A system and method for observing a fire monitor jet

Abstract

The application discloses a system for observing a fire monitor jet, comprising a marker post, a fire monitor arranged at the marker post and used for spraying a foam jet matched with a current experimental working condition, a first camera used for recording a first image representing a main visual angle of a fire monitor jet process, a second camera used for recording a second image representing a side visual angle of the fire monitor jet process, and a processor used for determining the current experimental working condition, identifying a jet trajectory curve feature according to the first image and the second image based on a marker post area in the first image, and the experimental working condition comprising a fire monitor elevation angle and a cannon pressure. The device has simple structure, high measurement precision and can be applied to various complex and severe environments.

Description

Technical Field

[0001] This invention relates to the field of experimental observation technology, and in particular to a system and method for observing fire monitor jets. Background Technology

[0002] In recent years, the booming petrochemical industry has brought severe challenges to fire safety work. Serious fires caused by flammable liquids (referred to as Class B fires) are occurring frequently, causing serious casualties and property losses in my country. Firefighting foam cannons are important firefighting equipment for extinguishing large and medium-sized fires from a distance, and predicting their jet trajectory is crucial for timely and accurate fire control.

[0003] Existing technologies offer various methods for observing the jet trajectory of foam, primarily including: field measurement and estimation, binocular vision, and monocular vision. However, these methods rely entirely on ground measurements and rough estimations, resulting in low efficiency or large errors, and thus failing to achieve precise observation of the foam trajectory. Summary of the Invention

[0004] The purpose of this invention is to provide a detection scheme that can observe the dynamic position of the fire monitor jet trajectory and accurately calculate the moving distance.

[0005] To address the aforementioned technical problems, embodiments of the present invention provide a system for observing fire monitor jets, comprising: a benchmark; a fire monitor positioned at the benchmark for spraying a foam jet matching the current experimental conditions; a first camera for recording a first image representing the fire monitor jet process from a main perspective; a second camera for recording a second image representing the fire monitor jet process from a side perspective; and a processor for determining the current experimental conditions, identifying jet trajectory curve features based on the benchmark area in the first image and the first and second images, wherein the experimental conditions include the fire monitor elevation angle and the pressure applied by the monitor.

[0006] Preferably, the target and the fire monitor are located on the same plane.

[0007] Preferably, the field of view of the first camera simultaneously covers the horizontal range and altitude of the target and the jet trajectory; the field of view of the second camera simultaneously covers the altitude and landing point of the target and the jet trajectory.

[0008] Preferably, the processor includes: an image preprocessing module, used to extract several key main view images from the first image and several key side view images from the second image; an intermediate quantity interaction module, used to import the key main view images and the key side view images into a preset trajectory recognition model, so as to use the trajectory recognition model to identify the horizontal distance of the trajectory curve in the key main view image and the vertical height of the trajectory curve in the key side view image, and obtain the coordinates of each position point within the trajectory curve; and a curve feature generation module, used to calculate the actual size of a single pixel based on the size data of the benchmark, and based on this, convert the coordinates of each position point into the range and height of each position point, thereby obtaining the jet trajectory curve features.

[0009] Preferably, the trajectory recognition model is built using LabVIEW based on the NI system, wherein the trajectory recognition model includes a to-be-processed image selection unit, a to-be-extracted region selection unit, a to-be-processed region noise reduction unit, a horizontal boundary determination unit, a horizontal distance recognition unit, and a vertical distance recognition unit.

[0010] Preferably, the image preprocessing module is further configured to convert several extracted single-frame key main view images into 8BMP format, and to convert several extracted single-frame key side view images into 8BMP format.

[0011] Preferably, the curve feature generation module is further configured to remove abnormal position points in the current curve based on the coordinates of each position point within the obtained trajectory curve, so as to use the coordinates of each position point after the abnormal point removal process to form the jet trajectory curve feature.

[0012] Preferably, the system further includes a weather instrument for recording meteorological information in the current experimental scenario, the meteorological information including at least wind direction and wind speed.

[0013] Preferably, the processor is further configured to match the meteorological data with the jet trajectory curve characteristics under the current experimental conditions, thereby constructing a jet trajectory feature database under different experimental conditions and different meteorological data conditions.

