A system and method for generating a volume scatter medium suitable for photoelectric imaging

Abstract

The application discloses a kind of body scattering medium generation system and method suitable for photoelectric imaging, system includes fog box main body, water mist generation module, air intake control module, exhaust control module, circulating air duct module, optical negative feedback monitoring module and auxiliary control module;Each module is realized by mechanical docking and circuit communication to cooperate with each other.Wherein water mist generation module, air intake control module and exhaust control module are directly connected with fog box main body by pipeline or mechanical structure, and the three are electrically connected with auxiliary control module by control circuit, and the working parameters are adjusted by the control signal output by auxiliary control module;Optical negative feedback monitoring module is cooperated with fog box main body using transmission type light path layout, and its signal output end is connected with auxiliary control module by data line, and monitoring data is transmitted to auxiliary control module to realize negative feedback regulation to water mist generation module, finally realizes the accurate generation and long-term stable maintenance of body scattering medium.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic imaging technology, and in particular to a gas environment volume scattering medium generation system and method suitable for optoelectronic imaging. It can be widely used in various optoelectronic imaging scenarios that rely on gas volume scattering media, such as scattering environment optical path simulation of scattering imaging systems, channel characteristic simulation of optical communication systems, and scattering pattern generation for optical anti-counterfeiting. Background Technology

[0002] Volume scattering media are a key imaging environment in the field of optoelectronic imaging. Through the scattering of incident light by internal medium particles, they enable functions such as light field manipulation, signal modulation, and information degradation simulation. They play an irreplaceable role in scenarios such as scattering environment optical path simulation in scattering imaging systems, channel characteristic simulation in optical communication systems, and scattering pattern generation for optical anti-counterfeiting. Traditional methods for generating volume scattering media in gaseous environments mainly include combustion and spraying. Combustion generates scattering particles by burning specific fuels (such as smoke cakes or vulcanized rubber), which then disperse in the gaseous environment to form the volume scattering medium. Spraying atomizes liquid scattering media (such as deionized water or specialized oily scattering liquids) using a heated and pressurized spraying device, forming tiny droplets that disperse in the gas to construct the volume scattering medium.

[0003] However, existing gaseous environment bulk scattering medium generation technologies have many shortcomings, making it difficult to meet the high precision and stability requirements of the scattering environment in the field of optoelectronic imaging: First, the scattering particles generated by the combustion method have complex compositions, and the combustion process cannot be stopped, making it impossible to precisely control the concentration, particle size distribution, and combustion completeness of the scattering particles. Furthermore, combustion products easily contaminate the optical path and corrode optical components, resulting in poor compatibility. Second, the spray method relies on positive pressure for ejection, and its minimum spray volume is limited by system wind resistance, making it impossible to slowly and precisely control from zero. Spraying phenomena inevitably occur upon startup, not only causing airflow disturbances that interfere with the imaging optical path but also leading to significant fluctuations in medium homogeneity, making precise concentration control difficult. Third, both traditional methods lack precise feedback control mechanisms and have insufficient self-adjustment capabilities, failing to achieve precise adaptation of scattering parameters. Fourth, the combustion method poses a safety hazard due to open flame, and the oil-based liquids used in the spray method are prone to residual adhesion, making both unsuitable for the long-term stable operation of high-precision optoelectronic imaging systems. In summary, existing technologies have significant shortcomings in terms of control precision, operational stability, adaptability, and safety, making it difficult to meet the stringent requirements of optoelectronic imaging for the scattering environment.

[0004] With the rapid development of optoelectronic imaging technology, fields such as scattering imaging and optical communication have placed higher demands on the controllability, concentration uniformity, stability, and control precision of the scattering characteristics of bulk scattering media in gaseous environments. There is an urgent need for a gaseous environment bulk scattering media generation system and method that uses ultrasonic water mist technology combined with negative feedback regulation to achieve precise control of scattering parameters and a stable and safe generation process, so as to overcome the shortcomings of existing technologies. Summary of the Invention

[0005] In view of this, the present invention provides a volume scattering medium generation system and method suitable for photoelectric imaging. It can construct a closed, pollution-free, and precisely controllable volume scattering medium generation fog box system, which is adapted to the needs of photoelectric experiments and realizes fine control of the concentration and uniformity of gaseous scattering medium. At the same time, it supports multi-band optical path adaptation and dense fog scene expansion, and can be further extended to the generation of oil mist-like volume scattering media. It has the advantages of flexible structure, strong stability and no contamination of devices.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: a volume scattering medium generation system suitable for photoelectric imaging, comprising a fog chamber body, a water mist generation module, an air intake control module, an exhaust control module, a circulating air duct module, an optical negative feedback monitoring module, and an auxiliary control module; each module cooperates through mechanical docking and circuit communication; wherein the water mist generation module, the air intake control module, and the exhaust control module are directly connected to the fog chamber body through pipelines or mechanical structures, and all three are electrically connected to the auxiliary control module through control lines, and their operating parameters are adjusted by the control signals output by the auxiliary control module; the optical negative feedback monitoring module adopts a transmission optical path layout and cooperates with the fog chamber body, and its signal output end is connected to the auxiliary control module through a data line to transmit the monitoring data to the auxiliary control module to realize negative feedback adjustment of the water mist generation module, ultimately achieving accurate generation and long-term stable maintenance of the volume scattering medium.

[0007] Furthermore, the fog chamber's main body is a closed cavity structure, entirely constructed from assembled acrylic materials. Its inner wall is lined with a light-shielding black frosted material with an absorption rate of no less than 95%, used to shield against external stray light interference and internal multiple reflections, ensuring the stability of the ambient light environment for photoelectric experiments. Inside the fog chamber's main body, two detachable perforated boxes are symmetrically arranged along a vertical square center: an upper perforated box and a lower perforated box. These two layers divide the interior of the fog chamber into three areas. Above the upper perforated box is a fog buffer area; between the two perforated boxes is a volume scattering medium stabilization area, i.e., the area through which the experimental light path penetrates; below the lower perforated box is an exhaust buffer area. Both the upper and lower perforated boxes of the fog chamber's main body are made of acrylic material. The perforated surfaces of the boxes facing the volume scattering medium stabilization area are evenly distributed with perforations to achieve uniform diffusion of water mist and smooth airflow, preventing airflow disturbances from disrupting the stability of the scattering medium.

[0008] The volume scattering medium stabilization zone of the fog chamber body has detachable light-transmitting windows at both the light path incident end and the light path exit end. These windows are fixed to the front and rear walls of the fog chamber by fixing devices and sealed with rubber pads to ensure airtightness. The light-transmitting windows can be replaced with optical glass of the corresponding wavelength band according to the experimental requirements. The thickness is generally not less than 3mm to ensure strength while efficiently transmitting light of different wavelength bands.

[0009] Furthermore, the water mist generation module is installed in the upper perforated box of the mist chamber, including a water box, an ultrasonic water mist plate assembly, and a liquid level stabilization component. These components work together to achieve precise water mist generation and supply. The water box is a rectangular cavity, open at the top and closed at the bottom, made of acrylic material, and is installed in the upper perforated box of the mist chamber. Multiple ultrasonic water mist plates are evenly fixed inside the water box. The number and rated power of the ultrasonic water mist plates are selected according to the volume and concentration requirements of the mist chamber. The entire assembly is connected to the auxiliary control module, which precisely adjusts the power output voltage to change the mist generation power of the ultrasonic water mist plates, thereby precisely controlling the amount of water mist generated. The liquid level stabilization component includes a float switch, an external water source, and a water inlet valve. The float switch installation adjustment device extends outside the mist box via a support rod for external liquid level observation and control. Using purified water as the source, a water inlet valve controlled by the float switch is connected in series on the water injection pipeline. The float is installed inside the water box. When the liquid level is lower than the preset value, the float switch triggers the water inlet valve to open and replenish water. When the liquid level reaches the preset value, the water inlet valve closes, achieving automatic stabilization of the liquid level. The installation height of the float switch can be manually adjusted via an adjustment bracket extending outside the mist box, thus achieving adjustable liquid level. Combined with the selection of the ultrasonic water mist plate model, size specifications, and immersion depth, a multi-dimensional water mist concentration control mechanism is formed, achieving precise control of the mist generation.

