A composite variable pitch propeller system and control method based on circulation control

Abstract

The application provides a composite variable-pitch propeller system based on circulation control and a control method, and relates to the technical field of aviation. The composite variable-pitch propeller system based on circulation control comprises a double-rotor variable-pitch motor, which is arranged in a propeller hub. The double-rotor variable-pitch motor comprises a first rotor and a second rotor. The first rotor is connected with an inner worm, and the inner worm is connected with a variable-pitch mechanism. The second rotor is connected with an outer worm, and the outer worm is connected with a rudder surface deflection mechanism. The propeller blade comprises fixed blades and movable rudders. The fixed blades are connected with the propeller hub, and the movable rudders are rotatably connected with the fixed blades. The propeller blade is provided with a jet slit. A transmission mechanism is connected with the rudder surface deflection mechanism and the movable rudders, and is used for the deflection movement of the movable rudders, so that the efficiency and adaptability of the propeller are improved, and the flight performance is optimized.

Description

Technical Field

[0001] This application relates to the field of aviation technology, and in particular to a compound variable pitch propeller system and control method based on circulation control. Background Technology

[0002] Tiltrotor aircraft, with their ability to take off and land flexibly on complex terrains such as rooftops, decks, mountains, and forests without the need for runways, combined with hovering capabilities and fixed-point operation advantages, demonstrate unique value in scenarios such as reconnaissance, surveying, search and rescue, emergency disaster relief, and border patrol. This type of aircraft integrates the high-speed cruise efficiency of fixed-wing aircraft with the vertical takeoff and landing performance of rotary-wing aircraft, and has broad application prospects in fields such as civilian material transport, aerial photography, and military reconnaissance.

[0003] Efficient switching and stable control of the propulsion system across different flight modes have become core technological bottlenecks. Among these, the propeller, as a key component for power output and attitude control, directly determines flight quality through its aerodynamic performance. Existing tiltrotor aircraft generally employ fixed-blade propeller designs. To meet the high lift coefficient requirements during takeoff, this is typically achieved by increasing the blade area or adding a twist angle in specific regions along the blade diameter. While this design ensures lift characteristics during takeoff, the excessively large blade area and twist angle lead to significant aerodynamic losses during cruise, causing a sharp drop in propeller efficiency.

[0004] Since the cruise phase constitutes a significant portion of the overall flight profile, a decrease in propeller efficiency directly restricts an aircraft's flight time and range, making it difficult for tiltrotor aircraft to achieve their expected performance advantages under the same aerodynamic conditions. Therefore, there is an urgent need to develop a propeller system that can dynamically adapt to changes in the flight phase to address the constraint of insufficient cruise efficiency on the overall performance of the aircraft. Summary of the Invention

[0005] This application provides a compound variable pitch propeller system and control method based on circulation control, so as to at least solve the above-mentioned technical problems.

[0006] The first aspect of this application provides a compound variable pitch propeller system based on circulation control, including: a dual-rotor variable pitch motor, the dual-rotor variable pitch motor is disposed in the propeller hub, the dual-rotor variable pitch motor includes a first rotor and a second rotor, the first rotor is connected to an inner worm gear, the inner worm gear is connected to a variable pitch mechanism, and the second rotor is connected to an outer worm gear, the outer worm gear is connected to a control surface deflection mechanism; The propeller hub connects to the propeller blades. The propeller blades include fixed blades and movable control surfaces. The fixed blades are connected to the propeller hub, and the movable control surfaces are rotatably connected to the fixed blades. The propeller blades are provided with jet slits. The transmission mechanism connects the rudder surface deflection mechanism and the movable rudder surface, and is used for the deflection motion of the movable rudder surface.

[0007] In one embodiment, the pitch mechanism includes a slide groove and a rotatable slider, the slide groove and the rotatable slider are connected, and the rotatable slider is fixedly connected to the propeller blade. The control surface deflection mechanism includes a rack, a rotating shaft, and a rocker arm. The rack meshes with an external worm gear, and the rocker arm is connected to the movable control surface through a transmission mechanism.

[0008] In one embodiment, the transmission mechanism includes a first rotating shaft and a second rotating shaft, a rocker arm is connected to the first rotating shaft and the second rotating shaft, the second rotating shaft is connected to a first gear, the first gear is connected to the second gear through a chain, a rotating shaft is fixedly connected to the second gear, and the rotating shaft is fixedly connected to a movable rudder surface.

[0009] In one embodiment, the propeller control module is electrically connected to the dual-rotor variable pitch motor, limit switch, high-pressure air source and circulation control module respectively. Plasma exciter electrodes are disposed at both ends of the jet slit, which is connected to the gas flow cavity. The high-pressure gas source is connected to the blade gas passage connector to provide high-pressure gas to the airflow cavity; the circulation control module is connected to and controls the energization status of the plasma actuator electrodes.

