Forest fire rapid positioning method

Abstract

The invention belongs to the technical field of video monitoring, and particularly relates to a forest fire rapid positioning method, which comprises the following steps of S1, determining angle information of a fire point relative to a spherical coordinate system of monitoring equipment; s2, calculating a linear distance between the fire point and a monitoring equipment mounting ground point; and S3, calculating latitude and longitude information of the fire point. The fire root is automatically determined according to the fire point image area, the fire latitude and longitude coordinates are calculated, manual operation is not needed, and the operation process is simplified. According to the method, the fire point projection coordinates are calculated through digital elevation information without professional tools such as GIS, the calculation process is simplified, and calculation is simple. Complex calculation and storage resources are not needed, the method can be completed on monitoring equipment, the cost of the whole system is saved, and the fire disaster is rapidly positioned.

Description

Technical Field

[0001] The invention belongs to the technical field of video monitoring, and in particular relates to a method for quickly locating a forest fire. Background Art

[0002] The forest fire positioning system plays a vital role in the emergency response and firefighting process of forest fires. The forest fire positioning system can quickly determine the specific location of the fire, providing accurate spatial coordinates for fire fighting command. This information is crucial for quickly mobilizing firefighting forces and planning the shortest rescue route. Commanders can quickly deploy firefighting teams, rescue materials and monitoring equipment based on the real-time location of the fire to ensure that the firefighting forces can reach the fire scene as quickly as possible, effectively shorten the response time, and win precious time for initial fire fighting.

[0003] Most of the current forest fire location methods first control the forest fire prevention video monitoring equipment, align the camera optical axis with the fire point, obtain the deflection angle of the optical axis, the longitude and latitude of the monitoring equipment, and the installation height information, and calculate the fire point location by combining the GIS engine and the DEM data of the monitoring area of ​​the monitoring equipment. The method of combining GIS with DEM data to achieve fire location is complex in calculation and cannot be implemented in forest fire prevention video monitoring equipment. It needs to be deployed on the back-end platform, which increases the implementation cost of the project.

[0004] Chinese patent CN112330917A discloses a "method, device and system for locating a fire point". This method obtains an infrared image of the area monitored by a thermal imaging camera, and obtains the longitude and latitude information of the location of the thermal imaging camera; obtains the coordinate information of the fire point in the infrared image; and determines the longitude and latitude information of the fire point based on the longitude and latitude information of the camera location and the fire point coordinate information. This method calculates the fire point location based on the ratio of the fire point pixel coordinates to the image size. When used for visible light images, the error is large as the field of view changes, affecting the accuracy of fire point positioning.

[0005] Chinese patent CN118967804A discloses "a method, device, equipment and storage medium for locating a fire point based on a monocular camera". This method controls the optical axis of the camera to align with the fire point based on the location information of the fire point, and then calculates the longitude and latitude information of the fire point based on the deflection angle corresponding to the optical axis of the camera, the digital elevation information of the monocular camera and the projection position of the fire point in the world coordinate system. This method requires controlling the camera so that the fire point is located at the center of the image, which increases the complexity of the positioning operation; using digital elevation information to calculate the projection position of the fire point involves complex calculation processes and elevation data storage, and the positioning module needs to be deployed to the server, and the positioning process cannot be implemented on the front-end device.

[0006] At present, the existing fire location methods have the following technical problems:

[0007] 1) Complex operation: Most existing fire location methods require controlling the camera so that the fire point is located at the center of the image. This operation requires manual intervention, which increases the complexity of the positioning operation.

[0008] 2) Complex calculations: Fire point positioning based on digital elevation information and fire point projection position calculation involve complex calculation processes and require professional GIS software to implement.

[0009] 3) The positioning function cannot be realized on the monitoring equipment: the storage of digital elevation information requires large storage resources, and the projection of fire points based on digital elevation information requires large computing resources. It can only be realized by configuring a professional server. Summary of the invention

[0010] The purpose of the present invention is to provide a forest fire rapid positioning method to solve the problems of the existing fire positioning method, such as complex operation, complex calculation and the positioning function cannot be realized on the monitoring equipment.