[0010] Furthermore, the air intake control module includes a continuously adjustable waterproof fan and a continuously adjustable air duct damper, both installed in series on the upper wall of the perforated box of the mist chamber and arranged sequentially along the air intake direction. Specifically, the fan is located on the inner side, and the damper is located on the outer side, both electrically connected to the auxiliary control module via control lines. The auxiliary control module adjusts the fan speed and damper opening through the output voltage to achieve fine control of the air intake volume. The dry intake air passes above the liquid surface in the water box, carrying some water mist into the mist chamber body, increasing the water mist intake rate. The exhaust control module includes a finely continuously adjustable waterproof fan and a continuously adjustable air duct damper. The barrier gate is installed on the side wall of the perforated box under the fog chamber. The fan is located on the inner side of the air path, and the barrier gate is located on the outer side. The interior of the fog chamber is considered the interior. The ventilation volume and diameter of the exhaust fan and valve are larger than those of the inlet section. The auxiliary control module adjusts the fan speed and barrier gate opening through the output voltage to achieve precise control of the exhaust volume and rapid fog removal. By adjusting the balance between the total exhaust volume and the total intake volume, the fog chamber body is kept under a slightly positive pressure or normal pressure. This ensures that fog production and fog removal are in dynamic balance, preventing excessive pressure inside the fog chamber from causing leakage or excessively low pressure from causing outside air to mix in and interfere with the stability of the scattering medium.

[0011] Furthermore, the circulating air duct module includes circulating fans and their independent power supplies, installed inside the fog box body in the gaseous scattering medium generation area, that is, between the upper and lower perforated plates, fixed in the corner of this area. The number of fans is selected according to the volume of the fog box. All fans are connected to an independent stepless power supply through control circuits. When a large flow of dense fog needs to be generated, all fans of the circulating air duct module are turned on to form a clockwise or counterclockwise circulating airflow. The airflow drives the scattering medium to circulate at high speed in the generation area. On the one hand, this can prevent water mist particles from settling, and on the other hand, it can make the water mist particles evenly distributed, quickly increase the fog concentration in the area, and further optimize the spatial uniformity of the scattering medium.

[0012] Furthermore, the optical negative feedback monitoring module includes an external laser source, a long sleeve, and a precision power meter. It adopts a transmission optical path monitoring layout. The laser source and the long sleeve are respectively installed on the outside of the optical path incident end and the output end of the fog box body, and the central axes of the three are collinear and consistent with the optical path penetration direction of the fog box body. The external laser source is a continuous output laser source, and the output wavelength can be selected according to experimental requirements. The output power stability error is ≤±1%. The long sleeve adopts a black threaded light-shielding structure with a length of not less than 50mm. A precision power meter is fixedly installed at the other end, with a measurement accuracy of not less than ±0.01mW. Its data output end is connected to the auxiliary control module to transmit laser transmission power data in real time.

[0013] Furthermore, the auxiliary control module is the core control unit, which includes an integrated power supply, a signal acquisition module, a signal output module, and a communication module. The power supply module provides stable power to all electrical components of the system. The signal acquisition module is used to receive the transmission power signal from the precision power meter. The signal output module is used to output voltage control signals to each fan, air duct damper, and ultrasonic transducer assembly. The communication module integrates a USB or Ethernet interface to achieve wired connection with a computer, supporting additional control of air intake, exhaust volume, and ultrasonic water mist generator power through computer software, and real-time reading and storage of all system operating parameters, including fan speed, ultrasonic transducer voltage, and transmittance.

[0014] Furthermore, the monitoring data is transmitted to the auxiliary control module to achieve negative feedback adjustment of the water mist generation module. The specific testing and implementation methods for negative feedback adjustment are as follows:

[0015] The first step is the calibration stage. Fully open the air inlet module valve, fix the air outlet module valve opening and fan speed, and gradually adjust the voltage or power of the ultrasonic water mist sheet. At the same time, record the laser transmission power data of the precision power meter until the ultrasonic water mist generator voltage or power parameter corresponding to the laser transmission power stabilizing at the target value is found. Calculate the ratio of "generator power ÷ transmittance = K" in this stable state, and store this ratio as the stability coefficient K in the auxiliary control module. The second step, the automatic adjustment phase, maintains the exhaust parameters consistent with the pre-test phase. The auxiliary control module reads the transmittance data from the precision power meter in real time and automatically calculates the target generator power based on the principle of "generator power ÷ transmittance = K". That is: target generator power = K × transmittance. When the transmittance is lower than the target value, the ultrasonic plate supply voltage or power is automatically reduced. When the transmittance is higher than the target value, the ultrasonic plate supply voltage or power is automatically increased. The adjustment process follows the preset delay time and drop curve. The delay setting range is 0-20s to avoid frequent adjustments of the ultrasonic plate power caused by instantaneous fluctuations in laser power. The adjustment drop curve is a linear or non-linear curve to control the adjustment rate of the ultrasonic plate power and avoid drastic fluctuations in fog concentration caused by sudden power changes.

[0016] Another aspect of the present invention provides a method for generating a volume scattering medium suitable for photoelectric imaging, which employs the above-described volume scattering medium generation system suitable for photoelectric imaging and includes the following steps: Step 1: Construct the above-mentioned volume scattering medium generation system suitable for photoelectric imaging; Step 2: Circuit connection and initialization, specifically including: Use a PC as an auxiliary control system adjustment device and connect the auxiliary control module; install the ultrasonic water mist generator plate and adjust its installation position in the water box to set the immersion depth; replace the light-transmitting window of the light path entrance / exit end of the mist box with optical glass of the required wavelength band for the experiment; connect an external pure water source and set the target liquid level height in the water box through a float level gauge; connect the auxiliary control module to the air inlet, exhaust, and water mist generation modules.

[0017] Step 3: Close the inlet and outlet air valves, generate mist, turn on all fans, check for any mist overflow, ensure the mist box is sealed, and ensure there is no leakage.

[0018] Step 4: Construct the negative feedback optical path, specifically: construct the optical negative feedback module optical path outside the enclosure, ensure that the laser source directly illuminates the test surface of the precision power meter, and ensure that the optical path is not affected by stray interference from mirror reflections; connect the negative feedback module to the auxiliary control system, and record the initial transmission power of the laser in the absence of a volume scattering medium.

[0019] Step 5: Perform standard parameter calibration for the scattering environment. Fully open the air inlet module valve, fix the air outlet module valve opening and fan speed to a low value, and gradually adjust the voltage or power of the ultrasonic water mist generator. At the same time, record the laser transmission power data of the precision power meter until the laser transmission power is found to be stable at the transmission power corresponding to the required scattering environment transmittance. Specifically: corresponding transmission power = initial laser transmission power in step 4 × transmittance. The PC records the voltage or power parameters of the ultrasonic water mist generator in this state, calculates the ratio of "generator power ÷ transmittance = K" in this stable state, and stores this ratio as the stability coefficient K in the auxiliary control module.

[0020] Step Six: Start the ultrasonic water mist filter drive power supply to generate water mist at the initial power. The water mist overflows from the water box and enters the scattering medium generation area of ​​the fog chamber body evenly through the perforated plate. Simultaneously turn on the air intake control component and the exhaust control component to maintain the balance between fog generation and exhaust. The initial parameters are the calibration parameters in Step Two. Do not turn on the optical negative feedback adjustment module. At this time, the volume scattering medium generation system is working in stable mode, and the steady-state volume scattering environment experiment of the photoelectric imaging system is carried out directly.

