SU1288911A1 - Photoelectric shift-to-digital converter - Google Patents

Abstract

The invention relates to the field of automation and computer technology and is intended for use in converters of angular displacements in code. The aim of the invention is to improve the accuracy of the converter. Dp this in the converter containing the emitter, code discs with code tracks, a photodetector, three zero-body, trigger, AND elements, a counter and a register, a multiplication unit, a pulse shaper, a frequency divider and an inverter are entered, and the code tracks of the disks have +1 strokes. With a relative movement of the disks, the light flux of the radiator is modulated by the disks and fed to the photodetector. From its output through the null-organ, the signals arrive at the trigger. The signals from the photodetector simultaneously arrive at the multiplication unit, where they are multiplied by the number 2. These signals through the pulse shaper, the inverter and the zero-body arrive at the inputs of the AND elements, the operation of which is controlled by a trigger. From the output of the pulse former, the signals simultaneously arrive at the input of the frequency divider, where they are divided by the number (). From its output, the signals pass a null organ and control the operation of the trigger and register. From the element outputs, And signals control the operation of the counter. At the same time, from the output of the element And each time they reset the counter to the initial state, and from the output of another element And form the information number in the counter. Each time the code is updated, the register and the counter are reset. This makes it possible to increase the accuracy of the converter during positional acquisition of information. 2 Il. i O)

Description

one . The invention relates to the field of automation and can be used for the systems converting linear or angular movements into a code.

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

FIG. The converter circuit is shown; figure 2 timing diagrams of his work.

The converter contains emitter 1, which includes the illuminator and the focusing lens, disks 2 and 3 with code tracks 4, photodetector 5, multiplication unit 6, pulse shaper 7, frequency divider 8, inverter 9, zero-organs 10-12, trigger 13 , Elements And 14 and 15, counter 16 and register 17.

The converter works as follows.

When moving disk 2 relative to disk. The 3 light flux from the emitter 1 is modulated by code tracks 4 and fed to a photodetector 5. At its output, a signal 18 is generated (Fig. 2):

and, and sin (2 + r) ot,

whose period is equal to

T, 1 / (2% 1) and,

where n 1,2, ... is any integer;

, WITH - angular velocity of movement

disk 2 relative to disk 3.

The signal 18 in block 6 is multiplied by the number 2 and converted to the signal 19 (FIG. 2) with amplitude

and, and. „sin 2 (,) cot.

and period of following

T 1/2 () with.

After conversion in shaper 7, signal I9 is converted into a sequence of pulses (20 in Fig. 2) and is fed to the input of frequency divider 8, where it is divided by number (). At the output of the divider 8, a signal 21 is formed with a period T

T 1/2 (o.

Thus, three sequences of signals 18, 20 and 21 are formed in the converter, while the signal 21 shifts in phase with the movement of the disk 2 in relation to the signal from the output of the photodetector 5. Since

five

o

P

five

thirty

g

40

50

55

112

the period of the signal 21 is the equivalent of moving the disk 2 by 2T

the order - „t, -, it is obvious that in the converter the displacement by

2fr. 7, j matches this

the same number of j periods of the signal 18, which is located in the time interval dTz, equal to the phase shift between the signals 18 and 21.

In the converter, the origin corresponds to zero phase shift at j 0. The displacement by 180 corresponds to the condition under which the phase shift between signals 18 and 21 is equal to half the period of signal 18.

The angular displacement of disk 2 by 21G corresponds to the condition in which the phase shift between signals 18 and 21 is equal to the period of signal 18, in which 2 periods of signals 19 fit.

In the positional acquisition of information on the movement of the disk 2, signals 18, 20 and 21 are fed to the inputs of the null organs 10-12, respectively. At the outputs of the zero-organs 10 and 11, control signals 22 to 23 are formed at the instants of the transition of signals 18 and 20 through zero. They control the operation of the flip-flop 13, at the direct output of which signals 25 are generated with a duration equal to the phase shift between signals 18 and 21. Signals 24 from the former 7 are inverted by inverter 9 and after the zero-body 12 arrive at the inputs of elements And 14 and 15. element And 14 signals 26 with a number in each measurement cycle equal to the offset relative to the origin by

2 ir. - j, arrive at the counting input

counter 16.,

The measurement cycle, equal to the period of signal 21, is completed each time at the time of the appearance of signal 23, which simultaneously gives permission to erase the information in register 17 recorded in the previous cycle. It gives permission to overwrite the current information about the amount of movement from counter 16 to the zero register 17, which is reset to zero by the first signal from the output of the And 15 element (27 in Fig. 2). Register information

12

17 is stored until the end of the cycle, equal to the period of signal 21.

Claims (1)

Invention A photoelectric transducer translates into a code containing an optically coupled emitter, a lens, a first disk with a code track, a second disk with a code track, and a photodetector, the output of which is connected to the input of the first null organ, the output of which is connected to the first trigger input, the second zero -organ, the output of which is connected to the second input of the trigger and the control input of the register, the third null-organ, the output of which is connected to the first inputs of the first and second element And, the first output of the trigger is connected to the second the course of the first element And, the second output of the trigger is connected to the second input of the second element And, the outputs of the first ; Editor A.Petrov Fig2 Compiled by Y. Kotov Tehred L. Serdyukova Proofreader G. R & shetnik Order 7823/58 Circulation 922 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 and the second elements And are connected to the information input and the control input of the counter, respectively, the outputs of the counter are connected to the corresponding inputs of the register, characterized in that, in order to increase the accuracy of the converter, the multiplication unit, pulse shaper, frequency divider and an inverter, and the code tracks of the first and second disks are made with the number of lines N 2 +1, where n is a natural number, the output of the photodetector is connected to the input of the multiplication unit, the output of which is connected to the input of the pulse shaper, output D of which is connected to the inputs of the inverter and a frequency divider, the output of which is connected to the input of the second null organ, the output of the inverter is connected to the input of the third null organ.