Distributed polarization detection system and method based on position regulation and control target reconstruction

Abstract

The invention discloses a distributed polarization detection system and method based on position regulation and control target reconstruction, and belongs to the field of distributed polarization cooperative detection and photoelectronic imaging. The distributed polarization detection system comprises a lighting device, a multi-parameter auxiliary detection objective table and a long-wave infrared polarization detection device; the long-wave infrared polarization detection device is provided with three sub-polarization detection devices, the method is implemented based on a distributed polarization detection system, and polarization information in three different directions can be collected at the same time through the distributed polarization detection system based on position regulation and control target reconstruction. The identification capability of the disguised / similar target at a single angle is improved; and errors caused by time delay are avoided. Polarization information obtained by reasonably distributing detection positions is mutually supplemented, polarization images are mutually fused, target signals are effectively extracted from scattered light to analyze the polarization characteristic difference between interference light and target reflected light, and the resolution, contrast and detection distance of polarization imaging can be improved.

Description

Technical Field

[0001] The present invention belongs to the field of distributed polarization cooperative detection and optoelectronic imaging, and in particular, relates to a distributed polarization detection system and method based on position-controlled target reconstruction. Background Art

[0002] Polarization detection imaging technology is to highlight the target from the environment, thereby improving the resolution of different targets and environments, but it is still affected by some harsh environments and the limitations of single detection. With the growing demand for detection, how to effectively detect the environment, accurately identify the physical characteristics of the target, and achieve collaborative detection in the process of polarization detection is a technical problem that needs to be solved urgently.

[0003] In actual polarization imaging detection, the dynamic changes of the detection environment and the need for real-time detection require that the detection device be changed according to the actual environment, and a single detection is difficult to achieve an ultra-large dynamic range and high spatial resolution. Summary of the invention

[0004] In view of this, the purpose of the present invention is to solve the problem of distributed polarization imaging collaborative detection of multiple targets in the long-wave infrared band, and to propose a distributed polarization detection system and method based on position-controlled target reconstruction.

[0005] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: According to the first aspect of the present invention, a distributed polarization detection system based on position-controlled target reconstruction is proposed, wherein the distributed polarization detection system comprises an illumination device, a multi-parameter auxiliary detection stage and a long-wave infrared polarization detection device, and the illumination device, the multi-parameter auxiliary detection stage and the long-wave infrared polarization detection device are respectively connected to an image display and control system; the illumination device has an artificial light source simulating the sun and a light source adjustment mechanism for adjusting the position and / or angle of the artificial light source; the multi-parameter auxiliary detection stage comprises a stage body, a first photodetector, a graphene heating plate, a thermal insulation plate and a second photodetector, wherein the first photodetector is fixedly attached to the central position of the upper surface of the stage body; the graphene heating plate is arranged above the first photodetector at a set interval; the thermal insulation plate is arranged on the periphery of the first photodetector and the graphene heating plate; the second photodetector is an annular photodetector, and the second photodetector is an annular photodetector. The detector is placed above the thermal insulation board, the central area of ​​the second photoelectric detector serves as the target placement area, and the bottom surface of the target is in contact with the upper surface of the graphene heating plate; the long-wave infrared polarization detection device has three sub-polarization detection devices, and the three sub-polarization detection devices are dispersed on one side of the multi-parameter auxiliary detection stage, and the three sub-polarization detection devices all have a polarization detection component and a polarization detection adjustment mechanism for adjusting the position and / or angle of the polarization detection component, the polarization detection component includes a long-wave infrared polarization detection module and a laser gas detection photoelectric module, the laser gas detection photoelectric module includes a laser, a collimating and expanding optical unit and a converging lens, and the lasers carried in the three sub-polarization detection devices are 671nm laser, 1064nm laser and carbon dioxide laser respectively; the long-wave infrared polarization detection module includes a long-wave infrared quarter-wave plate, a long-wave infrared polarizer and a long-wave infrared camera arranged in sequence along the propagation direction of the light.

[0006] Furthermore, the light source adjustment mechanism includes a light source adjustment mechanism base, a first retractable mechanical lower arm, a first rotatable upper arm and a first wrist rotation shaft, and the first retractable mechanical lower arm is installed on the light source adjustment mechanism base; the two ends of the first rotatable upper arm are respectively rotatably connected to the first retractable mechanical lower arm and the first wrist rotation shaft through bearings; an artificial light source is installed on the first wrist rotation shaft, and the light source adjustment mechanism base, the first retractable mechanical lower arm, the first rotatable upper arm and the first wrist rotation shaft are all equipped with separate drive motors.

[0007] Furthermore, the distance between the first photodetector and the graphene heating plate is 5 cm.

[0008] Furthermore, the long-wave infrared quarter-wave plate is mounted on a first electrically-controlled high-speed rotating wheel; and the long-wave infrared polarizer is mounted on a second electrically-controlled high-speed rotating wheel.

[0009] Furthermore, the polarization detection adjustment mechanism includes a polarization detection adjustment mechanism base, a rotating shaft, a second retractable mechanical lower arm, a retractable rotating middle arm, a second rotatable upper arm and a second wrist rotation shaft, which are connected in sequence from bottom to top, and a polarization detection component is installed on the second wrist rotation shaft. The polarization detection adjustment mechanism base, the rotating shaft, the second retractable mechanical lower arm, the retractable rotating middle arm, the second rotatable upper arm and the second wrist rotation shaft are all equipped with a separate drive motor.

