Method and device for enabling low-speed aircraft with high aspect ratio to pass through large wind layer

Abstract

The embodiment of the invention discloses a method and device for a high-aspect-ratio low-speed aircraft to pass through a large wind layer. The method comprises the steps that when the air speed of a traditional fixed-wing aircraft is larger than the wind speed, the traditional fixed-wing aircraft can fly forwards all the time; the high-aspect-ratio low-speed aircraft can not keep flying forwards when the space speed is possibly equal to or smaller than the wind speed at the high wind speed; and during flight retreating, in order to minimize the flight retreating distance, a sensor is installed to obtain the air speed, the ground speed, the speed course and the airframe course, the wind direction is calculated online in real time, and the airframe course is controlled to face the wind coming side, so that the flight retreating distance is minimized when the aircraft passes through the large wind layer.

Description

Technical Field

[0001] This invention relates to the field of aircraft design, and particularly to a method for low-speed passage through high-aspect-ratio wind layers. Background Technology

[0002] High-aspect-ratio low-speed aircraft, such as solar-powered drones and high-altitude long-endurance aircraft, face significant aerodynamic and structural challenges when traversing high wind layers. Traditional fixed-wing aircraft, with their relatively high flight speeds, generally maintain forward flight as their airspeed exceeds wind speed, only needing to be grounded in extreme weather conditions. Therefore, they typically do not consider the possibility of backing up when wind speed exceeds airspeed. However, traditional low-speed aircraft, due to their high aspect ratio and lightweight structure, are prone to aeroelastic instability (such as flutter and torsional divergence) in strong wind shear and turbulent environments, leading to loss of control and even structural damage. Furthermore, low-speed aircraft have limited control effectiveness, struggling to maintain a stable course in crosswinds or vertical wind gradients. The response delay of conventional control surfaces in low dynamic pressure environments further exacerbates the control difficulties. Therefore, there is an urgent need to provide a method for high-aspect-ratio low-speed aircraft to traverse high wind layers, ensuring their safe passage through complex wind fields. Summary of the Invention

[0003] To address the shortcomings of the aforementioned high aspect ratio low-speed aircraft, this invention provides a method for high aspect ratio low-speed aircraft to traverse high wind layers, minimizing the retreat distance when traversing high wind layers.

[0004] In a first aspect, embodiments of this application provide a method for a low-speed, high-aspect-ratio aircraft to traverse a high-wind layer, specifically including: A method for a low-speed, high-aspect-ratio aircraft to traverse the upper wind layer, specifically including: Step S01: Flight status assessment; Step S02: Automatic switching of control modes; Step S03: Calculate the height interpolation of the control parameters; Step S04: Manual control mode.

[0005] Preferably, step S01: flight status determination includes: Step S01a: Low ground speed condition determination; When Vg < 2 m / s, the aircraft is determined to have entered a low ground speed state; When Vg ≥ 2.5 m / s, the aircraft is determined to have exited the low ground speed state; Among them, the control system acquires the aircraft's ground speed Vg in real time; Step S01b: Determine the flight disengagement status: When Vg ≥ 2.5 m / s and At that time, it is determined that the aircraft has entered a shutdown state; When Vg < 2.5 m / s or When this happens, the aircraft is determined to have exited the anti-flight state; Among them, the system obtains the aircraft's heading angle. and speed and heading angle .

[0006] Preferably, step S02: automatic switching of control mode includes: Based on the judgment result of step S01, it is determined that the lateral control mode will be automatically switched to the true heading control mode if and only if the aircraft is simultaneously in a low ground speed state and a flight retreat state.

[0007] Preferably, step S03: height interpolation calculation of the control parameters includes: Based on the aircraft's real-time altitude H, interpolation calculations are performed from a preset parameter table to obtain the corresponding control gain parameters.

[0008] Preferably, step S04: manual control mode includes: Operators are allowed to manually switch control modes at any stage of flight, including normal, low ground speed and unflight. Furthermore, at low ground speeds and in a retreating state, switching back to speed and heading control is not permitted; however, yaw speed control and true heading control can be switched between each other.

