SU1282007A1 - Device for measuring instantaneous rotational speed of object - Google Patents

Abstract

The invention relates to a measurement technique and makes it possible to reduce measurement errors. From the code of the coincidence circuit 8, high-frequency packs n, and Uj, the number of pulses in which carries information about the instantaneous angular velocity, arrive at the inputs of the subtracting and summing counters 20 and 21. The subtractive counter 20 performs the operation of subtracting the number

Description

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Yu

from go

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pulses of the reverse flyback p are from the number of pulses of the forward n packet, and the summing counter 21- produces the addition of high-frequency packs n, and p. The subtracting and summing counters 20 and 21 are recorded and zeroed by pulses arriving at their inputs from the output of divider 10. The digital code from the outputs of the reading and summing counters 20 and 21 carries information about the difference in the sum of forward and reverse beams and enters dividing circuits 22, dividing and multiplying by a constant angular velocity, which is a measure of the instantaneous angular velocity of an object. 3 il.

one

The invention relates to measurement technology and can be used. Calibrated to measure instantaneous velocity oD beK j a, for example, shafts in a 1-record magnesium apparatus. five

The aim of the invention is to reduce errors.

Figure 1 shows the functional diagram of the device; Fig. 2, which explains the operation of the device; on fig.Z - relative location of photo receivers.

The device contains a raster disk 1 rigidly fixed on the j MOM shaft 2, on one side of the raster disk 1 there is an electro-optical scanner 3, and on its other side in the direction of its rotation there are fixedly fixed 20 first position photodetector 4, piiBHOM half the distance by the adjacent marks of the raster disk 1, from which the second photodetector is 5 noj-yuzhein, at the same 25 distance from which the measuring photodetector is fixed. The first 4 and second 5 photo sources are connected to the first and second inputs of the circuit 7 of the form, respectively.

NIN strobe, which is connected to the first input of the coincidence circuit 8, the second input of which is connected to the measuring photoreceiver 6.

The device also contains 5

torus 9 of the reference frequency, the output of the KOTOR is connected by JC to the third input of the circuit 8 and coincides with the input of the divider 10.

The second and third outputs of the splitter 10 are connected respectively to the third 40 and fourth inputs of the gate formation circuit 7, and a quarter of the output with

the second input of the processing unit 11, which is connected to the output of the coincidence circuit 8 by the first input. The output of block 11 processing is connected to the registering unit 12.

The device also contains a sawtooth voltage generator 13, the input of which is connected to the first output of the divider 10, and the output to the input of the electro-optical scanner 3. The latter contains optically coupled optical quantum oscillator 14, horizontal 15 and vertical 16 reflectors.

The strobe formation circuit 7 comprises a sequentially connected trigger 17 and the first circuit 18 and a second circuit 19, the first input of which is connected to the second output of the trigger 17. The outputs of the first 18 and second 19 circuits And are connected and are the output of the strobe formation circuit 7 .

The processing unit 11 contains a subtracting 20 and a summing 21 counters, the first inputs, which are connected and form the first input, the second inputs are also connected and form the second input of the processing unit 11. The latter contains a tactile dividing circuit 22, the first input of which is connected to the output of the subtracting counter 20, and the second input - :. with the output of the summing counter 21. The output of the dividing circuit 22 is the output of the processing unit 11.

I

The device works as follows.

 A raster disk 1 is fixed on the object shaft 2 being studied, the shaft is rotated. The light beam from the output of the optical quantum generator .. 14 falls on one of the faces

crystal horizontal reflector 15, where it undergoes total internal reflection. As a result of multiple reflections, the beam comes out and hits the face of the crystal, 5 of the vertical reflector 16, where, also undergoing reflection, goes outside and hits the raster disc 1.