[0021] Step 7: Start the laser source and power meter. The power meter collects the laser power penetrating the scattering medium in real time and feeds it back to the adjustment module. The system automatically adjusts the ultrasonic plate power according to the preset stability coefficient K, adjustment delay and descent curve to stabilize the scattering medium concentration within the target range. If dynamic fog needs to be generated, turn on the four corner fans of the circulation duct unit and adjust the speed to form a circulating airflow to improve fog concentration and uniformity. At this time, the volume scattering medium generation system works in negative feedback adjustment mode, which adjusts and compensates for external interference to a certain extent, and conducts a volume scattering environment experiment of the photoelectric imaging system to introduce interference.

[0022] Step 8: Based on Step 7, if it is necessary to increase or decrease the volume scattering medium concentration, manually calculate and adjust the K value coefficient. If the transmittance needs to be increased by N times, then K is reduced to K / N. Keep the exhaust parameters consistent with the pre-test stage. The auxiliary control module reads the transmittance data of the precision power meter in real time. According to the principle of "generator power ÷ transmittance = K / N" after adjustment, automatically calculate the target generator power after adjustment, that is, target power = transmittance × K ÷ N. When the transmittance is lower than the target value, automatically reduce the ultrasonic plate power supply voltage or power. When the transmittance is higher than the target value, automatically increase the ultrasonic plate power supply voltage or power. The adjustment process follows the preset delay time and drop curve. The setting range of the delay is 0-20s to avoid the instantaneous fluctuation of laser power causing frequent adjustment of ultrasonic plate power. Adjust the drop curve to be a linear or non-linear curve to control the adjustment rate of ultrasonic plate power and avoid sudden power changes causing drastic fluctuations in fog concentration. At this time, the volume scattering medium generation system works in negative feedback adjustment mode to conduct an adjustable concentration volume scattering environment experiment of the photoelectric imaging system to introduce interference.

[0023] Step Nine: After the power meter displays stable data, conduct photoelectric imaging-related experiments. During the experiment, the data acquisition module of the auxiliary control unit transmits various parameters in real time and records them on the PC. If it is necessary to adjust the scattering concentration, the target transmittance can be modified through the computer interface. The system will automatically recalculate and adjust the ultrasonic plate power according to Step Eight. At this point, the generation of the volume scattering medium environment for photoelectric imaging is completed.

[0024] Step 10: Experiment complete. Turn off the ultrasonic water mist filter and laser source, and keep the air intake and exhaust systems and the circulating air duct system running at full power for a period of time to remove any residual water mist from the mist chamber; turn off all power, clean the surface of the light-transmitting window, and the experiment is complete.

[0025] Beneficial effects: 1. The present invention discloses a volume scattering medium generation system and method suitable for photoelectric imaging, which can precisely control the concentration of the volume scattering medium, starting from 0% concentration with 100% transmittance and slowly increasing it, thus precisely controlling the transmittance of the volume scattering medium. At the same time, the system is completely closed and will not cause spillage or contamination of experimental equipment. It is suitable for photoelectric experimental scenarios that require precise control of transmittance, indoor experimental scenarios, and experimental scenarios with airflow interference, and has significant advantages in terms of safety, resistance to wind interference, accuracy of volume scattering medium concentration, and no pollution.

[0026] 2. The present invention discloses a volume scattering medium generation system and method suitable for photoelectric imaging, which has a precise feedback control mechanism, real-time control and recording output of parameters such as transmittance, fan speed, and ultrasonic water mist power. It can be controlled in real time, stabilized and reproduced on the PC according to experimental needs. It has significant advantages in terms of control speed accuracy, operational stability and integration, and can meet various needs of photoelectric experiments. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the volume scattering medium generation system according to a specific embodiment of the present invention; 1—Water box, 2—Float switch, 3—External water source and inlet valve, 4—Ultrasonic water mist sheet, 5—Air intake control module, 6—Upper perforated box, 7—Circulating air duct module, 8—Removable light-transmitting window, 9—External laser source, 10—Sleeve and precision power meter, 11—Lower perforated box, 12—Exhaust control module, 13—Auxiliary control module, 14—Mist box body.

[0028] Figure 2 This is a schematic diagram of the air intake control module in a specific embodiment of the present invention.

[0029] Figure 3 This is a schematic diagram of the exhaust control module in a specific embodiment of the present invention.

[0030] Figure 4 This is a schematic diagram of the optical negative feedback monitoring module in a specific embodiment of the present invention.

[0031] Figure 5 This is a schematic diagram of the auxiliary control module in a specific embodiment of the present invention. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] This invention discloses a laboratory-grade precision controllable bulk scattering medium generation system, the main structure of which is as follows: Figure 1 As shown, the system includes a fog chamber main body, a water mist generation module, an air intake control module, an exhaust control module, a circulating air duct module, an optical negative feedback monitoring module, and an auxiliary control module. Each module works in concert through mechanical connection and electrical communication. The water mist generation module, air intake control module, and exhaust control module are directly connected to the fog chamber main body via pipes or mechanical structures, and all three are electrically connected to the auxiliary control module via control lines, adjusting their operating parameters according to the control signals output by the auxiliary control module. The optical negative feedback monitoring module employs a transmissive optical path layout and works in conjunction with the fog chamber main body. Its signal output terminal is connected to the auxiliary control module via a data line, transmitting monitoring data to the auxiliary control module to achieve negative feedback adjustment of the water mist generation module, ultimately realizing the precise generation and long-term stable maintenance of the volume scattering medium.

[0034] 1. Fog Box Main Body The fog chamber's main body is a closed cavity structure, entirely molded from acrylic materials. Its inner walls are lined with a light-shielding black frosted material with an absorption rate of no less than 95%, used to shield against external stray light interference and internal multiple reflections, ensuring the stability of the ambient light for photoelectric experiments. Inside the fog chamber, two detachable perforated boxes are symmetrically arranged along a vertical square center: an upper perforated box and a lower perforated box. These two layers divide the interior of the fog chamber into three areas: the area above the upper perforated box is a fog buffer zone; the area between the two perforated boxes is a volume scattering medium stabilization zone (the area through which the experimental light path penetrates); and the area below the lower perforated box is an exhaust buffer zone. Notably, the perforated boxes can extend to cover the entire horizontal plane of the chamber, becoming perforated panels. The upper and lower perforations are generally placed diagonally, but can be placed on the same side as needed.

[0035] Both the upper and lower perforated boxes of the fog box are made of acrylic material. The perforated surfaces of the box body in the stable area of ​​the scattering medium are evenly distributed with through holes to achieve uniform diffusion of water mist and smooth airflow, avoiding airflow disturbance from damaging the stability of the scattering medium.

[0036] The volume scattering medium stabilization zone of the fog chamber body has detachable light-transmitting windows at both the light path incident end and the light path exit end. These windows are fixed to the front and rear walls of the fog chamber by fixing devices and sealed with rubber pads to ensure airtightness. The light-transmitting windows can be replaced with optical glass of the corresponding wavelength band according to the experimental requirements (such as visible light, near-infrared, and ultraviolet). The thickness is generally not less than 3mm, ensuring strength while efficiently transmitting light of different wavelength bands.

[0037] 2. Water mist generation module The water mist generation module is installed in the upper perforated box of the mist chamber. It includes a water box, an ultrasonic water mist plate assembly, and a liquid level stabilization component. These components work together to achieve precise water mist generation and supply. The water box is a rectangular cavity with an open top and a closed bottom, made of acrylic material, and is installed in the upper perforated box of the mist chamber. Multiple ultrasonic water mist plates (i.e., ultrasonic plates) are evenly fixed inside the water box. The number and rated power of the ultrasonic water mist plates are selected according to the volume of the mist chamber and the concentration requirements. The whole assembly is connected to the auxiliary control module. The auxiliary control module precisely adjusts the power output voltage to change the mist generation power of the ultrasonic water mist plates, thereby precisely controlling the amount of water mist generated.

