Intelligent fire extinguishing method and device based on multi-source perception and PID closed-loop control

Abstract

The present application relates to the technical field of fire safety and intelligent equipment, in particular to an intelligent fire extinguishing method and device based on multi-source sensing and PID closed-loop control. The method comprises the following steps: acquiring real-time multi-source fire information; obtaining the initial position of the fire source, correcting the initial position of the fire source, and obtaining the final position of the fire source; constructing a distance control error function through the final position of the fire source and the minimum safe fire extinguishing distance, so that the fire extinguishing device moves to the optimal fire extinguishing position for fire extinguishing; constructing a fire extinguishing effect evaluation index function according to the flame area and the average temperature of the flame area, and determining whether the fire extinguishing is completed. The present application realizes accurate positioning of the fire source position by fusing multi-source sensing information such as vision, temperature, heat flow, and smoke, effectively overcomes the problem of insufficient positioning accuracy of single sensing mode, and can realize automatic decision and execution of fire extinguishing operation in complex and high-risk fire environment, significantly improves the fire extinguishing efficiency and ensures the safety of personnel.

Description

Technical Field

[0001] This invention relates to the field of fire safety and intelligent equipment technology, specifically to an intelligent fire extinguishing device and method based on multi-source sensing and PID closed-loop control. Background Technology

[0002] With the rapid development of complex locations such as underground tunnels, urban complexes, and large-scale petrochemical storage facilities, the fire risk has increased significantly. Once a fire occurs, it typically presents characteristics such as high temperatures, strong radiation, and large amounts of toxic and harmful smoke, making it difficult for personnel to approach and extinguishing. Traditional firefighting operations mainly rely on firefighters operating firefighting equipment at close range, which not only poses a serious threat to personnel safety but also makes firefighting efficiency and effectiveness largely dependent on individual experience, making it difficult to achieve stable, precise, and controllable firefighting operations in complex and dynamically evolving fire environments.

[0003] Although existing fire extinguishing equipment has introduced remote or semi-automatic control methods, it usually has the following shortcomings:

[0004] (1) The means of fire source detection and location are limited, relying mainly on single visual or temperature information, which is easily affected by smoke obstruction and environmental interference, resulting in limited accuracy of fire source location.

[0005] (2) There is a lack of dynamic constraint mechanism for safe fire extinguishing distance, and there are still safety risks to equipment or personnel in strong radiation and high temperature environments;

[0006] (3) The fire extinguishing process often adopts open-loop or simple control strategies. Parameters such as spray flow rate, angle and height are difficult to adjust in real time according to the changes in fire intensity, resulting in low fire extinguishing efficiency and unstable fire extinguishing effect.

[0007] (4) The overall system is not sufficiently automated and intelligent, and still requires frequent human intervention, making it difficult to adapt to rapidly evolving and complex fire scenarios.

[0008] Therefore, developing an intelligent fire extinguishing method and equipment that can integrate multi-source fire information and has autonomous decision-making and closed-loop adjustment capabilities is of great significance for improving the safety of fire emergency response. Summary of the Invention

[0009] The purpose of this invention is to overcome the above-mentioned shortcomings and provide an intelligent fire extinguishing method based on multi-source sensing and PID closed-loop control, so as to realize intelligent control of the fire extinguishing process in high-risk and complex fire environments.

[0010] To achieve the above objectives, the present invention adopts the following technical solution: an intelligent fire extinguishing method based on multi-source sensing and PID closed-loop control, comprising the following sequential steps:

[0011] (1) Real-time acquisition of multi-source fire information, including fire image sequences, fire temperature data, fire smoke concentration data and fire heat flow data;

[0012] (2) Identification of flame region sets based on fire scene image sequences and based on the fire zone set Spatial location of the fire scene to obtain the initial location of the fire source. Then, by using fire temperature data and fire smoke concentration data, the initial location of the fire source can be determined. Multi-source information fusion and correction were performed to obtain the final location of the fire source. ;

[0013] (3) Calculate the intensity of thermal disaster at the fire site based on fire heat flow data According to the intensity of thermal disaster Calculate the final location of fire extinguishing equipment and fire source Minimum safe fire extinguishing distance between Then, through the final location of the fire source and minimum safe fire extinguishing distance Constructing the distance control error function ,when At this time, it indicates the current location of the fire extinguishing equipment and the minimum safe fire extinguishing distance. If a distance deviation exists, the controller will use the distance control vector. Calculate the optimal travel path and control the fire extinguishing equipment to move autonomously; when This indicates that the fire extinguishing equipment has reached the minimum safe fire extinguishing distance. The controller will then activate the fire extinguishing equipment to target the final location of the fire source. Extinguish the fire and proceed to the next step;

[0014] (4) Based on flame region set Calculate the flame area and average temperature of the flame zone and through the flame area and average temperature of the flame zone Constructing a fire extinguishing effectiveness evaluation index function ;when When, it indicates the flame area or average temperature of the flame zone If changes still occur and the fire is determined not to be completely extinguished, the controller will control the vector through the fire extinguishing parameters. Adjust the spray parameters of the fire extinguishing equipment to continuously extinguish the fire; when When, it indicates the flame area or average temperature of the flame zone The situation has stabilized, the fire has been determined to be extinguished, and firefighting efforts have ceased.

[0015] In step (1), the fire scene environment is captured in real time by a camera to obtain a sequence of fire scene images; the fire scene temperature data is obtained by a temperature sensor; the fire scene smoke concentration data is obtained by a smoke sensor; and the fire scene heat flow data is obtained by a heat flow sensor.

[0016] Step (2) specifically includes the following steps:

[0017] (2a) Perform flame region identification on the fire scene image sequence acquired at time t to obtain the set of flame regions. :

[0018] ;

[0019] ;

[0020] in, Located in spatial coordinates The flame feature determination value of the pixel at time t. , , These are the spatial coordinates of the fire scene image sequence. The red, green, and blue channel pixel values ​​of the pixel at time t; Spatial coordinates of the fire scene image sequence The brightness value of the pixel at time t; The maximum brightness value in the fire scene image sequence; , These are the weighting coefficients; The flame detection threshold; when At that time, determine the location in spatial coordinates The pixels belong to the flame area;

[0021] (2b) Group the flame areas Flame centroid image coordinates Mapping to a spatial coordinate system, obtain the initial position of the fire source. :

[0022] ;

[0023] in, As a scale factor, For the camera intrinsic parameter matrix, For extrinsic rotation matrix, It is a translation vector. is the coordinate in the three-dimensional space of the fire source, and 1 is the homogeneous coordinate;

[0024] (2c) By constructing the initial location of the fire source The mapping relationship between the data and the distribution of fire temperature data indicates the initial location of the fire source. To correct for errors caused by obstruction, reflection, or changes in lighting, the formula for calculating the fire source location at time t based on fire temperature data can be expressed as:

[0025] ;

[0026] in, Let N be the location of the fire source at time t based on fire temperature data, and N be the number of temperature sensors. Let be the measured temperature of the i-th temperature sensor. To predict temperature values, For the temperature data of the i-th temperature sensor, U is the heat release rate of the fire source, U is the ambient ventilation speed, and T is the temperature measured by the temperature sensor.

