SU1693381A1 - Photoelectric pickup of displacements - Google Patents

Abstract

This invention relates to a measurement technique. The purpose of the invention is to improve the accuracy by reducing the temperature measurement error. The generator 9 generates an electrical signal converted by the radiators 1, 2 into modulated radiation fluxes. With the help of the input and output fibers B-b, the radiation flux reflected from the object 19 falls on the photodetectors 7, 8. The reference signals are formed by additional supply fibers 12/13 and additional photo-detectors 10 11. The information signals shift the Phaser; .H1 14, 15. At the outputs of the adders 16, 17, signals are generated, the phase difference of the cocks is connected with the displacement of the volume 19. The phase difference is recorded with a phase meter 18. 3 Il.

Description

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The invention relates to measurement technology and can be used for contactless measurement of the movement of an object having a reflective surface.

The purpose of the invention is to improve the accuracy by reducing the 1 temperature measurement error.

Figure 1 presents the functional diagram of the sensor; 2 and 3 are vector diagrams of signals generated at the outputs of individual sensor assemblies.

The sensor contains optically coupled emitters 1 and 2, supplying 3 and 4 and outputting 5 and 6 optical fibers, photodetectors 7 and 8, a generator 9, the output of which is connected to radiators 1 and 2, additional photodetectors 10 and 11, additional outputting optical fibers 12 and 13, installed between radiators 1 and 2 and additional photodetectors 10 and 11, phase shifters 14 and 15. whose inputs are connected to photodetectors 7 and 8, adders 16 and 17, whose inputs are connected to additional photodetectors 10 and 11 and outputs, respectively phase shifters 14 and 15, phase meter 18, cat inputs They are connected to the outputs of the adders 16 and 17. The movement of the reflecting surface of the object 19 is measured.

The sensor works as follows.

The electrical signal generated by the generator 9 is supplied to the emitters 1 and 2, which form the intensity modulated radiation fluxes, which through the supplying optical fibers 3 and 4 fall on the reflecting surface of the object 19.

Reflected from the reflecting surface of the object 19, the radiation fluxes fall on the output optical fibers 5 and 6 and are converted into electrical signals by the photodetectors 7 and 8.

The electrical signals taken from the photodetectors 7 and 8, are fed to the phase shifters 14 and 15, the output of which is fed to one of the inputs of the adders 16 and 17.

The intensity modulated radiation fluxes formed by radiators 1 and 2, through additional diverting light guides 12 and 13, fall on additional photodetectors 10 and 11, the output signals from which are fed to the inputs of adders 16 and 17.

The phase shift introduced by phase shifters 14 and 15 is opposite in sign and can be, for example, ± 145 °.

Two voltages are formed at the outputs of the adders 16 and 17, the phase difference between them being measured by a phase meter 18.

When the distance to the reflecting surface of the object 19 changes, the intensity of the radiation flux reflected from it changes, which leads to a change in the phase difference of the signals taken from the outputs

adders 16 and 17 (Fig. 2), which is recorded by a phase meter 18.

A change in the power of the radiation fluxes generated by radiators 1 and 2 as the temperature changes does not lead to an additional temperature error, since the signals taken from the photoreceivers 7 and 8 and the additional photoreceivers 10 and 11 (fig.C) simultaneously change. The use of a sensor reduces the temperature error of the sensor by compensating for changes in the emissivity of the emitters.

Claims (1)

Invention Formula A photoelectric displacement sensor containing two optical channels, each of which is made in the form of optically coupled emitter, supply, and output light guides and photodetector, generator, two phase shifters, two adders, a phase meter whose inputs are connected to the outputs of the adders, different in that, in order to improve accuracy by reducing the temperature error of the measurements, it is equipped with two additional photodetectors and two additional light guides installed between the radiator mi and additional photodetectors, the output of the generator is connected to the inputs of the emitters, the inputs and outputs of the phase shifters are connected respectively to the outputs of the photoreceivers and the first input of the adder in, the second inputs of which are connected to the outputs additional photodetectors. Fig.b FIG, E