Forest fire simulation monitoring method and system

Abstract

The present application belongs to the technical field of forest fire research, and specifically discloses a forest fire simulation monitoring method and system. The method divides multiple forest fire simulation areas, determines the area where the ignition point is located as a target area; uses a UAV to carry a Fourier infrared spectrometer to collect spectral images in the target area; compares the spectral images with the spectral bands generated by the combustion of existing combustion products to determine the types of combustion products in the target area; based on the spectral images in the target area and the corresponding combustion product types, a flame spectral radiation model is constructed; multiple forest fire danger levels and the corresponding flame spectral radiation ranges of each forest fire danger level are set in advance, and the flame spectral radiation parameters output by the flame spectral radiation model are compared with all flame spectral radiation ranges to determine the forest fire danger level of the target area. By using the flame spectral radiation model, the present application realizes accurate detection and identification of forest fires.

Description

Technical Field

[0001] This invention belongs to the field of forest fire research technology and relates to a forest fire simulation monitoring method and system. Background Technology

[0002] Forest fires are a global natural disaster, characterized by their rapid spread, difficulty in control, and challenges in extinguishing. With climate change, forest fires are occurring more frequently, severely impacting the ecological environment and human safety, threatening lives and property, and posing significant challenges to economic development and firefighting efforts. Therefore, effective monitoring of forest fires is of paramount practical importance. Digital simulation methods are commonly used to simulate the spread of forest fires in the monitored area and present the fire's development trend through a visual interface. Based on the simulation results, fire risk assessments, fire suppression decision evaluations, and forest fire safety design are then conducted.

[0003] Forest fires, caused by burning vegetation, produce specific spectral signals and image data. Utilizing technologies such as satellite remote sensing imagery can improve the efficiency and accuracy of fire detection. However, while satellite remote sensing imagery covers a wide area, its accuracy is relatively low. Furthermore, it is affected by factors such as clouds, atmospheric interference, and time intervals, leading to data gaps or delays, which hinders accurate data acquisition. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for simulating and monitoring forest fires, so as to achieve accurate detection and identification of forest fires.

[0005] To achieve the above objectives, the basic solution of the present invention is: a forest fire simulation monitoring method, comprising the following steps:

[0006] Multiple forest fire simulation zones were divided, and the area where the fire ignition point was located was identified as the target area.

[0007] A drone equipped with a Fourier transform infrared spectrometer was used to collect spectral images of the target area.

[0008] By comparing the spectral image with the spectral bands generated by the combustion of existing combustion products, the types of combustion products in the target area can be determined.

[0009] A flame spectral radiation model is constructed based on the spectral images of the target area and the corresponding combustion product types.

[0010] Multiple forest fire hazard levels and the corresponding flame spectral radiation ranges for each forest fire hazard level are pre-set. The flame spectral radiation parameters output by the flame spectral radiation model are compared with all flame spectral radiation ranges to determine the forest fire hazard level of the target area.

[0011] The working principle and beneficial effects of this basic scheme are as follows: It utilizes a Fourier transform infrared spectrometer to acquire spectral information and determine the types of combustion products from forest fires, enabling targeted subsequent firefighting deployment. Furthermore, it constructs a flame spectral radiation model to invert the concentration of combustion products from forest fires and sets forest fire hazard levels, allowing for rapid response to forest fire risks and achieving accurate detection and identification of forest fires.

[0012] Furthermore, the method for constructing a flame spectral radiation model is as follows:

[0013] The interior of a forest fire flame is divided into n thermodynamic equilibrium regions, and the spectral radiation intensity value of region n is:

[0014] I v(n) =I′ v(n) τ v(n+1) τ v(n+2) ...τ v(6)

[0015] Among them, I v(n) τ is the spectral radiance value of region n. v(n) Let I′ be the combustion product permeability at region n. v(n) It is the spectral radiation intensity value at region n that does not penetrate other flame regions;

[0016] Overall spectral radiance value I v for:

[0017] I v =I v(1) +I v(2) +…+I v(n)

[0018] When the gas is in thermodynamic equilibrium, the total radiative transfer of the flame is:

[0019] I v =I b (v,T)α(v)=I b (v,T){1-exp[-ds·P·∑k i (v)·χ i ]}

[0020] Among them, I v It is the spectral radiance, I b (v,T) represents the blackbody radiation intensity under wavenumber v and temperature T; ds is the length of the gas element, P is the gas pressure, and k is the gas pressure. i (v) is the absorption coefficient of component i at wavenumber v; χ i Let be the concentration of component i; α(v) be the emissivity of gas molecules at wavenumber v;

[0021] A spectral model is constructed based on the overall radiative transfer of the flame when the gas is in thermodynamic equilibrium and the spectral bands generated by the combustion of existing combustion products.