[0027] Simultaneously, calculate the temperature spatial gradient. By utilizing the extreme points of the temperature spatial gradient and their variation over time, the location of the fire source can be determined. Perform inversion dynamic correction:

[0028] ;

[0029] ;

[0030] ;

[0031] in, This indicates the location of the fire source at time t, after dynamic correction based on fire temperature data. This indicates the step size factor for temperature location correction; This represents the rate of change of temperature along the x-direction; This represents the rate of change of temperature along the y-direction; This represents the rate of change of temperature along the z-direction; This represents the magnitude of the temperature spatial gradient, used to eliminate the influence of the magnitude of the temperature spatial gradient and retain only the direction information.

[0032] (2d) By constructing The mapping relationship between the data and the smoke concentration data at the fire scene is crucial for... Further corrections were made to obtain the data based on the smoke concentration at time t. Location of the fire ;

[0033] ;

[0034] Where M represents the number of flue gas sensors. Let be the measured concentration of the j-th flue gas sensor. To predict the concentration value, S is the flue gas concentration measured by the flue gas sensor;

[0035] Simultaneously, the spatial gradient of the fire smoke concentration data is calculated, and the gradient extreme points and their time-varying characteristics are utilized to... By performing inversion dynamic correction, the final location of the fire source at time t is obtained after inversion dynamic correction based on fire temperature data and fire smoke concentration data. ;

[0036] ;

[0037] ;

[0038] ;

[0039] in, This indicates the step size factor for correcting the location of flue gas concentration. Represents the spatial gradient of flue gas concentration; This represents the rate of change of flue gas concentration along the x-direction; This represents the rate of change of flue gas concentration along the y-direction; This represents the rate of change of flue gas concentration along the z-direction; This represents the spatial gradient magnitude of flue gas concentration, used to eliminate the influence of the magnitude of the flue gas concentration gradient and retain only the directional information.

[0040] Step (3) includes the following steps:

[0041] (3a) Calculate the intensity of thermal disaster based on fire heat flow data Determine the minimum safe fire extinguishing distance :

[0042] ;

[0043] ;

[0044] in, The critical heat flux threshold, The data represents radiative heat flux collected by a heat flux sensor. The convective heat flow received by the surface of the fire extinguishing equipment. Radiation fraction, The rate of heat release from the ignition source. The distance from the center of the fire to the fire extinguishing equipment. The angle between the height of the fire source center and the horizontal plane, and h is the convective heat transfer coefficient. The temperature at the fire scene, Ambient temperature;

[0045] (3b) Based on the final location of the fire source and minimum safe fire extinguishing distance Constructing the distance control error function :

[0046] ;

[0047] (3c) Distance control error function The controller makes a judgment and, based on the judgment result, uses the distance control vector... Output the motion control command at time t;

[0048] when When this occurs, it indicates that the fire extinguishing equipment has a safe redundancy distance, and the controller uses the distance control vector. Output a movement command to direct the fire extinguishing equipment to the final location of the fire source. Move in direction until Stop moving when; At this time, it indicates the final location of the fire extinguishing equipment from the fire source. At close range, within a dangerous distance, the controller uses distance control vectors. Output a movement command to move the fire extinguishing equipment to a final location away from the fire source. Move in direction until Stop moving when; This indicates that the fire extinguishing equipment has reached the minimum safe fire extinguishing distance. At the optimal fire extinguishing distance, the controller activates the fire extinguishing equipment to target the final location of the fire source. Extinguish the fire;

[0049] Distance control vector Represented as:

[0050] ;

[0051] in, , , These are the proportional, integral, and derivative coefficients of the control vector, respectively. The integral value of the distance error between the final location of the fire source and the fire extinguishing equipment over the time interval [0, t]; The rate of change of error over time; In time Distance error at any given time; For integration variables; The independent variable is time.

[0052] Step (4) includes the following steps:

[0053] (4a) Based on fire zone set Calculate the flame area and average temperature of the flame zone :

[0054] ;

[0055] ;

[0056] Where s is the spatial coordinate The area value corresponding to each pixel; This represents the number of pixels in the flame area. Spatial coordinates The temperature value of the pixel at time t;

[0057] (4b) Flame area and average temperature of the flame zone Constructing a fire extinguishing effectiveness evaluation index function :

[0058] ;

[0059] in, , These are the weighting coefficients; for The area of ​​the flame at any given moment; for Average temperature of the flame zone at any given time; The sampling interval;

[0060] (4c) Evaluation index function for fire extinguishing effect The controller makes a judgment and, based on the judgment result, controls the vector according to the fire extinguishing parameters. Output the fire extinguishing parameters at time t;

[0061] when When, it indicates the flame area or average temperature of the flame zone The overall trend is upward, and the fire has not been effectively contained. At this time, the spray parameters of the fire extinguishing equipment are dynamically adjusted through the controller to continue fire extinguishing. The spray parameters specifically refer to the foam solution flow rate, gas flow rate, spray gun angle, and spray gun height. When, it indicates the flame area or average temperature of the flame zone The overall trend is downward, the fire extinguishing process is effective, and the fire extinguishing equipment continues to extinguish the fire; when When, it indicates the flame area or average temperature of the flame zone Once the fire has stabilized and dropped below the preset safety threshold, it is determined that the fire is extinguished, and the fire extinguishing equipment stops working.

[0062] Fire Extinguishing Parameter Control Vector Represented as:

[0063] ;

[0064] in, , , These are the proportional, integral, and differential coefficients of the fire extinguishing parameter correction vector, respectively. Evaluation index function for fire extinguishing effectiveness The cumulative integral value within the time interval [0,t]; Evaluation index function for fire extinguishing effectiveness Rate of change over time; For integration variables; The independent variable is time.

