Aircraft stall sensing unit and aircraft stall sensing system

Abstract

This application relates to the field of aircraft stall detection technology, and discloses an aircraft stall sensing unit and an aircraft stall sensing system. The aircraft stall sensing unit includes a housing, a rotating unit, a triboelectric power generation unit, and a limiting component. The housing has an opening for connecting the interior and exterior of the housing. The rotating unit can rotate relative to the housing along the direction of the return airflow on the wing surface of the aircraft. The limiting component restricts the rotation of the rotating unit along the direction of the laminar airflow on the wing surface of the aircraft. The triboelectric power generation unit includes independent friction layers, electrode pairs, and a dielectric friction group. The electrode pairs include a first electrode and a second electrode spaced apart. The dielectric friction group includes a first dielectric friction layer and a second dielectric friction layer spaced apart. When the rotating unit rotates relative to the housing along the direction of the return airflow on the wing surface, the independent friction layers rotate relative to the dielectric friction group and generate an electrical signal through friction. The above-described aircraft stall sensing unit can be used to determine whether an aircraft is stalling.

Description

Technical Field

[0001] This application relates to the field of aircraft stall detection technology, and in particular to an aircraft stall sensing unit and an aircraft stall sensing system. Background Technology

[0002] Stall occurs when an aircraft's angle of attack exceeds its stall angle, causing a sudden decrease in lift provided by the wings. At this point, the amount of air adhering to the wing surface decreases, the boundary layer separates from the wing surface prematurely, and the wings are unable to provide sufficient lift. The lift and gravity are no longer in balance, leading to the aircraft crashing.

[0003] For small unmanned aerial vehicles (UAVs), current stall detection devices used in large manned aircraft, such as angle-of-attack sensors, Mach sensors, and flap position sensors, while precise and reliable, are not suitable for small UAVs due to their large size, weight, and complex structure. Furthermore, existing stall sensors require external power supplies. For small UAVs powered solely by batteries, this additional power module increases the burden of power management, hindering the lightweight design of small UAVs. Summary of the Invention

[0004] This application provides an aircraft stall sensing unit and an aircraft stall sensing system, which can not only be used to determine whether a small unmanned aerial vehicle has entered a stall state, but also does not require an additional power module, which is conducive to realizing the lightweight design of small unmanned aerial vehicles.

[0005] In a first aspect, this application provides an aircraft stall sensing unit, which is installed on the wing surface of an aircraft. The aircraft stall sensing unit includes a housing, a rotating unit, a triboelectric power generation unit, and a limiting component. The rotating unit, the triboelectric power generation unit, and the limiting component are disposed inside the housing. The housing has an opening for communicating between the inside and outside of the housing.

[0006] The rotating unit can rotate relative to the housing along the direction of the backflow airflow on the wing surface of the aircraft;

[0007] The rotating unit is connected to the housing via the limiting component, which restricts the rotating unit from rotating relative to the housing along the laminar airflow direction on the wing surface of the aircraft.

[0008] The triboelectric power generation unit includes an independent triboelectric layer, an electrode pair, and a dielectric triboelectric group. The electrode pair includes a first electrode and a second electrode spaced apart. The dielectric triboelectric group includes a first dielectric triboelectric layer and a second dielectric triboelectric layer spaced apart. The first dielectric triboelectric layer is located between the first electrode and the independent triboelectric layer, and the second dielectric triboelectric layer is located between the second electrode and the independent triboelectric layer.

[0009] The independent friction layer is fixed to the rotating unit, and the electrode pair and the dielectric friction group are fixed to the housing. When the rotating unit rotates relative to the housing along the direction of the return airflow on the surface of the wing, the independent friction layer rotates relative to the dielectric friction group and generates an electrical signal through friction.

[0010] The aircraft stall sensing unit provided in this application, by incorporating a rotating unit, a triboelectric generator unit, and a limiting component, is used to detect whether an aircraft is stalling. The aircraft stall sensing unit is mounted on the wing surface. When the aircraft is in flight, external airflow enters the casing through openings. If the aircraft is in level flight, the airflow entering the casing follows the laminar flow direction of the wing surface. In this case, the rotating unit cannot rotate relative to the casing due to the limiting component, and the triboelectric generator unit does not generate an electrical signal. If the aircraft is stalling, the airflow entering the casing follows the recirculation direction. In this case, the rotating unit can rotate relative to the casing, and the triboelectric generator unit generates an electrical signal. Therefore, the aircraft stall sensing unit in this application can determine whether the aircraft is stalling by whether the triboelectric generator unit generates an electrical signal. Its structure is simple and facilitates miniaturization. Furthermore, since the triboelectric generator unit can generate its own power, no additional power module is needed, which also contributes to the lightweight design of small unmanned aerial vehicles.

