SU600499A1

SU600499A1 - Shadow autocollimation device

Info

Publication number: SU600499A1
Application number: SU762330511A
Authority: SU
Inventors: Петр Петрович Боровский; Анатолий Павлович Копылов; Алексей Николаевич Королев; Эдуард Иосифович Красовский; Борис Валентинович Наумов
Original assignee: Предприятие П/Я Р-6681
Priority date: 1976-02-19
Filing date: 1976-02-19
Publication date: 1978-03-30

Description

(54) ТЕНЕВОЕ АВТОКОЛЛИМАЦИОННОЕ УСТРОЙСТВО(54) SHADOW AUTOCOLLIMATION DEVICE

Изобретение ошоснтс к оптическим прибо- рам дл нсследшани оптических характеристик прозрачных сред, а именно дл определенн пространсгвенной коррел ции составл вхцей градиента показате ш преломлени , и может примен тьс при исследовани х оптических неоднородностей, в которых отклшешш показател преломлени при изменении координат имеют стационарный характер, например при исследовани х в азродинамической ipy6e при установивишхс режимах.The invention is concerned with optical devices for investigating the optical characteristics of transparent media, namely, for a certain spatial correlation that was within the refractive index gradient, and can be used in studies of optical inhomogeneities, in which the refractive index of the refractive index changes stationary in nature, For example, in studies of the azydynamic ipy6e with the setting of its modes.

Известны теневые приборы дл исследовани прозрачных неоднородностей, ашлизирунхдие нх пространственные характеристики. Такие устройства состо т из двух идентичных частей, исследующих один и тот же участие среды под различными ракурсами; Ги, 2.Shadow devices for the study of transparent inhomogeneities are known, as well as their spatial characteristics. Such devices consist of two identical parts exploring the same media participation from different angles; Guy, 2.

Ближайшим по технической сущности к изобретению вл етс устройство, содержащее два раздельных идентичных теневых прибора, реагируккцих на составл ющую градиента показател преломленН исследуемой среды в двух выбранных точках про странства. Каждый из этих приборов состоит из осветительной - коллиматорной части с источником света и приемной части с теневой диафрагме и фотсшриемннком , отделенных от рабочих объеме с The closest in technical essence to the invention is a device containing two separate identical shadow devices, reacting to the component of the refractive index gradient of the medium under study at two selected points in space. Each of these devices consists of an illuminating - collimator part with a light source and a receiving part with a shadow diaphragm and a photo-lens, separated from the working volume with

исследуемот средот защитными стеклами. В процессе работы каждого прибора коллиматорный пучок света однократно проходит через соответствующий анализируемьга объем 3.examine the environment with protective glasses. In the process of operation of each device, the collimator beam of light passes once through the corresponding analyzing volume 3.

Определ емые коррел ционные характеристики процесса, развивающегос в среде, вычисл ютс путем совместны обработки сигналов, одновременно зарегистрированных на обоих приборах в виде временных реализаций дл р да рассто ний между анализируемыми объемами среды. Дл вычислени коэффициента коррел ции R (г) в этом сдучае (при условии однородности и изотропности пол ) примен етс формула.The determined correlation characteristics of the process developing in the medium are calculated by joint processing of the signals simultaneously recorded on both devices in the form of time realizations for a number of distances between the analyzed volumes of the medium. The formula is used to calculate the correlation coefficient R (r) in this case (assuming the field is homogeneous and isotropic).

где Jf Uc н UB () - текущие значени 1Ш1р жешш на выходе фотоприемников прибора А и прибора В, зарегистрированных в реализаци х при расстошш х между участками среды, через которые одновременно проход т свеювые пучки приборов А и В;where Jf Uc and UB () are the current values of 1W1r at the output of the photoreceivers of instrument A and instrument B recorded in realizations at distances between the medium sections through which the beam of instruments A and B are simultaneously passing;

TO радиусы-векторы, определ кхцие положение в пространстве ашлизируемых участков среды в выбранной шстеме координат;TO the radius vectors, determined by the position of the space in the spaced areas of the medium in the selected coordinate system;

Bji и©5 соответствугацие углы отклонени световых пучков, вызываемые наличием гра- g дкентов показател преломлени в анализируемых объемах и привод щие к по влению пропорциональных им электрических сигналов и Bji and © 5 correspond to the angles of deflection of the light beams, caused by the presence of gradients of the refractive index in the analyzed volumes and leading to the appearance of electrical signals proportional to them and

