SU1599915A1 - Photoelectric displacement digitizer - Google Patents

Abstract

The invention relates to analog-to-digital transformations of information and can be used in automatic control systems for converting both linear and angular displacements. The aim of the invention is to increase the resolution of the converter. The photoelectric converter contains a radiation source 1, a code element 2 with a uniformly quantized code scale, a diaphragm 3 installed on the same optical axis with a radiation source 1 and a photo receiver 5. The output of the latter is connected to the input of a multilevel threshold imager 6, the output of which is connected to the counter input 4, aperture 3 is made in the form of 2N + 1 equal slots, where N is an integer, the centers of the slots are offset relative to each other by T / (2N + 1), where T is the quantization period of the scale, and the width of one slit does not exceed T / 2 (2N + 1), which leads to the formation of a signal at the output of the photoreceiver 5, the repetition period of which is 2N + 1 times less than the period T of the quantization of the code scale. 2 Il.

Description

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The invention relates to analog-to-digital conversion of information and can be used in automatic control systems for the transformation of both linear and angular displacements.

The aim of the invention is to increase the resolution of the conversion.

FIG. i is a block diagram of a motion to code converter; in fig. 2 shows a part of a code element with a code track, a diaphragm with five slits, and diagrams describing the operation of the converter.

The displacement transducer to the code contains a radiation source 1, code element 2 with a uniformly quantized code scale with a quantization period T, aperture 3, a counter 4, a photoreceiver 5, a multiphased threshold driver 6. Aperture 3 contains 2p + 1 slits 7-11 (Fig. 2 ) for p 2, which are located in the limit of the period T of quantization of the code scale. The width of each slot 7-11 is equal to the tenth part of the period T

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  ) where t is the width of one slit

7-11. The centers of the slits 7-11 are shifted relative to each other by an amount equal to one-fifth of the period T (1

 ), where 1 is the distance

  T (2p + T)

between the centers of adjacent slots 7-11.

The motion to code converter operates as follows.

At any position of the code element 2 relative to the diaphragm 3, part of the slits 7-11 is in the open state, part is in the closed, only one of the slits 7-11, depending on the direction of movement, can be in the half-open or semi-closed state. When moving the code element 2 relative to the aperture 3, the intensity of the light flux at the output of each slit 7-11 varies with a period equal to the period T of the code scale. In the diagrams of FIG. 2a, b, c, d, e shows the changes in the intensities of the light flux at the outlets of the slots 7-11, respectively, when code element 2 is moved in the direction of the arrow in fig. 2. With a closed gap of 7-10 or 11 intents

The intensity of the luminous flux has a zero level, and with an open level it has a level and. The light fluxes at the outlets of the adjacent slits 7-11 are offset from each other by an amount equal to n T T of that part of the period T

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Claims (1)

The light fluxes are summed on the photosensitive surface of the photodetector 5, at the output of which an electric signal is formed with constant and variable components (Fig. 2e). . The value of the constant component is determined by the number of open slots 7-11, which in this example is two, and in the general case p. The amplitude of the variable component is determined by the intensity of the light flux at the output of one slit 7-10 or 11, since the variable only one of slots 7-11 forms the component. FIG. 2 shows the position of the code element 2 relative to the diaphragm 3, at which the slits 7-9 are open and the slits 10 and 11 are closed. When moving the code element 2 relative to the diaphragm 3 in the direction of the arrow, the slit 9 begins to close and modulates the light flux from moving (Fig. 2c). When code element 2 is moved by an amount equal to the tenth part of period T (or equal to the width of the slit 9), the slit 9 is completely closed. Upon further movement, the luminous flux is modulated by slit 11. (Fig. 2d), then slit 8 (Fig. 2b), slit 10 (Fig. 2g), slit 7 (Fig. 2a), and then the cycle repeats. Thus, the light fluxes modulated from the movement are summed at the input of the photodetector 5, at the output of which a signal is formed, the repetition period of which is five times, and in general 2p + 1 times less than the repetition period of the light flux at the output of each slit 7 -11 separately (Fig. 2. e). This signal is fed to the input of a multi-level threshold driver 6, at the output of which counting movement pulses are generated, which are fed to the input of counter A, at the outputs of which a movement code is generated. Thus, when code element 2 is moved relative to diaphragm 3, signals are generated at the output of photoreceiver 5, the repetition period of which is 1/10 part (generally o) part of the period T of the code scale quantization. Invention Formula A photoelectric converter translates into a code containing a radiation source optically coupled through a code element to a uniformly quantized code scale applied to it with a quantization period. Uc 1599915 equal to T, and the diaphragm with a photodetector, the output of which is connected to the input of a multilevel threshold shaper, the output of which is connected to the input of the counter, characterized in that, in order to increase the resolution of the converter, in it the aperture is made in the form of 0 2n + 1 equal gaps where n is an integer, the slots are located in increments equal to T / (2n + 1), and the size of each slit does not exceed the value T / 2 (2n + 1). at / / g and if. 2