[0022] The concentration and temperature data of combustion products during combustion in each thermodynamic equilibrium region of the flame are averaged and then input into the spectral model. The flame radiation spectrum is calculated using the line-by-line method.

[0023] Based on the internal response function and resolution of the spectral model, convolution operation is performed on the flame radiation spectrum calculation results to obtain the flame spectral radiation model.

[0024] It is simple to operate and easy to use.

[0025] Furthermore, the drone carries a camera module to collect aerial and ground image information of the target area. The aerial image information includes vegetation density, vegetation type, and smoke concentration information, while the ground image information includes terrain, slope, and ground elevation.

[0026] A digital surface model is constructed based on aerial and ground image information.

[0027] Digital surface models can reflect changes in topography and altitude before and after a fire, analyze the impact of fire on forest vegetation, provide important reference for post-fire recovery and reconstruction, and also provide reference and support for future forest management and protection.

[0028] The present invention also provides a forest fire simulation monitoring system based on the method described in the present invention, including a simulation room, wherein the simulation room is equipped with a forest vegetation status simulation system, a temperature, humidity and wind speed control system, a solar light source simulation system, an image monitoring system, an ignition mechanism and a fire-fighting mechanism;

[0029] The forest vegetation state simulation system includes a soil layer, vegetation on the soil layer, and a hydraulic mechanism for controlling the tilt angle of the soil layer.

[0030] The temperature, humidity and wind speed control system includes an air supply mechanism, a temperature sensor, a humidity sensor, an air conditioner, and a humidifier;

[0031] The solar light source simulation system includes an LED light source and an LED light source controller installed outdoors in the simulation room;

[0032] The image monitoring system includes a drone, as well as a Fourier transform infrared spectrometer and a camera module mounted on the drone;

[0033] The ignition and fire-fighting mechanisms are set up in various forest fire simulation areas within the simulation room to carry out ignition and fire-fighting within the areas.

[0034] The system simulates environmental data such as soil, vegetation, sunlight, temperature, humidity, and natural wind, making the simulated forest fire situation more realistic, the acquired data more accurate, and easier to use.

[0035] Furthermore, it also includes a slide rail mechanism, which includes a circular track and a movable component that slides around the circular track. The circular track is set on the inner wall of the simulation chamber, and a camera is mounted on the movable component, with the camera lens facing downwards from the simulation chamber.

[0036] The camera is set to move along a circular track, which can collect images of the circumference of the simulated indoor space, or collect images of a specific location within the simulated indoor space. The structure is simple and meets the usage requirements.

[0037] Furthermore, it also includes an exhaust gas collection mechanism, the input end of which is connected to the output end of the air supply mechanism.

[0038] By using exhaust gas collection devices, exhaust gases generated during simulated forest fires can be collected to avoid environmental pollution. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the forest fire simulation monitoring system of the present invention.

[0040] The reference numerals in the accompanying drawings include: slide rail 1, exhaust gas collection mechanism 2, fire-fighting mechanism 3, drone 4, moving part 5, camera 6, humidity sensor 7, air supply mechanism 8, temperature sensor 9, LED light source 10, simulation room entrance 11, forest vegetation status simulation system 12, vegetation 13, Fourier transform infrared spectrometer 14, camera module 15, hydraulic mechanism 16, soil layer 17, air conditioner 18, humidifier 19, fan 20, data receiving terminal 21, control panel of temperature, humidity and wind speed control system 22, LED light source control button 23, simulation room 24, control room 25. Detailed Implementation

[0041] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0042] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0043] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0044] This invention discloses a method for simulating and monitoring forest fires, comprising the following steps:

[0045] Multiple forest fire simulation zones were divided, and the area where the fire ignition point was located was identified as the target area.

[0046] By using a drone equipped with a Fourier transform infrared spectrometer, spectral images of the target area can be collected. Using a Fourier transform infrared spectrometer for detection can quickly acquire a large amount of spectral data and has the characteristics of high precision and high sensitivity, which can improve the quality and accuracy of the signal.

[0047] By comparing spectral images with the spectral bands (spectral feature library) generated by the combustion of existing combustion products, the types of combustion products in the target area can be determined. Different types of combustion products will produce different feature signals in different spectral bands. These feature signals are used to distinguish different types of combustion products, thereby improving the efficiency of fire monitoring and control.