[0010] In one embodiment, the jet slit is disposed on the back of the movable control surface and / or the back of the fixed propeller blade.

[0011] The second aspect of this application provides a control method for a compound variable-pitch propeller system based on circulation control, including: takeoff phase control: The propeller control module connects the first and second rotors of the dual-rotor variable pitch motor and controls the variable pitch mechanism to adjust the propeller blade angle to the minimum blade angle. When the propeller blade angle reaches the minimum blade angle position, the mechanical limit device performs mechanical limit, the limit switch is turned on and sends a position signal to the propeller control module. After receiving the arrival signal, the propeller control module disconnects the circuit of the first rotor, keeping only the second rotor powered on; The second rotor drives the control surface deflection mechanism through the external worm gear, and through the transmission mechanism, it drives the movable control surface to deflect to the maximum deflection angle, so that the propeller switches to high lift propeller mode. The propeller control module controls the high-pressure gas source to supply gas to the airflow cavity, and controls the circulation control module to connect the plasma exciter electrode to form a plasma jet at the jet slit.

[0012] In one possible implementation, takeoff transition phase control is also included: The propeller control module receives the aircraft's flight speed information and outputs control quantities for the first and second rotors respectively according to the flight speed. It simultaneously performs centering deflection of the movable control surfaces and pitch adjustment of the propeller blade angle to balance the torque fluctuations caused by the deflection of the movable control surfaces and prevent propeller over-rotation. When the takeoff transition phase ends, the movable control surfaces return to center, and the propeller switches to high-efficiency propeller mode.

[0013] In one possible implementation, cruise phase control is also included: The propeller control module calculates the pitch control amount based on the flight parameters input from the aircraft and controls the first rotor to drive the pitch-changing mechanism to change the propeller pitch. Simultaneously, the second rotor is controlled to keep the movable rudder surface in the center position by the rudder surface deflection mechanism. The propeller control module controls the disconnection of the high-pressure gas source and the plasma exciter electrodes.

[0014] In one possible implementation, landing transition phase control is also included: The propeller control module receives the aircraft's flight speed information and outputs control quantities to the first and second rotors respectively according to the flight speed. It simultaneously performs deflection and deployment of the movable control surfaces and pitch adjustment of the propeller blade angle to balance the torque fluctuations caused by the deflection of the movable control surfaces and prevent the engine speed from being too low or the motor current from being too high. When the descent transition phase ends, the movable control surfaces deflect to their maximum angle, and the propeller switches to high-lift propeller mode.

[0015] In one possible implementation, landing phase control is also included: The propeller control module maintains the maximum deflection angle of the movable control surfaces and the propeller blade angle unchanged. The high-pressure gas source is controlled to continuously supply gas, and the circulation control module is controlled to keep the plasma exciter electrodes energized, so that a plasma jet is continuously formed at the jet slit to suppress boundary layer separation.

[0016] As can be seen from the above, the compound variable pitch propeller system and control method based on circulation control provided in this application control the pitch and control surface deflection through a dual-rotor variable pitch motor, combined with circulation control technology, to achieve efficient switching and optimized control of the propeller in flight phases such as takeoff, cruise and landing. This solves the problem of low cruise efficiency caused by fixed blade design, and improves the efficiency and adaptability of the propeller, thus optimizing flight performance.

[0017] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0018] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings. Several embodiments of this application are illustrated in the drawings by way of example and not limitation, in which: In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts.

[0019] Figure 1 A schematic diagram of the compound variable pitch propeller system based on circulation control provided in this application; Figure 2 A schematic diagram of the dual-rotor variable-pitch motor structure provided in this application; Figure 3 A schematic diagram of the control surface deflection mechanism and pitch control mechanism provided in this application; Figure 4 A schematic diagram of the transmission mechanism provided in this application; Figure 5 A schematic diagram of the propeller blade provided in this application; Figure 6 A partial structural diagram of the compound variable pitch propeller system provided in this application. Figure 1 ; Figure 7 A partial structural diagram of the compound variable pitch propeller system provided in this application. Figure 2 ; Figure 8 A flowchart of the takeoff phase control method provided for this application is included. Figure 9 A flowchart of the takeoff transition phase control of the control method provided in this application; Figure 10 A flowchart of the cruise phase control of the control method provided in this application; Figure 11 A flowchart of the landing transition phase control of the control method provided in this application; Figure 12 A flowchart of the landing phase control of the control method provided in this application.