[0014] Preferably, the fire monitor is a mobile fire monitor; the working fluid foam sprayed by the fire monitor contains a dye.

[0015] On the other hand, embodiments of the present invention provide a method for observing fire monitor jets. The method is implemented by the system described above, wherein the method includes: determining the current experimental conditions, the experimental conditions including the fire monitor elevation angle and pressure; the fire monitor spraying a foam jet matching the current experimental conditions; simultaneously recording a first image representing the main perspective of the fire monitor jet process and a second image representing the side perspective of the fire monitor jet process; and identifying jet trajectory curve features based on a benchmark area in the first image and the first image and the second image.

[0016] Preferably, the step of identifying jet trajectory curve features based on the benchmark region in the first image and the second image includes: extracting several key main view images from the first image and extracting several key side view images from the second image; importing the key main view images and the key side view images into a preset trajectory recognition model to identify the horizontal distance of the trajectory curve in the key main view image and the vertical height of the trajectory curve in the key side view image using the trajectory recognition model, thereby obtaining the coordinates of each position point within the trajectory curve; calculating the actual size of a single pixel based on the size data of the benchmark, and based on this, converting the coordinates of each position point into the range and height of each position point, thereby obtaining the jet trajectory curve features.

[0017] Compared with the prior art, one or more embodiments of the above solutions may have the following advantages or beneficial effects:

[0018] This invention proposes a system and method for observing fire monitor jets. This invention overcomes the errors of binocular vision positioning systems (these errors mainly stem from system parameter calibration errors and actual measurements). The device has a simple structure, convenient and rapid data acquisition, and is a non-contact measurement method. The method is effective and practical, with high measurement accuracy, and can be applied to various complex and harsh environments. This makes the LabVIEW-based foam trajectory visualization observation method widely applicable and provides a more precise experimental tool for research and application in fire extinguishing tactics. Furthermore, this invention also solves the deviations caused by position-based servo control methods, resulting in high measurement accuracy, observation efficiency, and strong applicability.

[0019] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0021] Figure 1 This is a schematic diagram of the system for observing fire monitor jets according to an embodiment of this application.

[0022] Figure 2 This is a schematic diagram of the trajectory recognition model in a system for observing fire monitor jets according to an embodiment of this application.

[0023] Figure 3 This is an example diagram illustrating the jet trajectory curve characteristics in a system for observing fire monitor jets according to an embodiment of this application.

[0024] Figure 4 This is a step diagram of a method for observing fire monitor jets according to an embodiment of this application. Detailed Implementation

[0025] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings and examples, so that the process of how the present invention uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. It should be noted that, as long as there is no conflict, the various embodiments and features in the various embodiments of the present invention can be combined with each other, and the resulting technical solutions are all within the protection scope of the present invention.

[0026] Furthermore, the steps illustrated in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Also, although a logical order is shown in the flowcharts, in some cases the steps shown or described may be performed in a different order than that shown here.

[0027] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms “a” and “an” as used herein are also intended to include the plural. It should also be understood that the terms “comprising” and / or “including” as used herein specify the presence of the stated features, integers, steps, operations, units, and / or components, without excluding the presence or addition of one or more other features, integers, steps, operations, units, components, and / or combinations thereof.

[0028] In recent years, the booming petrochemical industry has brought severe challenges to fire safety work. Serious fires caused by flammable liquids (referred to as Class B fires) are occurring frequently, causing serious casualties and property losses in my country. Firefighting foam cannons are important firefighting equipment for extinguishing large and medium-sized fires from a distance, and predicting their jet trajectory is crucial for timely and accurate fire control.

[0029] Existing technologies offer various methods for observing the jet trajectory of foam, primarily including: field measurement and estimation, binocular vision, and monocular vision. However, these methods rely entirely on ground measurements and rough estimations, resulting in low efficiency or large errors, and thus failing to achieve precise observation of the foam trajectory.

[0030] To address the aforementioned technical problems, this application proposes a system and method for observing fire monitor jets. This system and method is a LabVIEW-based three-dimensional visualization observation method for foam jets, capable of observing and recording the complete motion process of fire monitor jets under different working conditions from different angles, and features high observation efficiency and strong applicability.

