Unmanned aerial vehicle

Abstract

The invention belongs to the technical field of aircrafts, and particularly relates to an unmanned aerial vehicle. The invention provides an unmanned aerial vehicle which comprises an unmanned aerial vehicle body and forced landing devices, and the forced landing devices are arranged at four wing tips of the unmanned aerial vehicle body; the forced landing device is a buoy. According to the technical scheme provided by the invention, buoyancy is provided by the buoy when the unmanned aerial vehicle is subjected to water forced landing, the unmanned aerial vehicle can be ensured not to sink and stably float without any inflating device during use, and the reliability is effectively improved. According to the unmanned aerial vehicle, the technical defects that in the prior art, an unmanned aerial vehicle provided with an inflation device is low in reliability and poor in adaptability are overcome.

Description

Technical Field

[0001] This application belongs to the technical field of aircraft, and particularly relates to a drone. Background Art

[0002] The water landing device of a drone is generally a passive device that relies on an inflation device to inflate and provide a certain buoyancy for the drone when approaching the water surface. It serves as a landing platform on the water surface and also has the ability of water transportation, which can be used for the water transportation of drones.

[0003] In the prior art, relying on the inflation device to inflate and provide buoyancy for the drone when approaching the water surface may encounter problems such as malfunctions or unconventional opening methods, resulting in abnormal operation and the inability to complete self-rescue. In addition, most of the water landing devices of drones are developed based on multi-rotor drones, and the center of gravity position of their fuselage is relatively consistent with the position of the frame. The dual-wing vertical takeoff and landing aircraft adopts a multi-wing surface tandem layout design, and the traditional water landing device cannot be directly applied to the dual-wing vertical takeoff and landing aircraft.

[0004] Therefore, developing a drone to solve the technical defects of low reliability and poor adaptability of drones with inflation devices in the prior art has become an urgent problem for those skilled in the art. Summary of the Invention

[0005] Based on this, it is necessary to provide a drone to address the technical defects of low reliability and poor adaptability of drones with inflation devices in the prior art.

[0006] This application provides a drone, which includes: a drone main body and a landing device, and the landing device is arranged at the four wing tips of the drone main body;

[0007] The landing device is a float.

[0008] In one embodiment, the landing device includes: a front float and a rear float. The front float is arranged at the front wing tip of the drone main body, and the rear float is arranged at the rear wing tip of the drone main body.

[0009] In one embodiment, the calculation method of the mass of the float includes:

[0010]

[0011] 2·m float-aft l float-aft =-m hull l hull +2·m float-front l float-front (2)

[0012]

[0013] Among them, m float-total is the total mass of the front and rear pontoons (single);

[0014] m total is the total mass of the aircraft;

[0015] m hull is the mass of the aircraft fuselage part immersed in water;

[0016] l float-front is the x distance from the center of buoyancy to the center of gravity of the front pontoon;

[0017] l float-aft is the x distance from the center of buoyancy to the center of gravity of the rear pontoon;

[0018] l hull is the x-axis distance from the center of buoyancy to the center of gravity of the immersed part of the fuselage;

[0019] yaw float is the lateral yaw moment generated by the pontoon;

[0020] angel stop is the parking angle of the aircraft on water;

[0021] factor kgtom 2 is the mass-lateral projected area conversion factor of the pontoon.

[0022] In one embodiment, the lateral projection ratio of the front pontoon to the rear pontoon is 1:(1.5 - 2).

[0023] In one embodiment, the UAV further includes: a power unit, and the power unit is disposed in the rear pontoon.

[0024] In one embodiment, the included angle between the power unit and the axis of the UAV body is 24° ± 6°.

[0025] In one embodiment, the UAV further includes: a control unit, and the control unit is electrically connected to the power unit for controlling the movement of the power unit.

[0026] In one embodiment, the power unit includes: a vector power type power unit and / or an underwater rudder surface type power unit.

[0027] In one embodiment, the UAV further includes: a connecting member, and the connecting member is respectively connected to the UAV body and the emergency landing device.