Большой объем вычислений по формуле (1) вызьшает йеобходимость использсжаки цифровой IQ В1,числительной техники, дл чего в частности требуетс применение аналого-цифровых преобразователей напр жени , а также множителыгых, квадрирующих и суммирующих устройств. Недостатком этого устройства вл етс также необходимость jg взаимного механического переме1чени лруг относительно друга обоих пртборов, вход щих в устршство , дл проведени измерений на различных рассто ни х 7 . Так как эксшгуатацдил данной ап паратуры обычно происходит в услови х воздействи вибраций, то необходимость эпос н емещешш налагает поБьпиенные требсжанв к жеспсости конструкции и ведет к ее усложнению.A large amount of computations using the formula (1) implies the need to use digital IQ B1, numerical technology, which, in particular, requires the use of analog-digital voltage converters, as well as multiplying, quadratic and summing devices. A disadvantage of this device is also the need for jg of reciprocal mechanical interchange between each other of the two devices included in the device for measuring at different distances 7. Since ekschguatatsdil of this apparatus usually occurs under the influence of vibrations, the need for an epic imposes a burden on the structural integrity of the structure and leads to its complication.

Цель изобретени - упрснцеиие коррел цио ной обработки сигиалсш та выходе устройства дл 25 определени коэффициента коррел ции н упрощение процесса изменени базы измерений.The purpose of the invention is to control the correlation processing of the sigal output of the device to determine the correlation coefficient and to simplify the process of changing the measurement base.

Это достигаетс тем, что в известном теневом устройстве, содержащем дэа теневых П1жбора, состо щих из коллиматорной осветительной части с ис- зо точикком света и приемнш части с теневой дкафрагл мш и фотоприемншсом, отделенных от рабочих объемов с исследуемой средой защитными стеклами, в одном из теневых приборсш установлен световозвращающий блок, вьшолненный в виде объектива с 35 размером зрачка, превышающим базу измерени , в фокальной плоскости которогоРасположено зеркало перпендикул рно к ттической оси, проход щей посредине между рабочиАШ объемами; перед фотоприемником находитс собирательна линза, «О входной зрачок которш сопр хжн с работами объе мами прибора, а («тическа ось второго теневого прибора ориентирована параллельно оптичеосой оси первого прибора и отстсмт от нее на рассто нии, меньшем размера области стационарности нсследуе- 45 мого процесса.This is achieved by the fact that in the well-known shadow device, which contains shadow shadow pickups, consisting of a collimator lighting part with a point of light and a receiving part with a shadow frame and phototransmitters, separated from working volumes with the test medium with protective glasses, in one of the A shadow device is fitted with a retroreflective unit, made in the form of a lens with a 35 pupil size exceeding the measurement base, in the focal plane of which the mirror is perpendicular to the ttic axis passing in the middle between abochiASh volumes; There is a converging lens in front of the photoreceiver, “About the entrance pupil is connected with the device volumes, and (the physical axis of the second shadow device is oriented parallel to the optical axis of the first device and is separated from it at a distance smaller than the stationary region of the studied process .

На чертеже представлена оптическа схема предлагаемого теневого прибора.The drawing shows the optical layout of the proposed shadow device.

Теневой прибор имеет источник 1 света, расположенный на оптической оси 00 конденсатора 2. 50 Его изображение можно рассматривать как вторичный источник света, размер которого ограничен величиной светового отверсти в зеркале 3, плоскость которого пересекает оптическую ось в месте изображеш1 источника 1 света при угле f между осью 55 00 и нормалью к зеркалу. Вторичный источник света рашоложсн в фокальной плоскости объектива 4, которьо : находитс р дом с защитным стеклом 5. Защитное стекло 5 представл ет собш плоскопараллельную пластину, отдел кнцую осветительную и 60The shadow device has a light source 1 located on the optical axis 00 of the condenser 2. 50 Its image can be viewed as a secondary light source, the size of which is limited by the size of the light hole in the mirror 3, whose plane intersects the optical axis at the image of the light source 1 at an angle f between axis 55 00 and normal to the mirror. The secondary light source is located in the focal plane of the lens 4, which is located next to the protective glass 5. The protective glass 5 is a flat-plane plate, separate light and 60