[0010] According to a second aspect of the present invention, a distributed polarization detection method based on position control target reconstruction is proposed. The method is implemented using the distributed polarization detection system, and specifically includes: Step 1: The target is placed on the graphene heating plate in the multi-parameter auxiliary detection stage and attached to it; Step 2: Start the 671nm laser, 1064nm laser and carbon dioxide laser. The laser beams emitted by the 671nm laser, 1064nm laser and carbon dioxide laser are collimated and expanded by their corresponding optical units to emit parallel beams. When there is no haze gas in the air, the parallel beams will be converged by the converging lens on the center of the second photodetector; when there is haze gas in the air, the laser will be scattered when encountering haze particles, and finally captured by each detection unit in the second photodetector; Step 3: Turn off the 1064nm laser and the carbon dioxide laser, use the 671nm laser as the transmitting end, and irradiate the target surface after passing through the collimating beam expansion optical unit and the converging lens. The first photodetector is used as the receiving end. If the target is opaque, the first photodetector under the graphene heating plate does not receive the signal; if the target is transparent, the light passes through the graphene heating plate after birefringence of the transparent target, and the first photodetector receives the light signal; Step 4: Turn off the 671nm laser, turn on the artificial light source of the lighting device, adjust the light source adjustment mechanism, determine the incident zenith angle of the artificial light source, and ensure that the light is incident on the target surface; Step 5: Turn on the polarization detection component of the long-wave infrared polarization detection device, adjust the polarization detection adjustment mechanism, and determine the detection zenith angle and relative azimuth angle of the polarization detection component; when the artificial light source is blocked, keep the detection zenith angle and relative azimuth angle unchanged, and adjust the polarization detection adjustment mechanism to avoid blocking; Step 6: Adjust the positions of the long-wave infrared quarter-wave plate and the long-wave infrared polarizer to generate 0° linear polarized light, 45° linear polarized light, 90° linear polarized light, 135° linear polarized light, left-handed circular polarized light, and right-handed circular polarized light. The six polarization states of light enter the long-wave infrared camera respectively, change the relative azimuth angle, repeat the experiment, and complete the polarization detection with a full relative azimuth angle ranging from 0° to 360°. Step 7: Change the detection zenith angle and repeat the experiment in step 6 to complete the detection of the full detection zenith angle ranging from 0° to 90° and the full relative azimuth angle ranging from 0° to 360° under the initial incident zenith angle; Step 8: Change the incident zenith angle, repeat steps 6 and 7, and complete the full-band polarization detection imaging experiment of the polarization characteristics of the unheated target; Step 9: Power the graphene heating plate to heat the target. When the target temperature reaches the set temperature, power is stopped for the graphene heating plate, and the thermal insulation plate maintains the target temperature. Step 10: Repeat steps 6 to 9, use the polarization detection component again to perform polarization detection imaging on the target polarization state of the set temperature, and read the image information of the polarization detection imaging; Step 11: After step 1 to step 10, the three sub-polarization detection devices have completed preliminary acquisition of the target polarization image information. The target images detected and acquired by the three sub-polarization detection devices respectively cover a part of the entire scene and there is an overlapping area between the three images, forming three groups of polarization state image data sets, each group of polarization state image data sets includes polarization state images of 0° linear polarized light, 45° linear polarized light, 90° linear polarized light, 135° linear polarized light, left-handed circularly polarized light and right-handed circularly polarized light, and the six polarization state images in each group are fused into a polarization degree image to establish three groups of polarization degree image data sets X1, X2, X3; Step 12: The position coordinates, overlapping areas, and polarization change information provided by the three sets of polarization image data sets X1, X2, and X3 are used as the input layer, and the BP neural network optimization algorithm based on particle swarm optimization is used to find the size of the overlapping area and the optimal position, determine the optimal coordinate positions of the three sub-polarization detection devices, and obtain the optimal distribution positions of the three sub-polarization detection devices; Step 13: Initialize the lighting device and the long-wave infrared polarization detection device, that is, set the incident zenith angle of the artificial light source, the detection zenith angle of the polarization detection component and the relative azimuth angle to 0°, and distribute the optimal coordinate positions of the three sub-polarization detection devices according to the optimal distribution positions obtained by optimization in step 12; set the target initial temperature to room temperature; change the relative azimuth angle in intervals of 10°, ranging from 0° to 360°; change the detection zenith angle in intervals of 10°, ranging from 0° to 90°; change the incident zenith angle in intervals of 10°, ranging from 0° to 90°; The detection is performed at intervals of 0° to 90°; three sub-polarization detection devices acquire images; when the temperature increases by 15°C on the basis of the initial temperature, the relative azimuth angle of the target is repeatedly changed at intervals of 10°, ranging from 0° to 360°; the detection zenith angle is changed at intervals of 10°, ranging from 0° to 90°; the incident zenith angle is changed at intervals of 10°, ranging from 0° to 90°; the detection is terminated until the temperature reaches 105°C, at which point the acquisition of distributed target polarization images is completed; Step 14: After the distributed target polarization image is acquired, the images of the three sub-polarization detection devices at different temperatures are used to calculate the polarization state information and intensity information of the target scene using a multi-view sparse scene reconstruction method; on this basis, based on visual saliency mapping, multi-dimensional information enhancement and feature fusion are performed on the original source image data, and finally a polarization fusion image is reconstructed; The original source image refers to the initial imaging image received by the detection.

[0011] Furthermore, the process of fusing the six polarization state images in each group into a polarization degree image is as follows: based on the multi-scale image fusion algorithm, the low-frequency coefficients are fused using the principal component analysis transformation method based on the wavelet transform, and the high-frequency coefficients are fused using the regional feature energy fusion rule. Finally, the polarization degree image fused from the six polarization state images in each group is obtained through the inverse wavelet transform.

[0012] Through the above design scheme, the present invention can bring the following beneficial effects: through the distributed polarization detection system and method based on position-controlled target reconstruction, polarization information in three different directions can be collected at the same time, improving the recognition ability of camouflaged / similar targets at a single angle and avoiding errors caused by time delay. The polarization information obtained by the reasonable distribution of detection positions complements each other, and the polarization images are integrated with each other, effectively extracting the target signal from the scattered light and analyzing the polarization characteristics difference between the interference light and the target reflected light, which helps to improve the resolution, contrast and detection distance of polarization imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The exemplary embodiments of the present invention and their descriptions are used to understand the present invention and do not constitute improper limitations of the present invention. In the drawings: Figure 1 A schematic diagram of the structure of a distributed polarization detection system based on position control target reconstruction; Figure 2 Schematic diagram of the top view of the three sub-polarization detection devices; Figure 3 is a structural schematic diagram of a lighting device; Figure 4 This is a schematic diagram of the structure of the multi-parameter auxiliary detection stage; Figure 5 This is a schematic diagram of the structure of a long-wave infrared polarization detection device; Figure 6 is a schematic diagram of the structure of a polarization detection component; Figure 7 Schematic diagram of the workflow of the distributed polarization detection method based on position-controlled target reconstruction.

