Method and device for enhancing static stability of unmanned aerial vehicle

Abstract

This application discloses a method and device for enhancing the static stability of a drone, relating to the field of drone technology. The method comprises: obtaining the pitch and yaw moments of the drone and stabilizing parachute assembly and performing a stability calculation analysis; determining the force area and parachute rope length of the stabilizing parachute based on the stability calculation analysis results; installing the stabilizing parachute at the tail of the drone, with its attachment point located at the center of the drone's longitudinal axis of symmetry; carrying the drone to a preset altitude in the air, releasing it with the wings extended, and then deploying the stabilizing parachute; and after the drone adjusts its posture and completes the dive and leveling operation, removing the stabilizing parachute. This method solves the problem of how to enhance the stability of a drone without changing its aerodynamic shape, thereby reducing the risk of accidents caused by control divergence during flight.

Description

Technical Field

[0001] The present application relates to the field of UAV technology, and in particular to a method and device for enhancing the static stability of a UAV. Background Art

[0002] In the drone development process, after the overall and aerodynamic design phases are completed, the drone undergoes wind tunnel testing after production. The wind tunnel data is then used to analyze and evaluate the drone's control and stability characteristics. Because production often deviates from the actual design, and certain drones, due to specific flight scenarios or phases, require specialized aerodynamic design to improve maneuverability or flight endurance, at the expense of stability. This reduced stability poses significant challenges to flight control and increases flight risk. Furthermore, since the drone has already been produced and its aerodynamic shape cannot be altered, autonomous and safe flight can only be achieved through flight control. However, this still faces significant uncertainty in actual operation, making flight risk difficult to effectively control.

[0003] Therefore, how to enhance the stability of the UAV without changing its aerodynamic shape to reduce the risk of accidents caused by control divergence during flight has become an urgent issue. Summary of the Invention

[0004] In an embodiment of the present application, a method for enhancing the static stability of a drone is provided, which solves the problem of how to enhance the stability of a drone without changing the aerodynamic shape of the drone, so as to reduce the risk of accidents caused by control divergence during flight.

[0005] In the first aspect, an embodiment of the present application provides a method for enhancing the static stability of a drone, the method comprising: obtaining the pitch moment and yaw moment of the drone and the parachute combination and performing a control and stability calculation analysis, and determining the force area and parachute rope length of the stabilizing parachute based on the control and stability calculation analysis results; installing a stabilizing parachute at the tail of the drone, with its hanging point located at the center of the drone's longitudinal symmetry axis; carrying the drone to a preset altitude in the air, releasing it with the wings extended, and then opening the stabilizing parachute; after the drone adjusts its own posture to complete the dive and leveling operation, the stabilizing parachute is removed.

[0006] In one possible implementation, the method of obtaining the pitch moment and yaw moment of the parachute-aircraft combination of the UAV and the stabilizing parachute and performing a stabilization calculation analysis, and determining the force area and parachute rope length of the stabilizing parachute based on the results of the stabilization calculation analysis, includes: superimposing the pitch moment and yaw moment of the stabilizing parachute onto the pitch moment and yaw moment of the UAV, respectively, to obtain the pitch moment and yaw moment of the parachute-aircraft combination; performing a stabilization calculation analysis based on the pitch moment and yaw moment of the parachute-aircraft combination; and determining the force area and parachute rope length of the stabilizing parachute using the damping ratio and overshoot of the parachute-aircraft combination as constraints of the results of the stabilization calculation analysis.

[0007] In one possible implementation, the pitch moment of the stabilizing parachute is calculated as follows: ;in, is the pitching moment of the stabilizing parachute, is the drag coefficient of the stabilizing parachute, is the force-bearing area of ​​the stabilizing parachute, is the distance between the parachute hanging point and the aerodynamic focus of the drone, is the angle of attack of the UAV; the calculation formula of the yaw moment of the stabilizing parachute is: ;in, is the sideslip angle of the UAV; ; is the radius of the stabilizing parachute, is a mathematical constant.

[0008] In one possible implementation, it is also included to verify whether the force area of ​​the stabilizing parachute meets the requirements based on preset principles through simulated flight. The preset principles specifically include: after the UAV completes the dive and leveling operation, the stabilizing parachute is cut off, the minimum speed of the UAV is greater than or equal to the preset multiple of the stall speed of the UAV, and the maximum speed of the UAV is less than or equal to the flutter speed of the UAV; wherein, the preset multiple is greater than 1.

