阅读说明：本技术 一种结构紧凑的自适应激光防御系统 (compact structure's self-adaptation laser defense system ) 是由 马晓燠 饶学军 杨奇龙 汪韬 于 2019-09-09 设计创作，主要内容包括：本发明提供了一种结构紧凑的自适应激光防御系统,包括：主镜、变形调焦次镜、倾斜镜、分束镜、哈特曼传感器、激光准直光学系统、激光器、照明系统和控制器。系统中变形调焦次镜主要有校正高阶像差和大范围离焦的功能；哈特曼传感器用于探测波前畸变,测量结果用于倾斜闭环和离焦高阶像差校正。本发明采用哈特曼传感器代替倾斜跟踪传感器探测波前像差,并配合变形调焦次镜进行校正,有效消除了大气湍流对光斑形状的影响,提高了光斑功率密度,提升了主动防御能力。相较于已有的自适应激光防御系统,本发明将调焦次镜与变形镜结合,使得光学系统结构更加紧凑,反射面更少能量损耗更小。(the invention provides a self-adaptive laser defense system with a compact structure, which comprises: the device comprises a primary mirror, a deformed focusing secondary mirror, an inclined mirror, a beam splitter, a Hartmann sensor, a laser collimation optical system, a laser, an illumination system and a controller. The deformed focusing secondary mirror in the system mainly has the functions of correcting high-order aberration and large-range defocusing; the Hartmann sensor is used for detecting wave front distortion, and the measurement result is used for inclined closed loop and defocusing high-order aberration correction. According to the invention, the Hartmann sensor is adopted to replace an inclined tracking sensor to detect the wavefront aberration, and the deformed focusing secondary mirror is matched for correction, so that the influence of atmospheric turbulence on the shape of the light spot is effectively eliminated, the power density of the light spot is improved, and the active defense capability is improved. Compared with the existing self-adaptive laser defense system, the invention combines the focusing secondary mirror and the deformable mirror, so that the optical system has more compact structure and less energy loss of the reflecting surface.)

1. A compact, adaptive laser defense system, comprising: the device comprises a main mirror, a deformed focusing secondary mirror, an inclined mirror, a beam splitter, a Hartmann sensor, a main laser emission system, an illumination system and a controller; the received light is transmitted to a Hartmann sensor through the reflection of a main mirror, the reflection of a deformed focusing secondary mirror, the reflection of an inclined mirror and a beam splitter in sequence; the emitted laser is transmitted out of the system through beam splitter reflection, inclined mirror reflection, deformation focusing secondary mirror reflection and main mirror reflection in sequence;

the illumination system emits laser to illuminate the search area to provide light signals for the Hartmann sensor;

The primary mirror is a part of the optical system and has a convergence effect on the light beam;

the secondary deformable focusing mirror is a part of an optical system and forms an optical receiving and transmitting optical system together with the primary mirror, and the secondary deformable focusing mirror can maximally correct 100mm large-range defocusing and higher-order aberration above third-order Zernike aberration;

the secondary deformable focusing mirror comprises a secondary deformable mirror, an electric adjusting mechanism and an electric translation mechanism; the deformed secondary mirror is composed of a plurality of unit mirror surfaces and forms a complete optical transmitting and receiving system with other optical devices in a free state; the electric adjusting mechanism is used for adjusting the position state of each unit of the secondary mirror, and the mirror surface is formed and used for correcting high-order aberration including defocusing and above orders; the electric translation mechanism realizes the focusing within the maximum range of 100mm by driving the secondary deformable mirror, and the correction data is measured by the Hartmann;

the tilting mirror plays a role in beam tilt correction in an optical path, tilt correction is carried out on a received optical signal in real time by calculating a correction quantity obtained by calculating a tilt error given by Hartmann, and the tilt correction quantity is measured by the Hartmann;

the Hartmann sensor is used for detecting wavefront inclination and defocusing and higher-order aberration of the orders, measuring results are used for inclining a closed loop and a self-adaptive correction closed loop, and the Hartmann receiving wavefront approaches to plane waves after closed loop correction;

The main laser emission system outputs high-power laser as a main means for target striking, and the main laser emission band is different from illumination laser. Before working, the initial state of the transmitting wave surface needs to be calibrated into a plane wave or a Hartmann calibration wave surface, and the transmitting laser is focused on a target point after closed-loop correction;

The beam splitter is used for distinguishing a main laser emission waveband from an illumination waveband, so that the Hartmann sensor is not interfered by the main laser emission light;

the controller is used for receiving signals of the Hartmann detector, calculating wave front inclination and defocusing, controlling the inclined focusing secondary mirror to correct, and controlling the illumination and the main laser emission system.