[0065] Another objective of this invention is to provide a fire extinguishing device based on multi-source sensing and PID closed-loop control, comprising a foam solution tank placed on a movable frame trolley, a foam liquid pump connected to the foam solution tank, a screw compressor, and a gas storage tank connected to the screw compressor, and a foam spray gun and spray gun bracket mounted on the top of the movable frame trolley. The foam liquid pump, gas storage tank, and foam spray gun are respectively connected to a gas-liquid mixing pipe through a first pipeline, a second pipeline, and a heat-insulated pipeline. The first pipeline is equipped with a measuring instrument and a regulating valve, and the second pipeline is equipped with a gas flow meter. The movable frame trolley is also equipped with a controller, a camera, a temperature sensor, a heat flow sensor, and a smoke sensor.

[0066] The controller uses an embedded microprocessor as the core control unit, and the microprocessor is an STM32 series chip based on the ARM Cortex-M architecture. The camera, temperature sensor, flue gas sensor, and heat flow sensor are connected to the input terminal of the controller through a signal acquisition module. The gas flow meter and measuring instrument are connected to the input terminal of the controller. The output terminal of the controller is electrically connected to the foam liquid pump drive module, screw compressor control module, spray gun control module, and drive control module of the movable frame trolley.

[0067] The foam spray gun is connected to the spray gun bracket via a rotating hinge. The spray gun bracket is fixed to the top of the movable frame trolley and its height is adjustable.

[0068] The lower part of the foam solution tank is equipped with a stainless steel heating tube and a thermocouple temperature sensor. The upper part of the foam solution tank is equipped with an LED touch screen. The top of the foam solution tank is equipped with a tank cover and the bottom is equipped with a drain port. The foam liquid pump is used to draw foam liquid from the foam solution tank and deliver it to the measuring instrument through the first pipeline. After the foam liquid flow rate is adjusted by the regulating valve, it enters the liquid inlet of the gas-liquid mixing pipe.

[0069] The screw compressor is connected to the air inlet of the air storage tank. The air storage tank is equipped with a pressure relief valve and a drain outlet. The compressed air in the air storage tank enters the second pipeline through the air outlet, and after passing through the gas flow meter, it is delivered to the gas inlet of the gas-liquid mixing pipe, where it mixes with the foam liquid in the gas-liquid mixing pipe.

[0070] The beneficial effects of this invention are as follows:

[0071] (1) By integrating multi-source sensing information such as vision, temperature, heat flow, and smoke, the location of the fire source can be accurately located, effectively overcoming the problem of insufficient positioning accuracy of a single sensing method under conditions of smoke obscuration and environmental interference.

[0072] (2) During the autonomous operation of the fire extinguishing equipment, a distance control error function is constructed in combination with the characteristics of the fire scene's thermal hazards. The optimal fire extinguishing path planning is automatically completed without human intervention, ensuring the safe operation of the fire extinguishing equipment in high-risk fire scene environments.

[0073] (3) Utilize the real-time feedback information of the fire extinguishing effect to construct a PID closed-loop control system, and continuously and dynamically correct key parameters such as fire extinguishing agent spray flow rate, spray height and spray angle to achieve refined and stable control of the fire extinguishing process.

[0074] (4) By integrating a foam liquid heating device into the fire extinguishing equipment, the high viscosity foam liquid is subjected to controllable heating treatment, which transforms it from a high viscoelastic state to a low viscosity state with better fluidity, thus expanding the adaptability of intelligent fire extinguishing equipment to multiple types of foam extinguishing agents.

[0075] (5) By using controller collaboration and PID closed-loop feedback control, the strong reliance on human experience is eliminated, and automatic decision-making and execution of fire extinguishing operations are achieved in complex and high-risk fire environments, which significantly improves fire extinguishing efficiency and ensures personnel safety. Attached Figure Description

[0076] Figure 1 This is a flowchart of the present invention;

[0077] Figure 2 This is a schematic diagram of the fire extinguishing device of the present invention;

[0078] Figure 3 This is a partial enlarged view of the fire extinguishing device of the present invention.

[0079] The labels in the above-mentioned attached figures are as follows: 1. Movable frame trolley; 2. Foam solution tank; 21. Stainless steel heating tube; 22. Thermocouple temperature sensor; 23. LED touch screen display; 24. Tank cover; 25. Drain outlet; 3. Foam liquid pump; 4. Screw compressor; 5. Gas storage tank; 51. Air inlet; 52. Pressure relief valve; 53. Drain outlet; 54. Air outlet; 6. Foam spray gun; 61. Spray gun bracket; 62. Rotary hinge; 7. Gas-liquid mixing pipe; 7. First pipeline; 71. Measuring instrument; 711. Regulating valve; 712. Second pipeline; 72. Gas flow meter; 721. Insulated pipeline; 73. Camera; 81. Temperature sensor; 82. Flue gas sensor; 83. Heat flow sensor; 84. Detailed Implementation

[0080] The present invention will be further described below with reference to the accompanying drawings:

[0081] like Figure 1 The intelligent fire extinguishing method based on multi-source sensing and PID closed-loop control, as shown, includes the following sequential steps:

[0082] (1) Real-time acquisition of multi-source fire information, including fire image sequences, fire temperature data, fire smoke concentration data and fire heat flow data;

[0083] (2) Identification of flame region sets based on fire scene image sequences and based on the fire zone set Spatial location of the fire scene to obtain the initial location of the fire source. Then, by using fire temperature data and fire smoke concentration data, the initial location of the fire source can be determined. Multi-source information fusion and correction were performed to obtain the final location of the fire source. ;

[0084] (3) Calculate the intensity of thermal disaster at the fire site based on fire heat flow data According to the intensity of thermal disaster Calculate the final location of fire extinguishing equipment and fire source Minimum safe fire extinguishing distance between Then, through the final location of the fire source and minimum safe fire extinguishing distance Constructing the distance control error function ,when At this time, it indicates the current location of the fire extinguishing equipment and the minimum safe fire extinguishing distance. If a distance deviation exists, the controller will use the distance control vector. Calculate the optimal travel path and control the fire extinguishing equipment to move autonomously; when This indicates that the fire extinguishing equipment has reached the minimum safe fire extinguishing distance. The controller will then activate the fire extinguishing equipment to target the final location of the fire source. Extinguish the fire and proceed to the next step;

[0085] (4) Based on flame region set Calculate the flame area and average temperature of the flame zone and through the flame area and average temperature of the flame zone Constructing a fire extinguishing effectiveness evaluation index function ;when When, it indicates the flame area or average temperature of the flame zone If changes still occur and the fire is determined not to be completely extinguished, the controller will control the vector through the fire extinguishing parameters. Adjust the spray parameters of the fire extinguishing equipment to continuously extinguish the fire; when When, it indicates the flame area or average temperature of the flame zone The situation has stabilized, the fire has been determined to be extinguished, and firefighting efforts have ceased.

