SU1411577A1 - Interferrometric device for measuring angular displacements of object - Google Patents

Abstract

This invention relates to instrumentation technology. The aim of the invention is to improve the accuracy. The beam of radiation from the source 7 falls on the beam splitter 3 and is divided into two streams. One stream is rotated 90® and falls on the reflector 2 and through the lens 9 falls on the photodetector 10.. Another stream passes through the translucent layer and falls on the beam splitter 3, reflecting from which, falls on the photodetector 10, where it forms the interference pattern together with the first stream. The resulting image is read in block 11. With a full turn of the object, the reflective surface of the splitter 3 must remain perpendicular to the reflecting surface of the reflector 2. This condition is preserved through the use of a three-disk planetary-frictional mechanism. The disk 6 and the reflector 2 are rigidly fastened to a fixed axis 12. If the object is rotated at some angle, then the disk 5 will rotate around its axis at the same angle, in the same direction, to compensate for the angle of rotation of the object. 1 il. WITH

Description

ate

This invention relates to a control & iHO measuring technique.

The aim of the invention is to increase accuracy.

) The drawing shows the scheme | of the proposed device. I The interferometric device contains a base 1, a reflector 2, an alidade 3 with a hole, mounted coaxially with a reflector 2, a three-disk planetary-friction mechanism with disks 4-6, a hole in the disk b for the passage of radiation, a source 7 of monochromatic radiation cheni, beam splitter 8, lens 9, photo receiver 10 and information processing unit 11, installed in series in the flow from beam splitter 3 on disk 6, fixed axis 12..

The device works as follows.

The beam of radiation from the source 7 falls on the beam splitter for 8 hours and is divided into two streams. After exiting the beam splitter 8, one stream is rotated by 90 ° and falls on the reflecting surface of the reflector 2 and after reflection from it passes through the translucent layer of the beam splitter 8, then goes through the lens 9 to the photodetector 10. Another flow passes through the semi-transparent layer, falls on the reflective surface the beam splitter 8, reflecting from which, falls on the photodetector 10, where I forms the interference pattern together with the first stream. The resulting image is alternating

with light and dark interference;

The strips are read using block 11.

The optical path difference tf during rotation is a function of the angle of rotation.

/ 4 + 2btgi / .r,

45

where (is the minimum difference in travel,

which corresponds to the origin of 0;

r is the reflector radius; (- angle of rotation; 50

b - maximum height of the truncated cylinder.

50

5 o

five

0

five

0

those. the change in the path difference should correspond to some reading of the measured angle.

With a full turn of the object (not shown), the reflective surface of the splitter 8 should remain perpendicular to the reflecting surface of the reflector 2. This condition is preserved by applying the planetary-friction mechanism, which consists of three disks 4-6 with equal diameters. The disk 6 and the reflector 2 are rigidly fastened to a fixed axis 12. If the object is rotated at some angle, the disk-5 rotates around its axis at the same angle in the same direction, compensating for the angle of rotation of the object.

Claims (1)

Invention Formula An interferometric device for measuring the angular displacements of an object, comprising a stand, an alidade intended to be attached to the object, and successively located sources of monochromatic radiation and a beam splitter that divides the radiation into two streams, one of which has a reflector, the other has a successively arranged lens, a photodetector and an information processing unit, characterized in that, in order to increase accuracy, it is equipped with a three-disk planetary-friction mechanism mounted on idad and with a hole in the center on the outer disk to pass radiation from the source, the reflector is made in the form of a truncated cylinder, on the surface of which, facing the alidade, a reflective coating is applied and is installed coaxially with it on the stand a splitter with one side, non-perpendicular a base on which, on the side opposite to the source, a reflective coating is applied, and the radiation source and the beam splitter are installed on the outer disk of the planetary mechanism.