[0031] Example 1

[0032] Figure 1 This is a schematic diagram of a system for observing fire monitor jets according to an embodiment of this application. Figure 1 As shown in the embodiment of the present invention, the system for observing fire monitor jets (also called "jet observation system") includes: a marker, a fire monitor installed at the marker, a first camera, a second camera, and a processor.

[0033] Furthermore, the spray directions of the marker and the fire monitor are located in the same plane. This plane, where the spray trajectories of the marker and the fire monitor lie, is designated as the first plane. The field of view of the first camera simultaneously covers the complete horizontal range and altitude of both the marker and the spray trajectory within the first plane. The field of view of the second camera simultaneously covers the altitude and impact point of both the marker and the spray trajectory. Preferably, the center of the field of view of the second camera is coplanar with the first plane.

[0034] Furthermore, the fire monitor is a mobile fire monitor. The working fluid used in the experiment was an aqueous film-forming foam extinguishing agent (e.g., 6% (AFFF, -14℃)). A dye was added to the foam sprayed by the fire monitor.

[0035] In practical applications, the fire monitor is used to spray a foam jet matching the current experimental conditions. A first camera records a first image representing the fire monitor jet process from a main perspective. A second camera records a second image representing the fire monitor jet process from a side perspective. The first and second cameras should be used simultaneously. Specifically, the first camera is the main perspective camera, primarily responsible for capturing the trajectory, range, altitude, and width of the fire monitor jet's impact point from a main perspective; the second camera is the side perspective camera, primarily responsible for capturing the width of the side perspective at the fire monitor jet's impact point.

[0036] The processor is used to determine the current experimental conditions. These experimental conditions include the fire monitor elevation angle and the pressure exerted by the monitor. In other words, before the experiment begins, this embodiment of the invention uses the processor to set a series of experimental condition parameters, with different parameters consisting of different combinations of fire monitor elevation angle parameters and different pressure parameters.

[0037] Furthermore, the processor is also used to identify the jet trajectory curve features based on the benchmark region in the first image and the second image. This invention uses the benchmark as a reference point; when processing the two types of images, it utilizes the known size of the benchmark to calculate the actual pixel size, thereby converting the jet trajectory point's height and horizontal range data.

[0038] In this embodiment of the invention, the jet trajectory curve features include: the jet height and horizontal range of each data point within the uppermost edge trajectory of the jet trajectory, and the jet height and horizontal range of each data point within the lowermost edge trajectory of the jet trajectory. Further, the processor is also configured to fit the uppermost edge jet curve under the current experimental condition based on the jet height and horizontal range of each trajectory data point within the uppermost edge trajectory in the jet trajectory curve features, and to fit the lowermost edge jet curve under the current experimental condition based on the jet height and horizontal range of each trajectory data point within the lowermost edge trajectory in the jet trajectory curve features. Figure 3 This is an example diagram illustrating the jet trajectory curve characteristics in a system for observing fire monitor jets according to an embodiment of this application. Figure 3 The data show the characteristic data of the jet trajectory curve under the current experimental conditions, and provides examples of expressions for the uppermost and lowermost edge curves of the fitted jet trajectory under these conditions.

[0039] In addition, the jet observation system described in this embodiment of the invention also includes a meteorological instrument. The meteorological instrument is used to record meteorological information in the current experimental scenario. The meteorological information includes at least wind direction and wind speed. During the experiment, the fire monitor jet is greatly affected by local air convection, so a meteorological instrument is used to measure the wind speed and wind direction during the experiment, and the measured data is recorded in the processor.

[0040] Furthermore, the processor is also used to match the recorded meteorological data under the current experimental conditions with the characteristics of the jet trajectory curve under the current experimental conditions, thereby constructing a database of jet trajectory characteristics under different combinations of experimental conditions and different meteorological data conditions.

[0041] In addition, since the fire monitor used in this invention has a large range and altitude, the experiment needs to be conducted in an open space that meets the requirements.

[0042] In practical applications, the experimental procedure is as follows:

[0043] (1) Set up the experimental site, install and fix the mobile fire monitor, connect the fire monitor to the fire truck, and add dye to the water tank of the fire truck;

[0044] (2) Erect a marker as a reference point, with the marker placed on the same plane as the fire monitor;

[0045] (3) Set up a main-view HD camera, a side-view HD camera and a weather instrument, and set up the camera and weather instrument;

[0046] (4) Adjust the elevation angle of the fire monitor and set the monitor pressure parameters;

[0047] (5) On-site personnel open the valve to operate the fire monitor, which causes the pressure to increase from zero. The main view and side view high-definition cameras simultaneously capture the footage.