[0014] The marks in the figure are as follows: 1 is a lighting device; 11 is an artificial light source; 12 is a base of a light source adjustment mechanism; 13 is a first retractable mechanical lower arm; 14 is a first rotatable upper arm; 15 is a first wrist rotation axis; 2 is a multi-parameter auxiliary detection stage; 21 is a stage body; 22 is a first photodetector; 23 is a graphene heating plate; 24 is a thermal insulation plate; 25 is a second photodetector; 26 is a target; 27 is an IV and AD conversion circuit; 28 is a monitor; 29 is a temperature controller; 30 is a DC regulated power supply; 3 is a long-wave infrared polarization detection device; 3-1 is a sub-polarization detection device A; 3-2 is a sub-polarization detection device B; 3-3 is a sub-polarization detection device Detection device C; 31 is a polarization detection component; 311 is a long-wave infrared polarization detection module; 312 is a collimating and expanding optical unit; 313 is a converging lens; 314 is a 671nm laser; 315 is a 1064nm laser; 316 is a carbon dioxide laser; 317 is a long-wave infrared quarter-wave plate; 318 is a long-wave infrared polarizer; 319 is a long-wave infrared camera; 320 is a first electrically controlled high-speed rotating wheel; 321 is a second electrically controlled high-speed rotating wheel; 32 is a base of a polarization detection adjustment mechanism; 33 is a rotating shaft; 34 is a second retractable mechanical lower arm; 35 is a retractable rotating middle arm; 36 is a second rotatable upper arm; 37 is a second wrist rotating shaft. DETAILED DESCRIPTION

[0015] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical scheme of the present invention is clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the present invention is not limited to the following embodiments, and the specific implementation method can be determined according to the technical scheme of the present invention and the actual situation. In order to avoid confusing the essence of the present invention, the known methods, processes, procedures, components and circuits are not described in detail.

[0016] like Figure 1 and Figure 2As shown, the distributed polarization detection system based on position control target reconstruction proposed by the present invention includes an illumination device 1, a multi-parameter auxiliary detection stage 2 and a long-wave infrared polarization detection device 3, and finally receives and stores images through the image display and control system on the software side, and controls the illumination device 1, the multi-parameter auxiliary detection stage 2 and the long-wave infrared polarization detection device 3. The image display and control system belongs to the prior art and will not be described in detail here. The lighting device 1 is equipped with an artificial light source 11 simulating the sun and a light source adjustment mechanism for adjusting the position and / or angle of the artificial light source 11. The light source adjustment mechanism includes a light source adjustment mechanism base 12 that realizes horizontal rotation through a rotating motor (not shown in the attached drawings), a first telescopic mechanical lower arm 13 that is driven to vertically extend and retract by a linear motor (not shown in the attached drawings), and a first rotatable upper arm 14 and a first wrist rotation shaft 15 that are respectively controlled by corresponding servo motors (not shown in the attached drawings). The first telescopic mechanical lower arm 13 is installed on the light source adjustment mechanism base 12; the two ends of the first rotatable upper arm 14 are rotatably connected to the first telescopic mechanical lower arm 13 and the first wrist rotation shaft 15 through bearings respectively; the artificial light source 11 is fixed on the first wrist rotation shaft 15. The first retractable mechanical lower arm 13 in the lighting device 1 is used to adjust the height of the light from the artificial light source 11, the first rotatable upper arm 14 is used to coarsely adjust the incident zenith angle of the light from the artificial light source 11 and to irradiate the light on the surface of the target 26, and the first wrist rotation axis 15 is used to achieve precise adjustment of the incident zenith angle of the light from the artificial light source 11. The entire lighting device 1 can achieve simulated lighting at different heights and different incident zenith angles through coordination.

[0017] The multi-parameter auxiliary detection stage 2 includes a stage body 21, a first photodetector 22, a graphene heating plate 23, a heat preservation and insulation plate 24, and a second photodetector 25. The first photodetector 22 is fixedly attached to the center of the upper surface of the stage body 21. The graphene heating plate 23 is fixed 5 cm above the first photodetector 22. The distance between the graphene heating plate 23 and the first photodetector 22 is 5 cm, so that the air layer forms a thermal resistance, ensuring that the working temperature of the first photodetector 22 is stable within a safe range, and avoiding aging or signal drift of the first photodetector 22 due to thermal stress. The heat preservation and insulation plate 24 is arranged on the periphery of the first photodetector 22 and the graphene heating plate 23 to prevent the temperature of the graphene heating plate 23 from rising and damaging other components. The second photodetector 25 is a ring-shaped photodetector. The second photodetector 25 is placed above the heat preservation and insulation plate 24. The central area of ​​the second photodetector 25 is used as the placement area of ​​the target 26, and the bottom surface of the target 26 is attached to the upper surface of the graphene heating plate 23. The graphene heating plate 23 uses the electric field after power-on to drive the migration and energy dissipation of carriers to achieve electric-thermal conversion heating. The external temperature controller 29 is powered by a DC stabilized power supply 30. The specific structure of the temperature controller 29 and the DC stabilized power supply 30, as well as the connection method with the graphene heating plate 23, belong to the prior art and will not be described in detail here. The second photodetector 25 measures the scattered light intensity at different angles, obtains the scattered light intensity distribution information and converts it into an electrical signal. The electrical signal is converted into a digital signal through the IV and AD conversion circuit 27 and displayed on the monitor 28 to complete the haze detection work. When the multi-parameter auxiliary detection stage 2 is used for polarization detection of the target 26, the target 26 is heated, and the experimental gas environment and the target 26 are auxiliary detected. If the target 26 is transparent, the light is birefringent through the transparent target 26. Due to the high light transmittance of the graphene heating plate 23, the light passes through the graphene heating plate 23, and the first photodetector 22 receives the light signal.