[0038] The liquid level stabilization component includes an external water source, a float switch, and an inlet valve. The float switch, with its adjustment device extending outside the mist chamber via a support rod, allows for external liquid level observation and control. A purified water source is used, with the inlet valve, controlled by the float level switch, connected in series on the water supply line. The float is installed inside the water tank. When the liquid level is below a preset value, the float level switch triggers the inlet valve to open and replenish water. When the liquid level reaches the preset value, the inlet valve closes, achieving automatic liquid level stabilization. The installation height of the float level switch can be manually adjusted via an adjustment bracket extending outside the mist chamber, thus enabling liquid level adjustment. Combined with the selection of the ultrasonic water mist plate model, size specifications, and immersion depth, a multi-dimensional water mist concentration control mechanism is formed, achieving precise control of mist generation.

[0039] The following explains the method for precise control of water mist production: The water mist generation rate L per unit time is controlled by three parameters: immersion depth l, area D, and water mist voltage V, which are nonlinear quantities. Immersion depth l is controlled by a float level switch, requiring it to be greater than 0 during operation, submerged within the water surface. Area D is determined by the water mist plate model and size specifications; after selecting the appropriate size for the desired mist generation, it is fixed, defining the upper limit of mist generation per unit time. Water mist voltage V is finely linearly adjusted via the power supply of the auxiliary control module for precise control and fine-tuning of mist generation. Water mist generation rate L = (Area D × Water mist voltage V) / (System-related constant C + Multiplier K × Immersion depth l). In this formula, the system-related constant C and multiplier K are system constants after the water mist generation module is finalized, measured by the immersion depth l being close to 0 on the surface and the deepest depth at which water mist can be generated when immersed in the ultrasonic plate. The specific water mist production rate L is precisely controlled primarily through linear adjustment of the area and water mist voltage.

[0040] 3. Air intake control module and air exhaust control module like Figure 2 As shown, the air intake control module includes a continuously adjustable waterproof fan and a continuously adjustable air duct damper. Both are installed in series on the upper wall of the perforated box in the mist chamber and arranged sequentially along the air intake direction (the fan is on the inner side, and the damper is on the outer side). Both are electrically connected to the auxiliary control module via control lines. The auxiliary control module adjusts the fan speed and damper opening by outputting voltage, achieving precise control of the air intake volume. The dry intake air passes above the liquid surface in the water box, carrying some water mist into the mist chamber body, thus increasing the water mist intake rate.

[0041] like Figure 3As shown, the exhaust control module includes a finely steplessly adjustable waterproof fan and a steplessly adjustable air duct damper, installed on the side wall of the perforated box below the fog chamber. The fan is located on the inner side of the air path, and the damper is on the outer side (with the inside of the fog chamber as the inner side). The ventilation volume and diameter of the exhaust fan and valve are larger than those of the inlet section. The auxiliary control module adjusts the fan speed and damper opening through output voltage to achieve fine control of the exhaust volume and rapid fog removal. By adjusting the balance between the total exhaust volume and the total inlet volume, the fog chamber is kept under a slightly positive or normal pressure, ensuring a dynamic balance between fog production and exhaust. This prevents excessive pressure inside the fog chamber from causing leakage or excessively low pressure from allowing outside air to mix in and interfere with the stability of the scattering medium.

[0042] 4. Circulating air duct module The circulating air duct module includes circulating fans and their independent power supplies. It is installed in the gaseous scattering medium generation area (between the upper and lower perforated plates) inside the fog box body and fixed in the corner of this area. The number of fans is selected according to the volume of the fog box. All fans are connected to an independent stepless power supply through control circuits. When a large flow of dense fog needs to be generated, all fans of the circulating air duct module are turned on to form a clockwise or counterclockwise circulating airflow. The airflow drives the scattering medium to circulate at high speed in the generation area. On the one hand, it can prevent water mist particles from settling, and on the other hand, it can make water mist particles evenly distributed, quickly increase the fog concentration in the area, and further optimize the spatial uniformity of the scattering medium.

[0043] 5. Optical negative feedback monitoring module like Figure 4 As shown, the optical negative feedback monitoring module includes an external laser source, a long sleeve, and a precision power meter. It adopts a transmission optical path monitoring layout. The laser source and the long sleeve are respectively installed on the outside of the optical path incident end and the output end of the fog box body, and the central axes of the three are collinear and consistent with the optical path penetration direction of the fog box body. The external laser source is a continuous output laser source, and the output wavelength can be selected according to experimental requirements. The output power stability error is ≤±1%. The long sleeve adopts a black threaded light-shielding structure with a length of not less than 50mm. A precision power meter is fixedly installed at the other end, with a measurement accuracy of not less than ±0.01mW. Its data output end is connected to the auxiliary control module to transmit laser transmission power data in real time.

[0044] 6. Auxiliary control module like Figure 5As shown, the auxiliary control module is the core control unit, which includes an integrated power supply, a signal acquisition module, a signal output module, and a communication module. The power supply module provides stable power to all electrical components of the system. The signal acquisition module is used to receive the transmission power signal from the precision power meter. The signal output module is used to output voltage control signals to each fan, air duct gate, and ultrasonic transducer group. The communication module integrates a USB or Ethernet interface to realize wired connection with a computer, and supports additional control of air intake, exhaust volume, and ultrasonic water mist generator power through computer software, and reads and stores all system operating parameters (fan speed, ultrasonic transducer voltage, transmittance, etc.) in real time.

[0045] The specific testing and implementation method of negative feedback regulation is as follows: First, in the calibration stage, fully open the air inlet module valve, fix the exhaust module valve opening and fan speed, and gradually adjust the voltage (power) of the ultrasonic water mist sheet. Simultaneously, record the laser transmission power data from the precision power meter until the ultrasonic water mist generator voltage (power) parameter corresponding to the stable laser transmission power at the target value is found. Calculate the ratio "generator power ÷ transmittance = K" under this stable state, and store this ratio as the stability coefficient K in the auxiliary control module. Second, in the automatic adjustment stage, keep the exhaust parameters consistent with the pre-test stage. The auxiliary control module reads the transmittance data from the precision power meter in real time, and adjusts the voltage (power) of the ultrasonic water mist sheet according to the "generator power ÷ transmittance = K" parameter. Following the principle of "generator power ÷ transmittance = K", the system automatically calculates the target generator power (target generator power = K × transmittance). When the transmittance is lower than the target value, the system automatically reduces the ultrasonic strip power supply voltage (power). When the transmittance is higher than the target value, the system automatically increases the ultrasonic strip power supply voltage (power). The adjustment process follows a preset delay time and a drop curve. The delay setting range is 0-20s to avoid frequent adjustments to the ultrasonic strip power caused by instantaneous fluctuations in laser power. The adjustment drop curve is either linear or non-linear (such as a logarithmic curve, determined based on the size of the chamber) to control the adjustment rate of the ultrasonic strip power and avoid sudden power changes that cause drastic fluctuations in fog concentration.

[0046] It should be noted that the current automatic adjustment scheme based on the "power-transmittance ratio" is an early basic method and is only used as an example. The overall system algorithm can be adjusted according to the size changes of the fog chamber body (such as the volume expanding from 250L to 500L) and experimental requirements (such as dynamically adjusting the fog concentration and simulating different scattering intensity scenarios). A multi-variable collaborative adjustment algorithm for air intake, exhaust volume and ultrasonic water mist generator voltage (power) can be introduced to make the adjustment more accurate, the response faster and the stability stronger.

[0047] Example 1: like Figure 1As shown in this embodiment, a laboratory-grade precision controllable volume scattering medium generation system includes: 1. a water box, 2. a float switch, 3. an external water source and inlet valve, 4. an ultrasonic water mist sheet, 5. an air inlet module, 6. an upper perforated box, 7. a circulating air duct module, 8. a detachable light-transmitting window, 9. an external laser source, 10. a sleeve and a precision power meter, 11. a lower perforated box, 12. an exhaust module, 13. an auxiliary control module, and 14. a mist box body.

