A dynamic gravity center real-time monitoring method and system for unmanned aerial vehicles

Abstract

The application provides a kind of unmanned aerial vehicle dynamic barycenter real-time monitoring method and system, comprising: step 1, corresponding oil tank database is established to the oil tank arranged for unmanned aerial vehicle;Step 2, the current unmanned aerial vehicle empty weight and barycenter are input into the flight tube computer by ground maintenance equipment;Step 3, during the flight of unmanned aerial vehicle, the flight tube computer receives each oil tank fuel oil quantity and atmospheric data, calculates the aircraft fuel level angle;Step 4, according to the oil tank database and the aircraft fuel level angle, the weight barycenter data of each oil tank is obtained, and then combined with the unmanned aerial vehicle empty weight and barycenter, the barycenter of unmanned aerial vehicle is calculated;Step 5, the flight tube computer calculates the change of the barycenter of unmanned aerial vehicle in the process of real-time fuel consumption, and is transmitted to the ground flight seat, and the pilot adjusts the flight attitude of the aircraft through the barycenter data.The application truly feedbacks the change of oil level in the oil tank through low-latency transmission mode, timely and effectively feedbacks the change of aircraft barycenter, and is beneficial to real-time and accurate acquisition of aircraft barycenter data.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) control, and in particular to a method and system for real-time monitoring of the dynamic center of gravity of an UAV. Background Technology

[0002] This invention relates to the rapid development of unmanned control technology in recent years. Unmanned aerial vehicles (UAVs) with inherent advantages such as strong battlefield adaptability, strong battlefield survivability, low cost, and high cost-effectiveness have developed rapidly, and a large number of high-altitude, high-speed, long-endurance UAVs have emerged globally.

[0003] In the design of drones, the position of the center of gravity is very important for the control of the drone. In this regard, for the main structure and airframe equipment of the drone with a fixed center of gravity, the change of the center of gravity mainly depends on the change of the center of gravity of the fuel in the drone's fuel system. The traditional method is to place the drone's fuel near the drone's center of gravity or close to the center of gravity required for aircraft control. However, with the requirement for longer flight time, the maximum fuel load of drones can reach 30% to 70% of the maximum takeoff weight. The influence of the fuel center of gravity on the aircraft's center of gravity is becoming more and more significant, and the change of the center of gravity during fuel consumption becomes non-negligible.

[0004] As fuel accounts for an increasingly larger proportion of an aircraft's takeoff weight, the layout of the fuel tanks has a significant impact on the aircraft's center of gravity. The order in which an aircraft consumes fuel has become one of the decisive factors affecting the aircraft's center of gravity envelope. The theoretical front and rear limits of the center of gravity during fuel consumption determine the theoretical front and rear limits of the UAV's center of gravity.

[0005] The center of gravity of a drone is the intersection of its gravity forces. In aircraft design, it is closely related to the aerodynamic focus of the aircraft. Whether the aircraft is statically stable or statically unstable, the matching relationship between its center of gravity and focus directly affects the aircraft's safety, flight quality, performance, economy, and geometric parameters.

[0006] The aerodynamic focus and flight quality of an aircraft determine the front and rear center of gravity limits. For long-endurance UAVs, the center of gravity is basically determined after the aircraft is manufactured. During flight, the change in the center of gravity is mainly affected by fuel consumption. The change in the center of gravity during fuel consumption affects the overall range of the aircraft's center of gravity. The traditional method is to simulate flight conditions by conducting a large number of repeated and complex ground tests on a ground test bench according to the flight profile, plot the fuel consumption center of gravity curve, and evaluate the front and rear limits of the aircraft's center of gravity during fuel consumption so that the center of gravity meets the aircraft control requirements during fuel consumption.