[0020] Reference numerals: 1. Propeller control module; 2. Dual-rotor variable-pitch motor; 3. Mechanical limit device; 4. Limit switch; 51. Control surface deflection mechanism; 52. Variable-pitch mechanism; 6. Fixed blade; 7. Movable control surface; 8. Jet slit; 81. First slit; 82. Second slit; 9. Plasma excier electrode; 10. Transmission mechanism; 11. Blade gas passage connector; 12. High-pressure gas source; 13. Circulation control module; 14. Propeller hub; 15. Propeller blade; 21. First rotor; 22. Second rotor; 23. External worm; 24. Internal worm; 511. Rack; 512. Rotating shaft; 513. Rocker arm; 521. Slide groove; 522. Slider; 101. First rotating shaft; 102. Second rotating shaft; 103. First gear; 104. Chain; 105. Second gear; 106. Rotating shaft. Detailed Implementation

[0021] To make the objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] In tiltrotor aircraft, the propeller system must simultaneously meet the high lift requirements of the vertical takeoff and landing phase and the high efficiency requirements of the cruise phase. Existing technology employs a fixed-blade structure, achieving high lift coefficients during takeoff by increasing blade area and setting large twist angles in specific regions along the blade diameter. However, during the cruise phase, this structure leads to increased induced drag and frictional drag, resulting in increased aerodynamic losses and reduced propeller efficiency. This problem causes a decrease in the aircraft's flight time and range, affecting overall flight performance. Particularly in the flight profile where cruise accounts for a large proportion, system energy consumption increases, and performance deteriorates significantly compared to fixed-wing aircraft. The low propeller efficiency during the cruise phase keeps the overall system energy consumption consistently high. In long-distance missions, reduced flight time may prevent the aircraft from completing planned reconnaissance or cargo transport missions. Especially under complex weather conditions, this deficiency further reduces flight stability and mission reliability, increasing the risk of mission failure.

[0023] like Figures 1-7 As shown, this application provides a compound variable-pitch propeller system based on circulation control, comprising: Dual-rotor variable-pitch motor 2 is installed inside the propeller hub 14. Dual-rotor variable-pitch motor 2 includes a first rotor 21 and a second rotor 22. The first rotor 21 is connected to an inner worm 24, which is connected to a variable-pitch mechanism 52. The second rotor 22 is connected to an outer worm 23, which is connected to a rudder surface deflection mechanism 51. The propeller hub 14 is connected to the propeller blade 15. The propeller blade 15 includes a fixed blade 6 and a movable control surface 7. The fixed blade 6 is connected to the propeller hub 14, and the movable control surface 7 is rotatably connected to the fixed blade 6. The propeller blade 15 is provided with a jet slit 8. The transmission mechanism 10 connects the rudder surface deflection mechanism 51 and the movable rudder surface 7, and is used for the deflection movement of the movable rudder surface 7.

[0024] The dual-rotor variable-pitch motor 2 is an electric motor containing two rotors, each capable of independent rotation. This motor is designed to simultaneously drive two different mechanical systems, which in this system are housed within the propeller hub 14 to achieve dual control of the pitch of the propeller blades 15 and the deflection of the movable control surface 7. The propeller hub 14 is the central component of the propeller system and is typically fixed to the aircraft's power output shaft. The propeller blades 15 are connected to the aircraft body via this hub and receive driving force from it. The propeller blades 15 are the components that generate lift and thrust, interacting with the air through rotational motion. In this system, the propeller blades 15 are designed as a composite structure, including fixed blades 6 and movable control surfaces 7. The fixed blades 6 are the main body of the propeller blades 15, fixedly connected to the propeller hub 14, forming the aerodynamic shape of the blades. The movable control surface 7 is a rotatable component on the propeller blades 15, rotatably connected to the fixed blades 6. By changing the deflection angle of the movable control surface 7, the aerodynamic characteristics of the propeller blades can be actively adjusted, such as changing the lift coefficient or suppressing boundary layer separation. The jet slit 8 is an opening on the propeller blade 15, designed to inject airflow or plasma jets onto the blade surface under specific conditions to control the propeller circulation or regulate boundary layer flow. The outer worm 23 is a component of the worm gear transmission mechanism 10. Through meshing with the worm wheel or rack 511, it converts the rotational motion of the dual-rotor variable-pitch motor 2 into linear motion or further rotational motion, thereby driving the variable-pitch mechanism 52 and the control surface deflection mechanism 51. The variable-pitch mechanism 52 is a mechanical device for adjusting the angle of the propeller blade 15. By changing the blade angle, the propeller thrust and efficiency can be adjusted to adapt to different flight conditions. The control surface deflection mechanism 51 is a mechanical device for driving the movable control surface 7 to deflect. This mechanism transmits the power output from the second rotor 22 of the dual-rotor variable-pitch motor 2 to the movable control surface 7, achieving its deflection control. The transmission mechanism 10 is a series of mechanical components that connect the rudder surface deflection mechanism 51 and the movable rudder surface 7. Its function is to accurately transmit the motion generated by the rudder surface deflection mechanism 51 to the movable rudder surface 7, so that it deflects according to the preset command.