[0011] In some possible implementations, the housing includes a bottom shell and a top cover, the bottom shell and the top cover being detachably connected, and the opening being provided in the top cover;

[0012] The rotating unit is located inside the bottom shell, and the electrode pair and the dielectric friction assembly are fixedly connected to the top cover.

[0013] In some possible implementations, the rotating unit includes a shaft, a connector, and multiple fan blades;

[0014] One end of the rotating shaft is connected to the bottom of the bottom shell, and the other end of the rotating shaft is connected to the connector. The axial direction of the rotating shaft is perpendicular to the laminar airflow direction on the wing surface of the aircraft.

[0015] Multiple fan blades are arranged circumferentially around the connector on the surface of the connector, one end of each fan blade is connected to the connector, and the other end of each fan blade is bent toward the connector along the laminar airflow direction on the wing surface.

[0016] In some possible implementations, the fan blades and the axis of the rotating shaft have an angle of 45° to 75°.

[0017] In some possible implementations, the limiting assembly includes a ratchet and a pawl mechanism;

[0018] The connector has a groove on the side facing the top cover, the ratchet is fixed in the middle of the groove, and the top of the ratchet protrudes out of the groove;

[0019] The pawl mechanism is fixed to the upper cover. When the upper cover is closed on the bottom shell, the ratchet abuts against the pawl mechanism. The pawl mechanism is used to restrict the ratchet from rotating along the laminar airflow direction on the surface of the aircraft wing.

[0020] In some possible implementations, the independent friction layer is fixed to the inner wall of the groove, the electrode pair and the dielectric friction assembly are located on the side of the upper cover facing the bottom shell, and when the upper cover is closed on the bottom shell, the electrode pair and the dielectric friction assembly are located within the groove.

[0021] In some possible implementations, the shaft is connected to the base shell via a bearing.

[0022] In some possible implementations, there are two independent friction layers, two electrode pairs, and two dielectric friction groups, with the two independent friction layers arranged symmetrically and spaced apart, and the two electrode pairs and two dielectric friction groups respectively corresponding to the two independent friction layers;

[0023] The two first electrodes of the two electrode pairs are connected by a first copper wire, and the two second electrodes of the two electrode pairs are connected by a second copper wire.

[0024] In some possible implementations, the two first electrodes are arranged symmetrically, and the two second electrodes are arranged symmetrically.

[0025] In a second aspect, this application provides an aircraft stall sensing system, including an aircraft and a plurality of aircraft stall sensing units as described in any possible embodiment of the first aspect.

[0026] Multiple aircraft stall sensing units are arranged and mounted on the wing surface of the aircraft along the chord direction of the wing, with one of the aircraft stall sensing units located near the tail of the wing. Attached Figure Description

[0027] Figure 1a This is a schematic diagram of the airflow patterns on the wing surface of an aircraft in level flight.

[0028] Figure 1b This is a schematic diagram of the airflow patterns on the wing surface of an aircraft when it is in a stall state.

[0029] Figure 2 This is a schematic diagram of an exploded structure of an aircraft stall sensing unit in an embodiment of this application;

[0030] Figure 3 This is a schematic diagram of a triboelectric power generation unit in one embodiment of this application;

[0031] Figure 4 This is a schematic diagram of the structure of the aircraft stall sensing unit installed on the wing surface in the implementation of this application;

[0032] Figure 5 This is a schematic diagram of the signal output of the aircraft stall sensing unit in an embodiment of this application.