[0086] In step (1), the fire scene environment is captured in real time by a camera to obtain a sequence of fire scene images; the fire scene temperature data is obtained by a temperature sensor; the fire scene smoke concentration data is obtained by a smoke sensor; and the fire scene heat flow data is obtained by a heat flow sensor.

[0087] Step (2) specifically includes the following steps:

[0088] (2a) Perform flame region identification on the fire scene image sequence acquired at time t to obtain the set of flame regions. :

[0089] ;

[0090] ;

[0091] in, Located in spatial coordinates The flame feature determination value of the pixel at time t. , , These are the spatial coordinates of the fire scene image sequence. The red, green, and blue channel pixel values ​​of the pixel at time t; Spatial coordinates of the fire scene image sequence The brightness value of the pixel at time t; The maximum brightness value in the fire scene image sequence; , These are the weighting coefficients; The flame detection threshold; when At that time, determine the location in spatial coordinates The pixels belong to the flame area;

[0092] (2b) Group the flame areas Flame centroid image coordinates Mapping to a spatial coordinate system, obtain the initial position of the fire source. :

[0093] ;

[0094] in, As a scale factor, For the camera intrinsic parameter matrix, For extrinsic rotation matrix, It is a translation vector. is the coordinate in the three-dimensional space of the fire source, and 1 is the homogeneous coordinate;

[0095] (2c) By constructing the initial location of the fire source The mapping relationship between the data and the distribution of fire temperature data indicates the initial location of the fire source. To correct for errors caused by obstruction, reflection, or changes in lighting, the formula for calculating the fire source location at time t based on fire temperature data can be expressed as:

[0096] ;

[0097] in, Let N be the location of the fire source at time t based on fire temperature data, and N be the number of temperature sensors. Let be the measured temperature of the i-th temperature sensor. To predict temperature values, For the temperature data of the i-th temperature sensor, U is the heat release rate of the fire source, U is the ambient ventilation speed, and T is the temperature measured by the temperature sensor.

[0098] Simultaneously, calculate the temperature spatial gradient. By utilizing the extreme points of the temperature spatial gradient and their variation over time, the location of the fire source can be determined. Perform inversion dynamic correction:

[0099] ;

[0100] ;

[0101] ;

[0102] in, This indicates the location of the fire source at time t, after dynamic correction based on fire temperature data. This indicates the step size factor for temperature location correction; This represents the rate of change of temperature along the x-direction; This represents the rate of change of temperature along the y-direction; This represents the rate of change of temperature along the z-direction; This represents the magnitude of the temperature spatial gradient, used to eliminate the influence of the magnitude of the temperature spatial gradient and retain only the direction information.

[0103] (2d) By constructing The mapping relationship between the data and the smoke concentration data at the fire scene is crucial for... Further corrections were made to obtain the data based on the smoke concentration at time t. Location of the fire ;

[0104] ;

[0105] Where M represents the number of flue gas sensors. Let be the measured concentration of the j-th flue gas sensor. To predict the concentration value, S is the flue gas concentration measured by the flue gas sensor;

[0106] Simultaneously, the spatial gradient of the fire smoke concentration data is calculated, and the gradient extreme points and their time-varying characteristics are utilized to... By performing inversion dynamic correction, the final location of the fire source at time t is obtained after inversion dynamic correction based on fire temperature data and fire smoke concentration data. ;

[0107] ;

[0108] ;

[0109] ;

[0110] in, This indicates the step size factor for correcting the location of flue gas concentration. Represents the spatial gradient of flue gas concentration; This represents the rate of change of flue gas concentration along the x-direction; This represents the rate of change of flue gas concentration along the y-direction; This represents the rate of change of flue gas concentration along the z-direction; This represents the spatial gradient magnitude of flue gas concentration, used to eliminate the influence of the magnitude of the flue gas concentration gradient and retain only the directional information.

[0111] Step (3) includes the following steps:

[0112] (3a) Calculate the intensity of thermal disaster based on fire heat flow data Determine the minimum safe fire extinguishing distance :

[0113] ;

[0114] ;

[0115] in, The critical heat flux threshold, The data represents radiative heat flux collected by a heat flux sensor. The convective heat flow received by the surface of the fire extinguishing equipment. Radiation fraction, The rate of heat release from the ignition source. The distance from the center of the fire to the fire extinguishing equipment. The angle between the height of the fire source center and the horizontal plane, and h is the convective heat transfer coefficient. The temperature at the fire scene, Ambient temperature;

[0116] (3b) Based on the final location of the fire source and minimum safe fire extinguishing distance Constructing the distance control error function :

[0117] ;

[0118] (3c) Distance control error function The controller makes a judgment and, based on the judgment result, uses the distance control vector... Output the motion control command at time t;

[0119] when When this occurs, it indicates that the fire extinguishing equipment has a safe redundancy distance, and the controller uses the distance control vector. Output a movement command to direct the fire extinguishing equipment to the final location of the fire source. Directional movement; when At this time, it indicates the final location of the fire extinguishing equipment from the fire source. At close range, within a dangerous distance, the controller uses distance control vectors. Output a movement command to move the fire extinguishing equipment to a final location away from the fire source. Directional movement; when This indicates that the fire extinguishing equipment has reached the minimum safe fire extinguishing distance. At the optimal fire extinguishing distance, the controller activates the fire extinguishing equipment to target the final location of the fire source. Extinguish the fire;

[0120] Distance control vector Represented as:

[0121] ;

[0122] in, , , These are the proportional, integral, and derivative coefficients of the control vector, respectively. The integral value of the distance error between the final location of the fire source and the fire extinguishing equipment over the time interval [0, t]; The rate of change of error over time; In time Distance error at any given time; For integration variables; The independent variable is time.

