SU1056243A1 - Photoelectric shaft rotation angle encoder - Google Patents

Abstract

A PHOTO-ELECTRIC CONVERTER of ANGLE OF SWIVELING OF A SHAFT INTO A CODE containing an illuminator, optically connected through an indicator and coded disc with accurate and coarse photoreceivers, the outputs of which are connected through amplifiers to the inputs of the first and second interpolators. coarse readings, shifted one relative to the other, differ from and with the fact that, in order to reduce overall dimensions and simplify the converter, the first and the second comparators, the first and second modulo two addition units, the sample matching unit, the inner edge of the code track are eccentric with respect to the center of rotation of the coded disk, two additional slit coarse diaphragms are made on the indicator disk, which are shifted one relative to another 90 and shifted relative to the corresponding: target rough diaphragms by 90 °, the largest and smallest radii of the slit diaphragms and the additional slit diaphragms of the rough from, the accounts are equal to cooTBe TCTBeliHo the radius of the smallest and the radius of the greatest width of the code track; and their width. . a multiple of two codepoints, the outputs of the first and second interpolators are connected to the inputs of the first and second comparators, respectively, the output of the first comparator is connected through the sample matching unit to the inputs of the first modulo unit two, the output of the second comparator is connected to the inputs of the second addendum unit Mo: 2, one of the outputs of which is connected to the auxiliary input from the sample matching unit, the outputs of the adder units modulo two is ND | output of the converter. four;; :with

Description

The invention relates to automation and computer technology and can be used in automatic control systems for converting shaft rotation angles to code. Known photoelectric: a converter containing an illuminator, indicator and coded discs, photodetectors and an inter unit. pol Ior. The disadvantage of this converter is its complexity. The closest technical solution to the invention is a photoelectric transducer of the angle of rotation of the shaft into a code containing an illuminator optically connected through an indicator and coded disc with an exact photovoltage and. coarse readings, the outputs of which through amplifiers are connected to the inputs of the first and second interpolators, on the indicator disk there are accurate aperture slit diaphragms and two rough slit apertures, shifted relative to each other on the 3rd converter, the coarse readout track is transparent and has eccentricity, and the rough photodetectors are arranged in pairs at two points of the coarse reference track of a coded disk through 90 ° 2. The disadvantages of the known converter are the relatively large dimensions associated with the presence of two tracks and an inter-bridge between them, and its complexity. The aim of the invention is to reduce the size and simplify the design of the converter. The goal is achieved by the fact that in a photoelectric converter the angle of rotation of the shaft into a code containing an illuminator, optically connected through indicator and coded disks with accurate and coarse readings, the outputs of which are connected through amplifiers to the inputs of the first and second interpolators, on the indicator disk precision slit diaphragms are made; slit diaphragms of a rough go-off, shifted one relative to the other by 90 °, the first 1 and the second comparators are introduced, the first and second. modulo-two addition units, a sample matching unit, the inner edge of the code track are eccentric with respect to the rotation center of the coded disk; two additional slit diaphragms of the coarse reference are on the indicator disk, which are shifted relative to each other by and shifted relative to the corresponding slit diaphragms of the coarse of reference at 90 the largest and smallest radii of the slit diaphragms of the rough count and additional slit diaphragms of the rough count are equal respectively to the radius of the smallest and p the maximum width of the code track, and their width is a multiple of two code track quanta. The outputs of the first and second interpolators are connected to the inputs of the first and second comparators, respectively, the output of the first comparator, connected via the matching unit of readings o to the inputs of the first addition unit modulo two, the output of the second comparator is connected to the input of the second addition unit modulo-two, one of whose outputs is connected to the additional input of the matching unit, the outputs of the addition blocks are two outputs reformer Figure 1 shows the encoded. a disk with a code scale and a mutual arrangement of the slits of the exact and coarse readings on the indicator m disk; in Fig. 2, the functional diagram of the prec; the generator / in FIG. 3 and 4 are signal diagrams explaining the operation of the converter. The converter contains a coded disk 1 with track 2 of exact readout and eccentric edge 3, indicator disc with four slit diaphragms. 4 and 5 of coarse and accurate readings, photodetectors b and 7 of coarse and exact readings, coarse reference channel (GO) containing amplifiers 8 , an interpolator 9, KOi sensors 10, a block 11 for matching samples and a block 12 for modulo two and a channel for exact counting (that) containing the amplifier 13, an interpolator 14, comparators 15 and a block 16 for modulo two. -20 shows the signals received at the outputs of the photo 21-24 are signals at the outputs of photodetectors 7. On the indicator disk, four slit diaphragms 4 with a width that is a multiple of the division of the code track, which are 90 ° apart from each other and are arranged in such a way that the radiant flux . They are modulated by the eccentric edge 3 of the code track 2. In Fig. 1, the encoded shaft and illuminator are conventionally not shown. The converter works as follows. When the encoded shaft is rotated one turn (FIG. 1), the radiant flux formed by the coarse diaphragms 4 is mainly modulated by the eccentric edge 3 of the code track 2. Since the edge 3 is eccentric and the four slit diaphragms 4 are coarse