[0033] In the picture:

[0034] 10-Aircraft stall sensing unit; 20-Wing; 100-Shell; 110-Bottom shell; 111-Stop; 120-Top cover; 121-Opening; 122-Receiving hole; 200-Rotating unit; 210-Shaft; 220-Connector; 221-Groove; 230-Fan blade; 300-Triboelectric power generation unit; 310-Independent friction layer; 320-Electrode pair; 321-First electrode; 322-Second electrode; 330-Dielectric friction assembly; 331-First dielectric friction layer; 331a-Friction section; 331b-Connecting section; 332-Second dielectric friction layer; 340-First copper wire; 350-Second copper wire; 400-Limiting assembly; 410-Ratchet; 411-Ratchet tooth; 420-Pawl mechanism; 421-Limiting surface; 500-Bearing. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] refer to Figure 1a and Figure 1b , Figure 1a This diagram illustrates the airflow patterns on the wing surface of an aircraft in level flight. Figure 1b This diagram illustrates the airflow patterns on the wing surface of an aircraft during a stall. For example... Figure 1a As shown, in level flight, the laminar airflow over the upper surface of the aircraft wing adheres to the wing due to the Coanda effect. Figure 1b As shown, when the aircraft's angle of attack is too large, airflow separation occurs on the wing surface. In this state, backflow occurs at the tail of the wing (such as...). Figure 1b (The airflow referred to by the number 2) The direction of the recirculating airflow is opposite to that of the laminar airflow.

[0037] refer to Figure 2 The aircraft stall sensing unit 10 in this embodiment includes a housing 100, a rotating unit 200, a triboelectric power generation unit 300, and a limiting component 400. The housing 100 has an internal accommodating space, and the rotating unit 200, triboelectric power generation unit 300, and limiting component 400 are all disposed within the housing 100. The housing 100 may include a bottom shell 110 and a top cover 120, with the top cover 120 covering the bottom shell 110. Exemplarily, the bottom shell 110 and the top cover 120 are detachably connected, allowing the top cover 120 to be disassembled later for maintenance or replacement of components within the housing 100, such as the rotating unit 200 and the triboelectric power generation unit 300.

[0038] Continue to refer to Figure 2 The rotating unit 200 includes a rotating shaft 210, a connecting member 220, and multiple fan blades 230. One end of the rotating shaft 210 is connected to the bottom of the base shell 110, and the other end is connected to the connecting member 220. The axial direction of the rotating shaft 210 can be considered as perpendicular to the laminar airflow direction of the aircraft's wing surface. The connecting member 220 has a cylindrical structure, and multiple fan blades 230 are circumferentially connected to the surface of the connecting member 220. The rotating shaft 210 can rotate relative to the shell 100 around its own axis to drive the fan blades 230 to rotate relative to the shell 100 around the axis of the rotating shaft 210. That is, the rotating unit 200 as a whole can rotate along the laminar airflow direction (X direction) or the return airflow direction (Y direction) of the aircraft's wing surface.

[0039] Furthermore, such as Figure 2As shown, the rotating unit 200 is connected to the upper cover 120 via a limiting assembly 400. Specifically, the limiting assembly 400 includes a ratchet 410 and a pawl mechanism 420. The ratchet 410 is fixedly connected to the rotating unit 200, and the pawl mechanism 420 is fixedly connected to the upper cover 120. A groove 221 is provided on the side of the connector 220 facing the upper cover 120. The ratchet 410 can be fixedly connected to the center of the groove 221, and the axis of the ratchet 410 can coincide with the axis of the rotating shaft 210. The ratchet 410 includes a plurality of circumferentially arranged ratchet teeth 411. Each ratchet tooth 411 can be bent towards the central axis of the ratchet 410 in the direction of laminar airflow on the wing surface of the aircraft. Simultaneously, the pawl mechanism 420 is provided with a limiting surface 421. One of the ratchet teeth 411 of the ratchet 410 abuts against the limiting surface 421, thereby restricting the ratchet 410 from rotating relative to the pawl mechanism 420 in the direction of laminar airflow on the wing surface of the aircraft. Since the ratchet 410 is fixedly connected to the rotating unit 200 and the pawl mechanism 420 is fixedly connected to the upper cover 120, the contact state between the ratchet 410 and the pawl mechanism 420 can be used to limit the rotation of the rotating unit 200 relative to the housing 100.

[0040] Furthermore, the surface of the pawl mechanism 420 facing the ratchet 410 is an arc-shaped surface, and the pawl mechanism 420 is curved towards the central axis of the ratchet 410 along the direction of the return airflow on the wing surface of the aircraft. In other words, the pawl mechanism 420 and the ratchet 411 extend in opposite directions. When the ratchet 410 rotates relative to the pawl mechanism 420 along the direction of the return airflow on the wing surface of the aircraft, the pawl mechanism 420 does not restrict the ratchet 410. In other words, under the action of the limiting component 400, the rotating unit 200 in this embodiment cannot rotate along the laminar airflow direction (X direction) of the wing surface of the aircraft, but can rotate along the direction of the return airflow on the wing surface of the aircraft (Y direction).