2. a compact adaptive laser defense system according to claim 1, characterized in that: the system also comprises a coarse tracking system used for large-field scanning and low-precision tracking, wherein the coarse tracking system comprises a coarse tracking sensor and a coarse tracking actuator; the coarse tracking sensor is used for searching and position feedback of a target in a 1-5-degree view field; the rough tracking actuator is used for carrying out rough tracking on the target through the control of a rough tracking sensor signal, and the low precision means that the tracking precision is superior to a Hartmann view field 1/3, so that the target enters the Hartmann view field.

3. A compact adaptive laser defense system according to claim 1, characterized in that: the lighting system and the main laser emission system are in different wave bands, and Hartmann does not receive the main laser emission wave band.

Technical Field

The invention relates to the technical field of light beam control in optical instruments, in particular to a self-adaptive laser defense system with a compact structure.

Background

The unmanned plane is an unmanned plane controlled by radio remote control equipment and a self-contained program control device. In the 90 s of the 20 th century, western countries fully recognized the role of unmanned aerial vehicles in war, and adopted various new technologies to develop unmanned aerial vehicles vigorously. Nowadays, unmanned aerial vehicles have had multiple functions such as investigation, bullet, interference. Along with the continuous emergence of military and civilian unmanned aerial vehicle, anti-unmanned aerial vehicle consciousness can constantly promote for national security and national soil safety demand, and each country has earlier carried out the research work in this aspect. . But adopt traditional means to combat unmanned aerial vehicle, not only the success rate is low, but also probably causes collateral damage to ground and crowd, and laser defense is one of more effective means.

in a laser defense system, the main laser destructive power is in positive correlation with the energy density of a light spot at a target, and the smaller the diameter of the light spot is, the stronger the laser destructive power is. The traditional laser defense system mainly controls the size of a light spot through a focusing system so as to obtain the minimum light spot and the maximum energy density. In some specific cases, laser propagation in the atmosphere can be affected by turbulence and influence, so that the light spot becomes dispersed, the energy of the light spot is not concentrated, and the active defense effect of the laser is reduced. Whereas aberrations due to atmospheric turbulence cannot be corrected by focusing.

the short-range laser defense system (201721280043.5), the unmanned airborne laser weapon anti-unmanned aerial vehicle system (201811097389.0), the laser defense system and high-altitude airship (201710296422.1) and the land defense system (201820945635.2) based on high-precision dual-wavelength strong laser adopt laser defense, but do not adopt a deformable mirror to correct so as to improve the power density of a facula. The article ' adaptive optics technology ' (doi:10.3969/j.issn.0253-9608.2006.01.002) and the article ' controlling the light beam near field intensity (doi:10.3788/HPLPB20102202.0243) based on the adaptive optics technology adopt a deformable mirror to carry out light path correction or light beam control, but the deformable mirror is applied to a laser defense system, and high-order aberration correction and focusing within a range are realized on a secondary mirror.

Disclosure of Invention

the technical problem of the invention is solved: the defects of the prior art are overcome, the self-adaptive laser defense system with the compact structure is provided, the Hartmann sensor is adopted to replace an inclined tracking sensor to detect wavefront aberration, and the Hartmann sensor is matched with a deformed focusing secondary mirror to correct, so that the influence of atmospheric turbulence on the shape of the light spot is effectively eliminated, the power density of the light spot is improved, and the active defense capability is improved. Compared with the existing self-adaptive laser defense system, the invention combines the focusing secondary mirror and the deformable mirror, so that the optical system has more compact structure and less energy loss of the reflecting surface.

In a first aspect, an embodiment of the present invention provides an adaptive laser defense system with a compact structure, where the system specifically includes: the system comprises a main mirror, a deformed focusing secondary mirror, an inclined mirror, a beam splitter, a Hartmann sensor, a main laser emission system, an illumination system and a controller, wherein received light sequentially passes through the reflection of the main mirror, the reflection of the deformed focusing secondary mirror, the reflection of the inclined mirror and the transmission of the beam splitter to the Hartmann sensor; the emitted laser is transmitted out of the system through beam splitter reflection, inclined mirror reflection, deformation focusing secondary mirror reflection and main mirror reflection in sequence;