[0123] Step (4) includes the following steps:

[0124] (4a) Based on fire zone set Calculate the flame area and average temperature of the flame zone :

[0125] ;

[0126] ;

[0127] Where s is the spatial coordinate The area value corresponding to each pixel; This represents the number of pixels in the flame area. Spatial coordinates The temperature value of the pixel at time t;

[0128] (4b) Flame area and average temperature of the flame zone Constructing a fire extinguishing effectiveness evaluation index function :

[0129] ;

[0130] in, , These are the weighting coefficients; for The area of ​​the flame at any given moment; for Average temperature of the flame zone at any given time; The sampling interval;

[0131] (4c) Evaluation index function for fire extinguishing effect The controller makes a judgment and, based on the judgment result, controls the vector according to the fire extinguishing parameters. Output the fire extinguishing parameters at time t;

[0132] when When, it indicates the flame area or average temperature of the flame zone The overall trend is upward, and the fire has not been effectively contained. At this time, the spray parameters of the fire extinguishing equipment are dynamically adjusted through the controller to continue fire extinguishing. The spray parameters specifically refer to the foam solution flow rate, gas flow rate, spray gun angle, and spray gun height. When, it indicates the flame area or average temperature of the flame zone The overall trend is downward, the fire extinguishing process is effective, and the fire extinguishing equipment continues to extinguish the fire; when When, it indicates the flame area or average temperature of the flame zone Once the fire has stabilized and dropped below the preset safety threshold, it is determined that the fire is extinguished, and the fire extinguishing equipment stops working.

[0133] Fire Extinguishing Parameter Control Vector Represented as:

[0134] ;

[0135] in, , , These are the proportional, integral, and differential coefficients of the fire extinguishing parameter correction vector, respectively. Evaluation index function for fire extinguishing effectiveness The cumulative integral value within the time interval [0,t]; Evaluation index function for fire extinguishing effectiveness Rate of change over time; For integration variables; The independent variable is time.

[0136] like Figure 2 , Figure 3 The fire extinguishing device shown is based on multi-source sensing and PID closed-loop control. It includes a foam solution tank 2 placed on a movable frame trolley 1, a foam liquid pump 3 connected to the foam solution tank 2, a screw compressor 4, and a gas storage tank 5 connected to the screw compressor 4. It also includes a foam spray gun 6, which is mounted on top of the movable frame trolley 1 via a spray gun bracket 61. The foam liquid pump 3, the gas storage tank 5, and the foam spray gun 6 are connected to a gas-liquid mixing pipe 7 via a first pipe 71, a second pipe 72, and an insulated pipe 73, respectively.

[0137] Furthermore, the first pipeline 71 is equipped with a measuring instrument 711 and a regulating valve 712. The measuring instrument 711 is used to measure the flow rate of the foam solution, and the regulating valve 712 is used to measure the flow rate of the foam solution. The foam liquid pump 3 is used to draw foam solution from the foam solution tank 2 and deliver it to the measuring instrument 711 via the first pipeline 71. After the flow rate of the foam solution is adjusted by the regulating valve 712, it enters the liquid inlet of the gas-liquid mixing pipe 7.

[0138] Furthermore, a gas flow meter 721 is installed on the second pipeline 72. The gas flow meter 721 is used to regulate the compressed gas supply. The screw compressor 4 is connected to the air inlet 51 of the air storage tank 5. The screw compressor 4 is used to generate compressed air. The air storage tank 5 is equipped with a pressure relief valve 52 and a drain outlet 53. The pressure relief valve 52 is used to release gas, and the drain outlet 53 is used to discharge condensate. The compressed air in the air storage tank 5 enters the second pipeline 72 through the air outlet 54, and after passing through the gas flow meter 721, it is delivered to the gas inlet of the gas-liquid mixing pipe 7. It is fully mixed with the foam solution in the gas-liquid mixing pipe 7 to form fine and uniform foam, which is then delivered to the foam spray gun 6 through the heat-insulated pipeline 73 and sprayed out.

[0139] Furthermore, the foam spray gun 6 is connected to the spray gun bracket 61 via a rotating hinge 62, which allows the foam spray gun 6 to rotate and adjust its angle. The spray gun bracket 61 is fixed to the top of the movable frame trolley 1, and its height is adjustable. The adjustable structure of the spray gun bracket 61 can be found in the prior art.

[0140] Furthermore, the foam solution tank 2 is used to store premixed polymer gel foam. The lower part of the foam solution tank 2 is equipped with a stainless steel heating element 21 and a thermocouple temperature sensor 22. The upper part of the foam solution tank 2 is equipped with an LED touch screen display 23. The top of the foam solution tank 2 is equipped with a lid 24, and the bottom is equipped with a drain outlet 25. Specifically, the stainless steel heating element 21 is used to heat the foam solution, controlling the temperature from room temperature to 60℃. The stainless steel heating element 21 has a power of 12KW, and at full power, it can heat 120L of foam solution from room temperature to 60℃ within 45 minutes. The LED touch screen display 23 displays the temperature of the foam solution in the foam solution tank 2 in real time via the thermocouple temperature sensor 22. The drain outlet 25 is used to drain excess foam solution.

[0141] Furthermore, the movable frame vehicle 1 is also equipped with a controller, a camera 81, a temperature sensor 82, a smoke sensor 83, and a heat flow sensor 84. The camera 81, temperature sensor 82, smoke sensor 83, and heat flow sensor 84 form a multi-source sensing system to acquire real-time fire scene image sequences, fire scene temperature data, fire scene heat flow data, and fire scene smoke concentration data. The controller of this invention uses an embedded microprocessor as the core control unit; the microprocessor is an STM32 series chip based on the ARM Cortex-M architecture. Camera 81, temperature sensor 82, smoke sensor 83, and heat flow sensor 84 are connected to the input of the controller via signal acquisition modules to collect real-time fire scene image information and environmental parameters. Simultaneously, gas flow meter 721 and measuring instrument 711 are also connected to the controller's input to obtain real-time flow feedback signals, enabling automatic control and parameter optimization during the fire extinguishing process. The foam liquid pump drive module, screw compressor control module, spray gun control module, and drive control module are embedded within their respective actuators and electrically connected to the controller's output. The controller incorporates a PID closed-loop control mechanism, employing a combination of proportional, integral, and derivative control strategies to construct a closed-loop feedback regulation system. It collects real-time fire scene parameters such as temperature, flame area, smoke concentration, and heat flow, comparing these with set target values ​​or reference values ​​for the next moment to obtain the control error. The controller performs comprehensive calculations based on the proportional, integral, and derivative terms, outputting corresponding control signals to dynamically adjust the foam solution flow rate, gas flow rate, spray gun angle and height, and the direction and speed of the movable frame trolley.