[0007] The movement of the center of gravity is mainly based on the longitudinal and transverse axes. Since the distance between the center of gravity and the center of lift on the longitudinal axis determines the pitch response and static stability of the aircraft, corresponding to the aerodynamic focus of the aircraft, each aircraft has its own gravity and center of gravity position limitations. Therefore, determining the position of the aircraft's center of gravity is one of the key points of attention before and during flight. If the center of gravity shifts, the aircraft will experience control divergence, making it difficult to control during flight, resulting in large changes in flight attitude, which seriously affects flight safety. In severe cases, it may even lead to the UAV going out of control, seriously affecting the execution of UAV missions and threatening the flight safety of UAVs.

[0008] Therefore, monitoring changes in the center of gravity during fuel consumption in flight is imperative. Current methods involve conducting ground tests on ground test benches according to the aircraft's flight conditions and mission profiles, then assessing the changes in the center of gravity. Once safety is assessed, no further action is taken. However, due to limited ground test conditions, it is impossible to simulate many actual flight conditions. Relying solely on ground verification has significant limitations for large-capacity UAVs.

[0009] Drones achieve precise control through accurate sensors during flight. Once installed and fixed, the onboard components remain largely unchanged. However, during fuel consumption, the center of gravity shifts dramatically. The aircraft's center of gravity changes continuously as fuel is consumed. According to the order of fuel consumption, the range of changes in the aircraft's center of gravity should not affect the aircraft's handling stability. If conditions that cannot be simulated on the ground occur, or if the fuel delivery system malfunctions, the changes in the drone's center of gravity cannot be accurately and intuitively perceived, posing many risks to the safe flight of the drone.

[0010] Unlike traditional manned aircraft, which lack the intuitive experience of pilots and rely solely on the small window of the forward-facing camera and data from sensors, it is impossible to perceive the actual changes in the aircraft's center of gravity. Furthermore, during actual flight, the aircraft's center of gravity changes as the aircraft's payload and mission equipment are added or removed. Traditional methods for calculating the fixed center of gravity are insufficient to handle the complex and ever-changing flight conditions, making a dynamic center of gravity monitoring method particularly important. Summary of the Invention

[0011] To address the problems existing in the prior art, a method and system for real-time monitoring of the dynamic center of gravity of unmanned aerial vehicles (UAVs) are provided. Through real-time calculation, the data is remotely transmitted via airborne remote control and telemetry equipment in a low-latency and low-error-rate manner, so that ground flight operators can handle and control the center of gravity of the aircraft.

[0012] The technical solution adopted in this invention is as follows: A method for real-time monitoring of the dynamic center of gravity of an unmanned aerial vehicle (UAV), comprising:

[0013] Step 1: Establish a corresponding fuel tank database for the fuel tanks deployed by the drone;

[0014] Step 2: Input the current empty weight and center of gravity of the UAV into the flight control computer via ground maintenance equipment;

[0015] Step 3: During the flight of the UAV, the flight control computer receives fuel level data from each fuel tank and atmospheric data, and calculates the aircraft's fuel level angle.

[0016] Step 4: Obtain the weight and center of gravity data of each fuel tank based on the fuel tank database and the aircraft fuel level angle. Then, combine the empty weight and center of gravity of the UAV to calculate the center of gravity of the UAV.

[0017] Step 5: The flight control computer calculates the change in the drone's center of gravity during fuel consumption in real time and transmits it to the ground pilot's station. The pilot adjusts the aircraft's flight attitude or strategy based on the center of gravity data to ensure flight safety.

[0018] Furthermore, in step 1, the database of each fuel tank is calculated by three-dimensional software and stored in the fuel computer. The fuel tank database stores the corresponding fuel level angle, centroid coordinates, pitching moment, and rolling moment. The fuel tank database is verified and corrected in ground tests.

[0019] Furthermore, in step 1, the empty weight and center of gravity of the UAV can be adjusted and input through ground maintenance equipment according to the UAV's own load conditions.

[0020] Furthermore, in step 4, the flight control computer interpolates and calculates the center of gravity data of each fuel tank based on the fuel level angle and the database of each fuel tank.

[0021] Furthermore, the empty weight and center of gravity of the drone can be adjusted according to the drone's own payload.

