring Fabry-Perot monochromatic light interferometer, in which at least one of the beam splitting mirrors is movable, and the white light channel with a white coherent light source and supporting and working interferometers installed in series along the channel white Fabry-Perot, in which at least one of the beam splitting mirrors is movable, while the moving beam splitting mirror of the working white interferometer is mounted on the optical focusing system, and the moving mirrors in the reference white light interferometer and in the measuring monochromatic light interferometer are made with the possibility of synchronous movement. 10. The device according to claim 6, characterized in that in the second measuring system of white light sources of monochromatic coherent light and white coherent light use sources of monochromatic coherent light and white coherent light of the first measuring white light system. 11. The device according to claim 6, characterized in that it comprises a third white light measuring system for measuring the optical lengths of the reference and working optical channels, including a monochromatic light channel with a monochromatic coherent light source and a Fabry-Perot measuring monochromatic light interferometer, in which at least one of the beam splitting mirrors is movable, and the white light channel with a white coherent light source and supporting and working interferences installed in series along the channel White Fabry-Perot white light meters, in which at least one of the beam splitting mirrors is movable, while the working white interferometer uses either the surface of the object or the reference mirror as the moving mirror and the moving mirrors in the white light reference interferometer and in the measuring interferometer of monochromatic light made with the possibility of synchronous movement. 12. The device according to claim 11, characterized in that in the third measuring system of white light sources of monochromatic coherent light and white coherent light use sources of monochromatic coherent light and white coherent light of the first measuring white light system or the second measuring white light system. 13. The device according to any one of claims 1 to 12, characterized in that it contains a cuff in the form of a pipe to reduce the flow of flowing fluid, in which part of the housing is corrugated, and the end surface of the housing in contact with the test object has a shape corresponding to the shape of the surface of the object . 14. The device according to item 13, wherein the cuff is equipped with a brush of elastic pins mounted on the end surface of the housing in contact with the object. 15. The device according to p. 13, characterized in that the cuff is equipped with vacuum suction cups mounted on the end surface of the housing in contact with the object, the exhaust fitting and pneumatic channels in the walls of the housing connecting the vacuum suction cups with the exhaust fitting.

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