[0028] In summary, the present application provides a drone, which includes a drone body and a forced landing device. The forced landing device is arranged at the four wing tips of the drone body; the forced landing device is a float. In the technical solution provided by the present application, when the drone makes a forced landing on water, the float provides buoyancy, and it can ensure that the drone will not sink and will float stably without any inflation device during use, effectively improving the reliability. The drone provided by the present application solves the technical defects of low reliability and poor adaptability of drones with inflation devices in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0030] Figure 1 It is a side view of a drone in the technical solution provided by an embodiment of the present application;

[0031] Figure 2 It is a bottom view of a drone in the technical solution provided by an embodiment of the present application;

[0032] Figure 3 It is a schematic structural diagram of a rear float in a drone provided by an embodiment of the present application;

[0033] Figure 4 It is a partial enlarged schematic diagram of the power unit and the drone body in a drone provided by an embodiment of the present application;

[0034] Figure 5 It is a schematic diagram of the drone floating on the water surface in the technical solution provided by an embodiment of the present application;

[0035] Figure 6 It is a schematic diagram of the steps for calculating the weight of the float in a drone provided by an embodiment of the present application;

[0036] Among them, the drone body 1, the front float 2, and the rear float 3. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] The embodiment of the present application provides a drone, which is used to solve the technical defects of low reliability and poor adaptability of drones with inflation devices in the prior art.

[0038] To make the above objects, features, and advantages of the present application more apparent and understandable, the following describes the specific embodiments of the present application in detail with reference to the accompanying drawings. Many specific details are set forth in the following description to facilitate a thorough understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0039] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application.

[0040] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0041] In the present application, unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0042] In the present application, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over", and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath", and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0043] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation.

[0044] Please refer to Figures 1 to 5 , an embodiment of the present application provides a drone, including: a drone body 1 and a forced landing device, and the forced landing device is disposed at the four wing tips of the drone body 1; the forced landing device is a float. The drone provided by the embodiment of the present application is used to solve the technical defects of low reliability and poor adaptability existing in the prior art for drones provided with an inflation device.

[0045] In the technical solution provided by the embodiment of the present application, when the drone equipped with floats makes a forced landing on water, the floats can provide buoyancy to keep the drone stable on the water surface, ensuring that the drone can float on the water surface. Further, the floats can provide a certain degree of roll and pitch floating stability for the drone on the water surface and have the ability to maintain stable floating under certain wind and wave conditions. At this time, part of the floats enters the water, and the stability of the floats is related to the parameter of the volume margin percentage of the floats, that is, the size of the volume of the floats except for the immersed volume during the design of the floats. The larger the volume margin percentage, the stronger the stability of the floats.

[0046] During the forced landing process, no additional inflation device is required, and the reliability is stronger. When the floats are specifically installed, the installation positions of the floats need to be higher than the landing gear position of the drone body 1, and it will not affect the normal takeoff and landing of the drone.

[0047] In the technical solution provided by the embodiment of the present application, the floats are installed at the wing tips. In traditional drones, an inflation device is relied on to inflate and provide buoyancy for the drone when approaching the water surface. The inflation device can only provide a fixed buoyancy for the drone, but cannot make the drone stably stay on the water surface in a controllable and recoverable state. In the embodiment of the present application, combined with the design characteristics of a twin-wing aircraft, corresponding floats are installed at the front and rear wing tips of the aircraft. It can not only provide sufficient buoyancy for the drone, but also make the drone stably float on the water surface, and can be adapted to a twin-wing vertical takeoff and landing drone using a multi-wing surface tandem layout design.

[0048] Further optimizing the technical solution, in the drone provided by the embodiment of the present application, the forced landing device includes: a front float 2 and a rear float 3. The front float 2 is disposed at the front wing tip of the drone body 1, and the rear float 3 is disposed at the rear wing tip of the drone body 1.

[0049] Further optimize the technical solution. The calculation method of the buoy mass includes:

[0050]

[0051] 2·m float-aft l float-aft =-m hull l hull +2·m float-front l float-front (2)

[0052]

[0053] where m float-total is the total mass of the front and rear buoys 3 (single);

[0054] m total is the total mass of the aircraft;

[0055] m hull is the mass of the immersed part of the aircraft fuselage;

[0056] l float-front is the x-distance from the center of buoyancy to the center of gravity of the front buoy 2;

[0057] l float-aft is the x-distance from the center of buoyancy to the center of gravity of the rear buoy 3;

[0058] l hull is the x-axis distance from the center of buoyancy to the center of gravity of the immersed part of the fuselage;

[0059] yaw float is the lateral yaw moment generated by the buoy;

[0060] angel stop is the parking angle of the aircraft on water;

[0061] factor kgtom 2 is the mass-lateral projection area conversion factor of the buoy.