[0048] Step 1: System Setup. Based on the experimental requirements, construct the sealed fog chamber, select the water mist sheet combination, intake and exhaust fans, air valves and corresponding power supply system, and the material of the light transmission window.

[0049] The specific implementation method for step one is as follows: Based on the requirements of visible light band photoelectric imaging experiments, the mechanical construction of the entire system was completed as follows: 1. Assemble the 250L acrylic fog box body 14, with the inner wall lined with light-shielding black frosted material to ensure no light leakage and no looseness; 2. Fix the upper-layer perforated box 6 and the lower-layer perforated box 11 inside the fog box body 14, using a diagonal perforation arrangement to ensure the perforation surface is flat and well-sealed; 3. Install the water box 1 inside the upper-layer perforated box 6, fixing it firmly to ensure the water box is not tilted or leaking; 4. Install the air inlet module 5 directly above the upper-layer perforated box 6, and install the exhaust module 12 on one side of the lower-layer perforated box 11, both using sealed flanges to ensure air path sealing; 5. Fix 8 circulating fans at the eight corners of the volume scattering medium stable area inside the fog box body 14, facing the center of the area; 6. Install detachable optical glass light-transmitting windows at the incident and exit ends of the fog box's light path, sealing them with rubber gaskets and tightening bolts to ensure airtightness; 7. Connect the external pure water source 3 to the water box 1 via the water injection pipeline, and connect the electromagnetic water inlet valve in series to ensure that the pipeline is unobstructed and leak-free; 8. Place the external laser source 9, sleeve, and precision power meter 10, and initially adjust the height of the bracket to align it with the center of the light transmission window of the fog box.

[0050] Step Two: Circuit Connection and Initialization. Use a PC as the auxiliary control system adjustment device and connect the auxiliary control module; install the ultrasonic water mist generator plate and adjust its installation position in the water box to set the immersion depth; replace the light-transmitting window of the incident / exit end of the mist box with optical glass of the required wavelength band; connect an external pure water source and set the target liquid level height in the water box using a float level gauge; connect the auxiliary control module to the air inlet, exhaust, and water mist generation modules.

[0051] The specific implementation method for step two is as follows: A PC with a USB interface was selected as an auxiliary control device. The PC was connected to the auxiliary control module 13 via a USB data cable, and the matching control software was installed, ensuring that the software could correctly recognize all modules of the system. The 220V AC power supply to the auxiliary control module 13 was connected, and the power module switched to DC output to power all electrical components of the system. The power indicator lights of each module were checked to ensure they were lit correctly. Then, four ultrasonic water mist sheets were fixed to the mounting holes at the bottom of the water box using waterproof sealant. The installation height was adjusted, and the immersion depth of the ultrasonic water mist sheets was set to 20mm, ensuring a good seal and no looseness. After installation, the sealing performance was checked again to prevent subsequent mist leakage. The target liquid level in the water box was set to 30mm using the adjustment knob of the float level gauge. Finally, the control circuit connections between the auxiliary control module 13 and the air inlet module, exhaust module, ultrasonic water mist sheets 4, and circulating air duct module were checked one by one to ensure good contact and no reverse connections, completing the circuit initialization.

[0052] Step 3: Airtightness check. Close the inlet and outlet valves, generate mist, turn on all fans, and check for any mist overflow to ensure the mist box is airtight and there are no leaks.

[0053] The specific implementation method for step three is as follows: Close the air duct gates of the air intake module 5 and exhaust module 12 (adjust the opening to 0%) through the PC control software to ensure that the air path is completely closed. Then turn on the ultrasonic water mist plate 4 and set the power supply voltage to 5V through the auxiliary control module 13 to make the ultrasonic water mist plate start generating water mist. At the same time, turn on the air intake module 5 and exhaust module 12 to allow the water mist to be externally circulated. After running continuously for 5 minutes, carefully observe the splicing points of the fog box body 14, the installation points of the light-transmitting window, the pipe interfaces, and the docking points between the air intake and exhaust modules and the fog box to check for any fog leakage. After observation, there is no fog leakage at any connection point in this embodiment, confirming that the fog box is well sealed and can proceed to the next step. If fog leakage occurs, the machine needs to be stopped to adjust the sealing rubber gasket or tighten the bolts, and then re-check until there is no leakage.

[0054] Step 4: Constructing the Negative Feedback Optical Path. Construct the optical negative feedback module's optical path outside the enclosure, ensuring the laser source directly illuminates the precision power meter's test surface and that the optical path is unaffected by stray interference from mirror reflections; connect the negative feedback module to the auxiliary control system, and record the initial laser transmission power in the absence of a volume scattering medium.

[0055] The specific implementation method for step four is as follows: Adjust the height and angle of the external laser source 9, sleeve, and precision power meter 10 support to ensure that the central axes of the laser source 9's output light path, the fog chamber's light-transmitting window, the long sleeve, and the power meter's test surface are collinear, the light path is perpendicular to the light-transmitting window, and the center height of the light path is consistent with the center height of the stable region of the volume scattering medium. The sleeve shields stray light to ensure that the laser light path is not interfered with by mirror reflection or external light. Reconnect the optical negative feedback monitoring module and the auxiliary control module 13 to confirm that the data output terminal of the precision power meter 10 and the signal acquisition terminal of the auxiliary control module 13 are reliably connected. Finally, turn on the laser source 9 and set the output power to 10mW. At this time, there is no volume scattering medium inside the fog chamber. Record the initial laser transmission power displayed on the PC software as 10mW and store this value in the storage unit of the auxiliary control module 13 as the reference value for subsequent transmittance calculation.

[0056] Step 5: Initial Parameter Calibration. Perform standard parameter calibration for the scattering environment. Fully open the air inlet module valve, fix the exhaust module valve opening and fan speed to a low value, and gradually adjust the voltage (power) of the ultrasonic water mist generator. Simultaneously, record the laser transmission power data from the precision power meter until the laser transmission power stabilizes at the required scattering environment transmittance (corresponding transmission power = initial laser transmission power in Step 4 × transmittance). The PC records the ultrasonic water mist generator voltage (power) parameters in this stable state, calculates the ratio "generator power ÷ transmittance = K" for this stable state, and stores this ratio as the stability coefficient K in the auxiliary control module.

[0057] The specific implementation method for step five is as follows: The air intake module 5's duct damper is fully opened via PC control software, while the exhaust module 12's duct damper opening is fixed at 50% and the fan speed at 1000 rpm to ensure stable exhaust parameters. Subsequently, the power supply voltage of the ultrasonic water mist plate 4 is gradually adjusted, ranging from 5V to 20V in 1V increments. Each voltage adjustment is followed by 3 minutes of stable system operation to ensure the scattering medium concentration within the mist chamber reaches a stable state. During this process, the laser transmission power data from the precision power meter 10 is recorded in real-time via PC software, and fluctuations in transmission power are observed. In this embodiment, the target transmittance of the scattering environment required for the experiment is [missing information - likely a specific value]. 50%, corresponding to the laser transmission power = initial transmission power recorded in step four (10mW) × 50% = 5mW. Continuously adjust the voltage of the ultrasonic water mist sheet until the laser transmission power displayed by the precision power meter 10 stabilizes at 5mW (fluctuation ≤ ±5%). At this time, record that the power supply voltage of the ultrasonic water mist generator displayed on the PC is 12V, and the total power of the ultrasonic water mist sheet is 120W (4 sheets × 30W). Finally, calculate the stability coefficient K. According to the formula "generator power ÷ transmittance = K", substitute the data to get K = 120W ÷ 50% = 240W. Store the stability coefficient K in the auxiliary control module 13 to complete the initial parameter calibration.

[0058] Step Six: System in Steady-State Operation Mode Without Feedback. Start the ultrasonic water mist filter drive power supply to generate water mist at the initial power. The water mist overflows from the water box and enters the scattering medium generation area of ​​the fog chamber body evenly through the perforated plate. Simultaneously activate the air intake and exhaust control components to maintain a balance between mist generation and exhaust. The initial parameters are the calibration parameters from Step Two. Do not activate the optical negative feedback adjustment module. At this time, the volume scattering medium generation system operates in steady-state mode, allowing direct steady-state volume scattering environment experiments for photoelectric imaging systems.

