SU767510A1 - Photoelectric device - Google Patents

Description

one

The invention relates to the field of measurement technology and can be used in the high-precision measurement of angular and linear displacements of various objects.

A photovoltaic device is known that contains a lens successively installed along the radiation from an object, a window separating prism, in each of two radiation streams from which a capacitor and a reflecting mirror are sequentially placed, a unit of radiation detectors and an amplifier, a reference branch made of a sequentially installed radiation source, a capacitor, a block of radiation receivers and an amplifier, a modulator located in the central part in front of the block of radiation detectors; the reference branch is located on the periphery of the modulator, which blocks the radiation flux entering the radiation receiver unit of the reference branch l.

A disadvantage of this device is its sensitivity to changes in signals in both channels, which is caused by a change in the image size of the object relative to the modulator slots.

radiant flux and the nature of the distribution of energy in the image, as well as inaccurate alignment. As a result, the device has a low measurement accuracy.

The aim of the invention is to improve the measurement accuracy.

For this device is equipped

To a synchronous detector connected by inputs to the output of the blocks of radiation detectors and an integrator connected to its output, the modulator is made with two rasters, concentrated on its surface: one raster having the same width of transparent and opaque portions is placed on the perimeter . modulator family, another having

The 20 slit width, which is a quarter of the raster period, is in its. The central part, and the condenser of the reference channel is a condenser that provides

25, the width of the reference radiation beam smaller than the regions of the peripheral raster, set so that the location of the center of the image of the reference radiation source is overlapped by the modulator simultaneously with one of the

thirty

radiation from the beam-splitting prism.

Figure 1 shows the described device; in fig. 2 - modulator.

The device includes a lens 1, a vegetation prism 2, condensers 3, 4, 5, mirrors 6.7, a radiant flux modulator 8, blocks 9, 10 of radiation detectors, amplifiers 11, 12 AC, radiation source 13, synchronous detector, 14 and integrator 15. The source 13, the radiation, the capacitor 5, the radiation emitter unit 10 and the amplifier 12 form a reference branch. The beam splitting prism 2 is an image analyzer and is installed in the image plane of the object

(not shown in figure 1), for example, in the focal plane, condensers 3

and 4 set behind the beam-splitting prism 2 in the path of the radiation beams reflected from the faces of this prism. Mirrors b, 7 are installed with two hundredpiOM at angles to the axes of the radiation beams, ensuring the intersection of these axes at the point located on the sensitive area of the block 9 of radiation detectors. The center of the radiation receiver unit 9 is located on the optical axis of the lens 1. The alternating current amplifiers 11, 12 are connected to the radiation receiver units 9, 10, for example, the output of which is.

connected to the synchronous detector 14. The output of the synchronous detector 14 is connected to the integrator 15.

Figure 2 shows a radiant flux modulator 8. Two rasters are applied on it, one of which is located in its Central part and has

slot width, which is even. the period of the raster period and the other is located on the periphery of the modulator and

It has the same width of transparent and opaque areas. Both rasters are concentric. The modulator axis is located on the optical axis of lens 1, and its raster plane is removed from the focal plane of lens 1 at a distance that intersects the axes of the inner beam raster and alternately overlaps the forked beams of rays from the object. The support branch condenser 5 focuses the reduced image of the radiation source 13 into the plane of the peripheral raster of the modulator 8, and the center of this image is located as follows. That it intersects the modulator simultaneously with one of the radiation fluxes from the beam splitting prism 2. The beam width of the reference radiation for obtaining a rectangular shape of the modulated flux is selected several times smaller than the slots of the external raster, which is ensured by

r; lJi; .. .. i.

condenser 5. Instead of lens condensers and flat, you can use spherical or aspherical mirrors that perform the functions of a condenser.

- The device works as follows.

The radiation flux from the object is focused by the lens 1 into the plane of the beam-splitting prism 2, is divided into two streams, which alternately pass through the slots of the central raster and irradiate the block 9 of radiation detectors. If the object is on the optical axis of lens 1, then the amplitudes of both

The 5 modulated streams and the corresponding voltages and the i and 2 V circuits of the block 9 of the receivers radiated by 1H are equal to each other. These signals along with the signal From the reference branch

0 after amplification. Are fed to the input of the synchronous detector 14, on. the output of which produces a signal proportional to the product of these signals. Signal strength

5 at the output of the integrator 15 is zero.

If the object is offset relative to the optical axis of the lens 1 ,. then the amplitudes of the signals and and U2 will not be equal to each other, and therefore a signal appears at the output of the integrator 15, the magnitude of which when square modulated in both comparison channels is proportional to the error angle, and the phase depends on the direction of displacement of the object. the integrator 15 will be proportional to the input error angle and is described independently of the signals U and U2 in both comparison channels by the same expression

.1 / AsL

and.

out

where Dos is the current angle of mismatch (linear displacement);,

Zoig is the angular size of an image of an object in the analysis plane;

 K is a certain constant coefficient depending on a specific device circuit,

The device completely eliminated errors due to the non-identity of the signal resolution in both comparison channels, which allows for an increase in the measurement accuracy.

Claims (1)

1. Nikolaev P.V. and Sabinin Yu.A. Photoelectric tracking systems. L., Energie, 1969, p. 34 (prototype). l / h. L