[0009] Secondly, this application discloses a device for a low-speed, high-aspect-ratio aircraft to traverse the upper wind layer, specifically comprising: Flight status judgment module; automatic control mode switching module; altitude interpolation calculation module for control parameters; manual control mode module.

[0010] Preferably, the flight status determination module includes: Low ground speed condition detection module; When Vg < 2 m / s, the aircraft is determined to have entered a low ground speed state; When Vg ≥ 2.5 m / s, the aircraft is determined to have exited the low ground speed state; Among them, the control system acquires the aircraft's ground speed Vg in real time; Flight termination status determination module: When Vg ≥ 2.5 m / s and At that time, it is determined that the aircraft has entered a shutdown state; When Vg < 2.5 m / s or When this happens, the aircraft is determined to have exited the anti-flight state; Among them, the system obtains the aircraft's heading angle. and speed and heading angle .

[0011] Preferably, the automatic switching of the control mode includes a module: Based on the judgment result of the flight status judgment module, it is determined that the lateral control mode will be automatically switched to the true heading control mode if and only if the aircraft is simultaneously in a low ground speed state and a flight retreat state.

[0012] Preferably, the height interpolation calculation module for the control parameters includes: Based on the aircraft's real-time altitude H, interpolation calculations are performed from a preset parameter table to obtain the corresponding control gain parameters.

[0013] Preferably, the manual control mode module includes: Operators are allowed to manually switch control modes at any stage of flight, including normal, low ground speed and unflight. Furthermore, at low ground speeds and in a retreating state, switching back to speed and heading control is not permitted; however, yaw speed control and true heading control can be switched between each other.

[0014] This invention discloses a strategy of turning the aircraft nose and flying into the wind to ensure the safety of the aircraft's attitude. By judging the relationship between wind speed and air speed, and the relationship between wind direction and heading, the aircraft determines the direction of nose adjustment and the climb or descent, thereby enabling it to escape the wind field area by climbing or descent as quickly as possible. Attached Figure Description

[0015] Figure 1 This is a flowchart illustrating the method for a low-speed, high-aspect-ratio aircraft to traverse the gale-force winds, according to an embodiment of the present invention. Figure 2 Simulation for embodiments of the present invention Figure 1 ; Figure 3 Simulation for embodiments of the present invention Figure 2 . Detailed Implementation

[0016] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0018] This embodiment provides a method for low-speed, high-aspect-ratio aircraft traversing high wind layers. This method is applicable to special operating conditions such as low ground speed and inverted flight, where the aircraft automatically selects a more stable control mode and dynamically matches control parameters based on altitude to improve the reliability and safety of flight control. The method mainly includes the following steps.

[0019] First, combine Figure 1 The method for a high aspect ratio low-speed aircraft to traverse a high wind layer, as shown in this embodiment, will be described in detail.

[0020] Step S01: Flight status judgment, which is divided into low ground speed status judgment and unflight status judgment; Step S01a: Low ground speed condition judgment The control system acquires the aircraft's ground speed Vg in real time and determines whether the aircraft is in a low ground speed state based on the following conditions: When Vg < 2 m / s, the aircraft is determined to have entered a low ground speed state; When Vg ≥ 2.5 m / s, the aircraft is determined to have exited the low ground speed state.

[0021] By setting speed thresholds of 2 m / s and 2.5 m / s to form a hysteresis zone, the aircraft can avoid frequently switching to low ground speed states near the critical speed, thus improving the stability of the judgment.

[0022] Step S01b: Determine the flight disengagement status: The system obtains the aircraft's heading angle. and speed and heading angle (i.e., ground speed azimuth angle), and determine the aircraft's unflight status based on the following conditions: When Vg ≥ 2.5 m / s and At that time, it is determined that the aircraft has entered a shutdown state; When Vg < 2.5 m / s or When the aircraft is in a state of flight termination, it is determined that the aircraft has exited the flight termination state.

[0023] in, This indicates a significant difference between the aircraft's attitude direction and velocity direction, suggesting the aircraft is in a clearly backward or inverted flight state. In this situation, the velocity-heading angle may no longer be suitable as the primary control reference, thus requiring subsequent control switching logic.