[0022] Furthermore, in step 4, the method for calculating the center of gravity of the UAV is as follows:

[0023]

[0024] Among them, X C Represents the coordinates of the aircraft's center of gravity, G0, X c,0 These represent the weight of the aircraft without fuel and the coordinates of its center of gravity, respectively; G i X c，i These represent the fuel weight of each fuel tank on the aircraft at the corresponding calculation point and its corresponding fuel center of gravity coordinates; k represents the number of fuel tanks.

[0025] The present invention also provides a real-time monitoring system for the dynamic center of gravity of an unmanned aerial vehicle (UAV), comprising:

[0026] The fuel computer is used to obtain the real-time fuel level of each fuel tank; it has a built-in fuel tank database to store the fuel center of gravity corresponding to the fuel level of each fuel tank under various attitudes of the drone.

[0027] The flight control computer calculates the aircraft's fuel level angle based on the received fuel level and atmospheric data from each fuel tank; then, based on the fuel tank database and the aircraft's fuel level angle, it obtains the weight and center of gravity data of each fuel tank, further calculates the UAV's real-time center of gravity, and transmits it to the ground flight station.

[0028] Atmospheric data sensor, used to collect atmospheric data and transmit it to the flight control computer;

[0029] The ground flight station is used to adjust the drone's flight attitude based on the drone's real-time center of gravity.

[0030] Furthermore, it also includes ground maintenance equipment used to adjust the unmanned aerial vehicle's empty weight and center of gravity in the flight control computer.

[0031] Furthermore, the fuel computer and the flight control computer communicate using RS422.

[0032] Furthermore, each fuel tank is equipped with sensors, and the fuel computer actually calculates the data from each sensor to obtain the amount of fuel in each fuel tank.

[0033] Compared with existing technologies, the advantages of adopting the above technical solution are as follows: It abandons the cumbersome simulation calculations of large ground-based test benches, and through a simple and effective method, leveraging the powerful calculation capabilities of the flight control computer, it can obtain the current center of gravity of the UAV in real time, understand the aircraft's flight status, assess flight safety through the center of gravity, and adjust flight attitude based on the dynamic center of gravity, enhancing the pilot's situational awareness. This is a high-benefit flight safety assessment and escort method. The invention uses a low-latency (millisecond-level) transmission method to accurately reflect changes in fuel level in the fuel tank and timely and effectively reflect changes in the aircraft's center of gravity, facilitating the real-time and accurate acquisition of aircraft center of gravity data. It provides an intuitive assessment method for aircraft control, is safe to use, easy to operate, and features a simple and user-friendly human-machine interface. Through various high-precision sensors, it provides real-time feedback of various data for the flight control computer to make real-time judgments, ensuring good synchronization and timely feedback, avoiding the risks caused by lag. Attached Figure Description

[0034] Figure 1 This is a schematic flowchart of the real-time monitoring method for the dynamic center of gravity of an unmanned aerial vehicle (UAV) proposed in this invention.

[0035] Figure 2 This is a schematic diagram of the real-time dynamic center of gravity monitoring system for unmanned aerial vehicles (UAVs) proposed in this invention.

[0036] Figure 3 This is a schematic diagram of the database for tank #1 in one embodiment of the present invention.

[0037] Figure 4 This is a schematic diagram of the database for tank #2 in one embodiment of the present invention.

[0038] Figure 5 This is a schematic diagram of the database for fuel tank #3 in one embodiment of the present invention.

[0039] Figure 6 This is a schematic diagram of the database for fuel tank #4 in one embodiment of the present invention.