When a voltage is applied from the sawtooth generator to horizontal crystals of the horizontal 15 and vertical 16 reflectors, the crystals change their refractive index. As a result, the light beam at the output of each of the reflectors 15 and 16 is displaced by a certain amount. As the beam passes through two mutually perpendicular deflecting deflectors 15 and 16, the resultant. the path of the beam is an arc. That is, in a 20 KIM manner, when applying a sawtooth voltage (Fig. 2) to an electro-optical scanner 3 at its output. a beam is formed which scans from the output of the strobe formation circuit 7, and to the third input — high-frequency filling pulses from the output of the generator 9 of the reference frequency. As a result, at the output of the coincidence circuit 8, a bundle of high-frequency pulses n, and n with a duration equal to t, Kt, and carrying information about the instantaneous angular velocity of the shaft, are formed.

Since the labels of the raster disk 1 move continuously, then there comes a moment when the next label crosses the border of the measuring photodetector 6. This leads to errors in the formation of pulses t, and, consequently, to measurement errors. Therefore, the first 4 and second 5 photodetectors are introduced into the device, the gate forming circuit 7, and the arrangement of the photodetectors is chosen so that the distance between the first 4 and second 5 photodetectors is positioned and

arc along with a constant angular distance between the second photoreceiver speed tO. The length of the beam scanning arc is equal to the length of the arc on which the first 4 and second 5 position photodetectors and measuring photodetector 6 are located (Fig. 3). ZO

When the beam moves in the direction of rotation of the shaft 2 along the transparent label of the raster disc 1, the measuring photodetector 6 generates a pulse g., (FIG. 2), the duration of which is 35

 ) g

S ™

where o) is the angular velocity of the beam; ij is the angular velocity of the label; S - the angular width of the label. When the beam moves in the direction opposite to the direction of rotation of the shaft 2, the pulse duration is equal to

..

. S

The 5 position and the measuring photodetector 6 are equal to half the distance between adjacent marks, and the length of the measuring photodetector is longer than the distance between the adjacent marks by the width of one mark.

It is with this arrangement of the photoreceivers 4, 5 and 6 and the introduction of these blocks it is possible to process the pulses t 1 oi oh mark, which at a given moment of time is located completely above the measuring photoreceiver 6, and do not process the pulses t and 2 from the one that crosses the measuring boundary photodetector 6.

Suppose the raster disk 1 is in such a position that its labels are arranged as shown in 45 in FIG. Since mark A is opposite the first photodetector of the 4 position, when passing a laser beam, a signal appears at its output

40

Wherein

u) lL

where it comes from

Suppose the raster disk 1 is in such a position that its labels are arranged as shown in 45 in FIG. Since mark A is opposite the first photodetector of the 4 position, when passing a laser beam, a signal appears at its output

and}

(. ,,

Secondly, having entered the first entry a triggered expression for an instantaneous angular velocity-50 Gera 17, it switches it so that it grows on the object. its first output is 1, and

the second is O. In this case, the first scheme,., and 18 transmits pulses arriving

the second input from the second output is the pulses of the forward and reverse stroke 55 of the divider 10 (figure 2), these pulses of the beam t, and “.j from the measurement output correspond to the time when the photodetector 6 enters the second beam passes over the left half of - the input of the coincidence circuit 8, to the first measuring photodetector 6. The second input of which enters the gate gate And 19 is closed at the first input O.

74

From the output of the strobe formation circuit 7, and to the third input are high-frequency filling pulses from the generator 9 output of the reference frequency. As a result, at the output of the coincidence circuit 8, a bundle of high-frequency pulses n, and n with a duration equal to t, Kt, and carrying information about the instantaneous angular velocity of the shaft, are formed.

Since the labels of the raster disk 1 move continuously, then there comes a moment when the next label crosses the border of the measuring photodetector 6. This leads to errors in the formation of pulses t, and, consequently, to measurement errors. Therefore, the first 4 and second 5 photodetectors are introduced into the device, the gate forming circuit 7, and the arrangement of the photodetectors is chosen so that the distance between the first 4 and second 5 photodetectors is positioned and

the distance between the second photoreceiver

The 5 position and the measuring photodetector 6 are equal to half the distance between adjacent marks, and the length of the measuring photodetector is longer than the distance between the adjacent marks by the width of one mark.

It is with this arrangement of the photoreceivers 4, 5 and 6 and the introduction of these blocks it is possible to process the pulses t 1 oi oh mark, which at a given moment of time is located completely above the measuring photoreceiver 6, and do not process the pulses t and 2 from the one that crosses the measuring boundary photodetector 6.