spaced apart from each other by 90, then four sinusoidal signals 17–20 are generated at the outputs of the corresponding photodetectors of the coarse count b, shifted in phase relative to each other by a quarter of a period (Fig. 3 | The period of these signals corresponds to one revolution of the shaft. These signals through the amplifiers 8 of the coarse reference channel, they are fed to the input of the corresponding interpolator 9, in which signals with a phase shift equal to 2 are formed (2m, corresponding to the dividing quantum of the codecoding of the exact counting, where m is the coefficient. interpolator interpolator 9 coarse reference. These computer signals, 10 are converted to right angles and fed to the input of the And srlasov block, in which the coarse read is coordinated with the exact one; the exact reference channel works as follows. Radiant flux, passed Through four slit diaphragms 5 precise readings, separated by 90 space, shifted relative to each other by four steps of dividing the code track and located on its middle diameter, are modulated by dividing tracks 2 of exact tracks account as it rotates and is supplied to the respective photodetectors 7 accurate reading. Thus, at the outputs of the photodetectors 7, for one shaft rotation, four signals 21-24 are generated (FIG. 4) shifted by a quarter period. The period of these signals is equal to the ifiary and dividing track 2. The signals through the amplifiers 13 arrive at the interpolator 14, in which intermediate signals with phase shift / are formed, where P is the interpolator 14 interpolation coefficient of the exact reference. These signals are formed by rectangles by comparators 15 and are fed to modulo two ad unit 16, in which they are converted into binary code of the corresponding bits (mr and n)

Control unit 11 approval

0 is performed by the high-order signal of the exact count. The principle of operation of the sample matching scheme is similar to the principle of matching with. double brush

five

Coordinated coarse channel signals arrive at addendum 12 modulo 2, in which they are converted into binary code from ti -1 to the first digit.

Thus, the proposed device allows to perform a positional transducer with one code track, which reduces the dimensions of the coded shaft and simplifies the transducer. Also decreases

5, the moment of inertia of the movable part of the converter, its weight and the number of gradations of the mask, which improves the manufacturability of the encoded disk and the entire converter.

0

And eliminating the effect of transducer errors associated with the radial runout of a coded disk also makes it possible to increase the resolution of the transducer without complicating its design and manufacturing technology.

The economic effect of the use of the invention is due to its technical features given above.

Claims (1)

A PHOTOELECTRIC CONVERTER OF THE SHAFT TURN ANGLE IN THE CODE, containing a illuminator optically connected through indicator and coded disks to photodetectors of accurate and coarse readings, the outputs of which are connected through amplifiers to the inputs of the first and second interpolators, slotted diaphragms of the exact readout and two 'are made on the indicator disk coarse-shifted relative to one another by 90 ^e, wherein u and d with me that, in order to reduce the size and simplify the converter, it introduced the first and second the first comparators, the first and second addition blocks are modulo two, the sample matching block, the inner edge of the code track is eccentric with respect to the center of rotation of the coded disk, two additional coarse slit diaphragms are made on the indicator disk, which are shifted one relative to the other by 90® and are shifted relative to the corresponding coarse aperture diaphragms by '90 °, the largest and smallest radii of the aperture diaphragms and additional coarse aperture diaphragms are equal to the radius, respectively the smallest and the largest width of the code track radius) and their width. . is a multiple of two quanta of the code path, the outputs of the first and second interpolators are connected to the inputs of the first and second comparators, respectively, the output of the first comparator is connected through the block matching samples with the inputs of the first block of addition modulo two, the output of the second comparator is connected to the inputs of the second block of modulo two, one of the outputs of which is connected to an additional input of the block matching samples, the outputs of the blocks of addition modulo two is the outputs of the Converter. SU.> 1056243 1.056243