[0142] Example 1: A fire scenario simulating a polar fuel leak in a chemical storage area was studied, using an ethanol pool with a diameter of 0.8 m as the ignition source. 5 L of anhydrous ethanol was added as fuel, and the heat release rate of the ignition source after combustion stabilized was measured. A 420kW heat source was tested, and multiple sensors were deployed around the heat source, including: a SONY FDR-AX45A camera with a resolution of 1920×1080 and a sampling frequency of 50 fps; a K-type thermocouple array with a diameter of 0.5 mm, a range of 0~1300 ℃, with 8 measuring points and a sampling frequency of 1 Hz; a CO sensor with a range of 0~5000 ppm, with 6 measuring points; and an STT-10-100-WT / R type heat flow meter with a range of 0~50 kW / m 2The acquisition cycle is 1 s. Fire source localization is performed through steps (2a) to (2d). The average localization error obtained using only flame area identification is approximately 0.38–0.45 m, with the main sources of error being flame swaying, light reflection, and smoke obstruction. The average localization error corrected by temperature inversion is approximately 0.20–0.26 m, representing an improvement of approximately 40%–48% compared to single fire source localization. The average localization error based on the fusion of image, temperature, and smoke sources is approximately 0.09–0.13 m, representing an improvement of approximately 70%–76% compared to single fire source localization. The critical heat flux threshold for ethanol fire is 4.2–4.8 kW / m³. 2 The minimum safe distance for extinguishing fires is approximately 2.0~2.3 m, and the PID parameters of the distance control vector... , , The fire extinguishing equipment is controlled to move at a speed of 1.5 m / s to a distance of 2.1 m from the final location of the fire source to begin extinguishing the fire. An alcohol-resistant foam extinguishing agent is used, with a foam liquid flow rate of 26–30 L / min and a gas flow rate of 0.32–0.38 m³ / min. 3 / min, spray gun angle 30°~35°, spray gun height 1.2~1.4 m, PID parameters , , Ultimately, complete flame suppression is achieved within 15–19 seconds, reducing extinguishing time by approximately 28%–35% compared to fixed-parameter fire suppression systems.

[0143] Example 2: A 1.0 m diameter n-heptane oil pool fire was used as the research object to simulate a traffic accident fire scenario caused by fuel leakage from a vehicle transporting fuel in an underground tunnel. 8 L of n-heptane was added as fuel, and the heat release rate of the ignition source after combustion stabilized was... A 1.05 MW fire source was monitored by deploying multiple sensors around it, including: a SONY FDR-AX45A camera with a resolution of 1920×1080 and a sampling frequency of 50 fps; a K-type thermocouple array with a diameter of 0.5 mm, a range of 0–1300 ℃, deployed at 8 points, and a sampling frequency of 1 Hz; a CO sensor with a range of 0–5000 ppm, deployed at 6 points; and an STT-10-100-WT / R type heat flow meter with a range of 0–50 kW / m³. 2The acquisition cycle is 1 s. Fire source localization is performed through steps (2a) to (2d). The average localization error of the fire source location obtained solely by identifying the flame area is approximately 0.70–0.80 m. The error mainly stems from factors such as high smoke concentration in the tunnel space, significant flame oscillation, and light reflection. The average localization error corrected by temperature inversion is approximately 0.38–0.45 m, representing an improvement of approximately 42%–48% compared to single fire source localization. The average localization error based on the fusion of image, temperature, and smoke sources is approximately 0.20–0.26 m, representing an improvement of approximately 65%–70% compared to single fire source localization. The critical heat flux threshold for n-heptane fire is 6.6–7.5 kW / m³. 2 The minimum safe distance for extinguishing fires is approximately 3.4–3.8 m, and the PID parameters of the distance control vector are... , , The fire extinguishing equipment is controlled to move at a speed of 0.5 m / s to a distance of 3.6 m from the final location of the fire source to begin extinguishing the fire. An environmentally friendly gel foam extinguishing agent is used, with a foam liquid flow rate of 40–45 L / min and a gas flow rate of 0.55–0.65 m³ / min. 3 / min, spray gun angle 35°~40°, spray gun height 1.1~1.3 m, PID parameters , , Ultimately, complete flame suppression is achieved within 24–28 seconds, reducing extinguishing time by approximately 25%–30% compared to fixed-parameter fire suppression systems.

[0144] Example 3: Taking the thermal runaway of a ternary lithium-ion battery module as the research object, a fire accident scenario of a new energy vehicle occurring in an underground tunnel was simulated. The lithium iron phosphate battery has a capacity of 48 Ah, and the module contains 12 batteries. The heat release rate of the fire source after combustion stabilizes is... A 580kW heat source was tested, and multiple sensors were deployed around the heat source, including: a SONY FDR-AX45A camera with a resolution of 1920×1080 and a sampling frequency of 50 fps; a K-type thermocouple array with a diameter of 0.5 mm, a range of 0–1300 ℃, with 8 measuring points and a sampling frequency of 1 Hz; a CO sensor with a range of 0–5000 ppm, with 6 measuring points; and an STT-10-100-WT / R type heat flow meter with a range of 0–50 kW / m³. 2The acquisition cycle is 1 second. Fire source localization is performed through steps (2a) to (2d). The average localization error of the fire source location obtained solely by identifying the flame area is approximately 0.48–0.55 m, mainly due to factors such as battery flame ejection, smoke obstruction, and changes in illumination. The average localization error corrected by temperature inversion is approximately 0.13–0.18 m, representing an improvement of approximately 65%–72% compared to single-fire-source localization. The average localization error based on the fusion of image, temperature, and smoke sources is approximately 0.10–0.13 m, representing an improvement of approximately 74%–78% compared to single-fire-source localization. The critical heat flux threshold for a power battery fire is 5.0–5.7 kW / m³. 2 The minimum safe distance for extinguishing fires is approximately 2.5–2.9 m. The PID parameters for the distance control vector... , , The fire extinguishing equipment is controlled to move at a speed of 1.2 m / s to a position 2.7 m from the final location of the fire source to begin extinguishing the fire. An environmentally friendly gel foam extinguishing agent is used, with a foam liquid flow rate of 16–20 L / min and a gas flow rate of 0.22–0.30 m³ / min. 3 / min, spray gun angle -15° to -25°, spray gun height 1.6 to 2.0 m, PID parameters , , Ultimately, flame suppression is achieved within 20–24 seconds, effectively reducing the battery surface temperature. Compared to fixed-parameter fire extinguishing systems, the extinguishing time is shortened by approximately 30%–35%.

