RU2525652C1 - Angle measurement device - Google Patents

Abstract

FIELD: measurement equipment.SUBSTANCE: angle measurement device comprises a lens, a matrix radiation receiver, a calculation unit and a channel of geometric reference, comprising the following components optically coupled with the lens of the lighting unit, having three sources of light arranged at the angle of 120° to each other, a collimator unit including three input and three output point diaphragms, and a mirror-prism unit, forming a monoblock with diaphragms applied on it and rigidly connected to the reference plane of the angle measurement device. The mirror-prism monoblock is made of six side mirror faces and parallel refracting bases that limit them, the larger hexagonal of which with applied outlet point diaphragms faces the lens, besides, its adjacent ribs are arranged at the angle 120° to each other. The monoblock is made with three additional refracting faces, placed between large bases and appropriate side mirror face, making a sharp angle with the large base and placed in front of the output point diaphragm, each additional face is equipped with an input point diaphragm, and angles between the large base and three additional refracting faces and three side mirror faces, arranged in front of three input point diaphragms, are equal to 90°.EFFECT: increased accuracy of a device without complication of its design and increase of weight and dimension characteristics.7 dwg

Description

The invention relates to the field of optoelectronic technology, and more specifically, to optoelectronic devices that measure the angular coordinates of a target in a dynamic mode, and can be used to automatically control the orientation and navigation of spacecraft (SC).

Optoelectronic devices (astro devices) are widely known that determine the angular position of a spacecraft relative to astronomical radiation sources. These devices on modern spacecraft solve the problems of astro-orientation and astro-correction. Such angle measuring devices are described in the article “Non-tunable optical systems of goniometers with a fixed line of sight”, ed. AND I. Gebgart, M.P. Kolosov, Optical Journal, 2010, v.77, No. 10, 48-53 s. In addition, the functional diagram of such a device is also disclosed in the book “Optics of adaptive goniometers”, auth.M. Kolosov, Moscow: Logos, 2011, pp. 149-151. The disadvantages of these devices include insufficiently high accuracy characteristics.

A similar angle measuring device is described in the patent for invention No. 2399871, which is selected as a prototype.

The device contains a geometric reference channel (CGE), made in the form of a lighting unit, a collimator unit and a mirror-prism unit, introducing radiation from the lighting unit into the lens, objective, photodetector and computing unit, while the lighting unit is made in the form of three radiation sources installed in front of the input diaphragms and located at an angle of 120 ° to each other, the collimator unit is made in the form of three input point diaphragms and three output point diaphragms, located on the back, facing the lens, outside its entrance pupil, the face (base) of the mirror-prism block, and the mirror-prism block is a single monoblock, made in the form of parallel hexagonal faces, smaller edges in front and the larger back, facing the lens, adjacent edges which are located at an angle of 120 ° to each other and form six lateral mirror faces between themselves, which are inclined at an acute angle to the rear face, while the mirror-prism block with its rear face is mounted on the reference plane oizmeritelnogo device.

In the angle measuring star device, a hood is additionally installed in front of the smaller front face of the mirror-prism block, and six side mirror faces of the mirror-prism block are inclined, for example, at an angle of 45 ° to its rear face. The inclination of the lateral mirror faces of the mirror-prism block located opposite the output diaphragms is chosen so as to provide the necessary deviation of the light beam from the optical axis of the device at the input of the lens to form a reference coordinate system on the photodetector. In this case, the location of the apertures in the device is selected in such a way as to provide the necessary deviation of the light beam from the axis of the device at the input of the lens to form a reference coordinate system on the photodetector. In a stellar angle instrument, the front and rear faces of the base are similar hexagons formed from equilateral triangles with vertices equally truncated parallel to the sides, while the front and rear faces are similar hexagons.

A known device (device) is shown in figure 1. It contains a lens hood 1, lens 2, a matrix radiation receiver (MPI) with a computing unit 3, and a CGE, including a illuminator 4, consisting of three radiation sources, a mirror-prismatic monoblock 6 with six point transparent diaphragms 5 and 7, which are part of collimator. The mirror-prismatic monoblock 6 is made in the form of a single optical part (monoblock) with two parallel refracting faces (bases) and with six side mirror inclined faces, the diaphragms 5 and 7 are deposited on the back large surface (base) of the mirror-prismatic monoblock 6, facing lens 2, and as illuminators 4, for example, LEDs are used. MPE with the accumulation of photoelectrons associated with the computing unit 3 can be performed on the basis of a CCD matrix.