[0041] Please refer to the above. Figure 2 and Figure 3The triboelectric power generation unit 300 includes an independent triboelectric layer 310, an electrode pair 320, and a dielectric triboelectric assembly 330. The independent triboelectric layer 310 is fixed to the rotating unit 200, and the electrode pair 320 and the dielectric triboelectric assembly 330 are fixed to the side of the upper cover 120 facing the bottom shell 110. Specifically, the electrode pair 320 may include a first electrode 321 and a second electrode 322, spaced apart. The dielectric triboelectric assembly 330 includes a first dielectric triboelectric layer 331 and a second dielectric triboelectric layer 332, spaced apart. The first dielectric triboelectric layer 331 may be fixedly connected to the first electrode 321 and is located between the first electrode 321 and the independent triboelectric layer 310. Similarly, the second dielectric triboelectric layer 332 may be fixedly connected to the second electrode 322 and is located between the second electrode 322 and the independent triboelectric layer 310.

[0042] As previously described, the ratchet 410 is located in the center of the groove 221, thus maintaining a certain space between the ratchet 410 and the sidewall of the groove 221. The independent friction layer 310 can be fixedly attached to the inner wall of the groove 221. When the upper cover 120 is closed on the bottom shell 110, the electrode pair 320 and the dielectric friction assembly 330 can also extend into the space between the ratchet 410 and the inner wall of the groove 221, and the dielectric friction assembly 330 is in contact with the independent friction assembly. When the rotating unit 200 rotates relative to the housing 100, the independent friction layer 310 slides relative to the dielectric friction assembly 330, thereby generating an electrical signal.

[0043] Continue to refer to Figure 2 The upper cover 120 has an opening 121, which can be used to connect the interior of the housing 100 with the outside. When the aircraft stall sensing unit 10 in this embodiment is installed on the wing surface of the aircraft, the external airflow can enter the interior of the housing 100. When the aircraft is in level flight, the airflow direction inside the housing 100 is the same as the laminar airflow direction on the wing surface. At this time, the fan blade 230 tends to rotate along the laminar airflow direction on the wing surface, but under the limiting action of the ratchet 410 and the pawl mechanism 420, the fan blade 230 remains relatively fixed with respect to the housing 100, and the triboelectric power generation unit 300 does not generate an electrical signal. When the aircraft is in a stall state, the airflow direction inside the housing 100 is the same as the return airflow direction on the wing surface. At this time, the fan blade 230 rotates relative to the housing 100 along the return airflow direction on the wing surface, and the triboelectric power generation unit 300 generates an electrical signal.

[0044] It should be understood that the aircraft stall sensing unit 10 in this embodiment, by utilizing the rotation unit 200, the limiting component 400, and the triboelectric power generation unit 300, can quickly determine whether the aircraft is in a stall state by acquiring the electrical signal generated by the triboelectric power generation unit 300. Furthermore, since the triboelectric power generation unit 300 can generate its own electricity, the aircraft stall sensing unit 10 serves as both a stall sensor and a power source, eliminating the need for an additional power module on the aircraft and facilitating a lightweight design for the aircraft.

[0045] Continue to refer to Figure 2 The shaft 210 and the bottom of the base 110 can be connected by a bearing 500, which can also reduce the friction between the fan blade 230 and the base when the fan blade 230 rotates, thereby making the changes in the electrical signal generated when the fan blade 230 rotates more sensitive, and thus improving the accuracy of detection.

[0046] Furthermore, one end of each fan blade 230 is fixedly connected to the connector 220, and the other end can be bent towards the ratchet 410 along the laminar airflow direction of the aircraft's wing surface. This makes it easier to drive the fan blade 230 to rotate when the external return airflow enters the housing 100. In addition, a certain angle can be set between each fan blade 230 and the axis of the rotating shaft 210, which can be between 45° and 75°, to increase the contact area between the fan blade 230 and the return airflow. This allows the fan blade 230 to rotate under the action of a smaller return airflow, thereby enabling faster detection of the aircraft being in a stall state and improving the accuracy of the detection.

