Method for directing laser radiation at moving object

Abstract

FIELD: optical systems.SUBSTANCE: invention can be used for continuous exposure of a moving object to laser radiation. A method for directing laser radiation at a moving object, according to which a platform with sources and a detector of laser radiation is placed in a system of electromagnets; sources of laser radiation are mounted on the outside of the platform, as well as a detector of radiation reflected from the object. On the inner side along the perimeter of the platform there are coils with electric current and a rotating mechanism installed in the centre of gravity of the platform. The detector is made from a set of light-sensitive elements combined into a flat matrix, in the centre of which an opaque cylinder is installed orthogonally to its surface. The diameter of the cylinder is selected equal to the transverse size of the photosensitive element, the height of the cylinder is selected based on the condition that the shadow of the cylinder hits the surface of the matrix when the angle of incidence of the laser radiation reflected from the object changes within specified limits. The mounting surface of the platform is made flat, the laser radiation sources and the axis of the opaque cylinder are oriented orthogonally to the mounting plane, based on the signal from the reflected radiation detector, the source of the acting laser radiation is turned on and the orientation of the platform is maintained from the condition of minimizing the number of light-sensitive elements of the detector shaded by the cylinder.EFFECT: increase in the efficiency of aiming laser radiation at a moving object.1 cl

Description

[0001] The invention relates to the field of control of optical systems and can be used for continuous exposure of a moving object to laser radiation.

[0002] A patent-protected invention is known - an analogue: application No. 2002107476 / 09, IPC G02F 1 / 29, 2002 "Optical-mechanical deflector" (Efimenko A.V., Efimenko A.V., Shalobaev E.V.). The deflector is designed to deflect a laser beam at a significant angle with a frequency exceeding 300 Hz. The mirror, on which the beam is intended to fall, is fixed on a rotor capable of performing rotational-oscillatory motion around the longitudinal axis. Coaxial placement of an elastic torsion bar, returning the rotor to the equilibrium position within the axial cavity of the latter, ensures uniform load distribution, eliminates the translational motion of the deflector elements, their fatigue and residual deformation. If beam control in space is required, two deflectors, for example, are used. The disadvantage of the analogous invention is the impossibility of quickly aiming the laser beam in any direction.

[0003] A patent-protected invention is known - an analogue: application No. 2003117524 / 28, IPC H02K 57 / 00, H02K 41 / 00, G05D 1 / 00, 2003 "Method for Moving an Object in Space and a Device for Moving an Object in Space" (Luzhnykh S.N.). The method is based on the effect of an electromagnetic field on a conductor rigidly connected to the object being moved. A distinctive feature of the method is that the conductor is positioned in space so that it intersects the plane formed by the propagation vector of the electromagnetic field and the vector of the magnetic component of this field. An alternating current is generated in the conductor with a frequency equal to the frequency of the electromagnetic field and a phase determined by the direction of its movement relative to the field source. The conductor can be made in the form of a wire winding, the turns of which have a rectangular shape. The device contains elements that provide the required control of the current phase in the conductor.The disadvantage of the prototype invention is the inability to perform arbitrary angular turns.

[0004] A patent-protected invention is known - an analogue: patent No. 2639609, IPC G02B 26 / 10, 2016 "Method for controlling a laser beam" (Yakovlev M.V., Yakovlev D.M., Yakovleva T.M.). According to the method, a rotating platform with a mirror for reflecting an incident laser beam, located on one of its sides, is placed in a magnetic field. An electric conductor and a rotating mechanism are placed on the other side of the platform. Moreover, the conductor is made in the form of annular turns, which are located along the perimeter of the rotating platform. The rotating mechanism is installed at the center of gravity of the platform. The magnetic field is generated by a system of electromagnets. The current of the annular turns and electromagnets is regulated based on the condition of reflection of the laser beam from the mirror in a given direction. The technical result is increased efficiency of laser beam control. A disadvantage of this method is the inability to detect and track moving objects with the laser beam.

[0005] A patent-protected invention similar to Patent No. 2676999, IPC B64G 1 / 64, 2018, "Method for Determining the Direction to a Space Object" (Yakovlev M.V.). The method involves scanning a given spatial region with a laser beam by reflecting the beam off a mirror on a rotating platform mounted in an electromechanical suspension. The platform's movement in azimuth and elevation is controlled by a system of electromagnets powered by a sawtooth pulse train. The direction to the object is determined based on the parameters of the sweep pulses, which register the signal of laser radiation reflected from the object. A disadvantage of this method is the inability to track moving objects with the laser beam.

