SU1326885A1 - Method of remote checking of linear measurements - Google Patents

Abstract

This invention relates to a measurement technique. The aim of the invention is to improve the measurement accuracy by eliminating errors from the instability of the modulating frequency. Luminous flux is directed at the surface, limiting the size of measure 6 by the reference frequency transmitted over communication channels, modulate the luminous flux by autogeneration. At a certain frequency, the rays reflected from the faces of measure 6 are switched, and the frequencies of the autogeneration from the different faces are read separately from this frequency. The frequency of the autogeneration, due to the reflection of the beam from the front edge of the measure, automatically adjusts the frequency, keeping it constant by affecting the offset of the operating point of the modulator 4. After that, the frequencies of the autogeneration are averaged separately and by the difference of the periods of the averaged frequencies are measured 6. 1 Il. g (L S

Description

one

This invention relates to a measurement technique and can be used to calibrate linear measures.

The purpose of the invention is to improve the measurement accuracy by eliminating errors from the instability of the modulating frequency.

The drawing shows a block diagram of a device that implements a method for remote verification of linear measures in relation to limit measures of length.

The device contains an exemplary frequency receiver, a frequency meter 2, a source of light 3, a modulator A of light, a translucent mirror 5j measure 6, a contact plate 7, a photodetector 8, a waiting multivibrator 98, a obturator 10, a low-frequency generator 11, a computing unit 12, a digital-to-analog converter (DAC) 13 and integrator 14,

Source Ij frequency meter 2, D / A converter: 13 and integrator 14 are connected in series. The outputs of the generator 1 are connected to the obturator To and to the control inputs of the frequency meter 2, the computing unit 12 and the CCP 13. The light source 3 is connected to the first input of the light modulator 4, the other two inputs are connected to the output of the integrator 14 and the output of the multivibrator 9, also connected to the second input of the frequency meter 2, the input of the multivibrator 9 is connected to the output of the photodetector 8,

The method is carried out as follows.

The reference frequency is transmitted over the communication channels from the center - the time unit storage and is received by receiver 1 to calibrate the frequency reference of frequency meter 2,

The light beam from the light source 3 is directed to the light modulator 4. The light signal from the modulator 4 of the light through the semitransparent mirror 5 is directed to the free (measuring) face of measure 6 and to the surface of the contact plate 7 ground to its other measuring surface (or mirrors rigidly attached to the tubes of two photoelectric MICROSCOPES) mounted respectively on initial to final stroke of a linear linear measure).

Reflected normally from the free face of measure 6 light signal Translucent mirror 5 directions -

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on the photoreceiver 8, the electrical signal received at the output of the photodetector 8 is fed to the input of the waiting multivibrator 9, the output signal of the multivibrator 9 is fed to the modulator 4 light.

Thus, in the above closed circuit, a positive feedback is formed and oscillations occur in the circuit, the period of which is equal to the time it takes to travel along the elements of the closed circuit. Then, using the obturator 10, which is controlled by the 15th generator P, the light signal reflected from the surface of measure 6 is interrupted and the light signal reflected from plate 1 is fed to the photodetector 8, as a result, 2Q oscillations occur in the circuit equal to the transit time signal on a closed path. At the same time, the input of the generator 11 is connected to the input of the frequency meter 2 and the computing unit 12 for 25 synchronous reading and averaging of frequencies.

The autogeneration frequency due to the reflection of the beam from the front face of measure 6 "synchronously with the frequency 30 of the generator 11 is read from the frequency meter 2 and the difference of this frequency with the set frequency converts the DAC 13 to an analog value which through the integrator 14 is fed to the light modulator 4, E result Automatic regulation of the autogeneration frequency, caused by the reflection of the beam from the front edge of the measure, which makes it possible to completely eliminate the effect

40

modulator 4 light drift.

The frequencies obtained as a result of the signal passing through two closed circuits are averaged separately, the corresponding periods are determined.

/ 1 and, f i f cf n fri

 sr

1 7

2 1 -. 2

t - 1

t., - p-

Have

and by the difference of the periods, judge about the length of the measure by

(T-Trc-L,

where C is the speed of CBeraj

L is the length of measure 6. The use of the proposed method (as compared to the known method) excludes the influence of the drift of the operating point of the modulator 4, since automatic adjustment and synchronous reading of frequencies are performed,

Claims (1)

Invention Formula The method of remote verification of linear measures, which consists in the fact that the luminous flux is directed to the surface, limiting the measure, by means of the reference frequency, forms the modulating frequency, modulates it Editor A. Rezin Compiled by E. Glazkova Tehred V. Kadar Corrector T, Kolb Order 3269/34 Circulation 676 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Design, 4. 6885 luminous flux directed at the surface and perform autogeneration, characterized in that, in order to increase the measurement accuracy, periodic beams are recorded that are reflected, respectively, from each of the surfaces that limit the measure, synchronously with 10, the frequency of the autogeneration frequencies from different surfaces separately, use one of the fixed frequencies for comparison with the reference frequency during auto-tuning 15 of the modulating frequency, and the length of the measure is judged by the difference between the periods of averaged separately frequencies of autogeneration from different surfaces.