Suppose the raster disk 1 is in such a position that its labels are arranged as shown in FIG. 3. Since mark A is opposite the first photodetector of the 4 position, when passing a laser beam, a signal appears at its output

Thus, at the output of the strobe formation circuit 7, a strobe is formed at the moment of passing the beam along the left half of the measuring photodetector 6. Circuit 8 is closed at the first gate from the absence of a gate. High-frequency bursts of pulses n and n, corresponding only to mark B, are passed to the input of processing unit 11, as long as mark B moves over the left half of measuring photoreceiver 6 (FIG. 3). This is equivalent to the specified relative positioning of the photodetector A between the first 4 and second 5 photodetectors of the position indicated by the relative positioning of the photodetectors 4, 5 and 6.

Upon further movement of the raster disk 1, label A passes over the second photodetector of the 5 position, which switches the trigger 17 to another steady state. At the first input of the first circuit, And 18 O — it is closed, at the first input of the second circuit, And 19 1 — it passes pulses with the third output of the divider 10; As a result, at the output of the gate forming circuit 7, a gate is formed (Fig. 2), which is fed to the first input of the matching circuit 8. The latter only passes high-frequency packs n and p from the B mark, i.e. soot12

corresponding to the passage of the beam along the right half of the measuring photodetector 6 (Fig. 3). This continues until the mark B moves over the right half of the measuring photodetector 6,

Then, the next mark D passes over the first photodetector 4, which corresponds to finding the mark A above the left half of the photodetector 6, and the strobe formation circuit 7 again forms strobes (FIG. 2) corresponding to the times when the beam passes over the left half of the measuring photoreceiver 6.

G output of circuit B, high frequency bursts p and n, the number of pulses in which carries information about the instantaneous angular velocity, arrive at the first inputs of the subtracting 20 and the totaling 21 counters. Subtractive counter 20 produces one

The number of pulses of the reverse cycle n is counted from the number of pulses of the forward cycle n, and the summing counter 21 performs the addition of n, and n. Recording and zeroing of the subtracting 20 and summing 21 meters is produced by pulses arriving at their second inputs from the fourth output of the divider 10 ,

The digital code from the outputs of the subtractor 20 and the summing 21 meters carrying information about the difference (ti-Tj, and the sum (, + 2)) goes to the first and second inputs of the dividing circuit 22, which performs the division and multiplication by a constant value

oi

.Bi-lSj-.j n, + n 1

which is the measure

instantaneous angular velocity of the object. The digital code of the instantaneous angular velocity is fixed on the recording unit 12. The output of the processing unit 11 can be easily connected to the computer input for spectral analysis of the instantaneous angular velocity signal of the object.

Claims (1)

Invention Formula thirty A device for measuring the instantaneous speed of rotation of an object, containing a raster disk with marks attached to the object, and a source of light and a measuring photodetector, J5 optically matched via a raster disc and a processing unit connected to the output of the recorder, characterized in that, with the aim of reducing the error, it is entered 40 controllable electro-optical scanner installed between the light source and the raster disk, two position photo detectors, a gate formation circuit, a reference generator The 45 frequencies, the divider and the coincidence circuit, in this case, the distance between the photodetectors and the distance between the second photodetector and the measuring photoreceiver exceeds 50 times the distance between adjacent marks of the raster disk by the width of one label, the outputs of the photosensor poysenis are connected to the first and the second inputs of the formation circuit of st5555, connected by the output with the first input of the coincidence circuit, the second and third inputs of which are connected respectively to the output of the measuring photodetector and the output of the generator 71282007 8 pa of the reference frequency connected to it and the fourth input of the forma- tion circuit also with the divider input, the first strobe extension, and the fourth output to which is connected to the control of the first input of the processing unit, the second input of the electro-optical scanner whose input is connected to the output of the scheme, the second and third outputs - to the third - we are coincidences. (Rez. 2 h) i- Zone lzdzdly D7Lyu uud  F f AU N d P D P in and P in and si D U8. 3