SU1460606A1 - Displacement measurement device - Google Patents

Abstract

This invention relates to instrumentation technology. The purpose of the invention is the expansion of functional possibilities, achieved through the additional measurement of the angular displacements of the object. The light beam from the light source 1 is incident on the ultrasonic modulator 3 of the light. As a result of the diffraction of the beam on the periodic structure of the ultrasonic modulator 3, the light rays plus the first and minus first diffraction orders fall on the photoreceivers 5 and 6, respectively. The total signal from these photodetectors weakly depends on the angle of incidence of the beam, The summing block 8 and from it one can judge the magnitude of the linear displacement. The linear size is determined by the delay of the signal from the output of the summing unit 8 relative to the pulse of the 4 gating pulse generator. The magnitude of the angular displacement is determined by subtracting the signals plus the first and minus of the first diffraction order using the subtracting unit 7. 2 sludge. (L

Description

and optically coupled images; 30, transferring it to the included state;

a light source 1, a reference light beam forming system 2, an ultrasonic light modulator 3 (CMS), kinematically connected with an object, an oscillating frequency generator 4, the output of which is connected to the CMS input 3, two photodetectors 5 and 6, located; respectively, along the diff1 $ promotional beams plus the first and minus first diffraction orders, subtractive -block 7, C5gmming block 8, inputs (connected to the outputs of photodetectors, measuring instrument 9 pulse amplitude, bistable element 10, strobing generator 11 pulses.:

Bistable element 10 can be made in the form of a trigger. The UMS 3 used is made operating in an intermediate mode, using the Raman-Nath diffraction mode and Bragg diffraction mode.

In this case, the ratio

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X, is the width of the ultrasound

beam a: .. X - wavelength of light;

Ldlin wave ultrasound.

five

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ABOUT

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Generator 4 operates in pulse modulation mode. At the time of the pulse from generator J1 of the generating pulses, generator 4 generates a radio pulse that is converted into the AMC 3 into an ultrasonic wave, which after a period of time equal to the time it takes from the end of the AMC 3 to intersect of the reference beam i of the light, causes the diffraction of this beam. The diffracted beams of the phor in the signals of the photodetectors 5 and 6, delayed in time. This time-delay is proportional to the linear: th displacement of the UMS 3 relative to the reference light Beam. Signals from photodetectors are transmitted to summing 8 and subtracting 7 blocks. The pulses at the output. Photogrims 5 and 6 have | amplitudes j proportional to intensities 1, and I., diffraction rays,: the intensity of which depends on O s of the angle of inclination of the fronts of the ultrasonic wave to the reference beam (Fig. 2a). The amplitude of the pulse at the output of the subtracting unit 7 is avisit from the angle about within ± br (Г .2б) and corresponds to the difference of values and, Thus, the amplitude

the pulse at the output of the subtracting unit 7 uniquely determines the angular position 3 of the light relative to the reference light beam. The amplitude is measured by a pulse amplitude meter 9. The amplitude of the pulse at the output of the summing unit 8 of FIG. 2c) over the whole range of measurement of angles, 4 0 g differs from zero, has a maximum value and practically does not change. The signal from the output of the summing block 8, delayed in time, arrives at the bistable element 10 and puts it into the off state.

The duration of a single impulse output bistable element 10

1460606

mounted in the zone of the first-order diffracted beam, a carrier frequency generator, the output of which is connected to the input of an ultrasonic light modulator, a bistable element, a strobe impulse generator, the output of which is connected to the generator input of the frequency carrier 10 and the first input a bistable element, which differs in that, in order to expand its functionality, along with linear and 15 angular displacements, it is also equipped with a second photodetector, a subtractive unit, a summing unit meter pulse amplitude Rin rows subtractor and adder blo

r-1 --- “. % lx y, y ninnj ypcc C 1 J UJIO

equal to the propagation time of ultra-2okov connected to the outputs of the first and

SOUND WAVE from TOPPNYMP P hp ". l

the sound wave from the end of the MCM 3 to the reference light beam and determines the linear mismatch of the object associated with the MCM 3.

the second photodetector, the output of the summing unit is connected to the second input of the bistable element, the input of the measuring instrument of the amplitude of the pulse connect

Formula

the invention

An apparatus for measuring displacements comprising a light source optically coupled and mounted j along the beam path, a system for forming a reference light beam and an ultrasonic light modulator, a photodetector,

1460606

installed in the zone of the first-order diffracted beam, a carrier frequency generator, the output of which is connected to the input of an ultrasonic light modulator, a bistable element, a strobe pulse generator, the output of which is connected to the modulation input of the carrier frequency generator and the first input of the bistable element, which the fact that, in order to extend the functionality by measuring along with linear also angular displacements, it is equipped with a second photodetector, a subtractive unit that summarizes the the eye and the pulse amplitude meter, the inputs of the subtracting and summing blog-1 --- “. % lx y, y ninnj ypcc C 1 J UJIO

cov connected to the outputs of the first and

cov connected to the outputs of the first and

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the second photodetector, the output of the summing unit is connected to the second input of the bistable element, the input of the pulse amplitude meter is connected to the output of the subtractor unit, the second photodetector is located in the diffracted beam zone, symmetrically to the first diffraction beam, the ultrasonic light modulator is in intermediate mode between the lines. Roman-Nath diffraction and Bragg diffraction.

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Claims (1)

Claim A device for measuring displacements containing a light source optically coupled and installed along the beam, a reference light beam forming system and an ultrasonic light modulator, a photodetector installed in the first-order diffracted beam zone, a carrier frequency generator, the output of which is connected to the ultrasonic input a light modulator, a bistable element, a strobe pulse generator, the output of which is connected to the modulation input of the carrier frequency generator and the first input of the bistable element a, which is distinguished by the fact that, in order to expand the functionality by measuring along with linear angular displacements as well, it is equipped with a second photodetector, a subtracting block, a summing block, and a pulse amplitude meter, the inputs of the subtracting and summing blocks are connected to the outputs of the first and a second photodetector, the output of the summing unit is connected to the second input of the bistable element, the input of the pulse amplitude meter is connected to the output of the subtracting unit, the second photodetector is located in the diffraction zone beam, symmetric to the first. With respect to the zero-order diffraction beam, the ultrasonic light modulator is made in an intermediate mode between the Roman-Nath diffraction and Bragg diffraction modes. Figure 2