[0006] A patent-protected invention is known - an analogue: patent No. 2678256, IPC F41H 3 / 00, 2018 "Method for illuminating optoelectronic devices of small-sized unmanned aerial vehicles" (Yakovlev M.V.). The invention relates to the field of receiving and converting laser radiation and can be used to illuminate optoelectronic devices of small-sized unmanned aerial vehicles (SUVs). To illuminate the optoelectronic devices, radiation propagating from the SUV is received by flat detectors located on the surface of a spherical shell orthogonally to the radius vector from the center of the shell to the point of contact with the detector. A radiation absorber material is placed inside the spherical shell. The direction to the SUV is determined by the radius vector to the detector with the maximum amplitude of the recorded signal. The laser radiation power is calculated in the automated information processing system (AIPS). The power of the laser radiation from the source is regulated using the ASOI signals.The radiation direction is controlled by a mirror mounted in a magnetic field on a rotating platform with an electric conductor and a rotating mechanism on the side opposite the mirror. The conductor is made in the form of annular coils arranged around the platform's perimeter. The rotating mechanism is mounted at the platform's center of gravity. The magnetic field is generated by a system of electromagnets. The electric currents of the electromagnets and the annular coils are determined based on the results of the ASOI calculations, assuming that the laser source is oriented normal to the detector surface with the maximum amplitude of the recorded signal. This improves the efficiency of illumination of the microunmanned aerial vehicle's optical-electronic devices. A disadvantage of the invention is that the condition of aligning the laser source with the normal to the detector surface with the maximum amplitude of the recorded signal is insufficiently accurate for determining the angular characteristics of the microunmanned aerial vehicle.

[0007] A patent-protected invention similar to patent No. 2706844, IPC B64G 1 / 64, 2019, "Method for Determining the Direction to a Space Object" (Yakovlev M.V.), is known. The method involves scanning a given spatial region with a laser beam by reflecting the beam from a mirror on a rotating platform mounted in an electromechanical suspension. The platform's movement in azimuth and elevation is controlled by a system of electromagnets powered by a sawtooth pulse train. The direction to the space object (SO) is determined based on the parameters of the sweep pulses at which the signal of laser radiation reflected from the SO is recorded. The intensity of the laser radiation in the source is modulated by a harmonic oscillation, the laser radiation reflected from the space object is recorded by a photomultiplier, and the recorded signals are amplified by a radio device tuned to the frequency of the harmonic oscillations of the radiation in the source. At the same time, the range of controlled KOs increases.The disadvantage of the invention is the lack of the ability to influence the controlled KO with a laser beam of a given intensity.

[0008] A patent-protected invention similar to patent No. 2698944, IPC G01S 3 / 782, 2019, "Method for Determining the Direction to a Laser Radiation Source" (Yakovlev M.V.) is known. The invention relates to the field of receiving and converting laser radiation. According to the method, laser radiation is recorded by photosensitive elements, and the direction to the radiation source is determined based on the results of processing the recorded signals. To determine the direction to the laser radiation source while reducing the weight and dimensions of the measuring device, the photosensitive elements are combined into a flat matrix, a light-tight cylinder is installed in the center of the matrix orthogonally to its surface, the diameter of the cylinder is selected to be approximately the transverse dimension of the photosensitive element, and the height of the cylinder is selected so that the shadow of the cylinder falls on the surface of the matrix when the angle of incidence of the laser radiation varies within specified limits.The technical result is the ability to determine the direction of a laser radiation source while reducing the weight and dimensions of the measuring instrument. A disadvantage of the invention is the inability to affect the monitored objects with laser radiation.

[0009] A patent-protected invention similar to Patent No. 2716610, IPC B64G 1 / 64, 2019, "Method for Tracking a Space Object with a Laser Beam" (M.V. Yakovlev). The method involves scanning a given spatial region with a laser beam by reflecting the beam from a mirror on a rotating platform mounted in an electromechanical suspension. The platform's movement in azimuth and elevation is controlled by a system of electromagnets powered by a sawtooth pulse train. The direction to the space object (SO) is determined based on the parameters of the sweep pulses at which the signal of laser radiation reflected from the SO is recorded. The direction to the space object is determined in repeated sessions. A disadvantage of this invention is the inability to affect the monitored objects with laser radiation.