[0024] Step S02: Automatic switching of control mode Based on the judgment result of step S01, it is determined that the lateral control mode will be automatically switched to the true heading control mode if and only if the aircraft is simultaneously in a low ground speed state and a flight retreat state.

[0025] Under the above operating conditions, due to distortion or instability of the velocity direction, the velocity heading angle is... The control method may lead to control deviation, therefore a control method based on the airframe heading angle is adopted. The control mode can significantly improve flight stability.

[0026] Step S03: Height interpolation calculation of control parameters When the aircraft is at low ground speed or in a retreating state and enters true heading control mode or sideslip speed control mode, the system performs interpolation calculations from a preset parameter table based on the aircraft's real-time altitude H to obtain the corresponding control gain parameters. The following table shows examples of control gain parameters used in this embodiment: Low ground speed control parameter comparison table Height (unit: m) landing 0 5000 10000 15000 20000 25000 kr_psiv Speed, heading angle, and direction -0.4 -0.25 -0.25 -0.25 -0.25 -0.25 -0.25 kr_psi True heading angle to direction - 0.25 0.25 0.25 0.25 0.25 0.25 <![CDATA[kr_dlat * ]]> Lateral velocity to direction - -2 -1.65 -1.32 -0.99 -0.66 -0.33 kw_psiv Speed, heading angle, and differential -5.6 -2.8 -3.8 -5.4 -7.5 -11 -17 kw_psi True heading angle to differential - 2.8 3.8 5.4 7.5 11 17 <![CDATA[kw_dlat * ]]> Lateral speed to differential - 22 25.9 28.4 30.2 30.7 20.5 The above parameters cover: Control gains from speed and heading angle to direction: kr_psiv, kw_psiv; control gains from true heading angle to direction: kr_psi, kw_psi*; gains from sideslip speed to direction / differential control: kr_dlat, kw_dlat*.

[0027] The height interpolation calculation includes: Given the parameter k1 corresponding to height h1 and the parameter k2 corresponding to height h2. The formula for calculating k3 corresponding to height h3 is as follows: Taking a height of 1000m as an example, calculate kw_psiv: At 5000m, kW_psiv_5000 = -3.8; at 5000m, kW_psiv_0 = -2.8; At 1000m: Calculation results =-3 Step S04: Manual Control Mode The system allows the operator to manually switch control modes at any stage of flight, including normal, low ground speed, and unflight, but the following constraints must be met: (1) Speed ​​and heading control mode under low ground speed or retreat conditions When the aircraft is at low ground speed or in a retreating state, the system does not allow manual switching back to the speed and heading angle control mode. (Control) to avoid flight control deviations caused by using unstable speed and direction information.

[0028] (2) Allows switching between yaw speed control and true heading control. In all states, the operator can switch between the yaw rate control mode and the true heading control mode in both directions to use the most appropriate lateral control method for different flight missions.

[0029] Furthermore, this application provides a device for a high-aspect-ratio, low-speed aircraft to traverse a high-wind layer, comprising: The flight status judgment module is divided into a low ground speed status judgment module and a flight retreat status judgment module. The low ground speed state determination module is used for determining low ground speed states: The control system acquires the aircraft's ground speed Vg in real time and determines whether the aircraft is in a low ground speed state based on the following conditions: When Vg < 2 m / s, the aircraft is determined to have entered a low ground speed state; When Vg ≥ 2.5 m / s, the aircraft is determined to have exited the low ground speed state.

[0030] By setting speed thresholds of 2 m / s and 2.5 m / s to form a hysteresis zone, the aircraft can avoid frequently switching to low ground speed states near the critical speed, thus improving the stability of the judgment.

[0031] The unflight status determination module is used to determine the unflight status. The system obtains the aircraft's heading angle. and speed and heading angle (i.e., ground speed azimuth angle), and determine the aircraft's unflight status based on the following conditions: When Vg ≥ 2.5 m / s and At that time, it is determined that the aircraft has entered a shutdown state; When Vg < 2.5 m / s or When the aircraft is in a state of flight termination, it is determined that the aircraft has exited the flight termination state.