[0048] Based on the spectral images of the target area and the corresponding types of combustion products, a flame spectral radiation model is constructed to invert the concentration and temperature data of forest fire combustion products. The flame spectral model is established based on the detected spectral data and the corresponding chemical composition data, and can invert the concentration distribution of forest fire combustion products.

[0049] Multiple forest fire hazard levels and the corresponding flame spectral radiation ranges for each forest fire hazard level are pre-set. The flame spectral radiation parameters output by the flame spectral radiation model are compared with all flame spectral radiation ranges to determine the forest fire hazard level of the target area.

[0050] In a preferred embodiment of the present invention, the method for constructing a flame spectral radiation model is as follows:

[0051] The interior of a forest fire flame is divided into n thermodynamic equilibrium regions, and the spectral radiation intensity value of region n is:

[0052] I v(n) =I′ v(n) τ v(n+1) τ v(n+2) ...τ v(6)

[0053] Among them, I v(n) τ is the spectral radiance value of region n. v(n) Let I′ be the combustion product permeability at region n. v(n) It is the spectral radiation intensity value at region n that does not penetrate other flame regions;

[0054] Overall spectral radiance value I v for:

[0055] I v =I v(1) +I v(2) +…+I v(n)

[0056] When the gas is in thermodynamic equilibrium, the total radiative transfer of the flame is:

[0057] I v =I b (v,T)α(v)=I b (v,T){1-exp[-ds·P·∑k i (v)·χ i ]}

[0058] Among them, I v It is the spectral radiance, I b (v,T) represents the blackbody radiation intensity under wavenumber v and temperature T; ds is the length of the gas element, P is the gas pressure, and k is the gas pressure. i (v) is the absorption coefficient of component i at wavenumber v; χ i Let be the concentration of component i; α(v) be the emissivity of gas molecules at wavenumber v;

[0059] A spectral model is constructed based on the overall radiative transfer of the flame when the gas is in thermodynamic equilibrium and the spectral bands generated by the combustion of existing combustion products.

[0060] The concentration and temperature data of combustion products during combustion in each thermodynamic equilibrium region of the flame are averaged and then input into the spectral model. The flame radiation spectrum is calculated using the line-by-line method.

[0061] Based on the adaptation of the internal response function and resolution of the spectral model, convolution operations are performed on the calculated flame radiation spectrum to obtain the flame spectral radiation model. The higher the accuracy of the flame spectral radiation model, the higher the resolution of the flame radiation spectrum data, and the more accurate the obtained combustion product concentration data.

[0062] In a preferred embodiment of the present invention, an aerial image and a ground image of the target area are collected by a camera module mounted on a drone. The aerial image includes vegetation density, vegetation type and smoke concentration information, and the ground image includes terrain, slope and ground height.

[0063] Based on aerial and ground image information, images from different sources, resolutions, and angles are registered. The aerial and ground images are then fused to obtain a composite image. Feature extraction and image segmentation are performed on the composite image to generate a triangular mesh, which covers the entire digital surface model. The elevation value of each pixel is calculated using the triangular mesh and the elevation information of pixels within each triangle, thus obtaining the digital surface model. Post-processing is then applied to the generated digital surface model, including outlier removal, hole filling, and smoothing.

[0064] Digital surface models (DSMs) are obtained by integrating elevation information of objects such as soil layers and vegetation. They can reflect the changes in topography and height before and after a fire, analyze the impact of fire on forest vegetation, provide important references for post-fire recovery and reconstruction, and also provide references and support for future forest management and protection.

[0065] This invention also provides a forest fire simulation and monitoring system based on the method described in this invention, such as... Figure 1 As shown, the system includes a simulation room 24, with an entrance 11 on one side. A control room 25 is located outside the simulation room 24. Inside the control room 25, a data receiving terminal 21 (such as a computer terminal), a control panel 22 for a temperature, humidity, and wind speed control system, and LED light source control buttons 23 can be installed. The simulation room 24 contains a forest vegetation state simulation system 12, a temperature, humidity, and wind speed control system, a solar LED light source simulation system 10, an image monitoring system, an ignition mechanism, and a fire-fighting mechanism 3.

[0066] The forest vegetation state simulation system 12 is set at the bottom of the simulation chamber 24. The forest vegetation state simulation system 12 includes a soil layer 17, vegetation 13 (such as grassland, dry leaves, shrubs, trees, etc.) set on the soil layer 17, and a hydraulic mechanism 16 for controlling the tilt angle of the soil layer 17. The bottom of the soil layer 17 can be supported by a bearing plate or other structure.