[0009] In one possible implementation, the drone is carried to a preset altitude in the air, released in a wings-expanded posture, and then the stabilizing parachute is opened, including: when the drone is in a wings-folded state, it is carried to a preset altitude by an aerial carrier; when the drone reaches the preset altitude, the drone performs a wings-expanding action; after the wings-expanding action is completed, the aerial carrier releases the drone; the drone detects the release signal and opens the stabilizing parachute, at which time the fuselage attitude is adjusted while the propeller is in a stationary state.

[0010] In one possible implementation, after the UAV adjusts its own attitude to complete the dive and leveling operation, the stabilizing parachute is removed, including: the UAV performs the dive and leveling operation by adjusting its own attitude, gradually reducing the pitch angle, and transitioning to a horizontal flight state; when the UAV completes the dive and leveling operation, the stabilizing parachute is removed, the propeller is turned on, and the normal flight process is executed.

[0011] In a possible implementation, a criterion for determining whether the drone has completed a dive-to-level operation is that the pitch angle of the drone is greater than a preset angle and the duration is greater than a preset time.

[0012] In the second aspect, an embodiment of the present application provides a device for enhancing the static stability of a drone, the device comprising: a determination module for obtaining the pitch moment and yaw moment of the parachute combination of the drone and the stabilizing parachute and performing a control and stability calculation analysis, and determining the force area and parachute rope length of the stabilizing parachute based on the control and stability calculation analysis results; an installation module for installing the stabilizing parachute at the tail of the drone, with its hanging point located at the center of the longitudinal symmetry axis of the drone; an opening module for carrying the drone to a preset altitude in the air, releasing it in the wings-expanded posture, and then opening the stabilizing parachute; a cutting module for cutting off the stabilizing parachute after the drone adjusts its own posture and completes the dive and leveling operation.

[0013] In a third aspect, an embodiment of the present application provides a server for enhancing the static stability of a drone, comprising a memory and a processor; the memory is used to store computer-executable instructions; the processor is used to execute the computer-executable instructions to implement the method described in the first aspect or any possible implementation method of the first aspect.

[0014] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores executable instructions. When a computer executes the executable instructions, it can implement the method described in the first aspect or any possible implementation method of the first aspect.

[0015] One or more technical solutions provided in the embodiments of this application have at least the following technical effects: The embodiments of this application provide a method for enhancing the static stability of a drone. The method obtains the pitch and yaw moments of the drone and stabilizing parachute assembly, performs a stability calculation and analysis, and determines the parachute's force area and line length based on the stability calculation and analysis results. The parachute is attached to the tail of the drone, with its attachment point located at the center of the drone's longitudinal axis of symmetry. The drone is carried to a preset altitude and released with its wings extended, then the parachute deploys. After the drone adjusts its attitude and completes a dive-to-level maneuver, the parachute is removed. This application enhances the stability of a drone using the parachute without changing the drone's aerodynamic shape. Furthermore, the added parachute has a short testing and processing cycle, enabling rapid test verification. This method addresses the problem of enhancing drone stability without changing the drone's aerodynamic shape, thereby reducing the risk of accidents caused by control divergence during flight. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments of the present application or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A schematic diagram of the throwing and flying technology provided in an embodiment of the present application;

[0018] Figure 2 A graph showing the relationship between the yaw moment coefficient of the drone provided in the embodiment of the present application and the angle of attack and sideslip angle;

[0019] Figure 3 A flowchart of a method for enhancing the static stability of a drone provided in an embodiment of the present application;

[0020] Figure 4 A schematic diagram of installing a stabilizing parachute on the tail of a drone provided in an embodiment of the present application;

[0021] Figure 5 A schematic diagram of the radius of the stabilizing parachute provided in an embodiment of the present application;

[0022] Figure 6 A schematic diagram of a device for enhancing the static stability of a drone provided in an embodiment of the present application;

[0023] Figure 7 A schematic diagram of a server for enhancing the static stability of a drone provided in an embodiment of the present application. DETAILED DESCRIPTION

[0024] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0025] The following description of some of the technologies involved in the embodiments of this application is provided to facilitate understanding and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of this application. Similarly, for the sake of clarity and conciseness, some descriptions of well-known functions and structures are omitted from the following description.

