A fluid projection range measurement system and method

Abstract

This application provides a fluid delivery range measurement system and method, belonging to the field of aviation emergency rescue technology. Specifically, it includes an RTK base station, two RTK rover stations, and a timer. The RTK base station calculates the current GNSS positioning error and transmits the positioning error to the two RTK rover stations in real time via radio. The RTK rover stations receive the GNSS signal and the real-time positioning error transmitted by the RTK base station, use the positioning error data to correct the GNSS signal, calculate the precise position data, and store it locally. The operating frequency of the RTK base station and the RTK rover stations is not lower than 50Hz. This application's processing scheme improves the hit rate of fluid delivery from aircraft in the air.

Description

Technical Field

[0001] This application relates to the field of aviation emergency rescue, and in particular to a fluid projection range measurement system and method. Background Technology

[0002] my country has a vast territory and extensive forest area, facing enormous pressure in forest fire prevention. Currently, the most effective means of extinguishing forest fires is to use firefighting aircraft, carrying water or extinguishing agents, to visually drop them above the fire source. However, the success rate of this method depends entirely on the pilot's subjective judgment of the timing of the drop, resulting in low reliability. In addition, the high speed and altitude of the aircraft, along with the unpredictable spread and movement of the fluids after release, often lead to low hit rates, requiring more sorties to extinguish the fire. This also increases mission time and costs.

[0003] To address this issue, some research teams have proposed applying the traditional bombing algorithms CCIP (Continuously Computing Impact Point) and CCRP (Continuously Computed Release Point) to the field of water-based fire extinguishing. While this approach has merit, its application relies on mastering the range data of fluids such as water and extinguishing agents. However, fluids and bombs differ significantly in their physical properties, making it impossible to apply traditional rigid bomb range measurement methods to fluids. Therefore, solving this problem requires addressing the measurement of fluid-based range.

[0004] Currently, fluid range measurement methods mainly include the following two categories: 1) photographing the release process and estimating the fluid range through image scaling; 2) using GPS positioning to calculate the range using latitude and longitude.

[0005] However, whether it is image ratio analysis or GPS positioning, the measurement error is on the order of several meters or even tens of meters, which cannot meet the requirements of accurate measurement. Summary of the Invention

[0006] In view of this, this application provides a fluid delivery range measurement system and method, which solves the problems in the prior art and improves the hit rate of fluid delivery by aircraft in the air.

[0007] The fluid projection range measurement system provided in this application adopts the following technical solution:

[0008] A fluid projection range measurement system includes an RTK base station, two RTK rover stations, and a timer;

[0009] The RTK base station is used to calculate the current GNSS positioning error and transmit the positioning error to the two RTK mobile stations in real time via radio.

[0010] The RTK mobile station receives GNSS signals and real-time positioning errors sent by the RTK base station, uses the positioning error data to correct the GNSS signals, calculates accurate position data, and stores it locally.

[0011] The timer is used for timing.

[0012] The operating frequency of the RTK base station and RTK rover station shall not be lower than 50Hz.

[0013] Optionally, the location data calculated by the RTK rover is the coordinates (x, y, z) of the RTK rover in the RTK base station coordinate system, in meters.

[0014] Optionally, each location data stored by the RTK mobile station is accompanied by a UTC timestamp.

[0015] Optionally, the timer records the time in UTC time, and the timing accuracy is not less than 20 milliseconds.

[0016] On the other hand, the method for measuring the range of fluid projection provided in this application adopts the following technical solution:

[0017] A method for measuring the projection range of a fluid, characterized in that the measurement is performed using the aforementioned measurement system, and the measurement method includes:

[0018] Step 1: Fix and calibrate the RTK reference station in an open-air location near the test site;

[0019] Step 2: Establish the RTK base station coordinate system and record the angle Φ0 of the x-axis relative to true north;

[0020] Step 3: Establish connections between the RTK base station and two RTK mobile stations, namely the first RTK mobile station and the second RTK mobile station.

[0021] Step 4: Secure the first RTK mobile station inside the launcher and let it take off with the launcher;

[0022] Step 5: When the aircraft releases the fluid, record the UTC time T1 of the release moment using a timer, and at the same time record the aircraft heading Φ1 at the release moment;

[0023] Step 6: Retrieve the location data P1(x1,y1,z1) whose timestamp is closest to T1 from the location data stored in the first RTK mobile station;

[0024] Step 7: After the fluid lands, place the second RTK mobile station in the center of the fluid distribution area and record the position data P2(x2,y2,z2) of RTK mobile station 2.

[0025] Step 8: Calculate the horizontal range and lateral deviation of the fluid using coordinate transformation.