[0059] The specific implementation method for step six is ​​as follows: The drive power of the ultrasonic water mist plate 4 is activated by the auxiliary control module 13, generating water mist according to the initial power calibrated in step five. After the water mist overflows from the water box 1, it diffuses evenly through the perforations of the upper perforated box 6 and enters the volume scattering medium stable zone of the fog chamber body 14. Simultaneously, the air intake control module and the air exhaust control module are activated, and the parameters are set according to the calibration in step five: the air intake fan speed is 1500 rpm, the air duct damper opening is 100%, the air exhaust fan speed is 1500 rpm, and the air duct damper opening is 50%, maintaining a dynamic balance between fog production and exhaust. Then, the optical negative feedback adjustment function is turned off. At this time, the volume scattering medium generation system works in stable mode. Finally, the parameters displayed on the PC software are observed to ensure that the concentration of scattering medium in the fog chamber is stable. After the parameters are stable, the steady-state volume scattering environment experiment of the photoelectric imaging system can be carried out directly.

[0060] Step 7: System Negative Feedback Adjustment Mode. Start the laser source and power meter. The power meter collects the laser power penetrating the scattering medium in real time and feeds it back to the adjustment module. The system automatically adjusts the ultrasonic plate power according to the preset stability coefficient K, adjustment delay, and descent curve to stabilize the scattering medium concentration within the target range. If dynamic fog generation is required, turn on the four corner fans of the circulating air duct unit and adjust their speed to form a circulating airflow, improving fog concentration and uniformity. At this time, the volume scattering medium generation system operates in negative feedback adjustment mode, which can adjust and compensate for external interference to a certain extent, allowing for experiments on the volume scattering environment of photoelectric imaging systems that introduce interference.

[0061] The specific implementation method for step seven is as follows: Laser source 9 and precision power meter 10 are turned on. The power meter collects laser transmission power data through the volume scattering medium in real time and feeds it back to auxiliary control module 13 through the data line. Then, the optical negative feedback adjustment function of auxiliary control module 13 is activated. The system automatically adjusts the power supply of ultrasonic water mist plate 4 according to the preset stability coefficient K, adjustment delay and linear descent curve. When there is slight external interference (such as airflow fluctuation) that causes the transmittance displayed by precision power meter 10 to be low, auxiliary control module 13 automatically reduces the power supply voltage of ultrasonic water mist plate. When the transmittance is high, it automatically increases the power supply voltage to ensure that the concentration of scattering medium is stable within the target range. If the experiment requires the generation of a large flow of dense fog, the four corner fans of circulation channel module 7 are turned on through PC software and the fan speed is adjusted to 2000 rpm to form a clockwise circulating airflow. The airflow drives water mist particles to circulate at high speed in the stable area of ​​the volume scattering medium, avoiding water mist deposition, increasing fog concentration, and optimizing the spatial uniformity of the scattering medium. At this time, the system works in negative feedback adjustment mode and can automatically adjust and compensate for external interference. It can carry out experiments on the volume scattering environment of photoelectric imaging system with introduced interference.

[0062] Step 8: System Concentration Adjustment Working Mode. Based on Step 7, if it is necessary to increase or decrease the volume scattering medium concentration, manually calculate and adjust the K-value coefficient. If the transmittance needs to be increased by N times, then K is reduced to K / N. Keep the exhaust parameters consistent with the pre-test stage. The auxiliary control module reads the transmittance data of the precision power meter in real time. According to the principle of "generator power ÷ transmittance = K / N" after adjustment, it automatically calculates the target generator power after adjustment (target power = transmittance × K ÷ N). When the transmittance is lower than the target value, the ultrasonic plate power supply voltage (power) is automatically reduced. When the transmittance is higher than the target value, the ultrasonic plate power supply voltage (power) is automatically increased. The adjustment process follows the preset delay time and drop curve. The delay setting range is 0-20s to avoid frequent adjustments of the ultrasonic plate power due to instantaneous fluctuations in laser power. The adjustment drop curve is a linear or non-linear curve to control the adjustment rate of the ultrasonic plate power and avoid drastic fluctuations in fog concentration caused by power abrupt changes. At this time, the volume scattering medium generation system works in negative feedback adjustment mode, which can be used for experiments on adjustable concentration volume scattering environments of photoelectric imaging systems that introduce interference.

[0063] The specific implementation method for step eight is as follows: Based on the negative feedback adjustment working mode in step seven, if the experiment requires increasing the concentration of the bulk scattering medium (i.e., reducing the transmittance to 40%), the stability coefficient K is manually adjusted via PC software. The adjusted K value is calculated. The transmittance is adjusted from 50% to 40%, meaning the transmittance increases by N = 50% ÷ 40% = 1.25 times. Therefore, the adjusted K value = original K value ÷ N = 240W ÷ 1.25 = 192W. The exhaust parameters are kept consistent with the calibration stage in step five (exhaust fan speed 1500 rpm, duct damper opening 50%). The auxiliary control module 13 reads the transmittance data from the precision power meter 10 in real time and adjusts the value accordingly. The system automatically calculates the target generator power (target power = transmittance × 192W) based on the principle of "generator power ÷ transmittance = 192W". The adjustment process follows a preset delay time and a linear decrease curve. When the transmittance is below 40%, the power supply voltage of the ultrasonic plate is automatically reduced. When the transmittance is above 40%, the power supply voltage is automatically increased to avoid sudden power changes that cause drastic fluctuations in fog concentration. Once the transmittance displayed on the PC stabilizes at around 40%, the system enters the negative feedback adjustment mode after concentration adjustment. This allows for the conduct of adjustable concentration volume scattering environment experiments of the photoelectric imaging system. If it is necessary to reduce the concentration of the volume scattering medium, the K value can be adjusted in reverse according to the above method.

[0064] Step Nine: Experiment and Parameter Recording. After the power meter data stabilizes, conduct photoelectric imaging-related experiments. During the experiment, the data acquisition module of the auxiliary control unit transmits various parameters (power meter data, ultrasonic strip power, fan speed, etc.) in real time and records them on the PC. If it is necessary to adjust the scattering concentration, the target transmittance can be modified through the computer interface, and the system will automatically recalculate and adjust the ultrasonic strip power according to Step Eight.

[0065] The specific implementation method for step nine is as follows: Once the laser transmission power displayed by the precision power meter 10 stabilizes and all parameters within the fog chamber are stable, photoelectric imaging experiments are initiated. During the experiment, the data acquisition module of the auxiliary control module 13 collects various operating parameters in real time, including the transmission power data of the precision power meter, the power supply voltage and power of the ultrasonic water mist sheet, the speed of the air intake / exhaust fan, and the opening of the air duct gate. All parameters are transmitted to the PC via the USB interface and automatically recorded and stored at 1-second intervals. If the concentration of the scattering medium needs to be adjusted during the experiment, the target transmittance can be directly modified through the PC control software. The system will automatically recalculate the adjusted target generator power and adjust the ultrasonic sheet power according to the method in step eight, without manual intervention. During the experiment, the changes in parameters on the PC are continuously observed. If any abnormality occurs (such as excessive transmittance fluctuations or fog chamber leakage), the machine is stopped immediately for inspection to ensure the smooth progress of the experiment. After the experiment is completed, all parameter data recorded on the PC are retained for subsequent experimental analysis. Thus, the generation of the volume scattering medium environment for photoelectric imaging is completed.

[0066] This completes the generation of the volume scattering medium environment for photoelectric imaging.

[0067] Step 10: Experiment complete. Turn off the ultrasonic water mist filter and laser source, and keep the air intake and exhaust systems and the circulating air duct system running at full power for a period of time to remove any residual water mist from the mist chamber; turn off all power, clean the surface of the light-transmitting window, and the experiment is complete.