[0026] Figure 1Schematic diagram of the jettison flight technology provided in an embodiment of this application. This application uses a high-aspect-ratio drone as an example to describe its jettison flight technology. This technology allows the drone to be released from an aerial carrier in a nose-down position, jettisoned for flight, achieving a smooth dive and leveling maneuver, and ultimately autonomous flight along a predetermined route. The aerial carrier can include a parachute, hot air balloon, or other load-carrying aircraft.

[0027] To smoothly transition the drone from a vertically downward position to horizontal flight, the dive-to-level maneuver is divided into two phases: the initial phase (Phase 1) and the final phase (Phase 2). In the initial phase (Phase 1), the drone is released from the airborne carrier in a nose-down position with an initial velocity of zero. The drone then begins a downward free fall, converting gravitational potential energy into kinetic energy and gradually increasing its speed. In the final phase (Phase 2), the control surfaces are manipulated to gradually raise the drone's head, transitioning it from a vertically downward position to horizontal flight.

[0028] During the entire dive-to-level maneuver, the drone's speed is relatively low in the initial phase (Phase 1), resulting in relatively poor stability and placing higher demands on control quality in both the time and frequency domains. In particular, the drone exhibits significant deficiencies in directional static stability. The higher speeds in the final phase (Phase 2) place even higher demands on flight control, requiring the flight control law design to meet stringent stability margin requirements.

[0029] Figure 2 A graph showing the relationship between the yaw moment coefficient and the sideslip angle for a drone according to an embodiment of the present application. As can be seen from the graph, when the angle of attack is small (e.g., Alpha = 0°, 2°), the yaw moment coefficient of the drone generally increases with the sideslip angle, indicating that the drone is statically stable at these angles of attack. However, when the angle of attack exceeds 4°, the yaw moment coefficient generally decreases with increasing sideslip angle, indicating that the drone becomes statically unstable at these angles of attack. Figure 2 The Alpha in is the angle of attack.

[0030] Table 1 shows the time-domain and frequency-domain characteristics of the embodiment of this application under normal operating conditions (optimal stability at an angle of attack of 0°). Taking directional stability as an example, analysis shows that the Dutch roll mode damping ratio is only 0.291 (the corresponding Dutch roll mode damping ratio can also be calculated for longitudinal stability), indicating that the system's ability to suppress vibration is weak, vibration is relatively severe, and rapid stabilization is difficult. Further calculations using parameters such as the characteristic roots and natural frequencies reveal a 38.5% overshoot in the system's time-domain characteristics, indicating significant fluctuations in the system's response. Furthermore, during a UAV dive-to-level maneuver, the angle of attack varies significantly, further exacerbating the risk of control divergence. Therefore, to improve the stability and control performance of the UAV, its intrinsic characteristics must be adjusted to meet the time-domain and frequency-domain design specifications of the flight control law. Specifically, the Dutch roll mode damping ratio must be adjusted to approximately 0.7, and the overshoot must be kept within the ideal range of 5% to ensure the UAV maintains stable and reliable flight during dive-to-level maneuvers.

[0031] Table 1

[0032]

[0033] The present invention provides a method for enhancing the static stability of a drone. Figure 3 As shown, the method includes steps S101 to S104. Figure 3 This is only an execution order shown in the embodiment of the present application, and does not represent the only execution order of a method for enhancing the static stability of a drone. If the final result can be achieved, Figure 3 The steps shown may be performed in parallel or reversed.

[0034] S101: Obtain the pitch moment and yaw moment of the parachute assembly of the UAV and the stabilizing parachute and perform a control and stability calculation analysis. Based on the control and stability calculation analysis results, determine the force area and parachute rope length of the stabilizing parachute.

[0035] S102: Install a stabilizing parachute at the tail of the UAV, with its attachment point located at the center of the UAV's longitudinal symmetry axis.