[0047] like Figure 3 As shown, there can be two independent friction layers 310, which can be symmetrically and spaced apart. Furthermore, the two independent friction layers 310 can be arranged circumferentially around the inner wall of the connector 220. Correspondingly, there are also two pairs of electrode pairs 320 and two pairs of dielectric friction groups 330. That is, there are two first electrodes 321, two second electrodes 322, two first dielectric friction layers 331, and two second dielectric friction layers 332. One first electrode 321, one first dielectric friction layer 331, one second electrode 322, one second dielectric friction layer 332, and one independent friction layer 310 form a triboelectric power generation structure. The two first electrodes 321 are connected by a first copper wire 340, and the two second electrodes 322 are connected by a second copper wire 350. In this embodiment, the two triboelectric power generation structures form a triboelectric power generation unit 300. The electrical signals generated by the two triboelectric power generation structures are superimposed, increasing the number of electrical signals and more sensitively reflecting changes in the electrical signals, thus making it easier to determine whether the aircraft has stalled.

[0048] It is worth noting that the number of independent friction layers 310 in this embodiment is not limited to one or two. In some other embodiments, the number of independent friction layers 310 can also be three, four, etc. Correspondingly, the number of electrode pairs 320 and dielectric friction groups 330 is the same as the number of independent friction layers 310. It should be understood that, given limited space, increasing the number of independent friction layers 310 can increase the number of electrical signals to increase the current, making it easier to intuitively determine the aircraft's stall state through electrical signals.

[0049] Continue to refer to Figure 3 Taking one set of first electrodes 321 and first dielectric friction layer 331 as an example, the first dielectric friction layer 331 includes a friction section 331a for sliding frictional contact with the independent friction layer 310 and a connecting section 331b that bends and extends towards the middle of the two independent friction layers 310. The first dielectric friction layer 331 can be connected to the upper cover 120 through the connecting section 331b. In this way, by bending a portion of the first dielectric friction layer 331 towards the center, while ensuring a good fixation effect between the first dielectric friction layer 331 and the upper cover 120, it is also possible to ensure that the contact area between the first dielectric friction layer 331 and the independent friction layer 310 is sufficient, thereby generating more electrical signals.

[0050] Similarly, a portion of the second dielectric friction layer 332 is also bent towards the center to ensure that the second dielectric friction layer 332 not only has a good fixing effect with the upper cover 120, but also has sufficient contact area with the independent friction layer 310. In this embodiment, the length of each first electrode 321 is the same as the length of the first dielectric friction layer 331, and the length of the second electrode 322 is the same as the length of the second dielectric friction layer 332. That is, a portion of the first electrode 321 and the second electrode 322 are also bent towards the center, which facilitates the connection between the two first electrodes 321 and the two second electrodes 322.

[0051] Furthermore, the two first electrodes 321 can be symmetrically arranged with the axis of the ratchet 410 as the axis of symmetry, and the two second electrodes 322 can also be symmetrically arranged with the axis of the ratchet 410 as the axis of symmetry, thus ensuring that the electrodes do not interfere with each other. Moreover, the first electrodes 321 and the second electrodes 322 are staggered, ensuring that when the fan blade 230 rotates, regardless of the degree of rotation, each independent friction layer 310 can slide against a first dielectric friction layer 331 and a second dielectric friction layer 332.

[0052] Combination Figure 2 and Figure 3A space is formed between the two first electrodes 321 and the second electrode 322 for the ratchet 410 to pass through. The upper cover 120 also has a receiving hole 122 in the middle for accommodating the ratchet 410. The pawl mechanism 420 can be disposed on the inner wall of the receiving hole 122. The ratchet 410 protrudes from the groove 221. When the upper cover 120 is closed on the bottom shell 110, a part of the ratchet 410 is located in the receiving hole 122 and abuts against the pawl mechanism 420.

[0053] In addition, the side wall of the bottom shell 110 may be provided with a circumferentially arranged stop portion 111. When the top cover 120 is closed with the bottom shell 110, the side of the top cover 120 facing the bottom shell 110 abuts against the stop portion 111, and the outer surface of the top cover 120 abuts against the inner wall of the bottom shell 110, thereby ensuring the stability of the connection between the top cover 120 and the bottom shell 110.