The device operates as follows: radiation from a sighted star (Fig. 1), passing through hood 1, designed to suppress spurious illumination from lateral light noise, a mirror-prismatic monolithic block KGE 6 operating in the passage enters the entrance pupil of lens 2 and focuses on the MPI 3. The radiation from the illuminator 4, having passed the point transparent diaphragm 5, successively reflected from the inclined mirrors of the mirror-prismatic monoblock KGE 6 and passing the point diaphragm 7, leaves the KGE. The specified radiation, passing through the lens 2, is focused on MPI 3. Then the signals from the matrix are processed by block 14 with the subsequent issuance of information about the position and orientation of the spacecraft.

The corresponding location of the point diaphragms 5 and 7 on the rear surface on the larger base of the mirror-prismatic monoblock 6 allows you to provide the necessary angular deviation of the beam from the axis of the block.

Similarly, the other two identical channels work, located at an angle of 120 ° to each other. Thus, at the output of the CGE three beams of rays are formed, the axes of which make up the same angle α with the axis of the block, and make an angle of 120 ° between them. The angular position of the normal to the reference plane is determined by the orthocenter of an equilateral triangle, at the vertices of which the symmetry axes of the three working beams are located.

The necessary angular deviation of the axes of the emerged beams is also realized by changing the angles of inclination of the mirror faces located opposite the output diaphragms.

During operation, the beams outside the entrance pupil are focused by the lens 2 on the MPI 3 in the form of an image of three points located at the vertices of an equilateral triangle. The presence of the image of three points determines the reference coordinate system of the device on MPI 3, relative to which the position of the sighted star (target) is measured. The origin is in the orthocenter of the specified triangle, coinciding with the optical axis. All this allows us to measure the position of the sighted star relative to the obtained image of the marks and, therefore, to exclude errors in the determination of coordinates associated, for example, with micro displacements of MPI 3 in directions perpendicular to the optical axis of the lens 2. Also, errors in determining the coordinates of the sighted star associated with possible turning MPI 3 relative to the optical axis.

When defocusing the MPI 3, the newly formed triangle, at the tops of which the images of the stamps are located, retains its similarity to the original, while the orthocenter of the triangle remains on the optical axis. Therefore, in the new installation plane, the almost unchanged position of the coordinate system on MPI 3 is determined.

The implementation of the mirror-prismatic monoblock KGE 6 in the form of a single optical part, rigidly mounted by the rear refracting face on the reference plane, provides high stability of the angular position of the emitted from the CGE beams relative to the reference plane and transmitted by the CGE beams from the sighted star under significant temperature, vibration and shock effects, which increases the accuracy of the device. Moreover, the thickness of the CGE along the optical axis of the lens can be extremely small, which improves the overall mass characteristics of the entire device.

Figure 2 shows a view along arrow A of figure 1, which shows the relative position of three illuminators, three input point diaphragms 5 and three output point diaphragms 7.

The presence of two point diaphragms spaced along the beam forms a “filiform” beam of rays with a geometric divergence defined by the expression:

$$2\omega =2\arcsin \left\{n\sin \left[(arctg\left(D\mathrm{one}+D2\right)/L\right]\right\},\left(\mathrm{one}\right)$$

where D1, D2 are respectively the diameters of the diaphragms 5 and 7,

L is the optical length deployed in a plane-parallel plate of the CGE,

n is the refractive index.

The pinhole 7 acts as a collimator lens and acts as a pinhole camera. Thus, a functionally collimator block containing input and output pinhole diaphragms can be considered as three pinhole collimators that form three images on the MPI matrix. These images are round, and the distribution of their illumination has axial symmetry, which is very favorable for ensuring the accuracy of the device. However, as practice has shown, it is desirable to reduce the angular size (2ω) of these images to improve the accuracy of the device. But, essentially, this is impossible. Indeed, a decrease in D1 is limited by the technological capabilities for making point holes. With a decrease in D2, starting from a certain aisle, diffraction phenomena begin to dominate, and the angular size of the image becomes larger than the size 2ω defined by expression (1). The L value also cannot be increased, since it is determined by the diameter of the entrance pupil of the lens 2 and the above-described shape of the mirror-prismatic monoblock 6. Obviously, with an increase in the size L (with an increase in the size of the mirror-prismatic monoblock 6), the CGE radiation simply does not get into the lens 2 whose diameter is determined mainly by a given size of the entrance pupil of the lens.

The problem to which the claimed invention is directed is to create an automatic instrument for orientation and navigation of a spacecraft that meets a set of rather complex technical requirements, such as high accuracy of angular measurements without complicating its design without increasing weight and size characteristics.

