SU1179527A1 - Converter of shaft turn angle to time interval and number - Google Patents

Abstract

1. A TURNING ANGLE CONVERTER OF THE SHAFT INTO THE INTERVAL OF TIME AND A CODE containing the first and second radiation sources optically connected via a first code disk with slots to the first and second photodiodes, a third radiation source and an optically coupled photodetector, an engine kinematically connected to the first code disk, the first radiation source and the photodetector are located on the crank mounted coaxially with the first code disk on the input shaft of the converter, the second and third radiation sources and the photodetector and fixed, trigger, And element, a counter, characterized in that, in order to increase the resolution of the converter, three pairs of optical signal conditioners, three pulse drivers, two single vibrators, a recording unit, a reducer and a second code disk with m large-scale crevices, articulated with the motor shaft and the input shaft of the gearbox, the output shaft of which is articulated with the first kodo1M .. disk, the third radiation source and c. 13 / photodetector is installed against m large-scale slits of the second code disk, pairs of optical signal conditioners are installed on the same optical axis between the respective radiation sources and photodetectors on both sides of the code disks, the outputs of the first, second and third photodetectors are connected to the inputs of the corresponding pulse formers, the outputs of the first and second pulse shapers are connected to the trigger inputs, the first output of which is connected to the first input of the element I, the second input is connected to one with the third output (L pulse generator, the second trigger output is connected via the first one vibrator to the first input of the registration unit, to the input of the second one vibrator, the output of which is connected to the control input of the counter, whose information input is connected to the output of the element I, the output of the counter 4 is connected with the second input of the resistive unit. Q1 2. Transformer of claim 1, characterized in that the optical signal driver contains a lens, a group of optical fibers, an annular and frame holder, the lens is placed on the bird axis of the imager in front of the annular cage, which is connected to the input ends of a group of optical fibers, the output ends of which are connected to a frame cage made in the form of a rectangle, the sides of which are proportional to the linear dimensions of the slits of the code disks.

Description

The invention relates to a measurement technique, in particular, to analog-to-digital converters with optical reading of information.

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

FIG. 1 shows a functional diagram of the converter; in fig. 2 - a pair of optical .transformations of teles (sections A – A, B – B, B – B, G – D); in fig. 3 and 4 are timing diagrams that illustrate the operation of the converter.

The converter contains input shaft 1, crank 2, code disks 3 and 4, photodetectors 5-7, sources of 8-10 radiation, gearbox 11, engine 12, engine shaft 13, slots 14-1 of code disks 3 and 4, pairs 17-19 optical signal conditioners, pulse shaper 20-22, trigger 23, element 24, one-shot 25 and 26, counter 27, registration block 28. Each pair 17-19 of optical signal conditioners (Fig. 2) contains lenses 29 and 30, ring holders 31 and 32, groups 33 and 34 of optical fibers, frame holders 35 and 36.

The Converter operates as follows.

The transform angle about is defined by the angle of rotation of the crank 2, on which the radiation source 8, the photodetector 6 and the pair 18 of the optical signal conditioners are mounted. Engine 12 fulfills this angle by rotating the code disk 4 and through the reducer 11 with the reduction U of the code disk 3. The slit 14 forms the measurement start signal and is the initial mark forming the initial pulse 37 (Fig. 3), which is output by the photodetector 6. At the same time photodetector 7 is provided with a signal forming a large-scale pulse 38 (Fig. 5). Simultaneous occurrence of the initial 37 and large-scale 38 pulses is achieved by pre-adjusting code disks 3 and 4, at which they are set so that slots 14 and 16 are opposed and to one another, ie, had the same offset angle relative to the position of the crank 2. The installation of the code disks 3 and 4 is checked by the coincidence of the signals from the photodetectors 5 and 7 in time.

If the shaft 13 of the engine 12 rotates at a constant speed, then the photodetector 7 produces pulses 38 at equal intervals of time. If it rotates irregularly, these intervals change. FIG. 3 shows the change in the intervals between the pulses 38 during the acceleration of the engine 12.

If the number of revolutions of the shaft 13 and the code disk 4 is equal to P (, then the number of revolutions of the code disk W, p. I.e., therefore, until the slot 15, forming the final pulse 39 (Fig. 3), passes the corner, the slot 16 (or slit, if) can pass by the photodetector 7 several times. As a result, a number R of pulses 38 is output, which, despite possible inconvenience of rotational speeds of the code disks 3 and 4, is proportional to the value of the converted angle around the time interval t between pulses 38 t on the number of revolutions n, but each pulse 38 corresponds exists one and the same angle of rotation of the code disk 3