приемную часть прибора от исследуемой среды. Защитное стекло 6 идентично по размерам защитному стеклу S и отдел ет световозвращающий блок от исследуемой среды. Центры защитных стекол S и б наход тс на оптической оси 00, а их поверхности перпендикул рны .к ней. Световозвращающий элемент состоит из объектива 7, в фокальной плоскости которого расположено зеркало 8. Оптическа ось объектива 7 совпадает с осью 00. Конденсатор 9 р дом с зеркалом 3 таким образом, что его (эттическа ось Oi 0 и фокальна плоскость пересекают ось 00 в месте расположени вторичного источника света, при этом угол между ос ми составл ет 2v)- Центр зрачка собирательной линзы 10 находитс на рассто нии g от штической оси Oi Oj. Зрачок линзы 10 расположен в плоскости, штически сопр женнш посредством линз (4 и 9) с плоскостью, наход щейс в исследуемой среде. Пун. этом рассто ние между злементарными объемами II и 12, дл которых измер етс коэффици ент коррел ции, может быть выражено формулсжthe receiving part of the device from the medium. The protective glass 6 is identical in size to the protective glass S and separates the retroreflective block from the test medium. The centers of protective glasses S and b are on the optical axis 00, and their surfaces are perpendicular to it. The retroreflective element consists of a lens 7, in the focal plane of which mirror 8 is located. The optical axis of lens 7 coincides with the axis 00. The capacitor 9 is next to the mirror 3 in such a way that it (the ettic axis Oi 0 and the focal plane intersect the axis 00 at the location secondary light source, the angle between the axes being 2v) - The center of the pupil of the collecting lens 10 is located at a distance g from the axial axis Oi Oj. The pupil of the lens 10 is located in a plane, which is strictly connected by means of lenses (4 and 9) with a plane in the medium under study. Poon Thereby, the distance between the elementary volumes II and 12, for which the correlation coefficient is measured, can be expressed as

г 2R 2Кд,g 2R 2Kd,

где К - коэффициент подоби (увеличени ) между линейными размерами в с(Х1р женных плос кост х. Величина зрачка линзы 10 спредел ег величину сечений объемов среды 11 и 12. Фотоэлектртческий приемник 13 расположен таким образом, что шкицадь сечени световых лучей, сход щихс после прохождени линзы 10, полностью вписана в плоици ь его светочувствительиого сло .where K is the coefficient of similarity (magnification) between the linear dimensions in the c (H1 or R flat planes. The size of the pupil of the lens 10 is distributed by the size of the cross sections of the volumes of the medium 11 and 12. The photoelectric receiver 13 is positioned so that the pulley of the cross section of the light rays converging after the passage of the lens 10, is fully inscribed in the extension of its photosensitive layer.