[0036] This application installs a stabilizing parachute on the tail of a drone, without changing its aerodynamic shape, to improve its stability and reduce the risk of control divergence. The parachute's attachment point is precisely positioned at the center of the drone's longitudinal axis of symmetry, or the center of its X-axis. This location ensures even distribution of the parachute's force on the drone, avoiding unbalanced torque caused by misaligned mounting positions and thus ensuring the drone's stability during flight.

[0037] Figure 4A schematic diagram of an embodiment of the present application showing the installation of a stabilizing parachute on the tail of a drone. The X, Y, and Z axes are indicated in the diagram, with the parachute attachment point (point P) located at the center of the drone's longitudinal axis of symmetry, i.e., the center of the drone's X axis. The aerodynamic focus of the drone. It is the distance between the parachute hanging point and the aerodynamic focus of the UAV.

[0038] Obtaining the pitch and yaw moments of the parachute-aircraft assembly of the unmanned aerial vehicle (UAV) and the stabilizing parachute and performing a stability calculation and analysis, and determining the force area and parachute cord length of the stabilizing parachute based on the results of the stability calculation and analysis, includes the following steps: Superimposing the pitch and yaw moments of the stabilizing parachute onto the pitch and yaw moments of the UAV, respectively, to obtain the pitch and yaw moments of the parachute-aircraft assembly. Performing a stability calculation and analysis based on the pitch and yaw moments of the parachute-aircraft assembly. Using the damping ratio and overshoot of the parachute-aircraft assembly as constraints on the stability calculation and analysis results, determining the force area and parachute cord length of the stabilizing parachute.

[0039] Specifically, in order to accurately control the effect of the stabilizing parachute on the UAV torque, it is necessary to determine the parachute's force area and the parachute rope length. The calculation formula for the parachute's force area is: .in, is the force-bearing area of ​​the stabilizing parachute, is the radius of the stabilizing parachute, is a mathematical constant. During flight, the parachute generates resistance according to the direction of the airflow, thereby changing the pitch and yaw moments of the drone.

[0040] Figure 5 This is a schematic diagram of the radius of the stabilizing parachute provided in the embodiment of the present application. Point Q in the figure is the aerodynamic force point of the stabilizing parachute. is the radius of the stabilizing parachute.

[0041] The calculation formula of the pitching moment of the stabilizing parachute is: .in, is the pitching moment of the stabilizing parachute, is the drag coefficient of the stabilizing parachute, is the force-bearing area of ​​the stabilizing parachute, is the distance between the parachute hanging point and the aerodynamic focus of the drone, is the angle of attack of the drone.

[0042] It should be noted that the drag coefficient of the stabilizing parachute is related to the material of the stabilizing parachute itself.

[0043] The calculation formula of the yaw moment of the stabilizing parachute is: .in, is the sideslip angle of the UAV. . is the radius of the stabilizing parachute, is a mathematical constant.

[0044] Specifically, the pitch moment of the stabilizing parachute is and yaw moment Superimposed on the pitch moment of the drone and yaw moment To obtain the pitching moment and yaw moment of the parachute assembly, that is, , .in, is the pitching moment of the parachute-aircraft assembly, is the yaw moment of the parachute-aircraft combination.

[0045] It's important to note that the parachute-aircraft combination achieves a new moment equilibrium state, relative to the drone's original moment equilibrium. Without the parachute, the drone's aerodynamic layout, center of gravity, and other factors keep its pitch and yaw moments in equilibrium, allowing it to maintain a relatively stable flight attitude.

[0046] This application takes a large aspect ratio UAV as an example, and adds the pitch moment and yaw moment of the stabilizing parachute to the pitch moment and yaw moment of the UAV respectively. After forming a new moment equilibrium state, the stability calculation analysis is performed based on the pitch moment and yaw moment of the parachute-aircraft combination. When the force area of ​​the stabilizing parachute is 0.9m 2 When the distance between the parachute hanging point and the aerodynamic focus of the UAV is 1.2m, the calculation results of the control and stability characteristics after adding the stabilizing parachute are shown in Table 2. Table 2 is a time domain and frequency domain characteristic table of the new torque equilibrium state based on the parachute-machine combination provided in the embodiment of the present application. After adding the stabilizing parachute, the heading stability of the UAV changes, and the heading is stable within the range of the angle of attack, and the damping ratio and overshoot of the parachute-machine combination are within the ideal range, which effectively improves the heading stability of the UAV. It should be noted that the damping ratios in this application are all Dutch roll mode damping ratios.

