SU1350502A1 - Optronic angle-measuring device - Google Patents

Abstract

This invention relates to a measurement technique. The aim of the invention is to increase accuracy and speed, as well as to expand the measurement range by eliminating fluctuation errors, except. mechanical parts, as well as providing angle-tangent angle conversion. The device contains two radiators 2, illuminating the faces of the separation prism 3 with radiations that differ in phase from each other by an angle smaller than 180 °. Lens 11. projects the image into the analysis plane of the diaphragm 12, behind which is placed the receiver 5. At the output of the photodetector, a signal is formed, the phase of which changes with respect to the reference signal depending on the angle of rotation, this signal goes to The phase meter 17 receives a signal from the reference photodetector 6-Phase meter 17, measures the phase shift, determines the angle of rotation. The output signals from the power supply unit 15 are maintained at which the difference between the output signal of the reference photodetector 6 input signal from unit 15 to a power equal to 90. Thus there is a pressure reduction phase. 3.p. 1 f ly-2-yl. s (00 L ate of SP of IC.

Description

The invention relates to measuring equipment, in particular to automatic angle measuring devices, and can be applied in machine tool industry, in instrument engineering, in construction, during equipment installation, in geodesy.

The purpose of the invention is to improve accuracy and speed, as well as expanding the measurement range by eliminating errors from fluctuations, eliminating mechanical parts, and also providing angle-tangent angle conversion.

FIG. 1 is a block diagram of an incident beam recorder; in fig. 2 is a block diagram of a device for recording in a re-reflected beam.

The device contains a lens 1, two radiation sources 2, separation prism 3, aperture diaphragm 4, beam-splitting element 5, reference photodetector 6, reference amplifier 7 (AC), phase-shifting blocks 8 and 9 connected to the Inputs of the corresponding source 2. Described elements can be combined into collimator 10.

The device also contains an optically coupled second lens 11, a diaphragm 12 and a main photodetector 13, as well as a main amplifier 14, an adjustable emitter power supply unit 15, a phase-sensitive indicator 16 connected to the power supply unit 15 and a reference amplifier 7, a phase meter 17 and a function transducer 18 of magnitude tangent angle; The phase meter 17 is connected to the main amplifier 14 and the phase-sensitive indicator 16.

The device (Fig. 2) also contains a re-reflective surface 19 (formed on the object's surface) or a plate (fixed with the object), the separation prism 3 is made with a chamfer 20, while the main photodetector 13 and the main amplifier 14 are installed behind the prism 3 in the reflected ray.

The power supply unit 15 is designed to form two modulated in antiphase stresses, and the phase-shifting units 8 and 9 are designed to provide a phase shift of + / i and -jS, where ./3 45 °.

The device works as follows.

Diaphragms 4 and 12 may be rectangular. Phase sensitive indicator 16, if the phase of the incoming signal is shifted relative to the reference signal by 90, produces an output signal equal to zero. If the phase of the incoming signal is shifted relative to the reference signal by an angle greater or less than 90 °, then the indicator 16 produces a positive or negative control signal proportional to the phase shift. As indicator 5 1b, it is possible to use a device based on a signal multiplier.

The power supply unit 15 produces two voltage modulated in antiphase. The phase shifting block-8 shift- 0 phase of one of the voltages at a small angle + jb, less than .45 °. and the phase-shifting unit 9 is neither the angle - / з. These voltages are applied to sources 2. Thus, each of the sources 2 emits a variable luminous flux with equal amplitudes and phases that differ from each other by. angle somewhat smaller or larger

180.

0 Light from sources 2, reflected from the faces of separation prism 3, illuminates two zones of the diaphragm 4. These zones are separated by the edge of the prism 3. The illuminated zones are projected by 5 lenses 1 and 11 into the plane of the diaphragm 12. If the optical axes of the collimator 10 and the lens 11 is parallel, then each half of the diaphragm 12 is illuminated by an appropriate source of 0 nd 2. At the output of the photodetector 12 there is a constant signal and an alternating signal proportional to sin, shifted in phase by 90 ° with respect to the signal coming from the power supply unit 15.

When you rotate the collimator 10 or the system of the lens 11, the diaphragm 12 and the photodetector 13 on some 1 d d part of the diaphragm 12, illuminated by one of the sources 2, it will be larger than the diaphragm, illuminated by another source 2,

The phase of the variable signal at the output of the photodetector 13 varies approximately in proportion to the amount of movement of the diaphragm 4.

At the same time, a luminous flux from sources 2 enters the photodetector 6.

five

0

five

In that case, if the luminances of the sources 2 are the same, the output of the amplifier 7 is a variable signal proportional to sin / and shifted in phase by 90 relative to the signal from the power supply unit 15.. If one of the emitters becomes brighter than the other, the phase of the signal will change. The phase-sensitive indicator 16 generates a control signal, which is fed to the power supply unit 13. This signal changes the signals sent to sources 2 until the equalities of the sources 2 are obtained.