[0025] This embodiment provides a compound variable-pitch propeller system based on circulation control. Its technical features include a dual-rotor variable-pitch motor 2, a composite structure of propeller blades 15, and a transmission mechanism 10 for deflecting the movable control surface 7. The dual-rotor variable-pitch motor 2 is disposed inside the propeller hub 14 and includes a first rotor 21 and a second rotor 22. The first rotor 21 is connected to an inner worm gear 24, which is further connected to a pitch-changing mechanism 52 to realize the pitch-changing function of the propeller blades 15. The second rotor 22 is connected to an outer worm gear 23, which is connected to the control surface deflection mechanism 51 to drive the deflection of the movable control surface 7. For example, two independent motors could be used to drive the pitch-changing mechanism 52 and the control surface deflection mechanism 51 respectively, but this approach may increase the system's complexity and space requirements. Alternatively, a single-rotor motor could be used to achieve both functions via a clutch or gear set, but this could affect the switching response speed or structural reliability. This embodiment uses a dual-rotor variable-pitch motor 2 to provide a compact and functionally independent drive solution.

[0026] A propeller hub 14 connects to a propeller blade 15, which includes a fixed blade 6 and a movable control surface 7. The fixed blade 6 is connected to the propeller hub 14, forming the main structure of the blade. The movable control surface 7 is rotatably connected to the fixed blade 6, allowing it to deflect relative to the fixed blade 6. Furthermore, a jet slit 8 is provided on the propeller blade 15. For example, conventional propellers typically use blades whose aerodynamic shape is fixed after manufacturing and cannot be dynamically adjusted according to flight conditions. Even variable-pitch propellers can only change the overall angle of the blades, not the aerodynamic characteristics of the blade surface locally. This embodiment, by introducing the movable control surface 7 and the jet slit 8, aims to provide a structure capable of actively adjusting the local aerodynamic performance of the blades.

[0027] The transmission mechanism 10 connects the rudder deflection mechanism 51 and the movable rudder 7, and its function is to realize the deflection motion of the movable rudder 7. For example, the transmission mechanism 10 can consist of a series of links, gears, or wire ropes to transmit the output motion of the rudder deflection mechanism 51 to the movable rudder 7. In some designs, the rudder deflection mechanism 51 can be directly connected to the movable rudder 7 via a link, but this may affect the transmission efficiency or deflection accuracy. In this embodiment, the transmission mechanism 10 is designed to ensure that the motion of the rudder deflection mechanism 51 can be efficiently and accurately converted into the deflection of the movable rudder 7.

[0028] This embodiment achieves independent and synchronous control of pitch change and control surface deflection through the dual-rotor variable-pitch motor 2, simplifying the mechanical transmission chain and improving the system's response speed and control accuracy. For example, during takeoff, the system can quickly adjust the blades to the blade angle and deflect the movable control surface 7 to the angle, while simultaneously performing circulation control through the jet slit 8. This allows it to obtain lift exceeding that of a traditional fixed-blade propeller 6 or a simple variable-pitch propeller in a short time, effectively solving the problem of insufficient takeoff lift.

[0029] Furthermore, the composite structure of the propeller blade 15, especially the introduction of the movable control surface 7, allows the aerodynamic shape of the blade to be adjusted according to the flight mode. By deflecting the movable control surface 7, the blade can adapt to different aerodynamic requirements, such as increasing camber during takeoff to increase lift and centering out during cruise to reduce drag, thus balancing lift and efficiency. The combination of the jet slit 8 and circulation control technology further solves the boundary layer separation problem that may occur when the movable control surface 7 deflects, ensuring that the control surface maintains aerodynamic performance under various deflection states, which is challenging to achieve in existing technologies.

[0030] The transmission mechanism 10 ensures that the motion of the control surface deflection mechanism 51 can be accurately transmitted to the movable control surface 7, guaranteeing the reliability and accuracy of the entire control chain. This overall technical solution, through the integration of structural innovation and active flow control technology, enables the propeller system to achieve efficient switching and stable control in different flight modes, improving the efficiency of tiltrotor aircraft during the cruise phase and enhancing flight performance.

[0031] like Figure 2 As shown, the inner worm 24 is nested inside the outer worm 23 to form a coaxial double worm structure; the pitch mechanism 52 includes a groove 521 and a rotatable slider 522, the groove 521 and the rotatable slider 522 are connected, and the rotatable slider 522 is fixedly connected to the propeller blade 15; the control surface deflection mechanism 51 includes a rack 511, a rotating shaft 512 and a rocker arm 513, the rack 511 meshes with the outer worm 23, and the rocker arm 513 is connected to the movable control surface 7 through the transmission mechanism 10.