[0032] in, This indicates a significant difference between the aircraft's attitude direction and velocity direction, suggesting the aircraft is in a clearly backward or inverted flight state. In this situation, the velocity-heading angle may no longer be suitable as the primary control reference, thus requiring subsequent control switching logic.

[0033] The automatic control mode switching module includes: Based on the judgment result of the flight status judgment module, it is determined that the lateral control mode will be automatically switched to the true heading control mode if and only if the aircraft is simultaneously in a low ground speed state and a flight retreat state.

[0034] Under the above operating conditions, due to distortion or instability of the velocity direction, the velocity heading angle is... The control method may lead to control deviation, therefore a control method based on the airframe heading angle is adopted. The control mode can significantly improve flight stability.

[0035] The height interpolation calculation module for control parameters includes: When the aircraft is at low ground speed or in a retreating state and enters true heading control mode or sideslip speed control mode, the system performs interpolation calculations from a preset parameter table based on the aircraft's real-time altitude H to obtain the corresponding control gain parameters. The following table shows examples of control gain parameters used in this embodiment: Low ground speed control parameter comparison table Height (unit: m) landing 0 5000 10000 15000 20000 25000 kr_psiv Speed, heading angle, and direction -0.4 -0.25 -0.25 -0.25 -0.25 -0.25 -0.25 kr_psi True heading angle to direction - 0.25 0.25 0.25 0.25 0.25 0.25 <![CDATA[kr_dlat * ]]> Lateral velocity to direction - -2 -1.65 -1.32 -0.99 -0.66 -0.33 kw_psiv Speed, heading angle, and differential -5.6 -2.8 -3.8 -5.4 -7.5 -11 -17 kw_psi True heading angle to differential - 2.8 3.8 5.4 7.5 11 17 <![CDATA[kw_dlat * ]]> Lateral speed to differential - 22 25.9 28.4 30.2 30.7 20.5 The above parameters cover: Control gains from speed and heading angle to direction: kr_psiv, kw_psiv; control gains from true heading angle to direction: kr_psi, kw_psi*; gains from sideslip speed to direction / differential control: kr_dlat, kw_dlat*.

[0036] The height interpolation calculation includes: Given the parameter k1 corresponding to height h1 and the parameter k2 corresponding to height h2. The formula for calculating k3 corresponding to height h3 is as follows: Taking a height of 1000m as an example, calculate kw_psiv: At 5000m, kW_psiv_5000 = -3.8; at 5000m, kW_psiv_0 = -2.8; At 1000m: Calculation results =-3 The manual control mode module includes: The device allows the operator to manually switch control modes at any stage of flight, including normal, low ground speed, and unflight, but the following constraints must be met: (1) Speed ​​and heading control mode under low ground speed or retreat conditions When the aircraft is at low ground speed or in a retreating state, the system does not allow manual switching back to the speed and heading angle control mode. (Control) to avoid flight control deviations caused by using unstable speed and direction information.

[0037] (2) Allows switching between yaw speed control and true heading control. In all states, the operator can switch between the yaw rate control mode and the true heading control mode in both directions to use the most appropriate lateral control method for different flight missions.

[0038] This embodiment achieves improved flight reliability by accurately identifying special flight states such as low ground speed and backflight, and selecting appropriate control gains based on real-time altitude. This avoids the use of speed and heading control under unstable conditions. Dynamic altitude parameter matching ensures consistent control performance across different altitudes and density environments. Reasonable restrictions on manual operation maintain operational flexibility while ensuring safety. Therefore, this embodiment effectively improves the control stability of high-aspect-ratio low-speed aircraft traversing high wind layers in complex environments, demonstrating significant engineering application value for aircraft automatic control systems.