[0047] Table 2

[0048]

[0049] Specifically, the force-bearing area of ​​the stabilizing parachute is not necessarily larger, as it may bring about adverse effects such as additional resistance and interference with aerodynamic characteristics. Therefore, the reasonable force-bearing area range of the stabilizing parachute can be determined by means of simulated flight, combined with the aerodynamic characteristics of the UAV that need to be tested, and judged by speed.

[0050] This application also includes verifying, through simulated flight, whether the parachute's force-bearing area meets the requirements based on preset principles. The preset principles specifically include: after the drone completes a dive-to-level maneuver, the parachute is removed, the drone's minimum speed is greater than or equal to a preset multiple of the drone's stall speed, and the drone's maximum speed is less than or equal to the drone's flutter speed. The preset multiple is greater than 1. The preset multiple can be set to 1.3. When the drone's speed meets the preset principles, the parachute's force-bearing area meets the requirements.

[0051] Specifically, a drone's stall speed refers to the minimum speed required for it to maintain normal lift during flight. When a drone's speed drops below the stall speed, the lift becomes insufficient to support its weight, causing it to stall and potentially experience dangerous conditions such as a rapid drop in altitude and loss of attitude control. Flutter is a self-excited vibration phenomenon in a drone's structure caused by the coupling of aerodynamic, elastic, and inertial forces. The flutter speed is the critical speed at which a drone experiences flutter. When the flight speed exceeds the flutter speed, structural vibrations intensify, potentially leading to structural failure and catastrophic consequences.

[0052] Furthermore, a safety margin of 1.3 times the stall speed prevents the drone from falling into the stall range and ensures that the drone maintains lift balance despite external disturbances. The drone's maximum speed is less than or equal to its flutter speed, preventing structural flutter caused by excessive speed.

[0053] S103: Bring the drone to a preset altitude in the air, release it with the wings extended, and then deploy the stabilizing parachute.

[0054] The drone is carried to a preset altitude, released with its wings extended, and then deployed with its stabilizer parachute. The following steps are involved: With its wings folded, the drone is carried to a preset altitude by an aerial vehicle. Once the drone reaches the preset altitude, it deploys its wings. Once the wings are deployed, the aerial vehicle releases the drone. The drone detects the release signal, deploys its stabilizer parachute, and adjusts its posture while its propellers remain stationary.

[0055] S104: After the UAV adjusts its attitude and completes the dive and leveling operation, it removes the stabilizing parachute.

[0056] Specifically, during the dive and leveling operation of the drone, the stabilizing parachute plays a role in enhancing the stability of the drone. When the drone completes the dive and leveling operation, the stabilizing parachute is cut off in the air and it can fly autonomously according to the predetermined route.

[0057] After the drone adjusts its attitude and completes the dive and leveling maneuver, it removes the stabilizing parachute. This includes: the drone adjusts its attitude to perform the dive and leveling maneuver, gradually reducing the pitch angle and transitioning to a level flight state. After the drone completes the dive and leveling maneuver, the stabilizing parachute is removed, the propellers are turned on, and normal flight procedures are carried out.

[0058] Specifically, the judgment criteria for whether the drone completes the dive-to-level operation are that the pitch angle of the drone is greater than a preset angle and the duration is greater than a preset time.

[0059] In this application, the preset angle is set to -5° and the preset time is set to 1 second. That is, when the drone performs a dive-to-level maneuver, its pitch angle is monitored in real time. Once the pitch angle is greater than -5° and remains in this state for more than 1 second, it is determined that the drone has completed the dive-to-level maneuver.

[0060] This application enhances the stability of a drone by using a stabilizing parachute without changing its aerodynamic shape. Furthermore, the added parachute has a short testing and processing cycle, enabling rapid test verification. The addition of the parachute also avoids the problem of prolonged dive-to-level maneuvers, which can lead to excessive speed after the drone completes the dive-to-level maneuver and cause flutter in the drone.

[0061] The embodiment of the present application also provides a device 600 for enhancing the static stability of a drone, such as Figure 6 As shown, the device includes: a determination module 601 , a mounting module 602 , an opening module 603 and a cutting module 604 .