[0048] (6) When the pressure gradually increases to the set working condition (reaching the preset gun pressure parameters), wait for the jet trajectory to stabilize and be complete (for example, maintain this state for 3-5 seconds), then close the valve to end the jet process;

[0049] (7) The cameraman plays back the footage of the jet movement to check whether the jet trajectory is clear and whether it goes outside the frame;

[0050] (8) After checking that everything is correct, save the video recording and re-enter the shooting state;

[0051] (9) After the test under this condition is completed, proceed to the next test under the next condition and repeat the process (4)-(8).

[0052] Example 2

[0053] Based on the above embodiment one, the present invention further describes the image processing process of the processor.

[0054] In this embodiment of the invention, the processor includes at least: an image preprocessing module, an intermediate quantity interaction module, and a curve feature generation module.

[0055] The image preprocessing module is used to extract several key main view images from the first image obtained by the first camera. Similarly, the image preprocessing module is used to extract several key side view images from the second image obtained by the second camera, which is captured synchronously with the first camera. After opening the experimental first or second image, the current image is converted into a single-frame image format. To ensure image quality and facilitate post-processing, dedicated software for high-speed cameras is used to convert it into a single-frame image. Then, images showing stable water flow and complete trajectories from the fire monitor are selected as the corresponding key main view images or key side view images for subsequent data processing.

[0056] Since the trajectory recognition model described below is a model built on the NI system, the image preprocessing module described in this embodiment of the invention is further used to convert several extracted single-frame key main view images into 8BMP format, and to convert several extracted single-frame key side view images into 8BMP format, so as to convert the format of the key main view image or key side view image into an image format that the trajectory recognition model can recognize.

[0057] Since the data acquisition part of the trajectory recognition model can intelligently recognize 8BMP format images, the images to be processed need to be converted to 8BMP format for processing (for example, by using an image editor, MATLAB, or high-speed camera image processing software).

[0058] To maintain consistency throughout the process, camera software can be used for direct conversion. Then, as needed, the converted key main view or key side view images are cropped to extract the complete image area of ​​the fire monitor's water flow trajectory, which is then imported into the trajectory recognition model as the key main view and key side view images.

[0059] Furthermore, the intermediate quantity interaction module is used to import the key main view image and the key side view image into the preset trajectory recognition model, thereby using the trajectory recognition model to identify the horizontal distance of the trajectory curve in the key main view image and the vertical height of the trajectory curve in the key side view image, thereby obtaining the coordinates of each trajectory position data point within the current jet trajectory curve.

[0060] Furthermore, since the trajectory recognition model in this embodiment of the invention is built using LabVIEW software based on the NI system, the intermediate quantity interaction module described in this embodiment of the invention can import the key main view image and the key side view image into the LabVIEW software of the NI system, and simultaneously import them into the pre-built program block about the trajectory recognition model to identify the horizontal distance and vertical height of the trajectory curve, thereby obtaining the specific coordinates of each trajectory position point.

[0061] Figure 2 This is a schematic diagram of the trajectory recognition model in a system for observing fire monitor jets according to an embodiment of this application. In this embodiment, the trajectory recognition model is built using LabVIEW software based on the NI system. Figure 2As shown, the trajectory recognition model includes: Original Image (image selection / acquisition) unit, Image Mask1 (region selection / cropping) unit, Gray Morphology1 (region noise reduction) unit, EdgeDetector1 (horizontal boundary determination) unit, Clamp1 (horizontal distance recognition) unit, and Clamp2 (vertical distance recognition) unit.