[0054] In this embodiment, multiple fan blades 230 are evenly distributed along the circumference of the connector 220, and the number of fan blades 230 is not limited, for example... Figure 2 As shown, there can be eight fan blades 230. It should be understood that, with a fixed area of ​​fan blades 230, increasing the number of fan blades 230 can increase the overall contact area between the fan blades 230 and the return airflow. Furthermore, the diameter of the circle formed by the end of each fan blade 230 away from the connector 220 is at least 30mm to ensure the contact area between the fan blades 230 and the return airflow.

[0055] The height of each ratchet tooth 411 of the ratchet 410 is 6mm to 10mm, and the tooth tip circle diameter is 11mm to 18mm, so as to ensure that the ratchet tooth 411 and the pawl mechanism 420 have sufficient contact area, and ensure that the ratchet tooth 411 cannot rotate relative to the pawl mechanism 420 when the aircraft is in level flight.

[0056] The outer diameter of the shell 100 is 46mm~70mm, the thickness of the side wall of the bottom shell 110 is 7mm~10mm, the height of the side wall of the bottom shell 110 is 4mm~7mm, the thickness of the top cover 120 is 2mm~5mm, and the thickness of the bottom of the bottom shell 110 is 1mm~2mm. In this way, through the above-mentioned size design, the overall size of the aircraft stall sensing unit 10 can be minimized, thereby facilitating miniaturization design. When the aircraft stall sensing unit 10 is installed on a small unmanned aerial vehicle, it will not have a significant impact on the weight of the aircraft.

[0057] Furthermore, the material of the independent friction layer 310 can be polyamide, with a width of 2mm~6mm, a length of 10mm~20mm, and a thickness of 10μm~100μm. The materials of the first dielectric friction layer 331 and the second dielectric friction layer 332 can be fluorinated ethylene propylene copolymer, with a width of 2mm~6mm, a length of 10mm~20mm, and a thickness of 10μm~100μm. The materials of the first electrode 321 and the second electrode 322 can be conductive metallic materials such as copper, with a width of 2mm~6mm, a length of 10mm~20mm, and a thickness of 10μm~100μm. The first electrode 321 can be attached to the first dielectric friction layer 331 with an adhesive backing of the fluorinated ethylene propylene copolymer, and the second electrode 322 can be attached to the second dielectric friction layer 332 with an adhesive backing of the fluorinated ethylene propylene copolymer.

[0058] The shell 100 and the fan blade 230 can be made of one of the following materials: polylactic acid, sensitive resin, aerospace plastics, and metal, to ensure that the shell 100 and the fan blade 230 are not damaged by airflow during the flight of the aircraft.

[0059] Based on the same inventive concept, embodiments of this application can also provide an aircraft stall sensing system, combined with Figure 4 The system may include an aircraft and an aircraft stall sensing unit 10 as described in the embodiments of this application. The aircraft includes a wing 20, and there are multiple aircraft stall sensing units 10 mounted on the wing surface of the wing 20. One of the aircraft stall sensing units 10 is located near the tail of the wing 20, and the multiple aircraft stall sensing units 10 are arranged along the chord direction of the wing 20.

[0060] Combination Figure 5 The aircraft stall sensing unit 10 also includes a control unit, which is signal-connected to each aircraft stall sensing unit 10 to receive the electrical signals generated by each aircraft stall sensing unit 10. By processing the electrical signals and further analyzing the aircraft's flight state, the airflow separation state on the aircraft surface can be obtained to achieve the purpose of stall monitoring.

[0061] For example, when the aircraft experiences a slight stall, the fan blades 230 of the aircraft stall sensing unit 10 located at the tail of the wing 20 begin to rotate, while the fan blades 230 of the aircraft stall sensing unit 10 installed at a position farther from the tail do not rotate, indicating that airflow separation only exists in the tail portion of the wing 20. As the aircraft's angle of attack continues to increase, the fan blades 230 of the aircraft stall sensing unit 10 located at a farther position begin to rotate. Thus, by setting multiple aircraft stall sensing units 10, the location of the transition point can be roughly monitored, achieving the purpose of stall degree detection. Furthermore, when the aircraft stalls due to environmental influences or improper operator operation resulting in an excessive angle of attack, a corresponding warning can be issued to the operator, reminding the operator that the aircraft is currently in a specific stall state such as a slight stall or a deep stall, guiding the operator to take appropriate actions as soon as possible to ensure the aircraft's flight safety.