[0018] The long-wave infrared polarization detection device 3 has three sub-polarization detection devices, and the three sub-polarization detection devices are dispersed on one side of the multi-parameter auxiliary detection stage 2. The three sub-polarization detection devices all have a polarization detection component 31 and a polarization detection adjustment mechanism for adjusting the position and / or angle of the polarization detection component 31. The polarization detection component 31 includes a long-wave infrared polarization detection module 311 and a laser gas detection photoelectric module. The laser gas detection photoelectric module includes a laser, a collimating and beam expanding optical unit 312 and a converging lens 313. The collimating and beam expanding optical unit 312 is an optical system that combines collimation and beam expanding functions, and is used to convert divergent light beams into parallel light and expand its diameter. The specific structure of the collimating and beam expanding optical unit 312 belongs to the prior art and will not be described in detail here. The lasers carried in the three sub-polarization detection devices are respectively a 671nm laser 314, a 1064nm laser 315 and a carbon dioxide laser 316. For the convenience of description, the three sub-polarization detection devices are named sub-polarization detection device A 3-1, sub-polarization detection device B 3-2 and sub-polarization detection device C 3-3, among which the 671nm laser 314 is carried in the sub-polarization detection device A 3-1, the 1064nm laser 315 is carried in the sub-polarization detection device B 3-2, and the carbon dioxide laser 316 is carried in the sub-polarization detection device C 3-3. The polarization detection adjustment mechanism includes a polarization detection adjustment mechanism base 32, a rotating shaft 33, a second retractable mechanical lower arm 34, a retractable rotating middle arm 35, a second rotatable upper arm 36 and a second wrist rotating shaft 37, which are connected in sequence from bottom to top. The polarization detection adjustment mechanism base 32 and the rotating shaft 33 are respectively adjusted in horizontal direction by their corresponding rotating motors. The second retractable mechanical lower arm 34 is driven by a linear motor to vertically retract. The retractable rotating middle arm 35 is coordinated by the rotating motor and the linear motor. The second rotatable upper arm 36 and the second wrist rotating shaft 37 are respectively controlled by their corresponding servo motors. The polarization detection component 31 is installed on the second wrist rotating shaft 37. The polarization detection adjustment mechanism base 32 is used to determine the position of the entire sub-polarization detection device. The rotating shaft 33 drives the entire sub-polarization detection device to rotate by rotation. The second retractable mechanical lower arm 34 controls the height by retracting. The retractable rotating middle arm 35, the second rotatable upper arm 36 and the second wrist rotating shaft 37 can rotate 180° around the axis and coordinate with each other to position the polarization detection component 31.The long-wave infrared polarization detection module 311 includes a long-wave infrared quarter-wave plate 317, a long-wave infrared polarizer 318 and a long-wave infrared camera 319 which are sequentially arranged along the light propagation direction. The long-wave infrared quarter-wave plate 317 is mounted on a first electrically controlled high-speed rotating wheel 320; the long-wave infrared polarizer 318 is mounted on a second electrically controlled high-speed rotating wheel 321. The electrically controlled high-speed rotating wheel is a mechanical device that realizes high-speed and precise rotation through an electronic control system. It is widely used in industrial automation, scientific research instruments, optical systems and other fields. It belongs to the prior art and will not be described in detail here. It should be understood that the terms "first" and "second" are only used for descriptive purposes. The features defined as "first" and "second" do not indicate any order, quantity or importance, but are only used to distinguish different components. Sub-polarization detection device A 3-1, sub-polarization detection device B 3-2 and sub-polarization detection device C 3-3 respectively use 671nm laser 314, 1064nm laser 315 and carbon dioxide laser 316 as laser light sources, and then convert the light emitted by the light source into parallel light through the corresponding collimating and expanding optical units 312, and then irradiate the second photodetector 25 of the multi-parameter auxiliary detection stage 2 through the converging lens 313. The laser will be scattered when it meets the particles in the gas. The gas environment condition can be calculated by measuring the light intensity distribution after the laser scattering by the second photodetector 25.

[0019] The multi-parameter auxiliary detection stage 2 is located between the lighting device 1 and the long-wave infrared polarization detection device 3. The first photodetector 22 cooperates with the sub-polarization detection device A 3-1 to detect whether the target 26 is transparent; the second photodetector 25 cooperates with the sub-polarization detection device A 3-1, the sub-polarization detection device B 3-2 and the sub-polarization detection device C 3-3 to detect the haze concentration in the gas; the graphene heating plate 23 and the thermal insulation plate 24 provide a temperature change environment for the target 26.

[0020] The long-wave infrared polarization detection device 3 performs polarization detection on the hemispherical space where the target 26 is located, and solves the problem of the light emitted by the lighting device 1 being blocked by the long-wave infrared polarization detection device 3 during the detection process through the adjustment of the robotic arm; the long-wave infrared polarization detection device 3 combines the advantages of distributed polarization detection to solve the polarization detection problem of different types of targets in the long-wave infrared band.

[0021] The lighting device 1, the multi-parameter auxiliary detection stage 2 and the long-wave infrared polarization detection device 3 constitute a distributed infrared polarization detection system, which displays the detection image in the long-wave infrared polarization detection device 3 through the image display and control system, and controls the driving motors in the lighting device 1 and the long-wave infrared polarization detection device 3 to drive the mechanical components to the designated position for detection, thereby further promoting the coordination of the entire distributed polarization detection system based on position control and target reconstruction, realizing fully automatic, long-wave infrared band distributed polarization detection in a haze environment, and performing image processing on subsequent polarization images, position control of the three sub-polarization detection devices, and reconstruction of target polarization information.

[0022] In order to achieve the purpose of distributed polarization detection, the long-wave infrared polarization detection device 3 has three sub-polarization detection devices, which are set for coordinated detection. The three sub-polarization detection devices are randomly and dispersedly distributed around the detected target 26. First, the test gas environment is monitored by different band lasers carried by the three sub-polarization detection devices and preliminary polarization detection is performed. The optimal distribution position and overlapping area size of the three sub-polarization detection devices are calculated based on the image information of the preliminary polarization detection. Then, the three sub-polarization detection devices are re-detected according to the optimal distribution position, and the obtained image is reconstructed to obtain the polarization image of the reconstructed target after the final position control.

