SU1238236A1 - Shaft turn angle-to-digital converter - Google Patents

Abstract

The invention relates to automation and computing and is intended to control the position of optical and radio telescopes. The aim of the invention is to improve the accuracy of the converter, for which the measuring disk in it is made with an additional ring road, eccentric with respect to the axis of rotation, with a center located on a radius 90 degrees to the center of the main ring track, and sensitive elements are installed radially relative to the measuring disk against the main and additional ring tracks, and two differential rings are inserted into the fop-block of the output code and inverting amplifier, the first and second digital-to-analog converters, analogue comparator. - generator and reversible counter. During the rotations of the measuring disk, signals are formed at the outputs of the sensing elements, which include components caused by the eccentricity of the disk. After signal processing, these components are compensated and signals are generated at the output of the converter, in which the magnitude of the signals, due to the eccentricity error, is absent. Рз.п. f-L1, 2 ill. (L

Description

The invention relates to automation and computing and can be used in software systems that control optical and radio telescopes.

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

FIG. 1 shows a flowchart; converter; in fig. 2 is a block diagram of an output code generation unit.

The converter contains a radiator, an indicator disk with slots (not shown), a measuring disk 1 with main and additional annular tracks 2 and 3, sensitive elements 4-7, an output code generation unit 8 that contains differential amplifiers 9 and 10, inverting amplifiers 11 and 12, switch 13, digital-to-analog converters (D / A converters) 14 and 15, analog to the omperator 16, reversible counter 17, generator 18.

The converter works as follows.

When moving the measuring disk 1, the light of the radiation source, modulated by the slit diaphragm and the edges of the annular tracks 2. and 3 falls on the sensitive elements 4-7.

At the same time, at the inputs of the sensing elements 4 and 5 signals .and, are generated. . .

and, Uo + UH, sin0;

i o - Jb.ine,

(one)

where sig component is constant

Nala;

Uy signal amplitude; 0 is the angle of rotation of the converter shaft.

The components U, and U depend on the power of the radiation source, the sensitivity of elements 4 and 5, and the eccentricity value 00.

Due to the fact that the direction of the eccentricity 00 of the ring track 3 is shifted relative to the direction of the eccentricity 00 of the ring track 2 by 90, at the outputs of the sensitive elements 6, 7 signals and

3 s + U GpS & i

, and, -.

(2)

The signals described by expressions (1) and (2) are fed to the inputs of the differential amplifiers 9 and 10, respectively, at the outputs of which the signals U and II, which are symmetrical with respect to zero, are formed

Uh

Ui s U 2U sin9; | and, and, - U, 2U, cose ,.

which are fed to the inputs of inverting amplifiers 11 and 12.

Direct and inverted sine-cosine signals through a switch

13 enter the analog inputs of D / A converters

14 and 15, the digital inputs of which receive inverse and direct signals from the outputs 3, 4p, 5p, ... (t) -i) p, and the reversing counter 17, corresponding to the angle F on the digital output.

In this case, the signals U 8 b1-moves the DAC 14 and 15 are equal

and.

(1-f).

 sin ©;

The signals and, and Ug are fed to the inputs of the analog comparator 16, the potential from the output of which is controlled by the reversible counter 17, to the counting input of which the pulses are output from the output of the generator 18.

The circuit passes in the equilibrium state, when the voltage at the outputs of the D / A converters are 14 and 15 p. U U-,

I w

from where

F () tgS.

Thus, the digital equivalent of the angle F corresponds to the angular position of the converter shaft.

The first two weight bits (1p and 2p) of the reversible counter 17 are used to control the switch 13, to the outputs of which direct or inverse sine-cosine signals are passed. The switch 13 is controlled in such a way that the sine-cosine signals of the first quadrant only are fed to the inputs of the DAC 14 and 15. In this case, the two most significant bits of the counter 13 determine in which quadrant the converter operates.

3 1238236

formula of invention

. You aren’t the one who haven’t been in the middle of the day.

Claims (2)

one . Shaft rotation angle transducer B code containing the first sensitive elements optically connected to the emitter, which is optically connected through a slit diaphragm and an eccentric main annular track mounted on the shaft of the measuring disk with a second pair of sensitive elements, the outputs of the sensitive elements connected to the inputs of the output code generation unit characterized by the fact that, in order to improve the accuracy of the converter, the measuring disk is complete with an additional ring track, an eccentric relative to the axis of rotation, with a center located on a radius located at an angle of 90 with respect to the radius on which the center of the main ring track is located, and sensitive elements are installed radially relative to the measuring disk against the main and additional ring tracks. 2. The converter according to claim 1, about t - characterized in that the block forming the output code contains . the first and second differential amplifiers and inverters, the switch, the first and second digital-to-analog converters, the analog comparator, the generator and the reversible counter, the inputs of the first and second differential amplifiers are the inputs of the unit, and their outputs are connected via the first and second inverters with the first and second inputs of the switch and directly with the third and fourth inputs of the switch, the first and second outputs of which are connected to the analog inputs of the first, respectively and the second digital-to-analog converters, the outputs of which are connected to the inputs of an analog comparator, the output of which is connected to the first input of the reversible counter, the second input of which is connected to the generator output, the outputs of the two high-order bits of the reversing counter, and the rest of the The my and the inverse outputs are connected to the digital inputs of the second and first digital-to-analog converters, respectively, all the direct outputs of the reversible counter are the outputs of the converter. FIG. / Uj 1 / g and {1h. a and IR {I13 / 1 /; Editor L. Povhan Compiled by Y. Kotov Tehred M. Khodanych Order 3304/58 Circulation 816Under VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 Fig2 Proofreader A. Zimokosov