[0062] When the images to be processed (key main view image and key side view image) are imported into the trajectory recognition model, the image selection unit receives the imported images, and the region selection unit pops up a window to capture the current image to be processed. The on-site personnel capture the region related to the trajectory curve that needs to be recognized (i.e., the region encompassing the top edge trajectory and the bottom edge trajectory). Then, the region denoising unit performs denoising processing on the captured image region. The origin and landing position of the trajectory curve (top edge curve and bottom edge curve) are determined by the horizontal boundary determination unit. The horizontal distance recognition unit recognizes the horizontal coordinates of each position point in the curve (top edge curve and bottom edge curve), and the vertical distance recognition unit recognizes the vertical coordinates of each position point in the curve (top edge curve and bottom edge curve). Thus, the trajectory recognition model can derive the coordinate data of each position point in the top edge curve and the coordinate data of each position point in the bottom edge curve under the current experimental conditions.

[0063] Next, the curve feature generation module calculates the actual size of each pixel based on the size data of the benchmark, and converts the coordinates of each location point into range and altitude data based on the actual size of each pixel, thereby obtaining the jet trajectory curve features under the current experimental conditions. (See [link to relevant documentation]). Figure 3 .

[0064] In addition, to ensure the accuracy of the curve feature data points, the curve feature generation module described in this embodiment of the invention is also used to remove abnormal position points in the current curve based on the coordinates of each position point in the obtained trajectory curve before converting the coordinate data into range and altitude data, so as to use the coordinates of each position point after the abnormal point removal process to convert into the above-mentioned jet trajectory curve features.

[0065] Example 3

[0066] Based on Embodiment 1 or Embodiment 2 above, the present invention also provides a method for observing fire monitor jets (also referred to as a "jet observation method"). This jet observation method is implemented using the jet observation system described in Embodiment 1 or Embodiment 2 above.

[0067] Figure 4This is a step diagram illustrating a method for observing a fire monitor jet according to an embodiment of this application. Figure 4 As shown in the embodiment of the present invention, the jet observation method is as follows:

[0068] Step S401, the processor determines the current experimental conditions, wherein the experimental conditions include: fire monitor elevation angle and monitor pressure;

[0069] Step S402: The fire monitor sprays a foam jet that matches the current experimental conditions;

[0070] Step S403: When the jet trajectory is complete and stable, the first camera and the second camera respectively record the first image representing the main view of the fire monitor jet process and the second image representing the side view of the fire monitor jet process.

[0071] Step S404: Based on the benchmark region in the first image, the processor identifies the jet trajectory curve features according to the first image and the second image.

[0072] Specifically, step S404 includes:

[0073] Several key main view images are extracted from the first image, and several key side view images are extracted from the second image;

[0074] Import the key main view image and key side view image into the preset trajectory recognition model, so as to use the trajectory recognition model to identify the horizontal distance of the trajectory curve in the key main view image and the vertical height of the trajectory curve in the key side view image, and obtain the coordinates of each position point in the trajectory curve.

[0075] Based on the size data of the benchmark, the actual size of a single pixel is calculated. Based on this, the coordinates of each position point are converted into the range and height of each position point, thereby obtaining the characteristics of the jet trajectory curve.

[0076] Example 4

[0077] Based on the above embodiment three, the specific implementation process of the jet observation method described in the embodiment of the present invention will be explained below.

[0078] Taking the Bock-Katz 1000-3000ZB mobile fire monitor as an example, a trajectory recognition model was constructed using LabVIEW laboratory virtual instrument engineering platform software. The jet trajectory under steady-state conditions was identified, and quantitative test results of jet parameters under different experimental conditions were obtained, including basic data such as jet trajectory, jet height, and range.

[0079] 1. Experimental System:

[0080] The experimental system mainly consists of: a Bock-Katz 1000-3000ZB mobile fire monitor, two high-definition cameras, a beacon, a weather instrument, and a computer with an integrated processor. The Bock-Katz 1000-3000ZB, abbreviated as Bock 30 (pok30), has a 100mm diameter monitor base and a 65mm diameter muzzle. The working fluid used in the experiment is aqueous film-forming foam extinguishing agent. A schematic diagram of the experimental system is shown below. Figure 1 As shown.

[0081] The experiment was recorded by two high-definition cameras. The main-view camera was responsible for capturing the trajectory, range, height, and main-view width of the fire monitor jet, while the side-view camera was responsible for capturing the side-view width of the fire monitor jet's landing point.

[0082] A benchmark is used as a reference point to calculate pixel size during image processing; the actual size of the benchmark is 5.5m.