[0145] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An intelligent fire extinguishing method based on multi-source sensing and PID closed-loop control, characterized in that: The method includes the following steps in sequence: (1) Real-time acquisition of multi-source fire information, including fire image sequences, fire temperature data, fire smoke concentration data and fire heat flow data; (2) Identification of flame region sets based on fire scene image sequences and based on the fire zone set Spatial location of the fire scene to obtain the initial location of the fire source. Then, by using fire temperature data and fire smoke concentration data, the initial location of the fire source can be determined. Multi-source information fusion and correction were performed to obtain the final location of the fire source. ; (3) Calculate the intensity of thermal disaster at the fire site based on fire heat flow data According to the intensity of thermal disaster Calculate the final location of fire extinguishing equipment and fire source Minimum safe fire extinguishing distance between Then, through the final location of the fire source and minimum safe fire extinguishing distance Constructing the distance control error function ,when At this time, it indicates the current location of the fire extinguishing equipment and the minimum safe fire extinguishing distance. If a distance deviation exists, the controller will use the distance control vector. Calculate the optimal travel path and control the fire extinguishing equipment to move autonomously; when This indicates that the fire extinguishing equipment has reached the minimum safe fire extinguishing distance. The controller will then activate the fire extinguishing equipment to target the final location of the fire source. Extinguish the fire and proceed to the next step; (4) Based on flame region set Calculate the flame area and average temperature of the flame zone and through the flame area and average temperature of the flame zone Constructing a fire extinguishing effectiveness evaluation index function ;when When, it indicates the flame area or average temperature of the flame zone If changes still occur and the fire is determined not to be completely extinguished, the controller will control the vector through the fire extinguishing parameters. Adjust the spray parameters of the fire extinguishing equipment to continuously extinguish the fire; when When, it indicates the flame area or average temperature of the flame zone The situation has stabilized, the fire has been determined to be extinguished, and firefighting efforts have ceased.

2. The intelligent fire extinguishing method based on multi-source sensing and PID closed-loop control according to claim 1, characterized in that: In step (1), the fire scene environment is captured in real time by a camera to obtain a sequence of fire scene images; the fire scene temperature data is obtained by a temperature sensor; the fire scene smoke concentration data is obtained by a smoke sensor; and the fire scene heat flow data is obtained by a heat flow sensor.

3. The intelligent fire extinguishing method based on multi-source sensing and PID closed-loop control according to claim 1, characterized in that: Step (2) specifically includes the following steps: (2a) Perform flame region identification on the fire scene image sequence acquired at time t to obtain the set of flame regions. : ； ； in, Located in spatial coordinates The flame feature determination value of the pixel at time t. , , These are the spatial coordinates of the fire scene image sequence. The red, green, and blue channel pixel values ​​of the pixel at time t; Spatial coordinates of the fire scene image sequence The brightness value of the pixel at time t; The maximum brightness value in the fire scene image sequence; , These are the weighting coefficients; The flame detection threshold; when At that time, determine the location in spatial coordinates The pixels belong to the flame area; (2b) Group the flame areas Flame centroid image coordinates Mapping to a spatial coordinate system, obtain the initial position of the fire source. : ； in, As a scale factor, For the camera intrinsic parameter matrix, For extrinsic rotation matrix, It is a translation vector. is the coordinate in the three-dimensional space of the fire source, and 1 is the homogeneous coordinate; (2c) By constructing the initial location of the fire source The mapping relationship between the data and the distribution of fire temperature data indicates the initial location of the fire source. To correct for errors caused by obstruction, reflection, or changes in lighting, the formula for calculating the fire source location at time t based on fire temperature data can be expressed as: ； in, Let N be the location of the fire source at time t based on fire temperature data, and N be the number of temperature sensors. Let be the measured temperature of the i-th temperature sensor. To predict temperature values, For the temperature data of the i-th temperature sensor, U is the heat release rate of the fire source, U is the ambient ventilation speed, and T is the temperature measured by the temperature sensor. Simultaneously, calculate the temperature spatial gradient. By utilizing the extreme points of the temperature spatial gradient and their variation over time, the location of the fire source can be determined. Perform inversion dynamic correction: ； ； ； in, This indicates the location of the fire source at time t, after dynamic correction based on fire temperature data. This indicates the step size factor for temperature location correction; This represents the rate of change of temperature along the x-direction; This represents the rate of change of temperature along the y-direction; This represents the rate of change of temperature along the z-direction; This represents the magnitude of the temperature spatial gradient, used to eliminate the influence of the magnitude of the temperature spatial gradient and retain only the direction information. (2d) By constructing The mapping relationship between the data and the smoke concentration data at the fire scene is crucial for... Further corrections were made to obtain the data based on the smoke concentration at time t. Location of the fire ; ； Where M represents the number of flue gas sensors. Let be the measured concentration of the j-th flue gas sensor. To predict the concentration value, S is the flue gas concentration measured by the flue gas sensor; Simultaneously, the spatial gradient of the fire smoke concentration data is calculated, and the gradient extreme points and their time-varying characteristics are utilized to... By performing inversion dynamic correction, the final location of the fire source at time t is obtained after inversion dynamic correction based on fire temperature data and fire smoke concentration data. ; ； ； ； in, This indicates the step size factor for correcting the location of flue gas concentration. Represents the spatial gradient of flue gas concentration; This represents the rate of change of flue gas concentration along the x-direction; This represents the rate of change of flue gas concentration along the y-direction; This represents the rate of change of flue gas concentration along the z-direction; This represents the spatial gradient magnitude of flue gas concentration, used to eliminate the influence of the magnitude of the flue gas concentration gradient and retain only the directional information.