[0062] Here, further combine with Figure 6 , and calculate the total mass of the front and rear buoys 3 according to Equation 1; then give an initial value in Equation 2 and calculate the mass of the front and rear buoys 3; then enter Equation 3 to solve the magnitude of the yaw moment generated by the buoy, and iterate repeatedly until the calculated value of the yaw moment in Equation 3 is the smallest. According to the obtained buoy mass, combined with the common knowledge of those skilled in the art about the buoy shape, material, etc., the volume of the buoy can be obtained.

[0063] During the flight of the drone, the lateral projection area of the pontoon will have a certain impact on the lateral motion stability of the drone during actual flight. It is necessary to ensure that the drone still has the ability to maintain its stable flight after the pontoon is introduced. It is necessary to optimize and calculate the specific volume of the front and rear pontoons 3. On the premise of maintaining its ability to keep the drone balanced in still water, the specific optimization formula is as shown above. By optimizing the yaw float (used to measure the impact of the pontoon on the flight stability of the aircraft, the smaller the better) value, the mass of the front and rear pontoons 3 is obtained, and then the volume size is obtained according to the conversion factor. The volume obtained here is the lower limit of the pontoon volume, and the overall pontoon volume still needs to leave a volume margin of 30% - 50% to be the final overall pontoon volume size.

[0064] According to the yaw in the above formula float That is, it measures the impact of the introduction of the pontoon on the lateral motion stability of the drone during flight. When the calculated value is positive, it means that the introduction of the pontoon will weaken the stability of the drone. When it is negative, it means that the introduction of the pontoon can improve the flight stability of the drone. In a drone provided by an embodiment of the present application, the lateral projection ratio of the front pontoon 2 to the rear pontoon 3 is 1:(1.5 - 2). By restricting the area size of the pontoon projection on the XZ plane, the stability of the drone during flight is further effectively improved.

[0065] Furthermore, to optimize the technical solution, after the drone makes a water landing, to facilitate the recovery of the drone, the drone provided by the embodiment of the present application further includes: a power unit, and the power unit is arranged in the rear pontoon 3. The power unit can provide power for the drone body 1. When the drone makes a stable water landing, the power unit starts to work, provides underwater power for the drone to sail, and after sailing to a preset position, it is better for the recovery management of the drone. Furthermore, since the projection area of the rear pontoon 3 on the XZ plane is larger, while the projection area of the front pontoon 2 is smaller, the power axis direction of the power unit should be parallel to the horizontal plane when the drone is stationary on the water surface. Therefore, the power unit can only be installed in the rear pontoon 3. In addition, no matter whether the power unit is installed in the front pontoon 2 or the rear pontoon 3, when the power unit generates propulsion power, it will generate a certain lifting moment, causing the drone to have a tendency to lift its head. Therefore, if it is installed in the front pontoon 2, once the drone has a tendency to lift its head, the front pontoon 2 is likely to leave the water surface, thus affecting the propulsion efficiency, while installing it in the rear pontoon 3 can avoid this problem.

[0066] Furthermore, to optimize the technical solution, in the drone provided by the embodiment of the present application, the axis angle between the power unit and the drone body 1 is 24°±6°. Please refer to Figure 4 , θ powerWhen the aircraft parking angle is 24°±6°, the existence of this angle can keep the power axis provided by the power unit parallel to the horizontal plane when working underwater, ensuring that the power unit maintains the highest efficiency when working underwater.

[0067] In one of the embodiments, in order to more accurately control the startup, movement trajectory and speed of the power unit, the drone provided in the embodiment of the present application also includes: a control unit, which is electrically connected to the power unit and is used to control the movement of the power unit.

[0068] To further optimize the technical solution, in the technical solution provided in the embodiment of the present application, the power unit includes: a vector power unit and / or an underwater rudder power unit. The power units used in the embodiments of the present application have never been used in the water landing device of the unmanned aerial vehicle, nor have they been seen on the buoy device used in ordinary aircraft; the vector power unit has the advantages of simpler structure and more sensitive control effect, and the underwater rudder power unit has the advantages of being lighter and more reliable.

[0069] In the technical solution provided in the embodiment of the present application, the power output is connected to the control unit of the UAV, and when sailing on water, closed-loop control of the pitch angle of the UAV is achieved through the aircraft pitch angle controller in the control unit. When the UAV raises its head due to excessive speed, the controller will reduce the power output and at the same time control the deflection of the rudder surfaces on the wings to cause the wings to generate corresponding nose-down torque to suppress the UAV from raising its head, thereby preventing the aircraft from leaving the water due to excessive speed.