[0040] Figure 7 This is a schematic diagram of the database for fuel tank #5 in one embodiment of the present invention. Detailed Implementation

[0041] The embodiments of this application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar modules or modules 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 this application, and should not be construed as limiting this application. Rather, the embodiments of this application include all variations, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0042] Example 1

[0043] This embodiment proposes a method for real-time monitoring of the dynamic center of gravity of an unmanned aerial vehicle (UAV). According to different flight attitudes, a high-precision sensor system measures the aircraft's overload at various attitudes and converts the overload into corresponding fuel level angles. This data is then transmitted down using a low-latency remote control and telemetry protocol. High-precision fuel level sensors measure the fuel level in each fuel tank in real time. Combining this data with the center of gravity occupancy at various fuel levels and attitude angles, the center of gravity of the aircraft during flight is monitored in real time and used as an indicator for flight quality assessment, ensuring flight safety. The specific scheme is as follows:

[0044] A method for real-time monitoring of the dynamic center of gravity of an unmanned aerial vehicle (UAV) includes:

[0045] Step 1: Establish a corresponding fuel tank database for the fuel tanks deployed by the drone;

[0046] Step 2: Input the current empty weight and center of gravity of the UAV into the flight control computer via ground maintenance equipment;

[0047] Step 3: During the flight of the UAV, the flight control computer receives fuel level data from each fuel tank and atmospheric data, and calculates the aircraft's fuel level angle.

[0048] Step 4: Obtain the weight and center of gravity data of each fuel tank based on the fuel tank database and the aircraft fuel level angle. Then, combine the empty weight and center of gravity of the UAV to calculate the center of gravity of the UAV.

[0049] Step 5: The flight control computer calculates the change in the drone's center of gravity during fuel consumption in real time and transmits it to the ground pilot's station. The pilot adjusts the aircraft's flight attitude or strategy based on the center of gravity data to ensure flight safety.

[0050] Specifically, a database of fuel tanks under various attitudes and fuel levels will be established. The database will contain relevant data affecting aircraft handling stability, such as fuel level angle, center of mass coordinates, pitch moment, and roll moment.

[0051] First, based on the actual situation of the aircraft, the empty weight and center of gravity of the aircraft before refueling are input through the ground maintenance equipment. This method is adapted to changes in the aircraft's mission equipment and allows the empty weight and center of gravity of the aircraft to be adjusted according to the actual situation. Mission equipment includes, but is not limited to, fuselage and wing pylons, pylons, electro-optical mission equipment, and various types of dropable missiles and bombs. When the aircraft detects that the corresponding missile or bomb has been dropped, the empty weight and center of gravity can be adjusted in real time according to the aircraft's own load.

[0052] Secondly, the fuel computer calculates the fuel level in each fuel tank in real time. The fuel computer communicates with the flight control computer via RS422 serial communication protocol. The fuel computer transmits the fuel level of each fuel tank to the flight control computer in real time. The flight control computer combines atmospheric data measurement data to calculate the corresponding fuel level angle. Based on the fuel level angle, it performs interpolation calculation according to the database of each fuel tank to obtain the center of gravity data of each fuel tank.

[0053] Finally, the real-time weight and dynamic center of gravity data of the aircraft are calculated using the empty weight and center of gravity data of each fuel tank.

[0054] In this embodiment, the formula for calculating the center of gravity of the UAV is:

[0055]

[0056] Among them, X C —Aircraft center of gravity coordinates G0, X c,0 —The aircraft's weight and center of gravity coordinates, excluding fuel; G i X c，i —The fuel weight of each fuel tank of the aircraft at the corresponding calculation point and the corresponding fuel center of gravity coordinates; k—the number of fuel tanks. If a fuel tank is divided into several compartments and each compartment consumes fuel at different times, it can be considered as several independent fuel tanks.

[0057] In step 1, the database for a single fuel tank can be calculated using 3D software. After the calculation is completed, the values ​​are stored in the airborne storage device to form the corresponding fuel tank weight and center of gravity database. In actual use, the authenticity of the database is verified through ground tests, and the database calculated by the 3D software can be corrected through ground tests.

[0058] In actual use, the flight control computer calls data from the database and calculates the overall center of gravity change curve according to the set program. If the requirements are not met, the empty weight center of gravity needs to be adjusted until the control requirements are met.

[0059] like Figure 1 The diagram shown is a flowchart of the UAV center of gravity monitoring process proposed in this embodiment. A specific application scenario will be used to illustrate this process in detail.