[0062] The determination module 601 obtains the pitching moment and yaw moment of the parachute assembly of the UAV and the stabilizing parachute and performs a control and stability calculation analysis, and determines the force area and parachute rope length of the stabilizing parachute based on the control and stability calculation analysis results.

[0063] The installation module 602 is used to install a stabilizing parachute at the tail of the UAV, and its hanging point is located at the center of the longitudinal symmetry axis of the UAV.

[0064] The opening module 603 is used to carry the UAV to a preset altitude in the air, release it with the wings extended, and then open the stabilizing parachute.

[0065] The removal module 604 is used to remove the stabilizing parachute after the UAV adjusts its own attitude and completes the dive and leveling operation.

[0066] Some modules in the apparatus described herein may be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, classes, etc. that perform specific tasks or implement specific abstract data types. The present application may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communications network. In a distributed computing environment, program modules may be located in local and remote computer storage media, including storage devices.

[0067] The devices or modules described in the above application embodiments can be implemented by computer chips or physical devices, or by products with certain functions. For ease of description, the above devices are described separately by function in various modules. When implementing the embodiments of this application, the functions of each module can be implemented in the same or multiple software and / or hardware. Of course, a module that implements a certain function can also be implemented by combining multiple sub-modules or sub-units.

[0068] The methods, devices, or modules described herein can be implemented in the form of computer-readable program code. The controller can be implemented in any suitable manner. For example, the controller can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (e.g., software or firmware) executable by the (micro)processor, logic gates, switches, an application-specific integrated circuit (ASIC), a programmable logic controller, and an embedded microcontroller. Examples of controllers include, but are not limited to, the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicone Labs C8051F320. The memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art will also appreciate that, in addition to implementing the controller in the form of pure computer-readable program code, the controller can also be implemented in the form of logic gates, switches, an application-specific integrated circuit, a programmable logic controller, an embedded microcontroller, etc. by logically programming the method steps. Therefore, such a controller can be considered a hardware component, and the devices included therein for implementing various functions can also be considered as structures within the hardware component. Or even, the means for implementing various functions may be considered to be both a software module for implementing the method and a structure within a hardware component.

[0069] like Figure 7As shown, an embodiment of the present application also provides a server for enhancing the static stability of a drone, including a memory 701 and a processor 702; the memory 701 is used to store computer-executable instructions; the processor 702 is used to execute computer-executable instructions to implement a method for enhancing the static stability of a drone described above in an embodiment of the present application.

[0070] An embodiment of the present application further provides a computer-readable storage medium, which stores executable instructions. When a computer executes the executable instructions, it can implement the method for enhancing the static stability of a drone as described above in the embodiment of the present application.

[0071] Through the description of the above implementation methods, it can be seen that those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary hardware. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, or can be embodied through the implementation process of data migration. The computer software product can be stored in a storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a mobile terminal, a server, or a network device, etc.) to execute the method described in the embodiments of the present application.

[0072] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to in detail. Each embodiment focuses on the differences from other embodiments. All or part of this application can be used in many general or special computer system environments or configurations.

[0073] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A method for enhancing the static stability of an unmanned aerial vehicle, characterized in that: include: Obtain the pitching moment and yaw moment of the UAV and stabilizing parachute assembly and perform stability calculation analysis. Based on the results of the stability calculation analysis, determine the force area and parachute rope length of the stabilizing parachute. The method of obtaining the pitching moment and yaw moment of the parachute-aircraft assembly of the UAV and the stabilizing parachute and performing a control calculation and analysis, and determining the force-bearing area and parachute rope length of the stabilizing parachute based on the control calculation and analysis results, includes: superimposing the pitching moment and yaw moment of the stabilizing parachute onto the pitching moment and yaw moment of the UAV, respectively, to obtain the pitching moment and yaw moment of the parachute-aircraft assembly; Performing a control and stability calculation analysis based on the pitching moment and yaw moment of the parachute-aircraft assembly; determining the force area and parachute rope length of the stabilizing parachute using the damping ratio and overshoot of the parachute-aircraft assembly as constraints on the control and stability calculation and analysis results; A stabilizing parachute is installed at the tail of the UAV, with its attachment point located at the center of the UAV's longitudinal symmetry axis; Bring the drone to a preset altitude in the air, release it with the wings extended, and then deploy the stabilizing parachute; After the drone adjusts its attitude and completes the dive and leveling operation, it removes the stabilizing parachute.