[0026] Optionally, the range calculation formula in step 8 is:

[0027] Horizontal range = (x2-x1)cos(Φ1-Φ0) + (y2-y1)sin(Φ1-Φ0);

[0028] Lateral deviation = (y2-y1)cos(Φ1-Φ0)-(x2-x1)sin(Φ1-Φ0).

[0029] In summary, this application includes the following beneficial technical effects:

[0030] This application solves the problems of large errors and high difficulty in fluid range measurement, enabling accurate measurement of the delivery range of various processes at different altitudes at a relatively low cost, with measurement accuracy reaching the centimeter level. Furthermore, by combining this with a delivery algorithm and displaying the predicted delivery point in real time on an onboard display, the hit rate of aircraft delivering various fluids in the air can be significantly improved. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 Flowchart of the fluid projection path measurement method;

[0033] Figure 2 This is a schematic diagram of the fluid projection path measurement process;

[0034] Figure 3 This is a top-down view of the water being thrown from due north. Detailed Implementation

[0035] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0036] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0038] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0039] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0040] This application provides a system for measuring the range of fluid projection.

[0041] A fluid projection range measurement system includes: an RTK base station, two RTK rover stations, and a timer;

[0042] The RTK base station is used to calculate the current GNSS positioning error and transmit the positioning error to the two RTK mobile stations in real time via radio.

[0043] The RTK mobile station receives GNSS signals and real-time positioning errors sent by the RTK base station, uses the positioning error data to correct the GNSS signals, calculates accurate position data, and stores it locally.

[0044] The timer is used for timing.

[0045] The operating frequency of the RTK base station and RTK rover station shall not be lower than 50Hz.

[0046] The location data calculated by the RTK rover is its coordinates (x, y, z) in the RTK base station coordinate system, in meters. The positioning accuracy of the RTK rover can reach 0.01 meters.

[0047] Each location data stored by the RTK mobile station has a UTC timestamp.

[0048] The timer records UTC time and has a timing accuracy of no less than 20 milliseconds.

[0049] RTK stands for Real Time Kinematic. GNSS stands for Global Navigation Satellite System. UTC stands for Coordinated Universal Time.

[0050] This application also provides a method for measuring the range of fluid projection.

[0051] like Figure 1 As shown, a method for measuring the trajectory of a fluid projection is used, employing the aforementioned measurement system. The measurement method includes:

[0052] Step 1: Fix and calibrate the RTK reference station in an open-air location near the test site;

[0053] Step 2: Establish the RTK base station coordinate system and record the angle Φ0 of the x-axis relative to true north;

[0054] Step 3: Establish connections between the RTK base station and two RTK mobile stations, namely the first RTK mobile station and the second RTK mobile station.

[0055] Step 4: Secure the first RTK mobile station inside the launcher and let it take off with the launcher;

[0056] Step 5: When the aircraft releases the fluid, record the UTC time T1 of the release moment using a timer, and at the same time record the aircraft heading Φ1 at the release moment;

[0057] Step 6: Retrieve the location data P1(x1,y1,z1) whose timestamp is closest to T1 from the location data stored in the first RTK mobile station;

[0058] Step 7: After the fluid lands, place the second RTK mobile station in the center of the fluid distribution area and record the position data P2(x2,y2,z2) of RTK mobile station 2.

[0059] Step 8: Calculate the horizontal range and lateral deviation of the fluid using coordinate transformation.

[0060] The range calculation formula in step 8 is as follows:

[0061] Horizontal range = (x2-x1)cos(Φ1-Φ0) + (y2-y1)sin(Φ1-Φ0);

[0062] Lateral deviation = (y2-y1)cos(Φ1-Φ0)-(x2-x1)sin(Φ1-Φ0).

[0063] This application solves the problems of large errors and high difficulty in fluid range measurement, enabling accurate measurement of the delivery range of various processes at different altitudes at a relatively low cost, with measurement accuracy reaching the centimeter level. Furthermore, by combining this with a delivery algorithm and displaying the predicted delivery point in real time on an onboard display, the hit rate of aircraft delivering various fluids in the air can be significantly improved.

[0064] In one embodiment, the fluid used is water, and the test site is a straight, open runway. An aircraft will drop water in a designated area on the centerline of the runway.

[0065] like Figure 2 and Figure 3 As shown, the measurement process for the fluid projection path is as follows:

[0066] First, the RTK base station (201) is fixedly erected near the designated water drop area outside the runway. This ensures that the base station will not intrude into the water spill area, while also ensuring that the RTK mobile station is within the signal coverage range of the RTK base station.

[0067] Open-air installation ensures that the RTK base station has a good GNSS satellite search environment.

[0068] Power on the RTK base station and complete the calibration. At this point, the RTK base station can measure the positioning error in the area.

[0069] Establish an RTK base station coordinate system and record the azimuth of the coordinate system's x-axis relative to true north as Φ0 = 9°.