[0011] The present invention provides a method for rapid positioning of forest fires, which is mainly used for rapid positioning of fires in outdoor scenes such as forests and grasslands with flat terrain. The method includes: calculating the angle information of the fire point in the spherical coordinate system of the monitoring device based on the midpoint of the lower boundary of the fire point target, the camera field of view, the image size, and the current angle of the monitoring device; calculating the ground straight-line distance between the fire point and the monitoring device according to the angle information of the fire point in the spherical coordinate system of the monitoring device and the installation height of the monitoring device; and then realizing rapid positioning of the forest fire according to the ground straight-line distance between the fire point and the monitoring device, the angle between the line connecting the fire point and the monitoring device and the true north direction, and the longitude and latitude information of the monitoring device. The method of the present invention uses the midpoint of the lower boundary of the fire point target as the root of the fire point image coordinates, thereby eliminating the positioning error introduced by inaccurate positioning of the fire root caused by the floating of smoke, fire, etc.; at the same time, the present invention calculates the angle information of the fire point relative to the spherical coordinate system of the monitoring device through the current angle of the monitoring device, the camera field of view, and the fire point image coordinates, and does not need to control the camera to make the fire point located at the center of the image, thereby reducing the number of operation steps; in addition, the present invention directly calculates the fire point position through the ground straight-line distance between the fire point and the monitoring device, the direction of the fire point, and the longitude and latitude of the monitoring device, and does not need digital elevation information of the monitoring area, thereby reducing the calculation complexity, so that the fire positioning process can be quickly implemented on the monitoring device side.

[0012] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0013] The present invention provides a method for quickly locating a forest fire, which specifically comprises the following steps:

[0014] Step S1: Determine the angle information of the fire point relative to the spherical coordinate system of the monitoring device;

[0015] Step S2: Calculate the straight-line distance between the fire point and the ground point where the monitoring equipment is installed;

[0016] Step S3: Calculate the latitude and longitude information of the fire point.

[0017] Furthermore, in step S1, first obtain the angle information of the midpoint of the image when the monitoring device detects the fire point, then obtain the camera field of view angle and resolution, and then use the midpoint of the lower boundary of the fire point target in the image as the target point to calculate the pixel coordinates of the fire point, and finally determine the angle information of the fire point relative to the spherical coordinate system of the monitoring device.

[0018] Furthermore, the angle information of the midpoint of the image includes the horizontal angle device_pan and the pitch angle device_tilt of the monitoring device.

[0019] Furthermore, the camera is a visible light camera or an infrared camera.

[0020] Furthermore, the calculation formula of the fire point pixel coordinates is:

[0021] pt x =coor x +0.5*fire_wid

[0022] pt y =coor y +fire_hei

[0023] Among them, pt x Column coordinates for the root of the fire point, pt y is the row coordinate of the root of the fire point, coor x is the upper left corner column coordinate of the detected fire point with the upper left corner of the image as the coordinate origin, coor y is the row coordinate of the upper left corner of the detected fire point with the upper left corner of the image as the coordinate origin, fire_wid is the width of the detected fire point target image, and fire_hei is the height of the detected fire point target image.

[0024] Furthermore, the calculation formula of the angle information of the fire point relative to the spherical coordinate system of the monitoring device is:

[0025]

[0026] Among them, P_rad is the horizontal angle information of the fire point relative to the spherical coordinate system of the monitoring device, T_rad is the pitch angle information of the fire point relative to the spherical coordinate system of the monitoring device; device_pan is the horizontal angle of the monitoring device, device_tilt is the pitch angle of the monitoring device, image_wid is the width of the image, image_hei is the height of the image, pixel_length is the pixel size of the camera sensor, ptx Column coordinates for the root of the fire point, pt y is the row coordinate of the root of the fire point, f is the focal length of the camera, and a tan is the inverse tangent operation.

[0027] Furthermore, the calculation formula for the straight-line distance between the fire point and the ground point where the monitoring equipment is installed is:

[0028]

[0029] Among them, h is the height of the camera installation position, L is the straight-line distance between the fire point and the ground point where the monitoring equipment is installed, and T_rad is the pitch angle information of the fire point relative to the spherical coordinate system of the monitoring equipment.

[0030] Furthermore, in step S3, the longitude and latitude information of the fire point is calculated based on the longitude and latitude of the monitoring equipment installation location, the straight-line distance between the fire point and the ground point where the monitoring equipment is installed, and the angle of the fire point relative to the spherical coordinate system of the monitoring equipment. The straight-line distance L between the fire point and the ground point where the monitoring equipment is installed is projected in the longitude and latitude directions respectively, and the longitude and latitude information of the fire point is calculated based on the arc length.

[0031] Furthermore, the calculation formula of the latitude information in the latitude and longitude information of the fire point is:

[0032]

[0033] Among them, lat_rad_device is the latitude information of the installation location of the monitoring device, R is the radius of the earth, Lat_rad_fire is the calculated latitude information of the fire point, L is the straight-line distance between the fire point and the ground point where the monitoring device is installed, and P_rad is the horizontal angle information of the fire point relative to the spherical coordinate system of the monitoring device.

[0034] Furthermore, the calculation formula of the longitude information in the fire point longitude and latitude information is:

[0035]

[0036] Among them, lon_rad_device is the longitude information of the installation location of the monitoring device, R is the radius of the earth, Lat_rad_fire is the calculated latitude information of the fire point, Lon_rad_fire is the calculated longitude information of the fire point, L is the straight-line distance between the fire point and the ground point where the monitoring device is installed, and P_rad is the horizontal angle information of the fire point relative to the spherical coordinate system of the monitoring device.