The illumination system emits laser to illuminate the search area to provide light signals for the Hartmann sensor;

the primary mirror is a part of the optical system and has a convergence effect on the light beam;

the secondary deformable focusing mirror is a part of an optical system and forms an optical receiving and transmitting optical system together with the primary mirror, and the secondary deformable focusing mirror can maximally correct 100mm large-range defocusing and higher-order aberration above third-order Zernike aberration; the secondary deformable focusing mirror comprises a secondary deformable mirror, an electric adjusting mechanism and an electric translation mechanism; the deformed secondary mirror is composed of a plurality of unit mirror surfaces and forms a complete optical transmitting and receiving system with other optical devices in a free state; the electric adjusting mechanism is used for adjusting the position state of each unit of the secondary mirror, and the mirror surface is formed and used for correcting high-order aberration including defocusing and above orders; the electric translation mechanism realizes the focusing within the maximum range of 100mm by driving the secondary deformable mirror, and the correction data is measured by the Hartmann;

The tilting mirror plays a role in beam tilt correction in an optical path, tilt correction is carried out on a received optical signal in real time by calculating a correction quantity obtained by calculating a tilt error given by Hartmann, and the tilt correction quantity is measured by the Hartmann;

the Hartmann sensor is used for detecting wavefront inclination and defocusing and higher-order aberration of the orders, measuring results are used for inclining a closed loop and a self-adaptive correction closed loop, and the Hartmann receiving wavefront approaches to plane waves after closed loop correction;

The main laser emission system outputs high-power laser as a main means for target striking, and the main laser emission band is different from illumination laser. Before working, the initial state of the transmitting wave surface needs to be calibrated into a plane wave or a Hartmann calibration wave surface, and the transmitting laser is focused on a target point after closed-loop correction;

The beam splitter is used for distinguishing a main laser emission waveband from an illumination waveband, so that the Hartmann sensor is not interfered by the main laser emission light;

the controller is used for receiving signals of the Hartmann detector, calculating wave front inclination and defocusing, controlling the inclined focusing secondary mirror to correct, and controlling the illumination and the main laser emission system.

With reference to the first aspect, an embodiment of the present invention provides a first possible implementation manner of the first aspect, wherein the illumination system and the primary laser emission are in different wavelength bands. Hartmann does not receive the main lasing band.

With reference to the first possible implementation manner of the first aspect, an embodiment of the present invention provides a second possible implementation manner of the first aspect, where the anamorphic focusing secondary mirror includes an anamorphic secondary mirror, an electric adjusting mechanism, and an electric translating mechanism;

the deformed secondary mirror is composed of a plurality of unit mirror surfaces and forms a complete optical transmitting and receiving system with other optical devices in a free state;

The electric adjusting mechanism is used for adjusting the position state of each unit of the secondary mirror, and the mirror surface is formed and used for correcting high-order aberration including defocusing and above orders;

the electric translation mechanism realizes the focusing within the maximum range of 100mm by driving the secondary deformable mirror, and the correction data is measured by the Hartmann;

With reference to the second possible implementation manner of the first aspect, an embodiment of the present invention provides a third possible implementation manner of the first aspect, where the system further includes a coarse tracking system, which is used for large-range scanning and low-precision tracking, and the coarse tracking system includes a coarse tracking sensor and a coarse tracking actuator. The coarse tracking sensor is used for searching and position feedback of a target in a 1-5-degree view field; the rough tracking actuator is used for carrying out rough tracking on the target through the control of a rough tracking sensor signal, and the low precision means that the tracking precision is superior to a Hartmann view field 1/3, so that the target enters the Hartmann view field.

The coarse tracking sensor is used for searching and position feedback of targets in a large range;

The rough tracking actuator is controlled by a rough tracking sensor signal to perform rough tracking on the target, so that the target enters the detection view field of the system.

Compared with the prior art, the invention has the advantages that: according to the self-adaptive laser defense system with the compact structure, the Hartmann sensor is adopted to replace an inclined tracking sensor to detect the wave front aberration, and the deformed focusing secondary mirror is matched for correction, so that the influence of atmospheric turbulence on the shape of a light spot is effectively eliminated, the power density of the light spot is improved, the light spot is transmitted in a long distance in dense fluctuating atmosphere, the Snell ratio of the light spot can be improved by 3-20 times, and the active defense capability is improved. Compared with the existing self-adaptive laser defense system, the focusing secondary mirror is combined with the deformable mirror, so that the optical system is more compact in structure, the reflecting surface has less energy loss, and the energy loss can be reduced by 2-8%.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

in order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 shows a first schematic diagram of a compact adaptive laser defense system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram illustrating a schematic diagram of a deformable focusing secondary mirror in a compact adaptive laser defense system according to an embodiment of the present invention;