[0060] A certain type of UAV has 5 fuselage fuel tanks, an empty weight of 3000kg, an empty center of gravity (STA) of 4600, a horizontal line (WL) of 10, and the required control range of the aircraft's center of gravity is STA 4570~4630, BL -2~2, and WL -10~10.

[0061] The aircraft has a total of 5 fuel tanks. A database of each fuel tank at various fuel level angles is established according to the aircraft coordinate system, such as... Figures 3-7 As shown, a database for fuel tank #1 is established. This database can be created through a digital model and then verified using the actual loading conditions inside the tank. Similarly, databases for fuel tanks #2 through #5 are established. In each figure, each curve represents the change in the center of gravity under different attitudes (pitch angle, roll angle).

[0062] A database for each fuel tank is established and stored in the fuel computer. Atmospheric data sensors collect aircraft attitude data in real time and transmit the atmospheric data to the flight control computer in real time.

[0063] The flight control computer receives fuel levels from each fuel tank and combines this with atmospheric data (three-axis overload, pitch angle, roll angle, etc.) to calculate the aircraft's fuel level angle. Based on the fuel level angle and fuel tank weight data, it then... Figures 3-7 The database uses interpolation to calculate the center of gravity data of each fuel tank. Combined with the center of gravity of the empty aircraft, the real-time center of gravity of the aircraft is calculated according to the formula for calculating the center of gravity of the UAV.

[0064] During fuel consumption, the fuel levels in each fuel tank change. The flight control computer recalculates in real time at certain time intervals and transmits the aircraft's real-time center of gravity data to the ground pilots. This real-time center of gravity data accurately reflects the aircraft's current status. By using the data from the pilots' positions, combined with audible and visual warnings, the pilots assess the aircraft's safety and take timely action.

[0065] Example 2

[0066] like Figure 2 As shown, this embodiment also provides a real-time monitoring system for the dynamic center of gravity of an unmanned aerial vehicle (UAV), including:

[0067] The fuel computer is used to obtain the real-time fuel level of each fuel tank; it has a built-in fuel tank database to store the fuel center of gravity corresponding to the fuel level of each fuel tank under various attitudes of the drone.

[0068] The flight control computer calculates the aircraft's fuel level angle based on the received fuel level and atmospheric data from each fuel tank; then, based on the fuel tank database and the aircraft's fuel level angle, it obtains the weight and center of gravity data of each fuel tank, further calculates the UAV's real-time center of gravity, and transmits it to the ground flight station.

[0069] Atmospheric data sensor, used to collect atmospheric data and transmit it to the flight control computer;

[0070] The ground flight station is the interface between the drone and the user, which allows for real-time monitoring of the drone's flight status and enables corresponding measures to control the flight and adjust the drone's flight attitude in a timely manner.

[0071] In this embodiment, the flight control computer supports the input of the empty weight and center of gravity of the UAV and stores this data in the computer, which is then called up in real-time calculations. The corresponding monitoring system also includes ground maintenance equipment for inputting the empty weight and center of gravity of the UAV into the flight control computer.

[0072] In this embodiment, the fuel computer and the flight control computer communicate using RS422. Through low-latency (millisecond-level) transmission, the changes in fuel level in the fuel tank are accurately reflected, and the changes in the aircraft's center of gravity are reflected in a timely and effective manner, which is conducive to obtaining the aircraft's center of gravity data in real time.

[0073] In this embodiment, each fuel tank is equipped with a sensor, and the fuel computer calculates the data from each sensor to obtain the fuel level in each tank. All sensors used are high-precision, redundant sensors that can quickly feed back various data for the flight control computer to make real-time judgments. They have good synchronization and timely feedback, avoiding the risks associated with latency.