Simultaneously, the signal from the amplifier 7 is fed to the phase meter 17 and serves as a reference signal. Phase meter 17 also receives a signal from amplifier 14. Phase meter 17 measures the phase shift between the signals from amplifier 7 and amplifier 14,

The magnitude of the rotation angle d for small angles L / 5-10 (at which, tg q Lf) is proportional to the phase shift and is determined from equation 24X. „Lik 1

ctg kof,

05 ctg

such values ctg / (, f f, 1, so that the reduction coefficient k is much greater than unity, ie, k 1.

The strict relationship between the rotation angle oi and the phase shift i / is determined by the expression

Z / 1XZf

tg wh

ctg l

"

one

Itg y

ctg.

2fi5 g /

 mtg (4.

That is, at large angles tf, the relationship between I / and (Y is not completely linear; if, however, a functional converter 13 is connected to the output of phase meter 17, measured by a phase meter, the angle qj is converted to the value tgtc,

Then the output signal from converter 18 is proportional to the angle of rotation with (. At large angles of rotation.

The principle of operation of the device when the beam re-reflection (Fig. 2) is similar.

The fact that the device has a large phase reduction is predicted as follows.

The modulated light output to the photodetector 13 is equal to

f

o5

1 focal length object 35

t willow;

aperture width.

- - scale factor;

TO.

/ b - phase shift created by the phase-shifting unit (L 45),

dx is the amount of movement of the image of the diaphragm;

- 5 1. . ., „

of

reduction factor Measured by a phase meter 17 with a certain scale, the phase shift angle is the angle of rotation.

As can be seen from this expression, the device has a certain phase reduction, i.e. a small angle of rotation corresponds to a large phase shift q. The reduction factor is chosen constructively, based on the required accuracy, by adopting

(j h (r + jx) sin (wt +

+ ft,)

- Bj S

..

B (- - 4 x) sin (wt

-y5) A, sin (cot + / 5) - A sindxjt

- / 9) (A - A2) sin tat cos / 3- + + (A + Aj) sin / 3 coswt (A, -A2) cos / J cos ((jt - 90 °) + (A / + + Pi ) si-nI) costot,

de Bj, Bj is the brightness of the emitters 2; S is the design parameter of the optical path, depending on the aperture diaphragm, focal length, etc .; transmittance of collimator 10 and receiver;

h - the height of the diaphragm 13;

1 - aperture width (in

measurement direction);

about . p to r

1350502

light amplitude

flow, illuminating one part of the diaphragm; the amplitude of the light current g, illuminates another part of the diaphragm

de

tgq

() (- 90 °) + (Ai + A2) sin sinO ° (Ai-A2) (- 90) + (A,) cos / «cosO

 If the luminances of sources 2 are the same (BZ Bj), then

.cosft -2jx ctg / 5 1 sin 1

 -ctg / i 1

From the expression it can be seen that in the absence of a mismatch, the phase of the sum signal is zero, and when rotated by angle d, the phase of the signal fed to photo receiver 3 relative to the reference signal varies in proportion to the angle of rotation.

Similarly, the modulated luminous flux entering the photodetector 6 is equal to

F4, (A - A g) cos / 3sinu) t + (A - - A 2) S in / 3 with su) t.

The phase of the sum signal Lf is

t

-, (Ba - Br) cos / i (B, - + C) sin ft. At equal capacities, the phase of the total signal is zero, and when the brightness of one of the sources changes, the phase of the signal fed to the photodetector 6 changes with respect to the reference one and the phase-sensitive indicator 16 produces a control signal.

Since the phase shift between the signals coming from amplifiers 7 and 14 is measured, even with incomplete alignment of the sources 2, the error due to instability of the emitters will be reduced.

/ 1 is the phase shift created by the phase-scaling block.

The phase of the sum signal t is determined from the ratio

(Ath-A) p05; 9

(Ai + Aj) sin

Claims (2)

1. An optical electronic measuring device containing two emitters, an adjustable power supply unit for the emitters, an aperture diaphragm, a lens, a beam-splitting element, a main and reference photodetectors, the outputs of which are electrically connected to the inputs of the main and reference amplifiers, differing from that, in order to increase accuracy and speed, it is equipped with two phase-shifting units, made with the possibility of providing a phase shift by an angle of + / s and -ft, where (5 45, phase meter and phase-sensitive indicator, i dy phase shifting units are connected to the power supply unit outputs, the output of the first phase shifting unit is connected to the input of the first radiator, the output of the second phase shifting unit is connected with the input of the second radiator, the output of the main amplifier is connected to the first input of the phase meter, the output of the reference amplifier is connected to the second input of the phase meter via phase-sensitive an indicator, the first input of which is connected to one of the inputs of the power supply unit, and the output of the indicator is connected to the input of the power supply unit. t 2. The device according to claim 1, characterized in that, in order to increase the measuring range, a functional value converter is additionally introduced into it the angle in the tangent, the input of which is connected to the output of the phase meter. JSS ie1i sixteen Editor S.Patrusheva Compiled by E.Glazkova Tehred L. Oliynyk Proofreader A.Obruchar Order 3249/40 Circulation 677 Subscription VNIIPI State Committee of the USSR for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5  .. ".-" ..-- .. "..". ".-..---" in "cc ------ - - - - - Production and printing company, Uzhgorod, - st. Project, 4 2