[0037] The beneficial effects of the present invention are:

[0038] Aiming at the problems of the existing fire locating methods, such as complex operation and calculation, and the inability to realize the locating function on monitoring equipment, the present invention provides a forest fire rapid locating method.

[0039] Compared with the existing forest fire location method, the technical solution proposed by the present invention brings effect and convenience to forest fire location in the following aspects:

[0040] 1. Automatic positioning, no need for manual intervention, simple operation: The present invention automatically determines the fire root according to the fire point image area and calculates the longitude and latitude coordinates of the fire. It does not require manual operation and simplifies the operation process.

[0041] 2. Simple calculation: The present invention does not require professional tools such as GIS to calculate the projection coordinates of the fire point through digital elevation information, which simplifies the calculation process and makes the calculation simple.

[0042] 3. The positioning function can be realized on the monitoring device: the present invention does not require complex calculation and storage resources, can be completed on the monitoring device, saves the cost of the entire system, and quickly locates the fire. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The present invention is a schematic flow chart of a method for quickly locating a forest fire.

[0044] Figure 2 This is an example of calculating the distance between the video surveillance equipment and the fire point.

[0045] Figure 3 This is an example of the projection of the distance L between the fire point and the ground point where the monitoring equipment is installed in the longitude and latitude directions. DETAILED DESCRIPTION

[0046] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0047] A forest fire rapid locating method of the present invention specifically comprises the following steps:

[0048] (1) Determine the angle information of the fire point relative to the spherical coordinate system of the monitoring equipment;

[0049] (2) Calculate the straight-line distance between the fire point and the ground point where the monitoring equipment is installed;

[0050] (3) Calculate the longitude and latitude information of the fire point.

[0051] like Figure 1 As shown, a forest fire rapid positioning method of the present invention has the following specific implementation process:

[0052] Step S1: Determine the angle information of the fire point relative to the spherical coordinate system of the monitoring device;

[0053] S1.1: Obtain the angle information of the midpoint of the image when the monitoring device detects the fire point, including the horizontal angle device_pan and the pitch angle device_tilt of the monitoring device;

[0054] S1.2: Obtain the camera's field of view and resolution. The camera can be a visible light camera or an infrared camera.

[0055] S1.3: Take the midpoint of the lower boundary of the fire point target in the image as the target point and calculate the pixel coordinates of the fire point. The specific calculation formula is as follows:

[0056] pt x =coor x +0.5*fire_wid

[0057] pt y =coor y +fire_hei

[0058] Among them, pt x Column coordinates for the root of the fire point, pt y is the row coordinate of the root of the fire point, coor x is the upper left corner column coordinate of the detected fire point with the upper left corner of the image (the image obtained in step S1.1) as the coordinate origin, coor y is the row coordinate of the upper left corner of the detected fire point with the upper left corner of the image (the image obtained in step S1.1) as the coordinate origin, fire_wid is the width of the detected fire point target image, and fire_hei is the height of the detected fire point target image;

[0059] S1.4: Determine the angle information of the fire point relative to the spherical coordinate system of the monitoring equipment:

[0060]

[0061] Among them, P_rad is the horizontal angle information of the fire point relative to the spherical coordinate system of the monitoring device, T_rad is the pitch angle information of the fire point relative to the spherical coordinate system of the monitoring device (horizontal is pitch zero degrees, and upward is the positive direction); device_pan is the horizontal angle of the monitoring device, device_tilt is the pitch angle of the monitoring device, image_wid is the width of the image (the image obtained in step S1.1), image_hei is the height of the image (the image obtained in step S1.1), pixel_length is the pixel size of the camera sensor, f is the focal length of the camera, and a tan is the inverse tangent operation.

[0062] Step S2: Calculate the straight-line distance between the fire point and the ground point where the monitoring equipment is installed, such as Figure 2 As shown, the specific calculation formula is as follows:

[0063]

[0064] Among them, h is the height of the camera installation position, L is the straight-line distance between the fire point and the ground point where the monitoring equipment is installed, and T_rad is the pitch angle information of the fire point relative to the spherical coordinate system of the monitoring equipment.