Claims

In the process; Measurements of light rays emanating from the "3 secondary light source" fill the aperture of the objective 4 and, after passing through it and the protective glass 5, fall as a collimated beam into the volume of the medium under investigation. Each of the elementary beams passes through an elementary section of the volume, almost unchanged its area due to the collimation of the beam and the small size of the secondary light source and the distance from the optical axis to the distance R. Due to the fact that the mirror 8 is installed perpendicular to the optical axis The elementary beam, having passed through the protective glass 6 and the lens 7, is reflected from the mirror 8 under the same fragile relative to the optical axis and goes back into the volume under study in a direction strictly parallel to the direction under which it is cells from the medium. The angles of deflection of rays in a medium that usually take place for the values of the gradient of the refractive index in a medium are small and the cross section of a beam that has fallen into the environment for the second time is practically ia the same distance R from the axis 00, and io is symmetric with respect to the last position, i.e. volumes And and 12 is g 2R. When the secondary enters the medium, the elementary beam already has an angle. .J with the axis 00, equal, but reversed in sign, integrated over the course length t in the medium (11) by elementary deviations caused by the presence of a component of the refractive index gradient perpendicular to the direction rays, to them algebraically summed up the elementary deviations when passing through the volume of the medium 12. Thus, at the end of the second passage through the medium, the total angle of deviation is equal to the difference of the angles of deviations in the section. The direct light beams, having passed the lens 4, form an image of the secondary light source, offset relative to the light hole in. the plane of the mirror. 3. A part of the light reflected from the mirror coating (not a pseudigment into the light hole) forms a shadow pattern. The area of the shadow of the painting, coupled with the elementary volumes 11 and 12, is illuminated by a luminous flux, which is proportional in magnitude to 0 Oi-Sj. The surface of the sensitive layer of the photodetector 11, focused by the laser beam 10 w, this luminous flux produces an electrical signal Ui. Since the working section of the light reflector block blocks the light beams passing through all points of the medium, the distances between which are in the working interval of this device, to select light beams passing through points located from each other of this interval, it is enough to move the lens 10 and the camera coupled to it ' s associated with it. It should be noted that volumes 11 and 12 are equivalent, therefore the shadow pattern has axial symmetry and, in order to increase sishsha, instead of lens 10, you can use two symmetrical elements with corresponding receivers, the signals from which are added (or with one receiver receiver, the area of the sensitive layer is sufficiently large ). The second shadow device, working simultaneously with the shisan one, has the usual optical scheme, i.e. its light beam passes through only one working volume. The device can be made both according to the scheme with a single pass through the working volume, and with double. The autocollimation variant is preferable from the point of view of ease of operation due to constructive similarity with the first device, especially if both devices are located in the same housing. Since the investigation studies the correlation of the component of the refractive index gradient perpendicular to the optical axis of the first shadow device (the direction of the light beam), the optical axis of the second shadow device must be parallel to the optical axis of the first shadow device to measure the effect component. The second shadow device has a retroreflective element in the form of an autocollimation mirror 14. The optical axis Og Oj of the device is parallel to the optical axis 00 of the first device and is separated from the last one by a distance d, which must be less than the dimensions of the solidarity region for the process under study. Part of the luminous flux transmitted through the working volume 15 reflected by the surface of the mirror 3 completely enters the photodetector 16. The electrical signal Uj removed from the receiver 16 is proportional to the deflection angle of the light beam in the working volume. The calculation of the correlation coefficient in this case should be made according to the formula that can be obtained from formula (1) by means of transformations,. ..r) vl-Br, where Mr (Qfo is the covariance of the angles; D (C 75. and D (cr 5) is the dispersion of the corresponding quantities. It is known that for the quantities measured in the stationary region)) where D (br 5 is bg & n is the dispersion of the difference between the angles of deflection of the light beam acquired when it passes through the medium near the points with the coordinates TS and t0 + T of the stationary region. For this case, formula (2) is transformed (ter, & fsv .D (e) 4i) (&, &r; .T). DC H) -1 1)) This formula is valid for a single light rotor through the analyzed volumes. reading that the output of the Uj (VrZ) and Ui (B friW) electric signals to the angles of the PTB of the efS + rt fool (4) occurs at the output of the P1zhborov, (i) takes the form i (r) i- e. °:. (5) 2Uj (& rJ. In those cases, when the shadow instrument measuring the component of the refractive index gradient, following the autocollimation scheme, the beam passes two times in the analyzed volume, formula (5) is converted to Uf.) Formulas (6) both devices running in the device can be located and carrying out measurements at arbitrarily chosen points, but within the mentioned area, where the stationarity of the investigated procss is ensured. From formula (6) it can be seen that for carrying out a new volume of calculations when calculating the correlation coefficient for realizable Uj Uj values, only quadrilateral and summary are required that are generated automatically with simple dialog boxes for individual means in the course of this process. Equal spherams in connection with the volume of calculations can be carried out without removing the technicians. Thus, the use of the described device simplifies the calculation of the correlation coefficient of the component of the refractive index gradient over the implementations of the instrument signals. The p | score can be performed using aka logs quadrups and summaries. There is no need to use complex digital computing devices and sjBalo-digital converters. In order to change the base, for which the correlation factor is determined, it is sufficient to move the small block with photoshortcents instead of moving the device as a whole in the process of measuring crises. Claims of the invention A shadow auto-solvation device containing two shadow devices, consisting of a collimator lighting part with an HCIOVOIKOM light, and a part with a shadow diaphragm and a photo arrow. from the protective volumes divided from the working volumes with the test medium, characterized in that. that, in order to simplify the correlation processing of the output snapshots and to change the base of the 1Y measurement, a retroreflective unit was installed in one of the shadow devices, made in the form of a lens with a pupil size, exceeding the measurement base, in the focal plane of which the perpendicular mirror to the axis is located, passing in the middle between working volumes; A collector lens is installed in front of the photoreceiver, the entrance pupil of which is conjugated with the working volume of the device, and the optical axis of the second shadow device is oriented parallel (H1tichee ss (from the top of a boron beam and is smaller than the stationary region of the process under study. Information sources, taken into consideration when performing an examination :, USSR Copyright Certificate No. 161626, item G 02 B 27/30, 1963.

2. Vasiliev L. A. Shadow methods. M., Luca, 1968, p.52.

3. Wilson D., Damcomara D. Static properties of turbulent flotations, Fluid nechanics, 1970, 43, h. 29.