[0068] The specific implementation method for step ten is as follows: First, turn off the driving power of the ultrasonic water mist plate 4 and the laser source 9 to stop water mist generation and laser emission. Then, keep all fans of the air intake module 5, exhaust module 12, and circulating air duct module 7 running at full power. Adjust the speed of the air intake and exhaust fans to 3000 rpm and the speed of the circulating fan to 2500 rpm, and run continuously for 10 minutes to completely remove the residual water mist in the mist box. Observe the transmittance data displayed on the PC. When the transmittance returns to 100% (consistent with the initial transmission power recorded in step four), and confirm that there is no residual water mist in the mist box, turn off all fans and air duct gates, disconnect the power of the auxiliary control module 13, and gently wipe the surface of the light transmission window at the incident / exit end of the light path of the mist box with a lint-free cloth to clean up any residual water mist traces to avoid affecting the accuracy of subsequent experiments. Finally, close the valve of the external pure water source 3, tidy up all control lines and pipelines, clean the experimental site, and complete the entire experimental process.

[0069] The workflow of a computational ghost imaging system based on compressed sensing disclosed in this embodiment is as follows: Figure 2 As shown, (1) a preset speckle pattern is obtained by principal component analysis through the establishment of an image dictionary; (2) the number of data receptions is reduced and the imaging efficiency is improved by compressing the received light intensity signal; (3) the speckle optimization scheme is combined with the compressed sensing method to achieve fast and high-quality computational ghost imaging.

[0070] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A volume scattering medium generation system suitable for photoelectric imaging, characterized in that, The system includes a fog chamber main body, a water mist generation module, an air intake control module, an exhaust control module, a circulating air duct module, an optical negative feedback monitoring module, and an auxiliary control module. Each module works in tandem through mechanical connection and electrical communication. The water mist generation module, air intake control module, and exhaust control module are directly connected to the fog chamber main body via pipes or mechanical structures, and all three are electrically connected to the auxiliary control module via control lines, adjusting their operating parameters according to the control signals output by the auxiliary control module. The optical negative feedback monitoring module employs a transmissive optical path layout and works in conjunction with the fog chamber main body. Its signal output is connected to the auxiliary control module via a data line, transmitting monitoring data to the auxiliary control module to achieve negative feedback adjustment of the water mist generation module, ultimately realizing the precise generation and long-term stable maintenance of the volume scattering medium.

2. The volume scattering medium generation system for photoelectric imaging as described in claim 1, characterized in that, The fog chamber body is a closed cavity structure, and the whole body is made of acrylic material. Its inner sidewall is attached with light-shielding black frosted material with a light absorption rate of not less than 95%, which is used to shield external stray light interference and internal multiple reflections to ensure the ambient light stability of the photoelectric experiment. Two detachable perforated boxes are symmetrically arranged along the vertical square center inside the fog chamber body, namely the upper perforated box (6) and the lower perforated box (11). The two perforated boxes divide the inside of the fog chamber body into three areas: Above the upper perforated box (6) is a fog buffer area; The space between the two perforated boxes is the stable region of the bulk scattering medium, which is the region through which the experimental light path penetrates. Below the lower perforated box (11) is the exhaust buffer area; The upper perforated box (6) and the lower perforated box (11) of the main body of the fog box are both made of acrylic material. The perforated surface of the box body in the stable area of ​​the scattering medium is evenly distributed with through holes to achieve uniform diffusion of water mist and smooth airflow, so as to avoid airflow disturbance from damaging the stability of the scattering medium. The volume scattering medium stabilization region of the fog chamber body is provided with detachable light-transmitting windows at both the light path incident end and the light path exit end. These windows are fixed to the front and rear walls of the fog chamber by fixing devices and sealed with rubber pads to ensure airtightness. The light-transmitting windows are replaced with optical glass of the corresponding wavelength band according to the experimental requirements. The thickness is generally not less than 3mm to ensure strength while efficiently transmitting light of different wavelength bands.

3. The volume scattering medium generation system suitable for photoelectric imaging as described in claim 2, characterized in that, The water mist generation module is installed in the upper perforated box of the mist box, including a water box (1), an ultrasonic water mist sheet group (4), and a liquid level stabilization component. The components work together to achieve precise generation and supply of water mist. The water box is a rectangular cavity with an open top and a closed bottom, made of acrylic material, and installed in the upper hole box of the fog box; multiple ultrasonic water mist plates are uniformly fixed inside the water box (1). The number and rated power of the ultrasonic water mist plates are selected according to the volume and concentration requirements of the fog box. The whole is connected to the auxiliary control module. The power output voltage of the power supply is precisely adjusted by the auxiliary control module (13) to change the fogging power of the ultrasonic water mist plates, thereby precisely controlling the amount of water mist generated. The liquid level stabilization component includes a float switch (2), an external water source, and an inlet valve (3). The float switch (2) is equipped with an adjustment device that extends outside the mist box via a support rod for external liquid level observation and control. Pure water is used as the water source, and an inlet valve controlled by the float switch (2) is installed in series on the water injection pipeline. The float is installed inside the water box. When the liquid level is lower than the preset value, the float switch (2) triggers the inlet valve to open and replenish water. When the liquid level reaches the preset value, the inlet valve closes, thus achieving automatic stabilization of the liquid level. The installation height of the float switch (2) can be manually adjusted by the adjustment bracket extending outside the mist box, thereby achieving adjustable liquid level. Combined with the selection of ultrasonic water mist sheet model, size specifications, and immersion depth, a multi-dimensional water mist concentration control mechanism is formed to achieve precise control of mist generation.

4. The volume scattering medium generation system suitable for photoelectric imaging as described in claim 1, characterized in that, The air intake control module includes a stepless adjustable waterproof fan and a stepless adjustable air duct gate, which are installed in series on the upper wall of the perforated box of the fog box and arranged in sequence along the air intake direction. Specifically, the fan is located on the inner side and the gate is located on the outer side, and both are electrically connected to the auxiliary control module through control lines. The auxiliary control module adjusts the fan speed and the gate opening by outputting voltage to achieve precise control of the air intake; the dry air enters the mist box by passing above the liquid surface in the water box, carrying some water mist into the mist box body, thereby increasing the water mist intake rate. The exhaust control module includes a finely steplessly adjustable waterproof fan and a steplessly adjustable air duct damper, installed on the side wall of the perforated box under the fog chamber. The fan is located on the inner side of the air path, and the damper is located on the outer side, with the inside of the fog chamber as the inner side. The ventilation volume and diameter of the exhaust fan and valve are larger than those of the air inlet. The auxiliary control module adjusts the fan speed and damper opening through the output voltage to achieve fine control of the exhaust volume and rapid fog removal. By adjusting the balance between the total exhaust volume and the total intake volume, the fog chamber body is kept under a slightly positive pressure or normal pressure to ensure that fog production and fog exhaust are in dynamic balance. This avoids excessive pressure in the fog chamber causing leakage or excessively low pressure causing outside air to mix in and interfere with the stability of the scattering medium.

5. A volume scattering medium generation system suitable for photoelectric imaging as described in claim 1, characterized in that, The circulating air duct module includes circulating fans and their independent power supplies, installed inside the fog box body in the gaseous scattering medium generation area, that is, between the upper and lower perforated plates, fixed in the corner of this area. The number of fans is selected according to the volume of the fog box. All fans are connected to an independent stepless power supply through control lines. When a large flow of dense fog needs to be generated, all fans of the circulating air duct module are turned on to form a clockwise or counterclockwise circulating airflow. The airflow drives the scattering medium to circulate at high speed in the generation area. On the one hand, it can avoid the sedimentation of water mist particles, and on the other hand, it can make the water mist particles evenly distributed, quickly increase the fog concentration in the area, and further optimize the spatial uniformity of the scattering medium.