[0023] The present invention proposes to use the designed distributed polarization detection system based on position control target reconstruction to perform preliminary polarization detection to obtain images, use the BP neural network optimization algorithm based on particle swarm optimization to solve the image information and optimize the position layout of three sub-polarization detection devices, perform position control and detect the target 26 again to obtain image information, and use a multi-view sparse scene reconstruction method to reconstruct the target image information, wherein the calculation result of the visual saliency mapping is used as a weight, and iterative guided filtering is used to perform multi-dimensional information enhancement and feature fusion on the details of the image area, and finally a reconstructed target image is obtained and its polarization state information and intensity information are solved.

[0024] The distributed polarization detection method based on position control target reconstruction includes the following steps: Step 1: Place the target 26 on the graphene heating plate 23 of the multi-parameter auxiliary detection stage 2 and fit it with the graphene heating plate 23 to facilitate uniform heating.

[0025] Step 2: Start the 671nm laser 314, the 1064nm laser 315 and the carbon dioxide laser 316. The 671nm laser 314, the 1064nm laser 315 and the carbon dioxide laser 316 emit laser beams, which pass through their corresponding collimating beam expanding optical units 312 to form parallel light beams. When there is no haze gas in the air, the parallel light beams will be converged on the central ring of the second photodetector 25 by the converging lens 313. When there is haze gas in the air, the laser will be scattered when encountering haze particles. Finally, the second photodetector 25 captures the light intensity distribution after scattering at different angles, converts the optical signal into an electrical signal, and the IV and AD conversion circuit 27 converts the electrical signal into a digital signal, which is finally displayed on the monitor 28, so as to achieve accurate measurement of haze concentration.

[0026] Step 3: Turn off the 1064nm laser 315 and the carbon dioxide laser 316, use the 671nm laser 314 as the transmitting end, and irradiate the surface of the target 26 after passing through the collimating beam expansion optical unit 312 and the converging lens 313. The first photodetector 22 is used as the receiving end to determine whether the target 26 is transparent by detecting the transmittance and reflectivity of the target 26; if the target 26 is opaque, the light is reflected by the surface of the target 26, and the first photodetector 22 located below the graphene heating plate 23 has no light signal; if the target 26 is transparent, the light is double refracted by the transparent target 26, and due to the high light transmittance of the graphene heating plate 23, the light passes through the graphene heating plate 23, and the first photodetector 22 receives the light signal.

[0027] Step 4: Turn off the 671nm laser 314, turn on the artificial light source 11 of the lighting device 1, adjust the first retractable mechanical lower arm 13 until the light evenly illuminates the target 26, adjust the first rotatable upper arm 14 and the first wrist rotation axis 15 to determine the incident zenith angle of the artificial light source 11 and ensure that the light is incident on the surface of the target 26.

[0028] Step 5: Turn on the polarization detection component 31 of the long-wave infrared polarization detection device 3, the second retractable mechanical lower arm 34 and the retractable rotating middle arm 35 adjust the detection height, the second rotatable upper arm 36 and the second wrist rotation axis 37 determine the detection zenith angle, the rotation axis 33, the retractable rotating middle arm 35, the second rotatable upper arm 36 and the second wrist rotation axis 37 determine the relative azimuth angle; when the laser light source is blocked, keep the detection zenith angle and the relative azimuth angle unchanged, and adjust the angle between the arms to avoid blocking.

[0029] Step 6: Set the first electrically controlled high-speed rotating wheel 320 and the second electrically controlled high-speed rotating wheel 321 to control the positions of the long-wave infrared quarter-wave plate 317 and the long-wave infrared polarizer 318 to form 0° linear polarized light, 45° linear polarized light, 90° linear polarized light, 135° linear polarized light, left-handed circularly polarized light and right-handed circularly polarized light. Light in six polarization states enters the long-wave infrared camera 319, and the relative azimuth angle is changed at intervals of 10°. Repeat the experiment to complete polarization detection with a full relative azimuth angle ranging from 0° to 360°.

[0030] Step 7: Change the detection zenith angle and repeat the experiment in step 6 to complete the detection of the full detection zenith angle ranging from 0° to 90° and the full relative azimuth angle ranging from 0° to 360° under the initial incident zenith angle.

[0031] Step 8: Change the incident zenith angle, repeat steps 6 and 7, and complete the full-band polarization detection imaging experiment of the polarization characteristics of the unheated target 26.

[0032] Step 9: Use the DC regulated power supply 30 to power the graphene heating plate 23 to heat the target 26. When the temperature of the target 26 reaches the set temperature, the temperature controller 29 disconnects the power supply, and the thermal insulation plate 24 maintains the target temperature.

[0033] Step 10: Repeat steps 6 to 9, and use the polarization detection component 31 again to perform polarization detection imaging on the polarization state of the set temperature target 26, and read the image information of the polarization detection imaging.

[0034] Step 11: Figure 7 As shown, the preliminary data collection of the above steps 1 to 10 is completed, and the target 26 images detected and acquired by the three sub-polarization detection devices respectively cover a part of the entire scene and there is an overlapping area between the three images, forming three groups of six polarization state (0°, 45°, 90°, 135° four kinds of linear polarized light polarization states, and left-handed circularly polarized light and right-handed circularly polarized light) image data sets, based on the multi-scale image fusion algorithm, the low-frequency coefficients are fused by the principal component analysis (Principal Component Analysis, referred to as PCA) transformation method using the wavelet transform, and the high-frequency coefficients are fused by the regional feature energy fusion rule, and finally, the polarization degree image of each group of six polarization state images is obtained by inverse wavelet transform, and three groups of polarization degree image data sets X1, X2, X3 are established. The multi-scale image fusion algorithm and the regional feature energy fusion rule belong to the prior art and will not be described in detail here.