[0083] During the experiment, the fire monitor jet was significantly affected by local air convection; therefore, a meteorological instrument was used to measure the wind speed and direction, and the data were recorded in a computer. Due to the large range and altitude of the fire monitor used, the experiment needed to be conducted in an open area that met the required conditions. Different experimental conditions were also selected, such as: a pressure of 0.6 MPa and an elevation angle of 40°.

[0084] 2. Experimental Procedure:

[0085] (1) Set up the experimental site, install and fix the fire monitor and connect the fire monitor to the fire truck, and add dye to the water tank of the fire truck;

[0086] (2) Erect a marker as a reference point, with the marker placed on the same plane as the fire monitor;

[0087] (3) Set up high-definition cameras and weather instruments with main view and side view, and set up the cameras and weather instruments;

[0088] (4) Adjust the fire monitor elevation angle to 40° and set the pressure parameter to 0.6 MPa;

[0089] (5) Open the valve to operate the fire monitor. During this process, the pressure increases from zero. The main view and side view high-definition cameras shoot simultaneously.

[0090] (6) When the pressure gradually increases to the set working condition, maintain this state for 3-5 seconds, then close the valve to end the jetting process;

[0091] (7) The cameraman plays back the footage of the jet movement to check whether the jet trajectory is clear and whether it goes outside the frame;

[0092] (8) After checking that there are no errors, save the video recording.

[0093] 3. Image processing:

[0094] (1) Preliminary image preprocessing:

[0095] Open the experimental video and convert it into a single-frame image format. To ensure image quality and facilitate post-processing, we use dedicated software for high-speed cameras to convert it into a single-frame image and select images with stable water flow from the fire monitor for data processing.

[0096] (2) Secondary image preprocessing:

[0097] Since the NI system intelligently recognizes 8BMP format images when collecting data, the images to be processed need to be converted to 8BMP format for processing. This process can be achieved using a computer's built-in image editor, MATLAB, or high-speed camera image processing software. To maintain consistency throughout the process, camera software is used for direct conversion, and then the converted images are cropped as needed.

[0098] (3) Extraction of coordinate data:

[0099] Import the image into the NI LabVIEW software, and simultaneously import the trajectory recognition model (e.g., Figure 2 As shown, the horizontal distance and vertical height are identified to obtain the specific coordinates of each point. The specific process is as follows:

[0100] 1) Image mask settings: Click Original Image to import the image to be processed, double-click Image Mask1 to set the area to be processed, and click Set ROL after selecting the area to be processed.

[0101] 2) Boundary detection settings: Double-click Edge Detector1, set Edge Detector to Advanced EdgeTool, Look For to First & Last Edge, Edge Polarity to All Edges, InterplationType to Bilinear, and the difference between the horizontal coordinates X1 and X2 is the number of pixels at the horizontal distance;

[0102] 3) Then, double-click Clamp2, set the parameters, select the area from the point to be measured to the origin, and the Current Distance data is the number of vertical height pixels.

[0103] (4) Data export and post-processing:

[0104] After the previous step, the location information (coordinate information) of the foam jet under the current working condition can be obtained. Then, it can be exported to an Excel spreadsheet, and abnormal data can be checked and removed.

[0105] Finally, based on the dimensions of the reference object, the length represented by a single pixel is calculated. The collected data is then processed to obtain the specific elevation and range data for each point on the curve, and the jet trajectory curve is fitted, as shown below. Figure 3 As shown.

[0106] This invention discloses a system and method for observing fire monitor jets. Because existing binocular vision systems, in long-distance positioning, are limited by optical principles, their imaging field is small, the scene they can capture is limited, and their viewing angle is fixed and singular. This invention provides a technical solution capable of identifying jet trajectories from multiple working conditions and angles. This invention overcomes the errors of binocular vision positioning systems (these errors mainly come from system parameter calibration errors and actual measurements). The device has a simple structure, convenient and rapid data acquisition, is a non-contact measurement method, is effective and practical, and has high measurement accuracy. It can be applied to various complex and harsh environments, making the LabVIEW-based foam trajectory visualization observation method widely applicable and providing a more precise experimental means for the research and application of fire extinguishing tactics. Furthermore, this invention also solves the deviations caused by position-based servo control methods, resulting in high measurement accuracy, observation efficiency, and strong applicability.