This problem is solved due to the fact that in the inventive device containing a lens, a matrix radiation detector, a computing unit and a geometric standard channel, consisting of a lighting unit optically paired with the lens, having three radiation sources located at an angle of 120 ° to each other, a collimator a block including three input and three output point apertures, and a mirror-prism block, forming a monoblock with the diaphragms of the collimator deposited on it, rigidly connected to the reference plane measuring device, while the mirror-prismatic monoblock is made of six side mirror faces and parallel refracting bases bounding them, the larger hexagonal of which with the output pinhole diaphragms applied to it faces the lens, and its adjacent ribs are located at an angle of 120 ° to each other, this mirror-prismatic monoblock is made with three additional refracting faces located between the large base and the corresponding lateral mirror face, component with a large Warping acute angle and placed before the output pinhole, wherein each face is provided with an additional input pinhole, and the angles between the large base and three additional refracting faces and three side faces of the mirror arranged in front of three input point diaphragms, are 90 °.

Thus, the proposed technical solution is a combination of essential features that, in comparison with the prototype, have novelty.

The technical effect, expressed in increasing the accuracy of the device, is confirmed by the arguments below.

The essence of the claimed invention is illustrated by drawings, which depict:

In figure 1, 2 is an optical diagram of the closest analogue of the prototype.

Figure 3 is an optical diagram of the proposed device.

Figure 4 is a section of the CGE, which shows the beam path in a mirror-prismatic monoblock.

Figure 5 is a view along arrow B of figure 3.

Figure 6 is an isometric view of the mirror-prism block.

In Fig.7 is a section of the CGE, which shows the designation of the design parameters of the mirror-prism unit.

The proposed device (Fig. 3) contains a hood 1, a CGE, consisting of a mirror-prismatic monoblock 8, a collimator including three input point diaphragms (holes) 9 (one is shown in the drawing), and three output point diaphragms (holes) 10 (on the drawing shows one), which are applied to the surface of the monoblock 8, and the lighting unit 11, made in the form of three radiation sources (one is shown in the drawing), the lens 12, the matrix of pixels MPI 13, the computing unit 14. Figure 4 shows a large (output ) refractive face (base) 15, steam the smaller face (base) 16 that is lallellating to it, and the additional refracting face 17 (one of three is shown), the side mirror face 18 (one of three is shown), located in front of the entrance point diaphragm 9, which makes a right angle with the larger face (base), side a mirror face 19 (one of three is shown) located along the optical path of the beam in front of the output point diaphragm 10, an edge 20 formed by the intersection of the side mirror faces 19.

It should be noted that in the mirror-prism block of the proposed device (see FIGS. 5, 6), the input face (base) has the shape of a triangle, and the large (output) face (base) is hexagonal, although in the prototype both of these faces are hexagonal. The triangular shape of the input face is determined by the design of the device. With other size ratios, the input face of the CGE in the proposed device may be hexagonal. Moreover, of the eleven faces of the mirror-prismatic monoblock, the refracting face (base) 15 is always the largest. Six lateral mirror faces can be represented in the form of two groups: three faces make up an acute angle with a large base, and the other three make an angle of 90 °.

The device (Fig. 3) works as follows: radiation from a sighted star (target), passing through a lens hood 1, designed to suppress spurious illumination from lateral light interference, the prism-prismatic block of the CGE, which operates in the passage, enters the entrance pupil of the lens 12 and focuses on MPI 13. In this case, the faces 16, 15 with respect to the radiation from the target are functionally the input and output faces, respectively. The radiation from the illuminator 11, having passed the input point transparent diaphragm 9, successively reflected from the side mirror faces 18, 19 of the mirror-prism monoblock 8 CGE and passing the output point diaphragm 10, leaves the CGE (see the beam path in figure 4). The specified radiation after passing through the lens 12 is focused on the MPI 13, the processed signal from which is fed to the computing unit 14, which generates information about the angular position of the spacecraft.

The structural arrangement of the point diaphragms 9, 10 on the mirror-prismatic monoblock 8 and the inclination of the mirror faces 19 to the larger face (base) 15 (at an angle (3, see figure 4) provide such an angular deviation of the radiation beam from the axis of symmetry (O-O ') monoblock 8, in which it coincides with the optical axis of the lens 12.

Similarly, the other two identical channels work, located at an angle of 120 ° to each other. Thus, at the output of the CGE, three beams of rays are formed, the axes of which make the same angle α with the axis of the block (see Fig. 1), and make an angle of 120 ° between them. The specified angle α must be less than or equal to half the angular field of the lens. The angular position of the normal to the reference plane is determined by the orthocenter of an equilateral triangle, at the vertices of which the symmetry axes of the three working beams are located.

Further, the beams outside the entrance pupil area are focused by the lens 12 on the MPI 13 in the form of an image of three points located at the vertices of an equilateral triangle. The presence of the image of three points determines the reference coordinate system of the device on MPI 13, relative to which the position of the sighted star (target) is measured. The origin of coordinates is located in the orthocenter of the indicated triangle, which coincides with the optical axis of the lens 12. All this makes it possible to measure the position of the sighted star relative to the received image of the marks and, therefore, to exclude errors in the determination of coordinates associated, for example, with micro displacements of the MPI 13 in directions perpendicular to the optical axis lens 12. Also excluded are errors in determining the coordinates of the sighted star associated with the possible rotation of the MPI 13 relative to the optical axis.