4. The intelligent fire extinguishing method based on multi-source sensing and PID closed-loop control according to claim 1, characterized in that: Step (3) includes the following steps: (3a) Calculate the intensity of thermal disaster based on fire heat flow data Determine the minimum safe fire extinguishing distance : ； ； in, The critical heat flux threshold, The data represents radiative heat flux collected by a heat flux sensor. The convective heat flow received by the surface of the fire extinguishing equipment. Radiation fraction, The rate of heat release from the ignition source. The distance from the center of the fire to the fire extinguishing equipment. The angle between the height of the fire source center and the horizontal plane, and h is the convective heat transfer coefficient. The temperature at the fire scene, Ambient temperature; (3b) Based on the final location of the fire source and minimum safe fire extinguishing distance Constructing the distance control error function : ； (3c) Distance control error function The controller makes a judgment and, based on the judgment result, uses the distance control vector... Output the motion control command at time t; when When this occurs, it indicates that the fire extinguishing equipment has a safe redundancy distance, and the controller uses the distance control vector. Output a movement command to direct the fire extinguishing equipment to the final location of the fire source. Move in direction until Stop moving when; At this time, it indicates the final location of the fire extinguishing equipment from the fire source. At close range, within a dangerous distance, the controller uses distance control vectors. Output a movement command to move the fire extinguishing equipment to a final location away from the fire source. Move in direction until Stop moving when; This indicates that the fire extinguishing equipment has reached the minimum safe fire extinguishing distance. At the optimal fire extinguishing distance, the controller activates the fire extinguishing equipment to target the final location of the fire source. Extinguish the fire; Distance control vector Represented as: ； in, , , These are the proportional, integral, and derivative coefficients of the control vector, respectively. The integral value of the distance error between the final location of the fire source and the fire extinguishing equipment over the time interval [0, t]; The rate of change of error over time; In time Distance error at any given time; For integration variables; The independent variable is time.

5. The intelligent fire extinguishing method based on multi-source sensing and PID closed-loop control according to claim 1, characterized in that: Step (4) includes the following steps: (4a) Based on fire zone set Calculate the flame area and average temperature of the flame zone : ； ； Where s is the spatial coordinate The area value corresponding to each pixel; This represents the number of pixels in the flame area. Spatial coordinates The temperature value of the pixel at time t; (4b) Flame area and average temperature of the flame zone Constructing a fire extinguishing effectiveness evaluation index function : ； in, , These are the weighting coefficients; for The area of ​​the flame at any given moment; for Average temperature of the flame zone at any given time; The sampling interval; (4c) Evaluation index function for fire extinguishing effect The controller makes a judgment and, based on the judgment result, controls the vector according to the fire extinguishing parameters. Output the fire extinguishing parameters at time t; when When, it indicates the flame area or average temperature of the flame zone The overall trend is upward, and the fire has not been effectively contained. At this time, the spray parameters of the fire extinguishing equipment are dynamically adjusted through the controller to continue fire extinguishing. The spray parameters specifically refer to the foam solution flow rate, gas flow rate, spray gun angle, and spray gun height. When, it indicates the flame area or average temperature of the flame zone The overall trend is downward, the fire extinguishing process is effective, and the fire extinguishing equipment continues to extinguish the fire; when When, it indicates the flame area or average temperature of the flame zone Once the fire has stabilized and dropped below the preset safety threshold, it is determined that the fire is extinguished, and the fire extinguishing equipment stops working. Fire Extinguishing Parameter Control Vector Represented as: ； in, , , These are the proportional, integral, and differential coefficients of the fire extinguishing parameter correction vector, respectively. Evaluation index function for fire extinguishing effectiveness The cumulative integral value within the time interval [0,t]; Evaluation index function for fire extinguishing effectiveness Rate of change over time; For integration variables; The independent variable is time.

6. The fire extinguishing device based on multi-source sensing and PID closed-loop control as described in any one of claims 1 to 5, characterized in that: The system includes a foam solution tank (2) placed on a movable frame trolley (1), a foam liquid pump (3) connected to the foam solution tank (2), a screw compressor (4), and a gas storage tank (5) connected to the screw compressor (4). It also includes a foam spray gun (6) and a spray gun bracket (61) set on the top of the movable frame trolley (1). The foam liquid pump (3), the gas storage tank (5), and the foam spray gun (6) are connected to the gas-liquid mixing pipe (7) through a first pipeline (71), a second pipeline (72), and a heat insulation pipeline (73), respectively. The first pipeline (71) is equipped with a measuring instrument (711) and a regulating valve (712), and the second pipeline (72) is equipped with a gas flow meter (721). The movable frame trolley (1) is also equipped with a controller, a camera (81), a temperature sensor (82), a flue gas sensor (83), and a heat flow sensor (84).

7. The fire extinguishing device based on multi-source sensing and PID closed-loop control according to claim 6, characterized in that: The controller uses an embedded microprocessor as the core control unit. The microprocessor is an STM32 series chip based on the ARM Cortex-M architecture. The camera (81), temperature sensor (82), flue gas sensor (83), and heat flow sensor (84) are connected to the input terminal of the controller through a signal acquisition module. The gas flow meter (721) and measuring instrument (711) are connected to the input terminal of the controller. The output terminal of the controller is electrically connected to the foam liquid pump drive module, screw compressor control module, spray gun control module, and the drive control module of the movable frame trolley.

8. The fire extinguishing device based on multi-source sensing and PID closed-loop control according to claim 6, characterized in that: The foam spray gun (6) is connected to the spray gun bracket (61) via a rotating hinge (62). The spray gun bracket (61) is fixed on the top of the movable frame trolley (1) and the height of the spray gun bracket (61) is adjustable.

9. The device based on multi-source sensing and PID closed-loop control according to claim 6, characterized in that: The lower part of the foam solution tank (2) is provided with a stainless steel heating tube (21) and a thermocouple temperature sensor (22). The upper part of the foam solution tank (2) is provided with an LED touch screen (23). The top of the foam solution tank (2) is provided with a tank cover (24) and the bottom is provided with a drain outlet (25). The foam liquid pump (3) is used to draw foam liquid from the foam solution tank (2) and deliver it to the measuring instrument (711) through the first pipeline (71). After the foam liquid flow rate is adjusted by the regulating valve (712), it enters the liquid inlet of the gas-liquid mixing pipe (7).

10. The device based on multi-source sensing and PID closed-loop control according to claim 6, characterized in that: The screw compressor (4) is connected to the air inlet (51) of the air storage tank (5). The air storage tank (5) is equipped with a pressure relief valve (52) and a drain outlet (53). The compressed air in the air storage tank (5) enters the second pipeline (72) through the air outlet (54), and is then transported to the gas inlet of the gas-liquid mixing pipe (7) after passing through the gas flow meter (721), where it mixes with the foam liquid in the gas-liquid mixing pipe (7).

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