21G / Urn

Therefore, the number R of pulses 38, between the initial and final pulses 37 and 39, is equal to

about I (Urn RMnte er -g jToo),

where integer is the integer part of a number. Between the moment of issuing the R-ro pulse 38 and the moment of pulse 39, the code disk 3 is rotated by some other angle. Since the time intervals between the pulses 38 are small, it is possible with good reason to assume the speed of rotation of the shaft 13 over the last such interval to be constant. Then the angle L in can be estimated by the time interval Q (Fig. 4) between the R-M pulse 38 and the pulse 39 as

Q

/ i- / J-p-.

where P is the time interval between the R and (R + 1) -ro pulses 38. Urn P Although the intervals P depend on the speed of rotation of the shaft 13 and can vary, each such interval corresponds to the same angle 9, i.e. . counting the number of pulses 38 even at an inconsistent speed of rotation of the shaft 13 makes it possible to accurately convert the main part of the angle od. Then for the whole angle, we can write about ((RMl.g.4-, (Q Q IT: (This equation establishes the relationship between the transformation results and the angle oi. This shows that the value calculated from it does not depend on the number of revolutions n f of shaft 13, since the ratio Q / P u / V / 3 does not depend on n, if n, const. If the error is introduced, the less, h is less than the time intervals between the outputs of pulses 38. Equation (1) defines the conversion function at (R-1) Q / P, Q / P can be neglected and then the K-OTsG-p will be used by the AOs 20-22 on the leading fronts of the signals emitted by the photo-receivers 5-7 to form The initial, scale, and final pulses are 37-39, respectively.When a 37 pulse appears, the flip-flop 23 is set to the single position, and the signal from its single shoulder permits the passage of the pulses 38 from the output of the imager 22 through the AND 24 element to the counter input 27. At By the appearance of a pulse 39, the signal from the output of the generator 74 21 sets the trigger 23 to the zero position.At the same time, the element 24 ceases to pass pulses 38 to the input of the counter 27, in which the number R is fixed, one more (due to the pulse 38) the number of elementary angles y9, ulozhivshihs in the converted carbon with. At the same time, the signal from the zero arm of the trigger 23 acts on the one-shot 25. The pulse from its output enters the registration unit 28 and opens the key block 29. The code R from the counter 27 is rewritten into the registration block 28. A feature of the converter operation is that it considers pulses not from an autonomous generator, whose frequency may not be related to the speed of the turn of the shaft 13, but large-scale pulses 38, therefore the rotation of the shaft 13 may be unstable. The result of converting the angle to the code does not affect this. A further reduction in the random component of the conversion error is provided by the optical signal drivers 17-19. A pair of optical signal conditioners (Fig. 2) works as follows. The light from the radiation source 8 is collected by the lens 29 into a parallel beam that enters the inputs of the optical fibers 33, from where it falls in the form of a narrow strip onto the surface of the code disk 3. When the slit on the code disk 3 passes by this band of light, all the inputs are illuminated optical fibers 34, which collect light in a circular beam directed by the lens 30 onto the surface of the photodetector 5. As a result, the light pulse has a large amplitude and, therefore, steep fronts, which leads to an increase in the resolution of paddle as a whole.

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Claims (2)

1. A SHAFT ANGLE TRANSDUCER CONVERTER AND A CODE containing the first and second radiation sources optically connected through the first code disk with slots to the first and second photodetectors, <the third radiation source and a photodetector optically connected to it, an engine kinematically connected to the first the code disk, the first radiation source and the photodetector are located on a crank mounted coaxially to the first code disk on the input shaft of the converter, the second and third radiation sources and photodetectors are installed immovable, trigger, element And, counter, characterized in that, in order to increase the resolution of the converter, three pairs of optical signal conditioners, three pulse conditioners, two single vibrators, a recording unit, a reducer and a second code disk with w wide slots are introduced into it articulated with the motor shaft and the input shaft of the gearbox, the output shaft of which is articulated with the first code ..., disk, the third radiation source and photodetector are mounted against m scale slots of the second code disk, pairs of optical signal teley installed on the same optical axis between the radiation sources and photodetectors on both sides of the code disk, the outputs of the first, second and third photodetectors are connected to the inputs of respective pulse generators, outputs of the first and second pulse generators are connected to. inputs of the trigger, the first output of which is connected to the first input of the And element, the second input of which is connected to the output of the third pulse shaper, the second output of the trigger is connected through the first one-shot to the first input of the recording unit, with the input of the second one-shot, the output of which is connected to the control input of the counter, information the input of which is connected to the output of the And element, the output of the counter is connected to the second input of the registration unit. 2. The Converter according to claim 1, characterized in that the optical signal conditioner comprises a lens, a group of optical fibers, an annular and frame holder, the lens is placed on the optical axis of the former in front of the annular holder, which is connected to the input ends of the group of optical fibers, the output ends of which are connected with a frame clip made in the form of a rectangle, the sides of which are proportional to the linear dimensions of the slots of the code disks.