[0062] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present invention without departing from the spirit and scope of the invention. Therefore, if these modifications and variations fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A stall sensing unit for an aircraft, mounted on the wing surface of an aircraft, characterized in that, The aircraft stall sensing unit includes a housing, a rotating unit, a triboelectric power generation unit, and a limiting component. The rotating unit, the triboelectric power generation unit, and the limiting component are disposed inside the housing. The housing has an opening for communicating between the inside and outside of the housing. The rotating unit can rotate relative to the housing along the direction of the backflow airflow on the wing surface of the aircraft; The rotating unit is connected to the housing via the limiting component, which restricts the rotating unit from rotating relative to the housing along the laminar airflow direction on the wing surface of the aircraft. The triboelectric power generation unit includes an independent triboelectric layer, an electrode pair, and a dielectric triboelectric group. The electrode pair includes a first electrode and a second electrode spaced apart. The dielectric triboelectric group includes a first dielectric triboelectric layer and a second dielectric triboelectric layer spaced apart. The first dielectric triboelectric layer is located between the first electrode and the independent triboelectric layer, and the second dielectric triboelectric layer is located between the second electrode and the independent triboelectric layer. The independent friction layer is fixed to the rotating unit, and the electrode pair and the dielectric friction group are fixed to the housing. When the rotating unit rotates relative to the housing along the direction of the return airflow on the surface of the wing, the independent friction layer rotates relative to the dielectric friction group and generates an electrical signal through friction.

2. The aircraft stall sensing unit according to claim 1, characterized in that, The housing includes a bottom shell and a top cover, the bottom shell and the top cover are detachably connected, and the opening is provided in the top cover; The rotating unit is located inside the bottom shell, and the electrode pair and the dielectric friction assembly are fixedly connected to the top cover.

3. The aircraft stall sensing unit according to claim 2, characterized in that, The rotating unit includes a rotating shaft, a connecting component, and multiple fan blades; One end of the rotating shaft is connected to the bottom of the bottom shell, and the other end of the rotating shaft is connected to the connector. The axial direction of the rotating shaft is perpendicular to the laminar airflow direction on the wing surface of the aircraft. Multiple fan blades are arranged circumferentially around the connector on the surface of the connector, one end of each fan blade is connected to the connector, and the other end of each fan blade is bent toward the connector along the laminar airflow direction on the wing surface.

4. The aircraft stall sensing unit according to claim 3, characterized in that, The fan blades and the axis of the rotating shaft have an included angle, which is 45° to 75°.

5. The aircraft stall sensing unit according to claim 3, characterized in that, The limiting assembly includes a ratchet and a pawl mechanism; The connector has a groove on the side facing the top cover, the ratchet is fixed in the middle of the groove, and the top of the ratchet protrudes out of the groove; The pawl mechanism is fixed to the upper cover. When the upper cover is closed on the bottom shell, the ratchet abuts against the pawl mechanism. The pawl mechanism is used to restrict the ratchet from rotating along the laminar airflow direction on the surface of the aircraft wing.

6. The aircraft stall sensing unit according to claim 5, characterized in that, The independent friction layer is fixed to the inner wall of the groove. The electrode pair and the dielectric friction group are located on the side of the upper cover facing the bottom shell. When the upper cover is closed on the bottom shell, the electrode pair and the dielectric friction group are located in the groove.

7. The aircraft stall sensing unit according to claim 3, characterized in that, The rotating shaft is connected to the bottom shell via a bearing.

8. The aircraft stall sensing unit according to claim 1, characterized in that, There are two independent friction layers, two electrode pairs, and two dielectric friction groups. The two independent friction layers are symmetrically arranged and spaced apart. The two electrode pairs and the two dielectric friction groups are respectively arranged corresponding to the two independent friction layers. The two first electrodes of the two electrode pairs are connected by a first copper wire, and the two second electrodes of the two electrode pairs are connected by a second copper wire.

9. The aircraft stall sensing unit according to claim 8, characterized in that, The two first electrodes are arranged symmetrically, and the two second electrodes are arranged symmetrically.

10. An aircraft stall sensing system, characterized in that, Includes an aircraft and multiple aircraft stall sensing units as described in any one of claims 1 to 9; Multiple aircraft stall sensing units are arranged and mounted on the wing surface of the aircraft along the chord direction of the wing, with one of the aircraft stall sensing units located near the tail of the wing.

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