2. The method for enhancing the static stability of a UAV according to claim 1, characterized in that: The calculation formula of the pitching moment of the stabilizing parachute is: ;in, is the pitching moment of the stabilizing parachute, is the drag coefficient of the stabilizing parachute, is the force-bearing area of ​​the stabilizing parachute, is the distance between the parachute hanging point and the aerodynamic focus of the drone, is the angle of attack of the UAV; The calculation formula of the yaw moment of the stabilizing parachute is: ;in, is the sideslip angle of the UAV; in, ; is the radius of the stabilizing parachute, is a mathematical constant.

3. The method for enhancing the static stability of a UAV according to claim 1, characterized in that: It also includes verifying whether the force-bearing area of ​​the stabilizing parachute meets the requirements based on preset principles through simulated flight. The preset principles specifically include: After the drone completes the dive and leveling operation, the stabilizing parachute is removed, the drone's minimum speed is greater than or equal to a preset multiple of the drone's stall speed, and the drone's maximum speed is less than or equal to the drone's flutter speed; wherein the preset multiple is greater than 1.

4. The method for enhancing the static stability of a UAV according to claim 1, characterized in that: The method of carrying the drone to a preset altitude in the air, releasing it with the wings extended, and then deploying the stabilizing parachute includes: When the drone is in the wing-folded state, it is carried to a preset altitude by the aerial carrier; When the drone reaches the preset height, it unfolds its wings; After the wing deployment action is completed, the aerial carrier releases the drone; The drone detects the release signal and opens the stabilizing parachute. At this time, the fuselage attitude is adjusted while the propeller is stationary.

5. The method for enhancing the static stability of a UAV according to claim 1, characterized in that: After the UAV adjusts its attitude and completes the dive-to-level operation, the stabilizing parachute is removed, including: The drone performs a dive-to-level operation by adjusting its own attitude, gradually reducing the pitch angle and transitioning to a horizontal flight state; When the drone completes the dive and leveling operation, it removes the stabilizing parachute, starts the propellers, and executes the normal flight process.

6. The method for enhancing the static stability of a UAV according to claim 1, characterized in that: The criteria for determining whether the drone has completed a dive-to-level operation are that the drone's pitch angle is greater than a preset angle and the duration is greater than a preset time.

7. A device for enhancing the static stability of an unmanned aerial vehicle, characterized in that: include: a determination module for obtaining the pitching moment and yaw moment of the parachute-machine combination of the UAV and the stabilizing parachute and performing a stabilization calculation and analysis, and determining the force-bearing area and parachute rope length of the stabilizing parachute based on the results of the stabilization calculation and analysis; the obtaining the pitching moment and yaw moment of the parachute-machine combination of the UAV and the stabilizing parachute and performing a stabilization calculation and analysis, and determining the force-bearing area and parachute rope length of the stabilizing parachute based on the results of the stabilization calculation and analysis, comprising: superimposing the pitching moment and yaw moment of the stabilizing parachute onto the pitching moment and yaw moment of the UAV respectively to obtain the pitching moment and yaw moment of the parachute-machine combination; performing a stabilization calculation and analysis based on the pitching moment and yaw moment of the parachute-machine combination; and determining the force-bearing area and parachute rope length of the stabilizing parachute using the damping ratio and overshoot of the parachute-machine combination as constraints on the results of the stabilization calculation and analysis; The mounting module is used to install a stabilizing parachute on the tail of the UAV, with its attachment point located at the center of the longitudinal symmetry axis of the UAV; The opening module is used to carry the drone to a preset altitude in the air, release it with the wings extended, and then deploy the stabilizing parachute; The removal module is used to remove the stabilizing parachute after the drone adjusts its own attitude and completes the dive and leveling operation.

8. A server for enhancing the static stability of a drone, characterized in that: including memory and processor; The memory is used to store computer-executable instructions; The processor is configured to execute the computer-executable instructions to implement the method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores executable instructions, and when a computer executes the executable instructions, the method according to any one of claims 1 to 6 can be implemented.

Images