[0035] Step 12: The image data sets X1, X2, and X3 provide position coordinates, overlapping areas, and polarization degree change information as the input layer. The process of finding the optimal distribution position and overlapping area of ​​the three sub-polarization detection devices through the image is not a linear relationship, so the nonlinear change is used as the hidden layer, and the BP neural network optimization algorithm based on particle swarm optimization is used to find the overlapping area size and the optimal position, that is, the optimal coordinate distribution. The specific principles are as follows: (1); In formula (1), For the sub-polarization detection device A 3-1 at time location; For the sub-polarization detection device A 3-1 at time location; It is the speed calculated according to the speed update formula, that is: (2); In formula (2), The polarization detection device A 3-1 is at time speed; The polarization detection device A 3-1 is at time speed; is the inertia weight, which controls the influence of the speed of the sub-polarization detection device A 3-1; is the individual learning factor, also called cognitive coefficient, which affects the degree to which the sub-polarization detection device A 3-1 moves toward the optimal position; It is a random number in the range of [0, 1] to increase randomness; is the historical optimal position of the sub-polarization detection device A 3-1; is a social learning factor, also called a social coefficient, which affects the degree to which the sub-polarization detection device A 3-1 moves toward the optimal position of the distributed polarization detection system; is another random number in the range [0, 1], which also increases randomness; is the global optimal position, the optimal solution found by the sub-polarization detection device A 3-1 in the position coordinates.

[0036] In order to ensure that the sub-polarization detection device does not exceed the hemispherical space, a constraint condition is added after the position update. Assume that the center of the hemisphere is at the origin, and the sub-polarization detection device A 3-1, the sub-polarization detection device B 3-2 and the sub-polarization detection device C 3-3 form an circumscribed radius of The upper surface of the target 26 to be measured is the bottom surface of the hemispherical area, that is, the xy plane. Calculate the distance from the new position of the sub-polarization detection device A 3-1 to the far point : (3); like Greater than , the position of the sub-polarization detection device A 3-1 needs to be re-projected back onto the hemispherical surface. This can be done by normalizing the position vector of the sub-polarization detection device A 3-1 onto the unit sphere and then multiplying it by the radius To achieve: (4) ; If the detection position of the sub-polarization detection device A 3-1 is at the bottom of the hemispherical area (i.e., the z coordinate is negative), its z coordinate needs to be set to 0 and renormalized to remain on the hemispherical surface. In order to further ensure that the detection position of the sub-polarization detection device A 3-1 does not exceed the hemispherical space, similar restrictions are imposed on the velocity vector. If the moving velocity direction of the sub-polarization detection device A 3-1 points to the outside of the hemisphere, its velocity vector is projected back to the inside of the hemisphere.

[0037] Similarly, the BP neural network optimization algorithm based on particle swarm optimization is used to find the optimal coordinate positions of the sub-polarization detection device B 3-2 and the sub-polarization detection device C 3-3, and the fitness function and the root mean square error ( ) is used to measure the optimization performance and as an influencing factor to reversely optimize the weights and thresholds of the BP neural network until the prediction error of the network is minimized. The root mean square error is: (5); In the formula, is the sample size; For the The actual output value of samples; For the The predicted output value of samples. Fitness value Defined as: (6); minimize , thereby maximizing the fitness value and comprehensively considering the training error and test error ,like: (7); The optimal distribution position of the sub-polarization detection device is obtained by striking a balance between training and generalization ability, and the coordinate relationship of the three sub-polarization detection devices is further obtained. The size of the overlapping area is calculated by combining the angle between the fields of view. A set of image data sets is used to verify the optimized BP neural network and evaluate its accuracy in predicting the optimal position of the sub-polarization detection device.

[0038] Step 13: Figure 7As shown, the lighting device 1 and the long-wave infrared polarization detection device 3 are initialized, that is, the incident zenith angle of the light source, the detection zenith angle and the relative azimuth angle are set to 0°. The sub-polarization detection devices are distributed according to the optimal distribution position obtained by the above optimization; the initial temperature of the target 26 is set to room temperature, that is, 25°C; the relative azimuth angle is changed at intervals of 10°, ranging from 0° to 360°; the detection zenith angle is changed at intervals of 10°, ranging from 0° to 90°; the incident zenith angle is changed at intervals of 10°, ranging from 0° to 90° for detection, and the three sub-polarization detection devices acquire images; when the temperature increases by 15°C on the basis of the initial temperature, the target 26 is repeatedly detected with the relative azimuth angle changed at intervals of 10°, ranging from 0° to 360°; the detection zenith angle is changed at intervals of 10°, ranging from 0° to 90°; the incident zenith angle is changed at intervals of 10°, ranging from 0° to 90°; until the detection reaches 105°C and ends.

[0039] Step 14: The images of the three sub-polarization detection devices at different temperatures are used to calculate the polarization state information and intensity information of the target scene using a multi-view sparse scene reconstruction method. On this basis, based on the information weighting strategy driven by the visual saliency mapping model, the original source image data is subjected to multi-dimensional information enhancement and feature fusion, and finally a polarization fusion image with high information entropy is reconstructed, where the original source image refers to the initial imaging image received by the detection. The multi-view sparse scene reconstruction method is a technology in the field of computer vision for recovering the three-dimensional structure of a scene from images of multiple viewpoints, which belongs to the prior art and will not be described in detail here.

[0040] First, the images obtained by the three sub-polarization detection devices are subjected to scale-invariant feature transformation. The essence of the Scale-Invariant Feature Transform (SIFT) algorithm is to find feature points in images at different scales and calculate the direction of the feature points to solve problems such as target rotation, scaling, translation, image affine / projection transformation, illumination influence, and target occlusion. The extracted feature points are matched between different images, and the matching accuracy is improved by eliminating mismatched points.

[0041] The matched feature points are continuously added with new views and image points through image registration and triangulation. Images from different perspectives are aligned and registered by calculating homography matrix or basic matrix, etc. The three-dimensional coordinates of the feature points in the scene are calculated by triangulation method using the projection relationship of matching points under different perspectives, and a sparse three-dimensional point cloud is initially constructed.

[0042] The long-wave infrared camera 319 pose and sparse point positions of the distributed polarization detection system are optimized using bundle adjustment. Bundle adjustment minimizes the reprojection error of sparse image points in images of different viewing angles. The camera parameters and positions are adjusted iteratively to improve the reconstruction accuracy. During the optimization process, noise points are further eliminated by eliminating outliers and calculating the weights of image points.