[0032] The pitch-changing mechanism 52 is used to change the angle of the propeller blades 15 to adapt to different flight conditions. The groove 521 and the rotatable slider 522 are key mechanical components for achieving this pitch-changing motion. The groove 521 provides guidance, and the rotatable slider 522 moves within the groove 521, driving the blades to rotate. The groove 521 can be designed as an arc-shaped groove or a straight groove, its shape depending on the required pitch-changing motion trajectory of the blades. The rotatable slider 522 can be a block with a pin inserted into the fixed blade 6. When the pitch-changing mechanism 52 moves up and down, it drives the rotatable slider 522 to slide, and simultaneously the rotatable slider 522 rotates around its pin, thereby driving the fixed blade 6 to rotate, achieving pitch changing.

[0033] The control surface deflection mechanism 51 is used to precisely control the deflection angle of the movable control surface 7, thereby achieving mode switching. The rack 511, rotating shaft 512, and rocker arm 513 form the mechanical transmission chain that realizes this deflection motion. The rack 511 can be fixed to the outer surface of the outer worm 23, or connected to the outer worm 23 by a key; when the outer worm 23 rotates, the rack 511 moves accordingly. The rotating shaft 512 can be an independent shaft, supported by bearings, and fixedly connected to the rocker arm 513. One end of the rocker arm 513 is connected to the rotating shaft 512, and the other end is connected to the movable control surface 7 via the transmission mechanism 10.

[0034] The solution of this application achieves a compact integration of the pitch-changing mechanism 52 and the control surface deflection mechanism 51 by nesting the inner worm 24 inside the outer worm 23 to form a coaxial double worm structure. Specifically, the first rotor 21 in the dual-rotor pitch-changing motor 2 drives the inner worm 24. The rotation of the inner worm 24 is converted into the pitch-changing motion of the propeller blade 15 through the slide groove 521 and the rotatable slider 522 in the pitch-changing mechanism 52. The rotatable slider 522 is fixedly connected to the propeller blade 15 to ensure precise adjustment of the blade angle. At the same time, the second rotor 22 in the dual-rotor pitch-changing motor 2 drives the outer worm 23. The rotation of the outer worm 23 drives the rack 511 to move through meshing with the rack 511. The movement of the rack 511 then drives the rotating shaft 512 and the rocker arm 513 in the control surface deflection mechanism 51. The rocker arm 513 transmits the motion to the movable control surface 7 through the transmission mechanism 10, realizing the deflection of the movable control surface 7. This coaxial dual-worm gear design enables two independent control functions to be performed efficiently and independently within the limited space of the propeller hub 14, avoiding complex external transmission structures and thus improving the system's integration and reliability. Through this ingenious mechanical layout, the system can simultaneously and precisely control the propeller blade angle 15 and the deflection of the movable control surface 7, providing a solid mechanical foundation for circulation control.

[0035] Through the above technical solution, the inner worm 24 is nested inside the outer worm 23 to form a coaxial double worm structure, which greatly optimizes the utilization rate of the transmission space inside the propeller hub 14, allowing the pitch-changing mechanism 52 and the control surface deflection mechanism 51 to be compactly integrated within a limited volume. This design avoids the complex and redundant transmission paths and components that may exist in traditional solutions, thereby reducing the overall weight and structural complexity of the system. The pitch-changing mechanism 52 adopts a connection method of slide groove 521 and rotatable slider 522, and the control surface deflection mechanism 51 adopts a combination of rack 511, rotating shaft 512 and rocker arm 513, providing a direct and efficient mechanical transmission path for the pitch change of the propeller blade 15 and the deflection of the movable control surface 7. This not only ensures the accuracy and response speed of the pitch change and deflection actions, but also further improves the reliability and durability of the system due to the optimization of the number of components and the improvement of transmission efficiency. Ultimately, this solution provides a compact, efficient, and reliable mechanical basis for realizing a compound variable-pitch propeller system based on circulation control, enabling the aircraft to meet its stringent requirements for lightweighting and integration while maintaining high performance.

[0036] like Figure 4 As shown, the transmission mechanism 10 includes a first rotating shaft 101 and a second rotating shaft 102. A rocker arm 513 is connected to the first rotating shaft 101 and the second rotating shaft 102. The second rotating shaft 102 is connected to a first gear 103. The first gear 103 is connected to a second gear via a chain 104. A rotating shaft 105 is fixedly connected to the second gear 106. The rotating shaft 105 is fixedly connected to the movable control surface 7. The rocker arm 513 drives the first rotating shaft 101 to rotate, and transmits the rotational motion to the first gear 103 via the second rotating shaft 102. The first gear 103 drives the second gear to rotate via the chain 104. The second gear is fixedly connected to the rotating shaft 105, thereby causing the movable control surface 7 to deflect.

