RU2805284C1 - Method for dynamic control of alignment of direction-finding and laser channels - Google Patents

Abstract

FIELD: laser location.

SUBSTANCE: laser location and precise guidance of laser radiation. Method consists in introducing an auxiliary bidirectional beam of optical radiation, in the reference direction the beam goes to the auxiliary matrix photodetector, generates a signal about the position of the reference direction of the beam, is compared with the signal received at the auxiliary photodetector by laser radiation from the laser through a two-coordinate mechanism for correcting the direction of laser radiation and a node optical conjugation of the reference beam and division of laser radiation, the mismatch signal of the reference direction of the beam and laser radiation controls the two-coordinate mechanism for correcting the direction of radiation to achieve collinearity. In the information direction, the radiation beam goes to the optical assembly, the laser radiation output and the bearing signal input, enters the direction-finding photodetectors through the division node, generates signals about the reference direction, the mismatch signal between the target bearing and the reference direction in each photodetector controls the optical assembly so that the bearing signal coincides with the reference direction signal, which is the aiming point, when one of the direction-finding photodetectors is assigned as the leader.

EFFECT: high pointing accuracy.

1 cl, 1 dwg

Description

The invention relates to laser ranging and can be used to create means for accurately aiming laser radiation at an object.

Laser ranging stations (LLS) are known, the optical schemes of which include several lenses, position-sensitive photodetectors and one or more beam splitters that separate light beams in space in such a way that each beam is focused using the corresponding lens in the aperture of its FPU [1 ]. Since parallel rays are imaged by the lens at a certain point located in the focal plane of the lens, and the light from the remote and laser sources can be considered as beams of parallel rays, the position of this point (the center of the beam) in the PD aperture determines the angular displacement of the beam. Finding the positions of the beam centers, their mismatches and issuing control signals occurs in real time.

The disadvantage of dividing the receiving path into several channels is, firstly, the increase in size, weight and cost of the installation. Secondly, the impact of external disturbances on the elements of the optical path leads to identical or negligible angular displacements of the light beams. When installing such a structure on a mobile carrier, additional vibration protection measures are required. Thirdly, significant difficulties are caused by the initial adjustment of a laser laser with several photodetectors, which must be installed strictly in optically conjugate planes.

There is a known method for pointing laser beams, which includes receiving a direction-finding optical signal from a remote object, creating an image of the remote object using a single matrix FPU and finding the center of the direction-finding light beam. In this case, a laser beam is formed, which is divided into two parts, one part is sent in the direction of a distant object, and the other part is focused in the PD aperture to create an image of the laser source and the position of the center of the partial beam is determined [2]. Based on the measurement results, a mismatch is found between the positions of the centers of the direction-finding and partial beams, and control signals are generated to align the axes of the laser beam and the direction-finding beam. It is proposed to implement the known method using a simplified tracking system, including a telescope for receiving an optical signal from a remote object and transmitting a laser beam, a coordinate-sensitive digital device placed in the focal plane of the image former on the optical axis of the telescope, a beam splitter placed on the said optical axis between the said telescope and a FPU, a retroreflector placed on one side of the beam splitter, a deflector located on the other side of the beam splitter opposite the retroreflector, a laser installation that forms a laser beam incident on said deflector and deflected by the deflector onto said beam splitter, which reflects the first part of the laser beam into said telescope for transmission in the direction of the line of sight, and the second part of the laser beam is passed to the retroreflector for reflection back into the said beam splitter and then for deflection by the beam splitter into the mentioned FPU. The distance between the centers of the light beam and the second partial laser beam, found using the matrix FPU in the focal plane of the imager and determining the angular displacement of the first partial (output) beam relative to the bearing, is used to calculate the deflector control signals in order to align the direction of the output laser beam with the bearing.

The use of this method is limited by the possibility of crosstalk in cases where beam centers are close together, which leads to overlapping images of beam cross sections, an error in measuring the magnitude and sign of the said relative angular displacement, and, as a consequence, to failure of tracking. The closest in technical essence and the technical result achieved when using the invention - the prototype of the claimed invention - is a method of aiming a laser beam at any object, according to which an auxiliary bidirectional beam of optical radiation is introduced into the optical path between the laser and the direction finding photodetector, propagating from the point of entry into optically conjugate directions: in one direction (diagnostic) the beam goes to the laser resonator, forming a signal for the photodetector with information about the position of the optical axis of the laser resonator, in the other direction (reference) the beam goes to the photodetector, where the mismatch between the positions of the diagnostic, reference and direction finding (i.e., carrying information about the direction to the object) signals, on the basis of which the optical unit is controlled, serving as an output for laser radiation and an input for a bearing signal [3].

The known method is implemented using a device containing a position-sensitive photodetector, a deflector with one or more actuating elements of the control loop, a beam splitter that transmits laser radiation to the deflector and directs a direction finding signal and auxiliary radiation to the photodetector, an optical unit that distributes the auxiliary radiation into two optically coupled directions, source of auxiliary radiation. The disadvantages of the known solution are the technical complexity of creating an optical scheme for a bidirectional light beam, as well as the possibility of crosstalk when measuring mismatches between signal positions in cases where the direction of the laser radiation coincides with the bearing. The task and the technical result achieved by using the invention is to ensure high pointing accuracy by eliminating crosstalk and reducing the error in measuring the angular displacement of the first partial (output) beam relative to the bearing.