[0043] The basic image layer is weighted superimposed to generate a preliminary reconstructed image. The difference between every two iterations is calculated through the iterative guided filtering algorithm to extract the detail layer. The minimum weighted square method is used to superimpose the detail layer of each layer to further enhance the detail information of the image and finally generate a high-precision reconstructed image.

[0044] Iterative guided filtering focuses on optimizing local details during image reconstruction, so the parameter adjustment or regional priority of iterative guided filtering is guided by saliency mapping, that is, the result of visual saliency mapping is used as the weight; then iterative guided filtering is used to enhance the details of these areas.

[0045] The method based on visual saliency mapping utilizes the low-frequency information in the image. This method defines the saliency by the difference between one pixel and other pixels. For images Medium Pixels The intensity value of the pixel The significance value is , is defined as: (8) ; in, is the pixel intensity, is the number of pixels with intensity equal to . Then Normalized to [0,1]. , and They represent the visual saliency maps of the three input images respectively. The fused base layer is obtained by the following weighted average formula: (9); In formula (9), is the fused base layer, , and The base layer is obtained by decomposing three infrared images detected by the sub-polarization detection device A 3-1, the sub-polarization detection device B 3-2 and the sub-polarization detection device C 3-3, , and are the corresponding weights, which can be calculated through visual saliency mapping.

[0046] The detail layer fusion is performed by anisotropic diffusion processing on the three infrared images and then extracting the detail layer. The calculation of the weight is expanded to: (10); in, For the The saliency map of the image detail layer, For the The saliency map of the image detail layer, is the corresponding fusion weight. The final fusion of the detail layer is expressed as: (11); in, , and The detail layers of the three infrared images. The final fused image F The fused base layer and detail layer are obtained by assigning weights: (12); in, The weights are fused, and finally a polarization detection fusion image of a distributed detection system reconstructed based on the position control target is obtained.

[0047] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly explaining the present invention, and are not limitations on the embodiments of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the embodiments here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A distributed polarization detection system based on position control target reconstruction, the distributed polarization detection system comprising an illumination device (1), a multi-parameter auxiliary detection stage (2) and a long-wave infrared polarization detection device (3), wherein the illumination device (1), the multi-parameter auxiliary detection stage (2) and the long-wave infrared polarization detection device (3) are respectively connected to an image display and control system; characterized in that: The lighting device (1) comprises an artificial light source (11) simulating the sun and a light source adjustment mechanism for adjusting the position and / or angle of the artificial light source (11); the multi-parameter auxiliary detection stage (2) comprises a stage body (21), a first photodetector (22), a graphene heating plate (23), a heat-insulating plate (24) and a second photodetector (25); the first photodetector (22) is fixedly attached to the center of the upper surface of the stage body (21); the graphene heating plate (23) is arranged above the first photodetector (22) at a set interval; the heat-insulating plate (24) is arranged on the periphery of the first photodetector (22) and the graphene heating plate (23); the second photodetector (25) is an annular photodetector; the second photodetector (25) is arranged above the heat-insulating plate (24); the central area of ​​the second photodetector (25) serves as a placement area for a target (26); and the bottom surface of the target (26) is adjacent to the top surface of the graphene heating plate (23). Surface bonding; the long-wave infrared polarization detection device (3) comprises three sub-polarization detection devices, and the three sub-polarization detection devices are dispersed on one side of the multi-parameter auxiliary detection stage (2); the three sub-polarization detection devices all comprise a polarization detection component (31) and a polarization detection adjustment mechanism for adjusting the position and / or angle of the polarization detection component (31); the polarization detection component (31) comprises a long-wave infrared polarization detection module (311) and a laser gas detection photoelectric module; the laser gas detection photoelectric module comprises a laser, a collimating beam expansion optical unit (312) and a converging lens (313); and the lasers carried in the three sub-polarization detection devices are respectively a 671 nm laser (314), a 1064 nm laser (315) and a carbon dioxide laser (316); the long-wave infrared polarization detection module (311) comprises a long-wave infrared quarter-wave plate (317), a long-wave infrared polarizer (318) and a long-wave infrared camera (319) arranged in sequence along the light propagation direction.

2. The distributed polarization detection system based on position control target reconstruction according to claim 1, characterized in that: The light source adjustment mechanism comprises a light source adjustment mechanism base (12), a first telescopic mechanical lower arm (13), a first rotatable upper arm (14) and a first wrist rotation shaft (15); the first telescopic mechanical lower arm (13) is mounted on the light source adjustment mechanism base (12); two ends of the first rotatable upper arm (14) are rotatably connected to the first telescopic mechanical lower arm (13) and the first wrist rotation shaft (15) via bearings respectively; an artificial light source (11) is mounted on the first wrist rotation shaft (15); and the light source adjustment mechanism base (12), the first telescopic mechanical lower arm (13), the first rotatable upper arm (14) and the first wrist rotation shaft (15) are all equipped with separate drive motors.

3. The distributed polarization detection system based on position control target reconstruction according to claim 1, characterized in that: The distance between the first photodetector (22) and the graphene heating plate (23) is 5 cm.

4. The distributed polarization detection system based on position control target reconstruction according to claim 1, characterized in that: The long-wave infrared quarter-wave plate (317) is mounted on a first electrically controlled high-speed rotating wheel (320); and the long-wave infrared polarizing plate (318) is mounted on a second electrically controlled high-speed rotating wheel (321).

5. The distributed polarization detection system based on position control target reconstruction according to claim 1, characterized in that: The polarization detection adjustment mechanism comprises a polarization detection adjustment mechanism base (32), a rotation axis (33), a second telescopic mechanical lower arm (34), a telescopic rotating middle arm (35), a second rotatable upper arm (36) and a second wrist rotating shaft (37) which are connected in sequence from bottom to top; a polarization detection component (31) is mounted on the second wrist rotating shaft (37); and the polarization detection adjustment mechanism base (32), the rotation axis (33), the second telescopic mechanical lower arm (34), the telescopic rotating middle arm (35), the second rotatable upper arm (36) and the second wrist rotating shaft (37) are all equipped with separate drive motors.