FIG. 3 is a schematic diagram showing a spatial layout of a mirror surface and a driving unit of a deformable focusing secondary mirror in a compact adaptive laser defense system according to an embodiment of the present invention; wherein the left view is a front view of the anamorphic focusing secondary, and the right view is a side view of the anamorphic focusing secondary;

FIG. 4 is a second schematic diagram of a compact adaptive laser defense system according to an embodiment of the present invention;

FIG. 5 is a schematic diagram illustrating a second primary mirror and a secondary mirror of the compact adaptive laser defense system according to the embodiment of the present invention;

Description of the main element symbols:

1. a primary mirror; 2. deforming the focusing secondary mirror; 3. a tilting mirror; 4. a beam splitter; 5. a Hartmann sensor; 6. a main laser emission system; 7. an illumination system; 8. a controller; 9. a coarse tracking sensor; 10. tracking the rack; 21. deforming the mirror surface of the secondary mirror; 22. a deformed secondary mirror subunit; 23. a deformed secondary mirror driving unit; 24. fixing a mechanical part by the deformed secondary mirror; 25. a deformed secondary mirror connector; 26. an electric translation mechanism;

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

the existing laser defense system adopts a focusing mode to carry out focusing through an image processing mode. The image processing focusing mode is susceptible to ambient light, the focusing deviation and direction cannot be calculated quantitatively, the calculation amount of the algorithm is large, the convergence is poor, stable focusing cannot be achieved, and the target can escape due to long focusing time. And the Hartmann sensor is adopted to replace an oblique tracking sensor to detect the wave front aberration, compared with the original image algorithm, the method has the advantages of simple calculation process and good stability, and can quantitatively detect the wave front defocusing so as to realize quick correction.

As shown in fig. 1, an adaptive laser defense system with a compact structure provided by an embodiment of the present invention includes: the device comprises a main mirror 1, a deformed focusing secondary mirror 2, an inclined mirror 3, a beam splitter 4, a Hartmann sensor 5, a main laser emission system 6, an illumination system 7 and a controller 8. The received light is reflected by the primary mirror 1, reflected by the deformed focusing secondary mirror 2, reflected by the inclined mirror 3 and transmitted to the Hartmann sensor 5 by the beam splitter 4 in sequence; the emitted laser is reflected by a beam splitter 4, a tilting mirror 3, a deformed focusing secondary mirror 2 and a primary mirror 1 in sequence to be emitted out of the system;

The illumination system 7 emits laser to illuminate the search area to provide light signals for the Hartmann sensor;

The primary mirror 1 is a part of an optical system and has a function of converging light beams;

the secondary deformable focusing mirror 2 is a part of an optical system and forms an optical receiving and transmitting optical system together with the primary mirror, and the secondary deformable focusing mirror can maximally correct 100mm wide-range defocusing and higher-order aberration above third order of Zernike aberration;

The tilting mirror 3 plays a role in beam tilt correction in an optical path, tilt correction is carried out on a received optical signal in real time by calculating a correction quantity obtained by calculating a tilt error given by Hartmann, and the tilt correction quantity is measured by the Hartmann;

The Hartmann sensor 5 is used for detecting wavefront inclination and defocusing and higher-order aberration of the orders above, measuring results are used for an inclined closed loop and a self-adaptive correction closed loop, and the Hartmann receiving wavefront approaches to plane waves after closed loop correction;

The main laser emitting system 6 outputs high-power laser as a main means of target striking, and the wave band is different from that of illumination laser. Before working, the initial state of the transmitting wave surface needs to be calibrated into a plane wave or a Hartmann calibration wave surface, and the transmitting laser is focused on a target point after closed-loop correction;

the beam splitter 4 is used for distinguishing a main laser emission waveband from an illumination waveband, so that the Hartmann sensor is not interfered by the main laser emission light;

And the controller 8 is used for receiving the Hartmann detector signal, calculating wave front inclination and defocusing, controlling the inclined focusing secondary mirror to correct, and controlling the illumination and main laser emission system.

the system work flow is as follows: firstly, system calibration ensures that a receiving system and a transmitting system are aligned with the center of a view field and focused at infinity, and the system can normally work after being calibrated once; after calibration, the illumination system 7 emits illumination laser, wherein the illumination laser and the main emission laser are different wave bands; the wave front aberration is measured by a Hartmann sensor 5 after the target echo is received by a receiving optical system; the controller 8 respectively controls the tilting mirror 3 and the deformed focusing secondary mirror 2 to correct high-order aberrations such as tilting and defocusing; because the receiving and transmitting light path is common, the corrected target point is conjugated with the laser transmitting point, and the power density at the target is highest.