This goal is achieved due to the fact that in the method of dynamic control of the alignment of several direction-finding channels and a laser channel in an optical-electronic system, which consists in the formation of a bearing signal on several matrix direction-finding photodetectors of different spectral ranges, while in the optical path between the optical node serving as the output for laser radiation, an auxiliary bidirectional beam of optical radiation is introduced into both the input for the bearing signal and the laser, formed by a wide-spectrum optical marker emitter, propagating from the input point in optically conjugate directions:

in one reference direction, the optical radiation beam goes to the auxiliary matrix photodetector, forming on the auxiliary matrix photodetector connected to the optical interface unit of the reference beam and laser radiation division, a signal with information about the position of the reference direction of the beam, which is compared with the signal generated on the auxiliary matrix photodetector laser radiation and passing from the laser through a two-coordinate mechanism for correcting the direction of laser radiation and through a node for optical coupling of the reference beam and dividing laser radiation, and the mismatch signal between the reference direction of the beam and laser radiation from the auxiliary matrix photodetector controls the two-coordinate mechanism for correcting the direction of laser radiation to achieve collinearity laser radiation and reference direction;

in another information direction, the beam of optical radiation goes to the optical node, which serves as output for laser radiation and input for the bearing signal, and enters through an optical division node into several matrix direction-finding photodetectors of different spectral ranges, on which it generates signals with information about the reference direction, and the signal mismatch between the target bearing and the reference direction in each matrix direction-finding photodetector, the optical unit is controlled, serving as the output for laser radiation and the input for the bearing signal, so that the signal about the target bearing coincides with the signal about the reference direction, which is the aiming point, when assigning one of matrix direction finding photodetectors by leading commands of an external information and control device.

The features that distinguish the proposed invention from the known ones are that an auxiliary bidirectional beam is introduced:

in one reference direction, the optical radiation beam goes to the auxiliary matrix photodetector, forming on the auxiliary matrix photodetector connected to the optical interface unit of the reference beam and laser radiation division, a signal with information about the position of the reference direction of the beam, which is compared with the signal generated on the auxiliary matrix photodetector laser radiation and passing from the laser through a two-coordinate mechanism, for example, a piezo drive, correcting the direction of laser radiation and through an optical interface unit of the reference beam and dividing the laser radiation, and the mismatch signal between the reference direction of the beam and the laser radiation from the auxiliary matrix photodetector controls the two-coordinate direction correction mechanism laser radiation to achieve collinearity of laser radiation and reference direction;

in another information direction, the beam of optical radiation goes to the optical node, which serves as output for laser radiation and input for the bearing signal, and enters through an optical division node into several matrix direction-finding photodetectors of different spectral ranges, on which it generates signals with information about the reference direction, and the signal mismatch between the target bearing and the reference direction in each matrix direction-finding photodetector, the optical unit is controlled, serving as the output for laser radiation and the input for the bearing signal, so that the signal about the target bearing coincides with the signal about the reference direction, which is the aiming point, when assigning one of matrix direction finding photodetectors by leading commands of an external information and control device.

The proposed method for dynamically monitoring the alignment of several direction-finding channels and a laser channel is carried out using an optical-electronic circuit, which is presented in Fig. 1, where:

1 - matrix direction-finding photodetectors (N pieces);

2 - optical division unit;

3 - optical unit, which serves as an output for laser radiation and an input for a bearing signal;

4 - optical path;

5 - unit for optical coupling of the reference beam and division of laser radiation;

6 - two-coordinate correction mechanism (piezo drive);

7 - laser;

8 - auxiliary matrix photodetector;

9 - auxiliary beam source.

LI - laser radiation;

OH - reference direction;

SP - bearing signal.

The operation of the device occurs according to the appropriate method. Information sources:

1. Baryshnikov N.V. Use of semi-natural modeling methods in the design of complex laser optoelectronic systems. “Science and Education”, 2011, No. 2, p. 14-25. http://engineering-science.ru/doc/16641 l.html

2. US Patent No. 5517016.

3. Patent RU No. 2343412 - prototype.

Claims (3)

A method for dynamically monitoring the alignment of several direction-finding channels and a laser channel in an optical-electronic system, which consists in generating a bearing signal of different spectral ranges on several matrix direction-finding photodetectors, while in the optical path between the optical node serving as output for laser radiation and input for the bearing signal, and an auxiliary bidirectional beam of optical radiation is introduced with a laser, formed by a wide-spectrum optical marker emitter, propagating from the input site in optically conjugate directions: in one reference direction, the optical radiation beam goes to the auxiliary matrix photodetector, forming on the auxiliary matrix photodetector connected to the optical interface unit of the reference beam and laser radiation division, a signal with information about the position of the reference direction of the beam, which is compared with the signal generated on the auxiliary matrix photodetector laser radiation and passing from the laser through a two-coordinate mechanism for correcting the direction of laser radiation and through a node for optical coupling of the reference beam and dividing laser radiation, and the mismatch signal between the reference direction of the beam and laser radiation from the auxiliary matrix photodetector controls the two-coordinate mechanism for correcting the direction of laser radiation to achieve collinearity laser radiation and reference direction; in another information direction, the beam of optical radiation goes to the optical node, which serves as output for laser radiation and input for the bearing signal, and enters through an optical division node into several matrix direction-finding photodetectors of different spectral ranges, on which it generates signals with information about the reference direction, and the signal mismatch between the target bearing and the reference direction in each matrix direction-finding photodetector, the optical unit is controlled, serving as the output for laser radiation and the input for the bearing signal, so that the signal about the target bearing coincides with the signal about the reference direction, which is the aiming point, when assigning one of matrix direction finding photodetectors by leading commands of an external information and control device.

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