SU1368633A1 - Photoelectric autocollimator - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure angles in metrology and mechanical engineering. The purpose of the invention is to improve the accuracy of angle measurement by using a mask made in. the form of two slots located at a given angle. The mask allows the angular displacement of the measurement object to be converted into an electrical signal whose duration is proportional to the angular displacement. The scanner 3, mechanically associated with the mark 2, provides with a beam splitter 5 and lens 6 a scan of the light spot reflected from the object 10 in the plane of the mask of 7 sec. Two slits located at a given angle. The time between the moments of hit of the spot on the slit is proportional to the angular position of the object 10. This time is calculated using the recording unit 9, which is connected to the source of the control voltage 4. 4 Il. about s

Description

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uh so

ten

one

The invention relates to a measurement technique and can be used to measure angles in metrology and mechanical engineering.

about

The purpose of the invention is to improve the accuracy of measurement of angles by using a mask made in the form of two slits located at a given angle.

FIG. 1 shows a photoelectric autocollimator circuit diagram; in fig. 2 shows an embodiment of the mask; in fig. 3 is a block diagram of the registration unit; Figures 4 to 15 show timing diagrams for the operation of the auto-explorer.

The photoelectric autocollimator contains a radiation source 1, a mark 2 made in the form of a plate with a 20 round hole of small diameter, a scanner 3 with a source of control voltage 4, a beam splitter 5, a lens 6, a mask 7, a photodetector 8, a recording unit 9, and an object 10 25

Block 9 registration (Fig. 3) contains the selector 11 pulses, trigger

12, a counter 13, a clock pulse generator 14, a random access memory 15, an arithmetic logic unit 16, a persistent storage device 17, a decoder 18, and an indicator 19.

Photoelectric autocollimator works as follows.

The light beam from the radiation source 1 (Fig. 1) passes through the opening of mark 2 and the beam splitter 5 is directed to the lens 6. The light reflected from the object 10 passes through the lens 6 of the beam splitter 5 and is collected in the focal plane of the lens 6 on the mask 7. Thus On mask 7, an image of mark 2 is obtained, corresponding to a light of a common point. The signal from the output of the source 4 of the control voltage is applied to the registration unit 9 (Fig. 4a) and the scanner 3, which provides translational movement of the mark 2, and accordingly, its image along the mask 7, according to a linear law (Fig. 2 position A , Fig. 4b). With the passage of the beam of the slit I and II in the period of the forward scan stroke (T), two light pulses are formed, the time intervals between which are equal (Fig. 4c).

When turning the object 10 at some angle oi. which is needed out of 13686332

measure, the sretovy ray will move along the mask as shown in fig. 2 (position B), and the time interval between pulses will become equal to o (fig. 4d).

The known equation for measuring angles with autocollimators is

40

45

50

OS

d 2f

(one)

Where

ot - measured angle; f is the focal length of the lens;

d is the linear displacement of the image of the mark relative to the initial position. In the proposed autocollimator (Fig. 2)

  -l lx: Y have a Xg X, their t g 9

where 9 is the angle between the fissures. Besides

35

- y,

V v

C | - one

(2)

(3)

Where

V is the coupling coefficient between the linear displacement of the lines A and B and the difference in pulse durations € and Tj.

Substituting (3) into (2) and (1), we obtain the equation for measuring the angles of the proposed autocollimator:

L / -

one

2f

yt

(.) k (€, -r,) (4)

where k is the conversion factor.

From expression (4) it can be seen that by changing the angle E, it is possible to obtain various sensitivities of the autocollimator.

The registration unit (Fig. 3) works as follows.

Pulses from the photodetector are selected by the pulse selector 11 and fed to the counting input of the trigger 12, which generates pulses of duration C, (C) (Fig. 4e, e), during which the counter 13 is filled with clock pulses of the generator 14 clock pulses. The synchronizing pulses install the trigger 12 into O, excluding from its output signal 55 pulses from the photocurrent during the reverse scanning stroke (T). At the output of the counter 13, a binary code is generated, corresponding to the duration e, and c 2.

OS

d 2f

(one)

Where

ot - measured angle; f is the focal length of the lens;

d is the linear displacement of the image of the mark relative to the initial position. In the proposed autocollimator (Fig. 2)

  -l lx: Y have a Xg X, their t g 9

where 9 is the angle between the fissures. Besides

- y,

V v

C | - one

(3)

Where

V is the coupling coefficient between the linear displacement of the lines A and B and the difference in pulse durations € and Tj.

Substituting (3) into (2) and (1), we obtain the equation for measuring the angles of the proposed autocollimator:

L / -

one

2f

yt

(.) k (€, -r,) (4)

where k is the conversion factor.

From expression (4) it can be seen that by changing the angle E, it is possible to obtain various sensitivities of the autocollimator.

The registration unit (Fig. 3) works as follows.

Pulses from the photodetector are selected by the pulse selector 11 and fed to the counting input of the trigger 12, which generates pulses of duration C, (C) (Fig. 4e, e), during which the counter 13 is filled with clock pulses of the generator 14 clock pulses. The synchronizing pulses set the trigger 12 to O, excluding from its output signal the pulses from the photocurrent during the period of reverse scanning (T). At the output of the counter 13, a binary code is generated, corresponding to the duration e, and c 2.

The duration code is stored in the random access memory 15 and, after completion of the measurements, together with the duration code is fed to the input of the arithmetic logic unit 16. In addition, the input of the arithmetic logic unit 16 receives data from the fixed memory 17 that stores the data on transformation k in expression (4) and the program of operation of the arithmetic logic unit 16. Fixing the initial angular position of the object is determined by the moment of writing the code in the random access memory TBE 15 and can zadavats, the operator or automatically. After completing the measurements, the arithmetic logic unit 16 solves equation (4) and the calculated result is deciphered by the decoder 18 and displayed on the indicator 19.

In the autocollimator, as a pulse selector, as an example, in the simplest case, a porous device on the K55CHSA2 comparator can be used, a K155TV1 microcircuit can be used as a trigger, and a K15IE 7 microcircuit can serve as a trigger. The operational memory, the arithmetic logic unit and the decoder are made on the single-chip central processing unit KP580IK80, the permanent memory is set on the K573RF1 chip, and the indicator is on the LED matrix.

Claims (1)

Invention Formula A photoelectric autocollimator containing an optically coupled radiation source, a brand, a beam splitter, a lens, a scanner with a source of control voltage, a photodetector designed to be installed after the beam splitter in the reflected light The transducer can be used with a 25 flow lamp, and a registration unit, which is incandescent. The brand can be filled in the form of an opaque plate with a round hole of small diameter, a rectangular prism or a flat parallel plate is used as a beam splitter, and a sawtooth voltage generator loaded onto a piezoelectric element is used as a scanner. The photodetector can be made in the form of a photodiode. Due to the fact that, in order to increase the accuracy, the scanner is mechanically connected with the brand, the autocollimator is equipped with a mask set in 0 of the objective focal plane in front of the photoreceiver and made in the form of two slots located at a given (not equal to iT / Z) angle, one of which is oriented orthogonal to the brand's trajectory. A / h Fig2  Sync I input