[0037] The first rotating shaft 101 receives and transmits the motion of the rocker arm 513. It can be a solid or hollow structure, typically supported by bearings to reduce friction and ensure smooth rotation. For example, the first rotating shaft 101 can be made of high-strength alloy steel and supported by a pair of deep groove ball bearings. The second rotating shaft 102 receives the motion transmitted by the first rotating shaft 101 and further transmits it to subsequent gears. The second rotating shaft 102 can be coaxial or parallel to the first rotating shaft 101 and also requires support by bearings. For example, the second rotating shaft 102 can be made of lightweight aluminum alloy and supported by sliding bearings. The motion of the rocker arm 513 is transmitted to the first rotating shaft 101 and the second rotating shaft 102 through this connection. The rocker arm 513 can be directly fixed to the first rotating shaft 101, for example, through an interference fit or key connection, so that the swing of the rocker arm 513 directly drives the rotation of the first rotating shaft 101. The first rotating shaft 101 and the second rotating shaft 102 can be connected in various ways to transmit rotational motion, such as through gear pairs, synchronous pulleys, or universal joints. The connection between the second shaft 102 and the first gear 103 ensures that the rotational motion of the second shaft 102 can effectively drive the first gear 103. The second shaft 102 can be integrated with the first gear 103, meaning the first gear 103 is directly machined onto the second shaft 102. Alternatively, the first gear 103 can be securely fixed to the second shaft 102 using keys, splines, pins, or bolts to prevent relative slippage. The first gear 103 is connected to the second gear via a chain 104, which uses chain drive to transmit the rotational motion of the first gear 103 to the second gear. The chain 104 can be a roller chain, a sleeve chain, or a toothed chain, which meshes with the corresponding first gear 103 and second gear (as a sprocket), respectively. Chain drive allows power transmission over a certain distance and can achieve different transmission ratios, thereby adjusting the deflection speed and torque of the movable control surface 7. The fixed connection between the rotating shaft 105 and the second gear 106 ensures that the rotational motion of the second gear can be fully transmitted to the rotating shaft 105. The second gear 106 of the rotating shaft 105 can be rigidly fixed to the second gear through welding, interference fit, key connection, spline connection, or bolt connection, thereby ensuring synchronous rotation of both. The fixed connection between the second gear 106 of the rotating shaft 105 and the movable control surface 7 is key to achieving the deflection of the movable control surface 7. The second gear 106 of the rotating shaft 105 can directly pass through the movable control surface 7 and be fixed to its internal structure, for example, by bolts, rivets, or adhesive. Alternatively, the second gear 106 of the rotating shaft 105 can be connected to a bracket, which is then fixed to the movable control surface 7, thereby converting the motion of the second gear 106 of the rotating shaft 105 into angular deflection of the movable control surface 7.The motion path and function of the entire transmission chain 104 are as follows: the initial swinging or rotating motion of the rocker arm 513 is transmitted step by step through the first rotating shaft 101, the second rotating shaft 102, the first gear 103, the chain 104, the second gear, and the second gear of the rotating shaft 105; 106, ultimately transforming into the precise angular deflection of the movable control surface 7. This series of connections and transmission links work together to ensure the accuracy and reliability of motion transmission from the input end to the output end.

[0038] The solution of this application, through the refined design of the aforementioned transmission mechanism 10, precisely transmits the motion of the rocker arm 513 in the rudder surface deflection mechanism 51 to the movable rudder surface 7, thereby achieving its deflection. Specifically, when the rudder surface deflection mechanism 51 drives the rocker arm 513 to swing or rotate, the motion of the rocker arm 513 is first received by the first rotating shaft 101 and converted into its own rotation. Subsequently, the first rotating shaft 101 transmits this rotational motion to the second rotating shaft 102. The second rotating shaft 102 is fixedly connected to the first gear 103, so the rotation of the second rotating shaft 102 directly drives the first gear 103 to rotate. The first gear 103 forms a chain drive with the second gear through the chain 104, transmitting the rotational power to the second gear. Finally, the second gear is rigidly connected to the second gear 106 of the rotating shaft 105, so that the rotation of the second gear directly drives the second gear 106 of the rotating shaft 105 to rotate. Since the second gear 106 of the rotating shaft 105 is fixedly connected to the movable control surface 7, the rotation of the second gear 106 of the rotating shaft 105 directly causes the movable control surface 7 to deflect around its own axis. This multi-stage transmission chain design not only enables indirect and non-coaxial motion transmission between the rocker arm 513 and the movable control surface 7, but also allows for flexible adjustment of the transmission ratio through the combination of gears and chains 104. This ensures that the input motion of the rocker arm 513 can be efficiently, accurately, and stably converted into the desired deflection angle of the movable control surface 7 within the limited internal space of the propeller hub 14, effectively solving the challenge of achieving precise motion transmission in a compact space.