[0074] It should be noted that, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "set" and "connection" 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 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 the present invention based on the specific circumstances. The accompanying drawings in the embodiments are used to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0075] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for real-time monitoring of the dynamic center of gravity of an unmanned aerial vehicle (UAV), characterized in that, include: Step 1: Establish a corresponding fuel tank database for the fuel tanks deployed by the drone; Step 2: Input the current empty weight and center of gravity of the UAV into the flight control computer via ground maintenance equipment; Step 3: During the flight of the UAV, the flight control computer receives fuel level data from each fuel tank and atmospheric data, and calculates the aircraft's fuel level angle. Step 4: Obtain the weight and center of gravity data of each fuel tank based on the fuel tank database and the aircraft fuel level angle. Then, combine the empty weight and center of gravity of the UAV to calculate the center of gravity of the UAV. Step 5: The flight control computer calculates the change in the drone's center of gravity during fuel consumption in real time and transmits it to the ground flight station. The pilot adjusts the aircraft's flight attitude based on the center of gravity data.

2. The method for real-time monitoring of the dynamic center of gravity of an unmanned aerial vehicle (UAV) according to claim 1, characterized in that, In step 1, the database of each fuel tank is calculated by three-dimensional software and stored in the fuel computer. The fuel tank database stores the corresponding fuel level angle, centroid coordinates, pitching moment, and rolling moment. The fuel tank database is verified and corrected in ground tests.

3. The method for real-time monitoring of the dynamic center of gravity of an unmanned aerial vehicle (UAV) according to claim 1, characterized in that, In step 1, when the drone's own load changes, the drone's empty weight and center of gravity can be adjusted and modified through ground maintenance equipment.

4. The method for real-time monitoring of the dynamic center of gravity of an unmanned aerial vehicle (UAV) according to claim 1, characterized in that, In step 3, the onboard fuel computer acquires sensor data installed in each fuel tank, calculates the fuel level in each tank, and transmits it to the flight control computer.

5. The method for real-time monitoring of the dynamic center of gravity of an unmanned aerial vehicle (UAV) according to claim 1, characterized in that, In step 4, the flight control computer interpolates and calculates the center of gravity data of each fuel tank based on the fuel level angle and the database of each fuel tank.

6. The method for real-time monitoring of the dynamic center of gravity of an unmanned aerial vehicle (UAV) according to claim 1, characterized in that, In step 4, the method for calculating the center of gravity of the UAV is as follows: in, Indicates the coordinates of the aircraft's center of gravity. , These represent the weight of the aircraft without fuel and the coordinates of its center of gravity, respectively. , These represent the fuel weight of each fuel tank on the aircraft at the corresponding calculation point and its corresponding fuel center of gravity coordinates. This indicates the number of fuel tanks.

7. A real-time monitoring system for the dynamic center of gravity of an unmanned aerial vehicle (UAV), characterized in that, include: The fuel computer is used to obtain the real-time fuel level of each fuel tank; it has a built-in fuel tank database to store the fuel level angle, center of mass coordinates, pitch moment, and roll moment of each fuel tank. The flight control computer receives real-time data on fuel levels and atmospheric conditions from each fuel tank and calculates the aircraft's fuel level angle. Based on the fuel tank database and the aircraft's fuel level angle, it obtains the weight and center of gravity data of each fuel tank, further calculates the UAV's real-time center of gravity, and transmits it to the ground flight station. Atmospheric data sensor, used to collect atmospheric data and transmit it to the flight control computer; The ground flight station is used to adjust the drone's flight attitude based on the drone's real-time center of gravity.

8. The real-time monitoring system for the dynamic center of gravity of an unmanned aerial vehicle (UAV) according to claim 7, characterized in that, It also includes ground maintenance equipment for inputting the drone's empty weight and center of gravity into the flight control computer.

9. The real-time monitoring system for the dynamic center of gravity of an unmanned aerial vehicle (UAV) according to claim 7 or 8, characterized in that, The fuel computer and the flight control computer communicate using RS422.

10. The real-time monitoring system for the dynamic center of gravity of an unmanned aerial vehicle (UAV) according to claim 7, characterized in that, Each fuel tank is equipped with a sensor, and the fuel computer calculates the data from each sensor to obtain the amount of fuel in each fuel tank.

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