When defocusing the MPI 13, the newly formed triangle, at the vertices of which the images of the marks are located, retains its similarity to the original, while the orthocenter of the triangle remains on the optical axis. Therefore, in the new installation plane (image plane), the almost unchanged position of the coordinate system on the MPI 13 is determined.

The implementation of the mirror-prismatic monoblock of 8 CGEs in the form of a single optical part rigidly connected to the reference plane of the device ensures high stability of the angular position of the beams emitted from the CGE relative to the reference plane and transmitted by the CGE beams from the sighted star (target) under significant temperature, vibration and shock effects , which increases the accuracy of the device. In this case, the thickness of the CGE along the optical axis of the lens practically does not differ from the thickness of the CGE of the prototype, which ensures the preservation of the overall dimensions of the device. The complexity of the design of the proposed device and prototype are similar.

The main positive quality of the proposed device compared with the prototype is to increase the optical length deployed in a plane-parallel plate KGE - L about two times with almost no increase in the size of the mirror-prism system 8, which leads to the same decrease in the geometric divergence of the "filamentous" beam of rays - 2ω (see formula 1) emerging from the CGE. The indicated increase in the optical length of the CGE is clearly seen in Fig. 4, where it is shown that the rays in the section of the CGE pass a double path, reflected from the mirror face 18. In this case, the indicated decrease in the geometric divergence of the “filamentous” beam of rays will lead to the same decrease in the size of the input point image diaphragms on the matrix of MPI pixels, increasing the steepness of the fronts in the distribution of the illumination of this image, reducing noise in the optoelectronic path of the device and correspondingly increasing its accuracy.

Thus, the objective of the invention is achieved: improving the accuracy of the device without complicating its design and increasing weight and size characteristics.

At the same time, the design parameters of the angle measuring device (see Figs. 7 and 4) are calculated in such a way that the following relations (inequalities) are satisfied:

$$l>d>a>c>b,\left(2\right)$$

where l is the distance between the opposite edges of the mirror-prism block, formed by its large base and side faces (the height of the mirror-prism monoblock);

d is the distance between the input and the large (output) refracting faces of the mirror-prismatic monoblock (thickness of the mirror-prismatic monoblock);

a is the distance from the edge of the mirror-prismatic monoblock located on its large (output) refracting face to the center of the output point aperture;

c is the distance from the edge of the mirror-prismatic monoblock located on its large (output) refracting face to the additional refracting face;

b is the distance from the edge of the mirror-prismatic monoblock located on its large (output) refracting face to the center of the input point diaphragm.

$$w/n>|\; |\; |\pi /2-\left\{\left[\left(a\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="00000005.png"\; state="\{\{state\}\}">sin</figure-callout>}2\beta -b\right)/\left(2l-c\right)\right]+2\beta \right\}|\; |\; |,\left(3\right)$$

where w is half the angular field of the lens;

n is the refractive index of the material of the mirror-prismatic monoblock;

π = 3.1415.

In expression (3), the angles are taken in radians.

The input and large (output) refracting faces are configured to reflect the rays created by the lighting unit and the input point diaphragms of the collimator unit.

The mirror-prism monoblock is a protective glass of the angle measuring device.

Thus, when using the claimed device is achieved:

- high accuracy of angular measurements,

- resistance to various interfering radiation,

- performing various functions, such as searching, detecting astro-targets, tracking them, accurate measurement of angular coordinates,

- the functioning of the device under the influence of various factors from the spacecraft.

Claims (1)

An angle measuring device containing a lens, a radiation matrix detector, a computing unit and a geometric standard channel, consisting of a lighting unit optically coupled to the lens, having three light sources located at an angle of 120 ° to each other, a collimator unit that includes three input and three output point a diaphragm, and a mirror-prism block, forming with a collimator diaphragm applied on it a monoblock, rigidly connected to the reference plane of the angle measuring device, while the mirror the variable monoblock is made of six lateral mirror faces and parallel refracting bases bounding them, the larger hexagonal of which with the output pinhole diaphragms deposited on it faces the lens, and its neighboring ribs are located at an angle of 120 ° to each other, characterized in that the mirror-prismatic monoblock made with three additional refracting faces located between the large base and the corresponding lateral mirror face, which constitutes, with a large base, an acute angle and size angled between the large base and the three additional refracting faces, as well as the three side mirror faces located in front of the three input point apertures, are equal to 90 °.

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