6. A distributed polarization detection method based on position control target reconstruction, characterized in that: The method is implemented using the distributed polarization detection system described in any one of claims 1 to 5, and specifically includes: Step 1: The target (26) is placed above the graphene heating plate (23) in the multi-parameter auxiliary detection stage (2) and is bonded thereto; Step 2: Start the 671nm laser (314), the 1064nm laser (315) and the carbon dioxide laser (316); the laser beams emitted by the 671nm laser (314), the 1064nm laser (315) and the carbon dioxide laser (316) are collimated and expanded by the corresponding optical units (312) to emit parallel beams; when there is no haze gas in the air, the parallel beams are converged by the converging lens (313) on the center of the second photodetector (25); when there is haze gas in the air, the laser light encounters haze particles and is scattered, and is finally captured by the detection units in the second photodetector (25); Step 3: Turn off the 1064 nm laser (315) and the carbon dioxide laser (316), use the 671 nm laser (314) as the transmitting end, and irradiate the target (26) surface after passing through the collimating beam expansion optical unit (312) and the converging lens (313), and use the first photodetector (22) as the receiving end. If the target (26) is opaque, the first photodetector (22) below the graphene heating plate (23) does not receive the signal; if the target (26) is transparent, the light passes through the graphene heating plate (23) after being birefringent by the transparent target (26), and the first photodetector (22) receives the light signal; Step 4: Turn off the 671 nm laser (314), turn on the artificial light source (11) of the lighting device (1), adjust the light source adjustment mechanism, determine the incident zenith angle of the artificial light source (11), and ensure that the light is incident on the surface of the target (26); Step 5: turning on the polarization detection component (31) of the long-wave infrared polarization detection device (3), adjusting the polarization detection adjustment mechanism, and determining the detection zenith angle and relative azimuth angle of the polarization detection component (31); when the artificial light source (11) is blocked, keeping the detection zenith angle and relative azimuth angle unchanged, and adjusting the polarization detection adjustment mechanism to avoid blocking; Step 6: Adjust the positions of the long-wave infrared quarter-wave plate (317) and the long-wave infrared polarizer (318) to generate 0° linear polarized light, 45° linear polarized light, 90° linear polarized light, 135° linear polarized light, left-handed circular polarized light, and right-handed circular polarized light, and the six polarization states of light enter the long-wave infrared camera (319) respectively, change the relative azimuth angle, repeat the experiment, and complete the polarization detection in the full relative azimuth angle range of 0° to 360°; Step 7: Change the detection zenith angle and repeat the experiment in step 6 to complete the detection of the full detection zenith angle ranging from 0° to 90° and the full relative azimuth angle ranging from 0° to 360° under the initial incident zenith angle; Step 8: Change the incident zenith angle, repeat steps 6 and 7, and complete the full-band polarization detection imaging experiment of the polarization characteristics of the unheated target (26); Step 9: supplying power to the graphene heating plate (23) to heat the target (26), and when the temperature of the target (26) reaches the set temperature, the power supply to the graphene heating plate (23) is stopped, and the heat insulation plate (24) maintains the temperature of the target (26); Step 10: repeating steps 6 to 9, again using the polarization detection component (31) to perform polarization detection imaging on the polarization state of the target (26) at the set temperature, and reading image information of the polarization detection imaging; Step 11: After step 1 to step 10, the three sub-polarization detection devices have completed preliminary acquisition of polarization image information of the target (26). The target (26) images detected and acquired by the three sub-polarization detection devices respectively cover a part of the entire scene and there is an overlapping area between the three images, forming three groups of polarization state image data sets, each group of polarization state image data sets includes polarization state images of 0° linear polarization light, 45° linear polarization light, 90° linear polarization light, 135° linear polarization light, left-handed circular polarization light and right-handed circular polarization light, and the six polarization state images in each group are fused into a polarization degree image, and three groups of polarization degree image data sets X1, X2, X3 are established; Step 12: The position coordinates, overlapping areas, and polarization change information provided by the three sets of polarization image data sets X1, X2, and X3 are used as the input layer, and the BP neural network optimization algorithm based on particle swarm optimization is used to find the size of the overlapping area and the optimal position, determine the optimal coordinate positions of the three sub-polarization detection devices, and obtain the optimal distribution positions of the three sub-polarization detection devices; Step 13: Initialize the lighting device (1) and the long-wave infrared polarization detection device (3), that is, set the incident zenith angle of the artificial light source (11), the detection zenith angle and the relative azimuth angle of the polarization detection component (31) to 0°, and distribute the optimal coordinate positions of the three sub-polarization detection devices according to the optimal distribution positions obtained by optimization in step 12; set the initial temperature of the target (26) to room temperature; change the relative azimuth angle in intervals of 10°, ranging from 0° to 360°; change the detection zenith angle in intervals of 10°, ranging from 0° to 90°; The zenith angle is changed at intervals of 10°, ranging from 0° to 90° for detection; three sub-polarization detection devices acquire images; when the temperature increases by 15°C on the basis of the initial temperature, the relative azimuth angle of the target (26) is repeatedly changed at intervals of 10°, ranging from 0° to 360°; the detection zenith angle is changed at intervals of 10°, ranging from 0° to 90°; the incident zenith angle is changed at intervals of 10°, ranging from 0° to 90°; the detection is terminated until the temperature reaches 105°C, at which point the acquisition of the distributed target polarization image is completed; Step 14: After the distributed target polarization image is acquired, the images of the three sub-polarization detection devices at different temperatures are used to calculate the polarization state information and intensity information of the target scene using a multi-view sparse scene reconstruction method; on this basis, based on visual saliency mapping, multi-dimensional information enhancement and feature fusion are performed on the original source image data, and finally a polarization fusion image is reconstructed; The original source image refers to the initial imaging image received by the detection.

7. The distributed polarization detection method based on position control target reconstruction according to claim 6, characterized in that: The process of fusing the six polarization state images in each group into a polarization degree image is as follows: based on the multi-scale image fusion algorithm, the low-frequency coefficients are fused using the principal component analysis transformation method using wavelet transform, and the high-frequency coefficients are fused using the regional feature energy fusion rule. Finally, the polarization degree image fused from the six polarization state images in each group is obtained through inverse wavelet transform.

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