[0039] The propeller control module 1 is electrically connected to the dual-rotor variable-pitch motor 2, the limit switch 4, the high-pressure gas source 12, and the circulation control module 13, respectively. The plasma exciter electrode 9 is located at both ends of the jet slit 8, which is connected to the airflow cavity. The high-pressure gas source 12 is connected to the blade gas passage connector 11 and is used to provide high-pressure gas to the airflow cavity. The circulation control module 13 is connected to and controls the energization state of the plasma exciter electrode 9. The high-pressure gas source 12 is the engine bleed air system or the booster pump.

[0040] This application further proposes that the system also includes a propeller control module 1, plasma actuator electrodes 9, jet slits 8, airflow cavities, a high-pressure gas source 12, and a circulation control module 13. The propeller control module 1 is a centralized control unit responsible for receiving flight parameters, processing control logic, and outputting commands to coordinate the various functions of the propeller system. It can be an embedded microcontroller, digital signal processor (DSP), or industrial-grade programmable logic controller (PLC), achieving precise management of propeller pitch, control surface deflection, and circulation control through preset control algorithms and real-time data feedback. The plasma actuator electrodes 9 are used to generate plasma in a specific area, achieving boundary layer flow control through the excitation effect of the plasma on the airflow. It typically consists of at least one pair of asymmetric electrodes; for example, metal foil can be used as the electrode material and insulated with a dielectric material to form a dielectric barrier discharge (DBD) plasma actuator. These electrodes are arranged on the airflow interaction surface, and plasma is generated in the electrode gaps or on the surface by applying high-frequency, high-voltage alternating current. The jet slit 8 is an opening on the surface of the propeller blades 15 for ejecting high-pressure gas. The geometry and location of the slit are crucial to the airflow jet effect. It can be designed as a single elongated slot or multiple parallel or staggered slots. The width, length, and exit angle of the slit can be optimized according to the desired circulation control effect to ensure that the high-pressure gas can effectively interact with the airflow on the blade surface. The airflow cavity is a channel or space inside the propeller blade 15 used to transport and store high-pressure gas. This cavity can be formed by internal structural components of the blade, such as by constructing an internal piping system through integral molding, 3D printing, or segmented assembly. Its design should ensure that the high-pressure gas can be uniformly and stably delivered to the jet slit 8 and withstand the internal pressure. The high-pressure gas source 12 is a device that provides high-pressure gas to the airflow cavity. It can be the bleed air system of an aircraft engine, utilizing high-pressure air between compressor stages or at the compressor outlet; or it can be a separate booster pump, such as an electric turbocharger or a piston booster pump, specifically designed to provide the required high-pressure airflow for the circulation control system. The circulation control module 13 is responsible for managing and controlling the energizing state of the plasma exciter electrode 9 to achieve precise adjustment of the plasma excitation intensity. It typically includes a high-voltage power supply, a high-frequency oscillator, and control circuitry, and can output high-voltage alternating current with specific frequency, voltage, and pulse width according to the instructions of the propeller control module 1, thereby controlling the generation and intensity of the plasma.

[0041] The scheme in this application achieves centralized coordination and control of the entire propeller system by electrically connecting the propeller control module 1 to the dual-rotor variable-pitch motor 2, limit switch 4, high-pressure gas source 12, and circulation control module 13. The high-pressure gas source 12 supplies high-pressure gas to the airflow cavity inside the propeller blade 15 through the blade gas passage connector 11. This high-pressure gas is then ejected through a jet slit 8 in the propeller blade 15, forming a high-speed airflow. Simultaneously, plasma exciter electrodes 9, located at both ends of the jet slit 8, generate plasma under the drive of the circulation control module 13. The plasma interacts with the ejected high-pressure airflow, effectively changing the airflow state on the blade surface through mechanisms such as momentum injection, boundary layer separation suppression, or airflow deflection, thereby achieving precise adjustment of the propeller blade circulation. This active circulation control, combined with mechanical pitch control and control surface deflection, enables the propeller system to not only adjust the pitch and control surface angle mechanically, but also to precisely control the lift characteristics of the blades aerodynamically. Especially under flight conditions of low speed, high angle of attack, or requiring rapid response, it can significantly enhance the propeller's lift efficiency and control margin.