[0070] Establish connections between the RTK base station and two RTK rover stations. The RTK rover stations correct the GNSS signal based on the received positioning error data and calculate the precise position coordinates in the RTK base station coordinate system.

[0071] The RTK mobile station 1 (202) is placed in a fixed position inside the cabin of the aircraft (204), such as above the water drop hatch, and takes off with the aircraft.

[0072] Once the aircraft reaches the designated water drop area, it executes the water drop command. The crew uses a timer to record the UTC time T1 of the water drop and the water drop heading Φ1 = 62° (relative to due north).

[0073] Export the location data recorded by RTK rover 1, and find the location data P1 (-595.48, -325.17, 160.59) with the timestamp closest to T1, in meters.

[0074] After the water landed, the ground personnel placed RTK mobile station 2 (203) at the center of the water distribution area (205) and recorded the coordinates of RTK mobile station 2 at this time as P2(-348.32, 65.46, 0.65), in meters.

[0075] The range calculation process is as follows:

[0076] P1 and P2 are the coordinates of RTK mobile station 1 / 2 in the RTK base station coordinate system xoy (301). Taking P1 as the origin and the water-dropping direction as the x-axis, we obtain the x'o'y' coordinate system (302). Then, according to the coordinate system translation and rotation transformation formula, the coordinates of P2 in the x'o'y' coordinate system are:

[0077] X = (x2 - x1)cos(Φ1 -Φ0) + (y2 - y1)sin(Φ1 -Φ0)

[0078] Y = (y2 - y1)cos(Φ1 -Φ0)-(x2 - x1)sin(Φ1 -Φ0)

[0079] Therefore, the horizontal range (303) is the X coordinate of P2 in the x'o'y' coordinate system, and the lateral deviation (304) is the Y coordinate of P2 in the x'o'y' coordinate system. The calculation results are as follows:

[0080] Horizontal range = (x2 - x1)cos(Φ1 - Φ0) + (y2 - y1)sin(Φ1 - Φ0) = 459.12 meters

[0081] Lateral deviation = (y2 - y1)cos(Φ1 -Φ0) - (x2 - x1)sin(Φ1 -Φ0) = 53.75 meters.

[0082] The above description is merely a specific embodiment of this application, but the scope of protection of this application 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 this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for measuring the trajectory of fluid projection, characterized in that, Measurements are performed using a measurement system, which includes an RTK base station, two RTK rover stations, and a timer. The RTK base station is used to calculate the current GNSS positioning error and transmit the positioning error to the two RTK mobile stations in real time via radio. The RTK mobile station receives GNSS signals and real-time positioning errors sent by the RTK base station, uses the positioning error data to correct the GNSS signals, calculates accurate position data, and stores it locally. The timer is used for timing; Measurement methods include: Step 1: Fix and calibrate the RTK reference station in an open-air location near the test site; Step 2: Establish the RTK base station coordinate system and record the angle Φ0 of the x-axis relative to true north; Step 3: Establish connections between the RTK base station and two RTK mobile stations, namely the first RTK mobile station and the second RTK mobile station. Step 4: Secure the first RTK mobile station inside the launcher and let it take off with the launcher; Step 5: When the aircraft releases the fluid, record the UTC time T1 of the release moment using a timer, and at the same time record the aircraft heading Φ1 at the release moment; Step 6: Retrieve the location data P1(x1,y1,z1) whose timestamp is closest to T1 from the location data stored in the first RTK mobile station; Step 7: After the fluid lands, place the second RTK mobile station in the center of the fluid distribution area and record the position data P2(x2,y2,z2) of the second RTK mobile station. Step 8: Calculate the horizontal range and lateral deviation of the fluid using coordinate transformation.

2. The method for measuring the range of fluid projection according to claim 1, characterized in that, The range calculation formula in step 8 is as follows: Horizontal range = (x2-x1)cos(Φ1-Φ0) + (y2-y1)sin(Φ1-Φ0); Lateral deviation = (y2-y1)cos(Φ1-Φ0)-(x2-x1)sin(Φ1-Φ0).

3. The method for measuring the range of fluid projection according to claim 1, characterized in that, The operating frequency of the RTK base station and RTK rover station shall not be lower than 50Hz.

4. The method for measuring the range of fluid projection according to claim 1, characterized in that, The location data calculated by the RTK mobile station is the coordinates (x, y, z) of the RTK mobile station in the RTK base station coordinate system, in meters.

5. The method for measuring the range of fluid projection according to claim 1, characterized in that, Each location data stored by the RTK mobile station has a UTC timestamp.

6. The method for measuring the range of fluid projection according to claim 5, characterized in that, The timer records UTC time and has a timing accuracy of no less than 20 milliseconds.

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