[0107] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0108] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the 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, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0109] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0110] It should be understood that the embodiments disclosed herein are not limited to the specific structures, processing steps, or materials disclosed herein, but should be extended to equivalent substitutions of these features as understood by those skilled in the art. It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0111] The phrase "an embodiment" or "an embodiment" used in this specification means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Therefore, the phrase "an embodiment" or "an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0112] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in form and detail of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A system for observing the jet stream of a fire monitor, characterized in that, include: Benchmark; The fire monitor installed at the benchmark is used to spray foam jets that match the current experimental conditions. The first camera, used to record the first image from the main perspective characterizing the fire monitor jet process; A second camera is used to record a second image from a side view that characterizes the fire monitor jet process; A processor, configured to determine the current experimental conditions, based on a benchmark area in the first image, and to identify jet trajectory curve features according to the first and second images, wherein the experimental conditions include the fire monitor elevation angle and the monitor pressure, and wherein the processor comprises: An image preprocessing module is used to extract several key main view images from the first image and several key side view images from the second image. An intermediate quantity interaction module is used to import the key main view image and the key side view image into a preset trajectory recognition model, so as to use the trajectory recognition model to identify the horizontal distance of the trajectory curve in the key main view image and the vertical height of the trajectory curve in the key side view image, and obtain the coordinates of each position point within the trajectory curve. The trajectory recognition model is built using LabVIEW based on the NI system. The trajectory recognition model includes a to-be-processed image selection unit, a to-be-extracted region selection unit, a to-be-processed region noise reduction unit, a horizontal boundary determination unit, a horizontal distance recognition unit, and a vertical distance recognition unit. The curve feature generation module is used to calculate the actual size of a single pixel based on the size data of the benchmark. Based on this, the coordinates of each position point are converted into the range and height of each position point, thereby obtaining the jet trajectory curve feature.

2. The system according to claim 1, characterized in that, The target and the fire monitor are located on the same plane in the direction of their spray.

3. The system according to claim 1 or 2, characterized in that, The field of view of the first camera simultaneously covers the horizontal range and altitude of the target and the jet trajectory; The field of view of the second camera simultaneously covers the height and landing point of the target and the jet trajectory.

4. The system according to claim 1, characterized in that, The image preprocessing module is further configured to convert several extracted single-frame key main view images into 8BMP format, and to convert several extracted single-frame key side view images into 8BMP format.

5. The system according to claim 1, characterized in that, The curve feature generation module is further configured to remove abnormal position points in the current curve based on the coordinates of each position point within the obtained trajectory curve, so as to use the coordinates of each position point after the abnormal point removal process to form the jet trajectory curve feature.

6. The system according to claim 1, characterized in that, The system also includes: A weather instrument is used to record meteorological information in the current experimental scenario, including at least wind direction and wind speed.

7. The system according to claim 6, characterized in that, The processor is also used to match the meteorological data with the jet trajectory curve characteristics under the current experimental conditions, thereby constructing a jet trajectory feature database under different experimental conditions and different meteorological data conditions.

8. The system according to claim 1, characterized in that, The fire monitor is a mobile fire monitor; The working foam sprayed by the fire monitor contains a dye.

9. A method for observing the jet stream of a fire monitor, characterized in that, The method is implemented using the system as described in any one of claims 1 to 8, wherein the method comprises: Determine the current experimental conditions, which include the fire monitor elevation angle and the monitor pressure. The fire monitor sprays a foam jet that matches the current experimental conditions; Simultaneously record the first image from the main perspective representing the fire monitor jet process, and the second image from the side perspective representing the fire monitor jet process. Based on the benchmark region in the first image, the jet trajectory curve features are identified according to the first image and the second image, including: Several key main view images are extracted from the first image, and several key side view images are extracted from the second image; The key main view image and the key side view image are imported into a preset trajectory recognition model, so as to use the trajectory recognition model to identify the horizontal distance of the trajectory curve in the key main view image and the vertical height of the trajectory curve in the key side view image, and obtain the coordinates of each position point within the trajectory curve; Based on the size data of the benchmark, the actual size of a single pixel is calculated. Based on this, the coordinates of each position point are converted into the range and height of each position point, thereby obtaining the jet trajectory curve features.

Images