6. The volume scattering medium generation system suitable for photoelectric imaging as described in claim 1, characterized in that, The optical negative feedback monitoring module includes an external laser source, a long sleeve, and a precision power meter. It adopts a transmission optical path monitoring layout. The laser source and the long sleeve are respectively installed on the outside of the optical path incident end and the output end of the fog box body, and the central axes of the three are collinear and consistent with the optical path penetration direction of the fog box body. The external laser source is a continuous output laser source, and the output wavelength can be selected according to experimental requirements. The output power stability error is ≤±1%. The long sleeve adopts a black threaded light-shielding structure with a length of not less than 50mm. A precision power meter is fixedly installed at the other end, with a measurement accuracy of not less than ±0.01mW. Its data output end is connected to the auxiliary control module to transmit laser transmission power data in real time.

7. A volume scattering medium generation system suitable for photoelectric imaging as described in claim 1, characterized in that, The auxiliary control module is the core control unit, which includes an integrated power supply, a signal acquisition module, a signal output module, and a communication module. The power supply module provides stable power to all electrical components of the system. The signal acquisition module is used to receive the transmission power signal from the precision power meter. The signal output module is used to output voltage control signals to each fan, air duct gate, and ultrasonic transducer group. The communication module integrates a USB or Ethernet interface to realize wired connection with a computer, and supports additional control of air intake, exhaust volume, and ultrasonic water mist generator power through computer software. It can also read and store all operating parameters of the system in real time, including fan speed, ultrasonic transducer voltage, and transmittance.

8. A volume scattering medium generation system suitable for photoelectric imaging as described in claim 1, characterized in that, The monitoring data is transmitted to the auxiliary control module to achieve negative feedback adjustment of the water mist generation module. The specific testing and implementation method of negative feedback adjustment is as follows: The first step is the calibration stage. Fully open the air inlet module valve, fix the air outlet module valve opening and fan speed, and gradually adjust the voltage or power of the ultrasonic water mist sheet. At the same time, record the laser transmission power data of the precision power meter until the ultrasonic water mist generator voltage or power parameter corresponding to the laser transmission power stabilizing at the target value is found. Calculate the ratio "generator power ÷ transmittance = K" in this stable state, and store this ratio as the stability coefficient K in the auxiliary control module. The second step, the automatic adjustment phase, maintains the exhaust parameters consistent with the pre-test phase. The auxiliary control module reads the transmittance data from the precision power meter in real time and automatically calculates the target generator power according to the principle of "generator power ÷ transmittance = K". That is: target generator power = K × transmittance. When the transmittance is lower than the target value, the ultrasonic plate supply voltage or power is automatically reduced. When the transmittance is higher than the target value, the ultrasonic plate supply voltage or power is automatically increased. The adjustment process follows the preset delay time and drop curve. The delay setting range is 0-20s to avoid frequent adjustments of the ultrasonic plate power caused by instantaneous fluctuations in laser power. The adjustment drop curve is a linear or non-linear curve to control the adjustment rate of the ultrasonic plate power and avoid drastic fluctuations in fog concentration caused by sudden power changes.

9. A method for generating a volume scattering medium suitable for photoelectric imaging, characterized in that, The volume scattering medium generation system for photoelectric imaging as described in any one of claims 1 to 7 includes the following steps: Step 1: Construct a volume scattering medium generation system suitable for photoelectric imaging as described in any one of claims 1 to 8; Step 2: Circuit connection and initialization, specifically including: Use a PC as an auxiliary control system adjustment device and connect the auxiliary control module; install the ultrasonic water mist generator plate and adjust its installation position in the water box to set the immersion depth; replace the light transmission window of the light path entrance / exit end of the mist box with optical glass of the required wavelength band for the experiment; connect an external pure water source and set the target liquid level height in the water box through a float level gauge; connect the auxiliary control module to the air inlet, air outlet, and water mist generation modules; Step 3: Close the inlet and outlet air valves, generate mist, turn on all fans, check for any mist overflow, ensure the mist box is sealed, and ensure there is no leakage; Step 4: Construct the negative feedback optical path, specifically: construct the optical negative feedback module optical path outside the enclosure, ensure that the laser source directly illuminates the test surface of the precision power meter, and ensure that the optical path is not affected by stray interference from mirror reflections; connect the negative feedback module to the auxiliary control system, and record the initial laser transmission power in the absence of a bulk scattering medium; Step 5: Perform standard parameter calibration for the scattering environment. Fully open the air inlet module valve, fix the air outlet module valve opening and fan speed to a low value, and gradually adjust the voltage or power of the ultrasonic water mist sheet. At the same time, record the laser transmission power data of the precision power meter until the laser transmission power is found to be stable at the required scattering environment transmittance. Specifically: corresponding transmission power = initial laser transmission power in step 4 × transmittance. The PC records the voltage or power parameters of the ultrasonic water mist generator in this state, calculates the ratio of "generator power ÷ transmittance = K" in this stable state, and stores this ratio as the stability coefficient K in the auxiliary control module. Step Six: Start the ultrasonic water mist plate drive power supply to generate water mist at the initial power. The water mist overflows from the water box and enters the scattering medium generation area of ​​the fog chamber body evenly through the perforated plate. Simultaneously turn on the air intake control component and the exhaust control component to maintain the balance between fog generation and exhaust. The initial parameters are the calibration parameters in Step Two. Do not turn on the optical negative feedback adjustment module. At this time, the volume scattering medium generation system is working in stable mode, and the steady-state volume scattering environment experiment of the photoelectric imaging system is carried out directly. Step 7: Start the laser source and power meter. The power meter collects the laser power penetrating the scattering medium in real time and feeds it back to the adjustment module. The system automatically adjusts the ultrasonic plate power according to the preset stability coefficient K, adjustment delay and descent curve to stabilize the concentration of the scattering medium within the target range. If dynamic fog needs to be generated, turn on the four corner fans of the circulation duct unit and adjust the speed to form a circulating airflow to improve the fog concentration and uniformity. At this time, the volume scattering medium generation system works in negative feedback adjustment mode, which adjusts and compensates for external interference to a certain extent, and conducts a volume scattering environment experiment of the photoelectric imaging system with introduced interference. Step 8: Based on Step 7, if it is necessary to increase or decrease the volume scattering medium concentration, manually calculate and adjust the K value coefficient. If the transmittance needs to be increased by N times, then K is reduced to K / N. Keep the exhaust parameters consistent with the pre-test stage. The auxiliary control module reads the transmittance data of the precision power meter in real time. According to the principle of "generator power ÷ transmittance = K / N" after adjustment, automatically calculate the target generator power after adjustment, that is, target power = transmittance × K ÷ N. When the transmittance is lower than the target value, automatically reduce the ultrasonic plate power supply voltage or power. When the transmittance is higher than the target value, automatically increase the ultrasonic plate power supply voltage or power. The adjustment process follows the preset delay time and drop curve. The setting range of the delay is 0-20s to avoid the instantaneous fluctuation of laser power causing frequent adjustment of ultrasonic plate power. Adjust the drop curve to be a linear or non-linear curve to control the adjustment rate of ultrasonic plate power and avoid sudden power changes causing drastic fluctuations in fog concentration. At this time, the volume scattering medium generation system works in negative feedback adjustment mode to conduct an adjustable concentration volume scattering environment experiment of the photoelectric imaging system to introduce interference. Step Nine: After the power meter displays stable data, conduct photoelectric imaging-related experiments. During the experiment, the data acquisition module of the auxiliary control unit transmits various parameters in real time and records them on the PC. If it is necessary to adjust the scattering concentration, the target transmittance can be modified through the computer interface. The system will automatically recalculate and adjust the ultrasonic plate power according to Step Eight. At this point, the generation of the volume scattering medium environment for photoelectric imaging is completed. Step 10: Experiment complete. Turn off the ultrasonic water mist filter and laser source, and keep the air intake and exhaust systems and the circulating air duct system running at full power for a period of time to remove any residual water mist from the mist chamber; turn off all power, clean the surface of the light-transmitting window, and the experiment is complete.

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