[0039] like Figure 2 , Figure 3 The diagram shows a simulation of a step gust of wind at an altitude of 15,000 meters where the wind speed is greater than the airspeed. The airspeed in the trim state is about 21 m / s, and the wind speed is 22 m / s. The simulation shows the aircraft turning its nose towards the windward side after the gust. It can be seen that according to the scheme in this embodiment, the attitude can be converged and stabilized after the gust. Then, the aircraft can climb or descend according to the wind field conditions. Based on the aerodynamic data, the limit trim state of the aircraft's climb and descent can be calculated. Under the condition of ensuring flight safety, the aircraft can switch from the original flight state to rapid climb trim or rapid descent trim to get out of the high wind layer as soon as possible.

[0040] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A method for a low-speed, high-aspect-ratio aircraft to traverse a high-wind layer, specifically including: Step S01: Flight status assessment; Step S02: Automatic switching of control modes; Step S03: Calculate the height interpolation of the control parameters; Step S04: Manual control mode.

2. The method according to claim 1, wherein step S01: flight status determination includes: Step S01a: Low ground speed condition determination; When Vg < 2 m / s, the aircraft is determined to have entered a low ground speed state; When Vg ≥ 2.5 m / s, the aircraft is determined to have exited the low ground speed state; Among them, the control system acquires the aircraft's ground speed Vg in real time; Step S01b: Determine the flight disengagement status: When Vg ≥ 2.5 m / s and At that time, it is determined that the aircraft has entered a shutdown state; When Vg < 2.5 m / s or When this happens, the aircraft is determined to have exited the anti-flight state; Among them, the system obtains the aircraft's heading angle. and speed and heading angle .

3. The method according to claim 1, wherein step S02: automatic switching of control mode includes: Based on the judgment result of step S01, it is determined that the lateral control mode will be automatically switched to the true heading control mode if and only if the aircraft is simultaneously in a low ground speed state and a flight retreat state.

4. The method according to claim 1, wherein step S03: height interpolation calculation of the control parameters includes: Based on the aircraft's real-time altitude H, interpolation calculations are performed from a preset parameter table to obtain the corresponding control gain parameters.

5. The method according to claim 1, wherein step S04: manual control mode includes: Operators are allowed to manually switch control modes at any stage of flight, including normal, low ground speed and unflight. Furthermore, at low ground speeds and in a retreating state, switching back to speed and heading control is not permitted; however, yaw speed control and true heading control can be switched between each other.

6. A device for a low-speed, high-aspect-ratio aircraft to traverse the upper wind layer, specifically comprising: Flight status assessment module; Automatic switching module for control modes; Height interpolation calculation module for control parameters; Manual control mode module.

7. The apparatus according to claim 6, wherein the flight status determination module comprises: Low ground speed condition detection module; When Vg < 2 m / s, the aircraft is determined to have entered a low ground speed state; When Vg ≥ 2.5 m / s, the aircraft is determined to have exited the low ground speed state; Among them, the control system acquires the aircraft's ground speed Vg in real time; Flight termination status determination module: When Vg ≥ 2.5 m / s and At that time, it is determined that the aircraft has entered a shutdown state; When Vg < 2.5 m / s or When this happens, the aircraft is determined to have exited the anti-flight state; Among them, the system obtains the aircraft's heading angle. and speed and heading angle .

8. The apparatus according to claim 6, wherein the automatic switching of the control mode comprises a module: Based on the judgment result of the flight status judgment module, it is determined that the lateral control mode will be automatically switched to the true heading control mode if and only if the aircraft is simultaneously in a low ground speed state and a flight retreat state.

9. The apparatus according to claim 6, wherein the height interpolation calculation module for the control parameters comprises: Based on the aircraft's real-time altitude H, interpolation calculations are performed from a preset parameter table to obtain the corresponding control gain parameters.

10. The apparatus according to claim 6, wherein the manual control mode module comprises: Operators are allowed to manually switch control modes at any stage of flight, including normal, low ground speed and unflight. Furthermore, at low ground speeds and in a retreating state, switching back to speed and heading control is not permitted; however, yaw speed control and true heading control can be switched between each other.

11. An electronic device, comprising: One or more processors; Storage device, on which one or more programs are stored, When the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in any one of claims 1-5.

12. A computer-readable medium having a computer program stored thereon, wherein, When the program is executed by the processor, it implements the method as described in any one of claims 1-5.

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