[0067] The temperature, humidity, and wind speed control system includes an air supply mechanism 8, a temperature sensor 9, a humidity sensor 7, an air conditioner 18, and a humidifier 19. The air supply mechanism 8 can use a fan 20, ducts, etc., to supply air into the simulation chamber 24 to simulate the natural wind conditions of a forest. The air vents of the ducts of the air supply mechanism 8 are evenly distributed throughout the simulation chamber 24, enabling air supply from all directions. The air conditioner 18 and the humidifier 19 are evenly distributed around the area where the vegetation 13 is located within the simulation chamber 24. The temperature sensor 9 and the humidity sensor 7 can be fixedly installed (e.g., welded, glued, etc.) on the inner wall of the simulation chamber 24 or among the vegetation 13 within the simulation chamber 24.

[0068] The solar LED light source 10 simulation system includes an LED light source 10 and an LED light source 10 controller located outside the simulation chamber 24. The LED light source 10 controller can be a control button or other control panel. The LED light source 10 can be mounted on the top of the simulation chamber 24 or other locations using a omnidirectional rotating gimbal. The image monitoring system includes a drone 4, and a Fourier transform infrared spectrometer 14 and a camera module 15 mounted on the drone 4. The camera module 15 can be a high-definition camera. Ignition and fire-fighting mechanisms 3 are located in various forest fire simulation areas within the simulation chamber 24 for ignition and fire-fighting within the areas. The ignition mechanism uses a circuit-controlled igniter to ignite simulated fire sources (such as excessively dry vegetation 13 ignited by strong sunlight, cigarette butts, and other combustibles) within the simulation chamber 24 to simulate forest fires. The fire-fighting mechanism 3 includes sprinkler equipment, with sprinkler heads evenly installed throughout the simulation chamber 24 to meet fire-fighting requirements.

[0069] During the forest fire simulation, the conditions of the soil layer 17, the target combustible material, and the required vegetation 13 are determined. The target combustible material is placed on top of the soil layer 17 as the vegetation to be burned 13. The combustion environment is then adjusted, and the temperature and humidity readings are observed. The air conditioner 18 is turned on, and the humidifier 19 is turned on or the air conditioner 18 is used for dehumidification and drying according to the required humidity. The hydraulic mechanism 16 is adjusted to determine the slope of the simulated forest. The air supply mechanism 8 is adjusted in terms of airflow direction and speed, and is activated to ensure that the vegetation 13 burns under oxygen-rich conditions.

[0070] Turn on LED light source 10 and adjust its position and illumination angle. Adjust the wavelength of LED light source 10 to the required solar wavelength and select the desired solar power. Then, turn on drone 4 and hover it at a suitable position above vegetation 13. Turn on Fourier transform infrared spectrometer 14 and adjust its resolution, cumulative scan, and wavenumber interval. Turn on high-definition camera, adjust its angle and position, and use a data processing computer to observe, record, and store real-time image and spectral data.

[0071] Once combustion begins, temperature and humidity changes are monitored in real time. Temperature, humidity, and wind speed can also be adjusted during combustion, and the shape and size of the flames should be constantly observed. If the flames become too large to control, fire suppression system 3 can be activated for fire extinguishing.

[0072] In a preferred embodiment of the present invention, the forest fire simulation monitoring system further includes a slide rail mechanism 1. The slide rail mechanism 1 includes a circular track and a movable component 5 that slides around the circular track. The circular track is set on the inner wall of the simulation chamber 24. A camera 6 is mounted on the movable component 5, with the lens of the camera 6 facing downwards from the simulation chamber 24. An LED light source 10 can also be mounted on the movable component 5 for position adjustment. The movable component 5 is a trolley controlled by a conventional power source (such as a motor). A button can also be installed on the trolley, with its output electrically connected to the control terminal of the power source for start and stop control of the trolley. The camera 6 moves along the circular track, allowing for the acquisition of circumferential image information within the simulation chamber 24, as well as fixed-point image information at a specific location within the simulation chamber 24. The structure is simple and meets the usage requirements.

