SU1474551A1 - Method and apparatus for measuring speed of diffusion-dispersion objects - Google Patents

Abstract

This invention relates to a measurement technique and is intended to measure the velocity vector of flat illumination of diffuse objects in biology, medicine, and other applied fields of optical and physical research. Diffuse object A is illuminated by coherent radiation. Diffuse speckle — the field is spatially separated by an amplitude beam splitter and two-channel photoelectric recording of the optical signal is performed. After dividing, the speckle-field component is divided into different, mainly orthogonal directions in the plane of the object, while measuring the velocity of the speckle-structure by the number of fluctuations of the amplitude of the electrical signal per unit time. From the measured values of the velocity modulus in the absence of scanning and during scanning, the direction of the velocity vector is determined by calculation. An apparatus for carrying out the method comprises a source of specific radiation 1, a lens 2, an amplitude beam splitter 3, a first and a second optical scanners 4.5, a two-channel photoreceiver unit 6.6, b 7.7, b an electronic signal processing unit 8. 1 Cp. f., 2 ill.

Description

The invention relates to a measurement technique and can be used to study mobile diffuse reflecting objects in biology, medicine, and other applied areas of optical and physical measurements.

The purpose of the invention is to expand the functionality of the method by determining the direction of the velocity vector.

1 shows a block diagram of a device implementing the proposed method; FIG. 2 shows vector diagrams for the measurement method.

.

The device for measuring the speed of movement of diffuse-scattering objects contains a source 1 of coherent radiation j, lens 2, amplitude beam splitter 3, first 4 and second 5 optical scanners, photoreceiver unit 6, b, equipped with field diaphragms 7, electronic unit 8 for signal processing.

The method is carried out as follows.

The investigated diffuse object A is illuminated with coherent radiation in the direction perpendicular to the plane of motion of the object. The radiation scattered by the object, which is a speckle-field, is amplitude-divided.

Zo recorded in each of the channels of the photodetector unit, by counting the number of fluctuations of the speckle-floor per unit of time. In the absence of scanning, the magnitude of the velocity modulus | V | is determined. When scanning the speckle field in different directions X, Y (for example, X I Y) are determined

35

speed modules V., and IVal. Based on the measured values of the speeds, they are determined by the beam splitter 3, alternately or parallelly scanning the spatially separated speckle-field in two orthogonal directions X, Y in the plane perpendicular to the direction of illumination. Scattered at a fixed point, determined by the formula (1) the direction determined by the aperture of the lens 2 and the velocity vector, aperture 7.7 of the field of view, a photodetector unit 6.6, a speckle-field, the formula will go in the photodetector unit. The number of speckle structures observed in field 45 of the photodetector unit is directly proportional to the speed of movement.

the invention

speckle floor V M L /, where V0 - speed1. The method of measuring the speed of movement of diffuse-scattering objects, including the illumination of an object with coherent radiation, scanning the object's magnitude, M is the linear increased scattered objective speckle of the objective 2. The change in the intensity of the plane orthogonal to the direction of the speckle field in the plane of the diaphragms illumination, the photoelectric register is 7S7 converted into electrical signals, with the number of fluctuations

scattered speckle-field and determining the speed modulus of the speckle by the fluctuation cycle of the intensity of the scattered speckle-field per unit of time, according to which the velocity of the object, which is different in that

The electrical signal per unit of time is determined by the electronic unit 8. Scanning of the components of the speckle-field is carried out at predetermined cTV speeds (for example, in the X direction). and fVa (in the Y direction).

In the absence of scanning, the speed of movement of the speckle field is equal to (Fig.2). When scanning, the components of the speckle field move with the speeds V, V + (and V –h V + rfV2. The direction of the velocity vector is determined, for example, by calculating the angle at from the following relation

ten

tgc (

 .Ll -iЈV4 (1) v7i trfv7i2

The device works as follows.

) 5 The radiation from a coherent source 1 is directed to a moving diffuse object A. The diffuse speckle-field is split in two by an amplitude beam splitter 3 and sent to a two-channel Q2 photodetector unit 6.6, the optical inputs of which (field apertures 7.7) are optically matched to the outputs of the beam splitter through the first 4 and second 5 scanners.

25 The electrical signal from the output of the photodetector unit is fed to the input of the electronic unit 8 signal processing. Block 8 performs the determination of the velocity modulus IV-I speckle-field,

Zo recorded in each of the channels of the photodetector unit, by counting the number of fluctuations of the speckle-floor per unit of time. In the absence of scanning, the magnitude of the velocity modulus | V | is determined. When scanning the speckle field in different directions X, Y (for example, X I Y) are determined

35

speed modules V., and IVal. According to the measured values of the velocity m, it is determined by formula (1) the direction of the velocity vector, Formula 45

le (1) direction and,

the invention

1. A method of measuring the speed of movement of diffuse-scattering objects, including the illumination of an object with coherent radiation, scanning the obtained scattered speckle-field in a plane orthogonal to the direction of illumination, photoelectric register

scattered speckle-field and determining the speed modulus of the speckle by the fluctuation cycle of the intensity of the scattered speckle-field per unit of time, according to which the velocity of the object, which is different in that

by determining the direction of the velocity vector, the obtained speckle-field is additionally amplitude separated, scanning, photoelectric recording and determining the velocity modulus, the speckle-field is produced over the spatially separated components of the speckle-field in the absence and presence of scanning, and spatially separated The speckle field is conducted in two different directions xj and the direction of the velocity vector of the object is judged by the magnitude of the velocity modules of the speckle measured in the absence of a scan. Wani and two scanning directions.

2. Device for measuring the speed of movement of diffuse-scattering objects, containing sequentially installed and optically matched - a source of coherent radiation and a lens, as well as the first optical scanner, the output of which is optically matched with the first input of the photodetector unit, the output of which is connected to the input of the electronic signal processing unit , characterized in that, in order to expand the functionality of the device by determining the direction of the velocity vector, it is additionally equipped with amplitudes A single optical divider whose input is optically matched with the lens and a second scanner whose output is optically matched with the second input of the photoreceiver unit, while the first and second outputs of the beam splitter are optically matched with the inputs of the first and second optical scanners.

FIG. 2

Claims (2)

1. A method for measuring the speed of diffuse-scattering objects, including illumination of the object by coherent radiation, scanning the resulting scattered speckle field in a plane orthogonal to the direction of illumination, photoelectric registration of the scattered speckle field and determining the speckle field velocity module from the cycle of intensity fluctuations of the scattered speckle -fields per unit time according to which the speed of the object is judged, characterized in that, in order to expand the functionality of the method by determining the direction The velocity vector, the resulting speckle field are additionally amplitude-separated, scanning, photoelectric registration and the speckle-field velocity modulus are determined from spatially separated speckle field components in the absence and presence of scanning, and the | θ spatially separated speckle field components are scanned in two different directions, and the direction of the object’s velocity vector is judged by the magnitude of the speckle-15 field velocity moduli measured in the absence of scanning and in two directions yah scan. 2. A device for measuring the speed 20 of the motion of diffusely scattering objects, containing sequentially mounted and optically matched - a coherent radiation source and a lens, as well as a first optical scanner, the output of which is optically matched to the first input of the photodetector unit, the output of which is connected to the input of the electronic unit signal processing, characterized in that, in order to expand the functionality of the device by determining the direction of the velocity vector, it is additionally equipped with amplitudes udnym svetot divider whose input is optically matched to the lens, and a second Coordinate Scanning Devices whose output is optically matched to the second input of the photodetector unit, wherein the first and second outputs of the beam splitter optically aligned, respectively with the inputs of the first and second optical scanners.