The detection signal of the Hartmann sensor 5 can be obtained by calculating a wave front restoration formula, firstly, a facula slope matrix G of the Hartmann sensor is calculated, and a Zernike coefficient matrix of aberration can be obtained through a restoration matrix D-.

A＝D^-G

where the elements of G can be calculated from the spot displacement of each sub-aperture.

wherein, Δ x_iand Δ y_i G_x(i) And G_y(i) Respectively representing the spot offsets, G, in the X-and Y-directions of the ith sub-aperture_x(i) And G_y(i) respectively represent the slopes of the ith sub-aperture in the X-direction and the Y-direction, and G can be expressed as:

G＝[G_x(1),G_y(1),G_x(2),G_y(2),....G_x(m),G_y(m)]'

wherein, the D-restoration matrix is an inverse matrix of a slope matrix D of each order of the Zernike wave surface, and the slope of each order of the sub-apertures is as follows:

Wherein Z is_k(x, y) is a k-th order Zernike wave surface, S_inormalizing the area for the ith sub-aperture, Z_xk(i) and Z_yk(i) respectively, the slopes corresponding to the ith sub-aperture of the k-th order zernike wave surface, and the n-th order zernike m effective sub-aperture slope matrix D can be expressed as:

The first, second and third orders of the Zernike coefficients are X-direction tilt, Y-direction tilt and defocus, respectively, of the wavefront aberration, wherein the X-direction tilt aberration and the Y-direction tilt aberration can be corrected by the tilt mirror deflection, and the defocus aberration and higher order aberrations can be corrected by the anamorphic focusing secondary mirror.

the deformed focusing secondary mirror 2 comprises a deformed secondary mirror, an electric adjusting mechanism and an electric translation mechanism, which are shown in figure 2;

The deformed secondary mirror surface 21 is composed of a plurality of deformed secondary mirror units 22 and forms a complete optical transmitting and receiving system with other optical devices in a free state; when the Hartmann sensor 5 detects that the aberration is declivated, the controller 8 calculates a correction voltage matrix, and the deformed secondary mirror driving unit 23 drives and changes the shape of the deformed focusing secondary mirror 2 to correct the wavefront aberration. The spatial layout of the mirror surface and the driving unit of the deformed focusing secondary mirror is shown in fig. 3.

the defocusing aberration in the system can be corrected by changing the shape of the secondary mirror surface, and also can be corrected by changing the relative distance between the deformed focusing secondary mirror 2 and the primary mirror 1. In consideration of the requirement of large-range focusing, an electric translation mechanism such as an electric translation table, a ball screw and other adjusting mechanisms are added in the secondary deformable focusing mirror, and the maximum 100mm range focusing is realized by driving the secondary deformable focusing mirror;

embodiments of the present invention also include a coarse tracking system, allowing for scanning and tracking of large fields of view, see FIG. 3. The coarse tracking function in the system may be implemented in particular by the coarse tracking sensor 9 and the tracking gantry 10.

the coarse tracking sensor 9 is composed of an imaging lens and a photoelectric detector, the position information of a target can be obtained through the position of a light spot of the photoelectric detector, and the view field can be designed to be 1-5 degrees.

The tracking gantry 10 is used primarily as a load-bearing platform for the system, allowing both horizontal and pitch rotation.

When no suspicious target exists, the tracking rack 10 scans a specific area by a certain scanning path; when a target is found, the tracking frame 10 returns a signal through the coarse tracking sensor 9 to perform closed-loop tracking, so that the target enters a Hartmann 5 view field.

in addition, the embodiment of the invention also provides another spatial arrangement mode of the primary mirror and the secondary mirror, which can be seen in fig. 5. The optical axes of the primary mirror 1 and the deformed focusing secondary mirror 2 are superposed. This arrangement has the advantage of a larger focus range and less pupil plane translation than in figures 1 and 4. But has the disadvantage of a smaller optical receiving area.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: any person skilled in the art can modify or easily conceive the technical solutions described in the foregoing embodiments or equivalent substitutes for some technical features within the technical scope of the present disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the present invention in its spirit and scope. Are intended to be covered by the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.