[0065] Step S3: Calculate the latitude and longitude information of the fire point;

[0066] The latitude and longitude information of the fire point is calculated based on the longitude and latitude of the monitoring equipment installation location, the straight-line distance between the fire point and the ground point where the monitoring equipment is installed, and the angle of the fire point relative to the spherical coordinate system of the monitoring equipment, such as Figure 3 As shown, the straight-line distance L between the fire point and the ground point where the monitoring equipment is installed is projected in the longitude and latitude directions, and the longitude and latitude information of the fire point is calculated according to the arc length. The specific calculation formula is as follows:

[0067]

[0068] Among them, lat_rad_device is the latitude information of the installation location of the monitoring device, lon_rad_device is the longitude information of the installation location of the monitoring device, R is the radius of the earth, Lat_rad_fire is the calculated latitude information of the fire point, Lon_rad_fire is the calculated longitude information of the fire point, L is the straight-line distance between the fire point and the ground point where the monitoring device is installed, and P_rad is the horizontal angle information of the fire point relative to the spherical coordinate system of the monitoring device.

[0069] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for quickly locating forest fires, characterized in that: The following steps are involved: Step S1: Determine the angle information of the fire point relative to the spherical coordinate system of the monitoring device; Step S2: Calculate the straight-line distance between the fire point and the ground point where the monitoring equipment is installed; Step S3: Calculate the latitude and longitude information of the fire point.

2. A forest fire rapid location method according to claim 1, characterized in that: In step S1, first obtain the angle information of the midpoint of the image when the monitoring device detects the fire point, then obtain the camera field of view and resolution, and then use the midpoint of the lower boundary of the fire point target in the image as the target point to calculate the pixel coordinates of the fire point, and finally determine the angle information of the fire point relative to the spherical coordinate system of the monitoring device.

3. A forest fire rapid location method according to claim 2, characterized in that: The angle information of the midpoint of the image includes the horizontal angle device_pan and the pitch angle device_tilt of the monitoring device.

4. A forest fire rapid location method according to claim 2, characterized in that: The camera is a visible light camera or an infrared camera.

5. A forest fire rapid location method according to claim 2, characterized in that: The calculation formula of the fire point pixel coordinates is: pt x =coor x +0.5*fire_wid at y =color y +four_hi Among them, pt x Column coordinates for the root of the fire point, pt y is the row coordinate of the root of the fire point, coor x is the upper left corner column coordinate of the detected fire point with the upper left corner of the image as the coordinate origin, coor y is the row coordinate of the upper left corner of the detected fire point with the upper left corner of the image as the coordinate origin, fire_wid is the width of the detected fire point target image, and fire_hei is the height of the detected fire point target image.

6. A forest fire rapid location method according to claim 2, characterized in that: The calculation formula of the angle information of the fire point relative to the spherical coordinate system of the monitoring equipment is: Among them, P_rad is the horizontal angle information of the fire point relative to the spherical coordinate system of the monitoring device, T_rad is the pitch angle information of the fire point relative to the spherical coordinate system of the monitoring device; device_pan is the horizontal angle of the monitoring device, device_tilt is the pitch angle of the monitoring device, image_wid is the width of the image, image_hei is the height of the image, pixel_length is the pixel size of the camera sensor, pt x Column coordinates for the root of the fire point, pt y is the row coordinate of the root of the fire point, f is the focal length of the camera, and a tan is the inverse tangent operation.

7. A forest fire rapid location method according to claim 1, characterized in that: The calculation formula for the straight-line distance between the fire point and the ground point where the monitoring equipment is installed is: Among them, h is the height of the camera installation position, L is the straight-line distance between the fire point and the ground point where the monitoring equipment is installed, and T_rad is the pitch angle information of the fire point relative to the spherical coordinate system of the monitoring equipment.

8. A forest fire rapid location method according to claim 1, characterized in that: In step S3, the longitude and latitude information of the fire point is calculated based on the longitude and latitude of the monitoring equipment installation location, the straight-line distance between the fire point and the ground point where the monitoring equipment is installed, and the angle of the fire point relative to the spherical coordinate system of the monitoring equipment. The straight-line distance L between the fire point and the ground point where the monitoring equipment is installed is projected in the longitude and latitude directions respectively, and the longitude and latitude information of the fire point is calculated based on the arc length.

9. A forest fire rapid location method according to claim 1 or 8, characterized in that: The calculation formula of the latitude information in the latitude and longitude information of the fire point is: Among them, lat_rad_device is the latitude information of the installation location of the monitoring device, R is the radius of the earth, Lat_rad_fire is the calculated latitude information of the fire point, L is the straight-line distance between the fire point and the ground point where the monitoring device is installed, and P_rad is the horizontal angle information of the fire point relative to the spherical coordinate system of the monitoring device.

10. A forest fire rapid location method according to claim 1 or 8, characterized in that: The calculation formula of the longitude information in the fire point longitude and latitude information is: Among them, lon_rad_device is the longitude information of the installation location of the monitoring device, R is the radius of the earth, Lat_rad_fire is the calculated latitude information of the fire point, Lon_rad_fire is the calculated longitude information of the fire point, L is the straight-line distance between the fire point and the ground point where the monitoring device is installed, and P_rad is the horizontal angle information of the fire point relative to the spherical coordinate system of the monitoring device.

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