[0010] A known patent-protected invention - prototype: Patent No. 2822970, IPC G02B 26 / 10, 2024. "Method for continuous action of a laser beam on a randomly moving object" (Yakovlev M.V.). The invention relates to the field of optical systems control. According to the method, the direction of laser beams is controlled by rotating a platform located in a magnetic field. The platform has a mirror on one side, an electric conductor in the form of annular turns, and a rotating mechanism on the opposite side, mounted at the center of gravity of the platform. The magnetic field is formed by a system of electromagnets, and the current of the annular turns is maintained constant. The current of the electromagnets deflecting the object tracking beam is set in the form of a sequence of pulses providing a sweep along the azimuth angle and the angle of elevation. The direction to the object is determined by scanning based on the reflected signal of the tracking beam.The direction is recorded in repeated sessions. Based on the results, the electromagnet current is adjusted and the beam is moved in the direction and at the speed of the object's angular displacement. The laser beam is turned on. A dedicated system of deflecting electromagnets orients and irradiates the object with the beam, adjusting for the relative positions of the laser sources, for a specified time interval. The technical result is continuous laser beam action on a randomly moving object. A disadvantage of the invention is the need for repeated sessions to determine the direction to the space object. Based on these sessions, a correction for the relative positions of the probing and irradiating laser beams is calculated and the irradiating laser beam's movement mode is set.

[0011] The purpose of the proposed invention is to increase the efficiency of aiming laser radiation at a moving object.

[0012] This objective is achieved by the claimed method for directing laser radiation at a moving object. A platform containing laser sources and a detector is positioned within a system of electromagnets. Laser sources for detecting and irradiating the object, as well as a detector for reflected radiation, are mounted on the outer surface of the platform. On the inner surface, coils carrying electric current are positioned along the perimeter of the platform, along with a rotating mechanism mounted at the platform's center of gravity. The electromagnet system's current is set as a pulse sequence, providing laser scanning along the azimuth and elevation angles. The detector is made from a set of photosensitive elements combined into a flat matrix, in the center of which a light-tight cylinder is mounted orthogonally to the matrix's surface. The cylinder's diameter is selected to be equal to the transverse dimension of the photosensitive element.The cylinder's height is selected so that its shadow falls on the matrix surface when the angle of incidence of laser radiation reflected from the object varies within specified limits. The platform's mounting surface is made flat. The laser sources and the axis of the opaque cylinder are oriented orthogonally to the mounting plane. Upon receiving a signal from the reflected radiation detector, the laser source is activated, and the platform's orientation is maintained to minimize the number of detector light-sensitive elements obscured by the cylinder.

[0013] The justification for the feasibility of the claimed method is as follows.

[0014] According to the proposed invention, laser radiation sources for detecting and activating an object, as well as a detector of reflected radiation, are mounted on the exterior of a platform, which is installed in a system of electromagnets. On the interior of the platform, along its perimeter, are coils carrying an electric current, as well as a rotating mechanism, such as a movable hinge, located at the platform's center of gravity. The electromagnet current is generated as a pulse sequence, allowing the laser beam to scan the target region in azimuth and elevation.

[0015] The detector is made from a set of light-sensitive elements—pixels—that are structurally combined into a flat matrix. A light-tight cylinder is installed in the center of the matrix, perpendicular to its surface. The cylinder's diameter is proportional to the transverse dimension of an individual pixel. The cylinder's height is chosen so that the shadow of the cylinder, generated by laser radiation reflected from the observed object, falls on the matrix surface when the viewing angle changes within specified limits.

[0016] The platform surface on which the laser sources for object detection and exposure, as well as the detector of reflected radiation from the object, are mounted is manufactured flat. The direction of the laser sources and the axis of the opaque cylinder are oriented orthogonally to the mounting plane. The laser source is activated by a signal from the reflected radiation detector, and the platform orientation is maintained to minimize the number of pixels obscured by the cylinder on the surface of the matrix recording the laser radiation reflected from the observed object.

[0017] The reflected radiation detector signal, based on the minimum number of illuminated pixels, confirms the laser detection beam's accurate targeting of the object of interest. At this point, the laser beam is turned on, aiming at the object and aligning with the detection beam, as the beams are orthogonal to the same flat surface of the mounting platform. The laser beam continuously reaches the object simultaneously with the detection beam.

[0018] The advantage of the proposed method is that, in comparison with the prototype method, the time interval required for calculating the correction for the relative position of the probing and acting laser beams is eliminated, which is inevitable given the presence of two different systems for controlling the detection and acting beams in the prototype method.

[0019] Thus, the increase in the efficiency of the claimed method of directing laser radiation to a moving object and the possibility of its practical implementation are beyond doubt.