[0070] In the technical solution provided in the embodiment of the present application, heading control can also be provided by differential operation of the left and right motors. According to the difference in motor selection, the underwater propulsion force it can provide is -1.7 to 2.8 kgf. According to different installation positions, the navigation angle deviation that can be generated by the motor differential alone can be calculated by the following formula:

[0071] Among them, γ trust The yaw angle generated by the differential of the left and right motors;

[0072] T max ,T min are the maximum and minimum underwater thrust values ​​of the motor;

[0073] l y_float-aft is the y-axis distance from the buoyancy center to the gravity center of the rear pontoon 3;

[0074] I z is the z-axis moment of inertia of the aircraft.

[0075] For the convenience of the installation and maintenance of the drone, and to effectively ensure the connection stability and reliability between the drone body 1 and the crash landing device, the drone provided by the embodiment of the present application further includes: a connecting member, which is respectively connected to the drone body 1 and the crash landing device.

[0076] Please refer further here to Figure 6 , a drone provided by the embodiment of the present application can counter the stable recovery moment required to resist wind and waves. In the drone provided by the embodiment of the present application, neither of the front and rear floats 3 is completely immersed below the water surface. When the drone encounters waves and thus generates pitching (rotation along the y-axis) or rolling (rotation along the x-axis) directions, the floats will generate a certain recovery moment because they are completely immersed below the water surface, so that the aircraft has a tendency to restore its original attitude. Further, the moment here can be estimated by the following formula.

[0077] M recover =V float-front ·l y_float-front +V float-aft ·l y_float-aft

[0078] In summary, the present application provides a drone, which includes: a drone body and a crash landing device, and the crash landing device is arranged at the four wing tips of the drone body; the crash landing device is a float. In the technical solution provided by the present application, when the drone performs a water crash landing, the float provides buoyancy, and it is guaranteed that the drone will not sink and will float stably without any inflation device during use, effectively improving the reliability. A drone provided by the present application solves the technical defects of low reliability and poor adaptability of drones with inflation devices in the prior art.

[0079] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as these combinations of technical features do not conflict, they should all be considered as the scope described in this specification. At the same time, other embodiments can be derived from the above embodiments, so that structural and logical substitutions and changes can be made without departing from the scope of the present disclosure.

[0080] The above embodiments only express several implementation manners of the present application, and their descriptions are relatively specific and detailed, but they cannot be understood as a limitation to the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A drone, characterized in that: The drone comprises: a drone body and a forced landing device, wherein the forced landing device is arranged at the wingtips of four wings of the drone body; The forced landing device is a buoy.

2. The drone according to claim 1, characterized in that: The forced landing device comprises: a front buoy and a rear buoy, wherein the front buoy is arranged at the front wing tip of the drone body, and the rear buoy is arranged at the rear wing tip of the drone body.

3. The drone according to claim 2, characterized in that: The calculation method of the buoy mass includes: 2·m float-aft l float-aft =-m hull l hull +2·m float-front l float-front (2) Among them, m float-total is the total mass of the front and rear pontoons (single); m total is the total mass of the aircraft; m hull is the water-immersed mass of the aircraft fuselage; l float-front is the x distance from the center of buoyancy to the center of gravity of the front float; l float-aft is the x distance from the center of buoyancy to the center of gravity of the rear float; l hull is the x-axis distance from the center of buoyancy to the center of gravity of the submerged part of the fuselage; yaw float is the lateral yaw moment generated by the buoy; angel stop is the parking angle of the aircraft on water; factor kgtom 2 It is the conversion factor of the buoy's mass to lateral projection area.

4. The drone according to claim 3, characterized in that: The lateral projection ratio of the front pontoon to the rear pontoon is 1:(1.5-2).

5. The drone according to claim 3 or 4, characterized in that: The UAV further comprises: a power unit, and the power unit is arranged in the rear buoy.

6. The drone according to claim 5, characterized in that: The included angle between the axis of the power unit and the main body of the UAV is 24°±6°.

7. The drone according to claim 5 or 6, characterized in that: The drone further includes a control unit, which is electrically connected to the power unit and is used to control the movement of the power unit.

8. The drone according to claim 7, characterized in that: The power unit includes: a vector power unit and / or an underwater rudder power unit.

9. The drone according to claim 1 or 2, characterized in that: The drone also includes a connecting piece, which is respectively connected to the drone body and the forced landing device.

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