[0073] In a preferred embodiment of the present invention, the forest fire simulation monitoring system further includes an exhaust gas collection mechanism 2, the input end of which is connected to the output end of the air supply mechanism 8. The exhaust gas collection mechanism 2 includes an exhaust fan 20 and a purifier. The exhaust fan 20 is connected to the simulation chamber 24 via an air pipe, and then connected to the purifier via another air pipe. This allows for exhaust gas extraction and purification. During ignition, the exhaust gas absorption mechanism must be activated to remove the exhaust gas. After combustion, the exhaust gas absorption mechanism and the air supply mechanism 8 must continue to operate for 5-10 minutes to fully ventilate the combustion chamber. Only after sufficient ventilation can the exhaust gas enter the combustion chamber. The exhaust gas collection mechanism 2 collects the exhaust gas generated during the forest fire simulation, preventing environmental pollution.

[0074] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0075] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A forest fire simulation monitoring method characterized by, The method comprises the following steps: dividing a plurality of forest fire simulation areas, determining a region where a fire point is located as a target region; using a UAV to carry a Fourier infrared spectrometer to collect spectral images in the target region; comparing the spectral images with spectral bands generated by existing combustion products, to determine the types of combustion products in the target region; based on the spectral images in the target region and the corresponding types of combustion products, constructing a flame spectral radiation model; pre-setting a plurality of forest fire danger levels and corresponding flame spectral radiation ranges, comparing flame spectral radiation parameters output by the flame spectral radiation model with all flame spectral radiation ranges, to determine the forest fire danger level of the target region; using a camera module carried by the UAV to collect aerial image information and ground image information of the target region, the aerial image information including vegetation density, vegetation type and smoke concentration information, and the ground image information including terrain, slope and ground height; constructing a digital surface model according to the aerial image information and the ground image information; registering images of different sources, resolutions and angles, fusing the aerial image and the ground image to obtain a comprehensive image; performing feature extraction and image segmentation on the comprehensive image to generate a triangular mesh, i.e. covering the entire digital surface model with a triangular mesh; calculating the elevation value of each pixel point through the triangular mesh and the elevation information of the pixels in each triangle, to obtain the digital surface model.

2. The forest fire simulation monitoring method according to claim 1, wherein, The method for constructing the flame spectral radiation model is as follows: dividing the flame inside the forest fire into six thermodynamic equilibrium regions, the spectral radiation intensity value of region n being: ， wherein is the spectral radiance value of region n, is the transmissivity of the combustion products at region n, is the spectral radiance value at region n not passing through other flame regions; Spectral overall intensity value is: ， when the gas is in a thermodynamic equilibrium state, the overall flame radiation transmission is: ， wherein is the blackbody radiation intensity at wave number and temperature T; ds is the length of the gas element, and P is the gas pressure, is the absorption coefficient of the i component at wave number v; is the concentration of the i component; is the concentration of the i component; is the emissivity of the gas molecules at wave number v; and is the emissivity of the gas molecules at wave number v; and constructing a spectral model according to the overall flame radiation transmission when the gas is in a thermodynamic equilibrium state and the spectral bands generated by the combustion of existing combustion products; averaging the concentration and temperature data of the combustion products when each thermodynamic equilibrium region of the flame burns, and substituting the data into the spectral model to calculate the flame radiation spectrum by using the line-by-line method; convolving the calculation results of the flame radiation spectrum based on the spectral model adaptation of the internal response function and the resolution, to obtain the flame spectral radiation model.

3. A forest fire simulation monitoring system based on the method of claim 1 or 2, characterized by The simulation chamber is provided with a forest vegetation state simulation system, a temperature and humidity and wind speed control system, a sunlight source simulation system, an image monitoring system, an ignition mechanism and a fire-fighting mechanism. The forest vegetation state simulation system comprises a soil layer, vegetation arranged on the soil layer, and a hydraulic mechanism for controlling the inclination angle of the soil layer. The temperature and humidity and wind speed control system comprises a blower mechanism, a temperature sensor, a humidity sensor, an air conditioner and a humidifier. The sunlight source simulation system comprises an LED light source and an LED light source controller arranged outside the simulation chamber. The image monitoring system comprises a UAV, and a Fourier infrared spectrometer and a camera module arranged on the UAV. The ignition mechanism and the fire-fighting mechanism are arranged in each forest fire simulation area in the simulation chamber to ignite and fight fires in the area.

4. The forest fire simulation monitoring system of claim 3, wherein, The device also comprises a sliding rail mechanism, which comprises a ring-shaped rail and a moving part sliding around the ring-shaped rail, the ring-shaped rail is arranged on the inner wall of the simulation chamber, and a camera is arranged on the moving part, and the lens of the camera faces downward.

5. The forest fire simulation monitoring system of claim 3, wherein, The device also comprises a tail gas collecting mechanism, and the input end of the tail gas collecting mechanism is connected with the output end of the air supply mechanism.

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