[0042] Through the aforementioned technical solution, an active circulation control system was constructed by introducing a propeller control module 1, a plasma exciter electrode 9, a jet slit 8, an airflow cavity, a high-pressure air source 12, and a circulation control module 13, based on the original mechanical pitch control and control surface deflection. This system can precisely control the airflow on the surface of the propeller blades 15 through the synergistic effect of high-pressure airflow and plasma excitation, effectively suppressing boundary layer separation, increasing the effective lift of the blades, and reducing drag. This enables the propeller to achieve a higher lift coefficient and superior thrust efficiency under various flight conditions, especially during low-speed takeoff and landing, high angle-of-attack flight, or maneuvers requiring rapid response. Simultaneously, through the integrated management of mechanical pitch control, control surface deflection, and circulation control by the propeller control module 1, comprehensive optimization of propeller performance was achieved, significantly improving the system's adaptability and control accuracy. Thus, without significantly increasing the blade size and weight, the overall aerodynamic performance of the propeller was greatly enhanced.

[0043] In some embodiments described above in this application, a compound variable-pitch propeller system based on circulation control is proposed. This system uses a dual-rotor variable-pitch motor 2 to drive a variable-pitch mechanism 52 and a control surface deflection mechanism 51, which, in conjunction with a jet slit 8 on the propeller blade 15 and a plasma actuator electrode 9, achieve circulation control. However, in practical applications, the precise position and structure of the jet slit 8 are crucial for its effectiveness in suppressing boundary layer separation and improving aerodynamic performance. If the arrangement of the jet slit 8 is not optimized, it may lead to low circulation control efficiency, failing to fully realize its potential for increasing lift or reducing drag.

[0044] like Figure 1 and Figure 5 As shown, the jet slit 8 is located on the back side of the movable control surface 7 and / or the back side of the fixed blade 6; specifically, the location of the jet slit 8 is crucial to its function. The back side typically refers to the suction surface of the blade, where jet control helps suppress boundary layer separation, thereby increasing lift or altering aerodynamic characteristics. The jet slit 8 can be arranged along or near the trailing edge of the movable control surface 7 on the back side to directly affect the aerodynamic performance during control surface deflection; alternatively, the jet slit 8 can also be arranged along the back side of the fixed blade 6, especially at the blade root or middle, to regulate the aerodynamic circulation of the entire blade. Furthermore, the structure of the jet slit 8 is limited to a single-slit structure, meaning that each control area contains only one independent slit. Single-slit structures generally have advantages such as simple structure, relatively easy manufacturing, and intuitive control logic. A single slit can be designed as an elongated opening extending along the blade span, its width and length optimized according to the desired jet characteristics and the pressure of the airflow cavity; alternatively, a single slit can also consist of a series of closely spaced small holes, functionally equivalent to a continuous slit, but potentially offering greater manufacturing flexibility. Furthermore, the single slit structure is explicitly defined as being located on the back surface of the movable control surface 7 or the back surface of the fixed blade 6, rather than both simultaneously. If chosen to be located on the back surface of the movable control surface 7, the single slit will primarily serve to enhance the lift effect when the movable control surface 7 deflects, or to provide fine circulation control under specific flight conditions; if chosen to be located on the back surface of the fixed blade 6, the single slit will primarily serve to provide basic circulation control of the aerodynamic characteristics of the entire blade, especially providing auxiliary lift or drag reduction effects during blade pitch changes.

[0045] The jet slit 8 is a single-slit structure, located on the back surface of the movable control surface 7 or the back surface of the fixed blade 6. This application's solution precisely positions the jet slit 8 on the suction surface of the propeller blade 15, i.e., the back surface of the movable control surface 7 and / or the back surface of the fixed blade 6, and employs a single-slit structure. This allows the plasma jet formed by the gas supplied by the high-pressure gas source 12 and the plasma exciter electrode 9 controlled by the circulation control module 13 to directly and efficiently act on the region of the blade prone to boundary layer separation. When the high-pressure gas source 12 supplies gas to the airflow cavity and the plasma exciter electrode 9 is activated, the plasma jet is ejected from the single slit, injecting momentum into the boundary layer, thereby effectively suppressing airflow separation. This targeted jet location and single-slit structure ensure that the energy input is optimally used to improve the aerodynamic performance of the blade. For example, when the single slit is located on the back of the movable control surface 7, it can significantly enhance the lift effect when the movable control surface 7 deflects, allowing the control surface to generate greater aerodynamic control force even at a smaller deflection angle, thereby improving the propeller's response speed and control accuracy. If the single slit is located on the back of the fixed blade 6, the aerodynamic circulation of the entire blade can be fundamentally adjusted, optimizing the lift distribution of the blade and reducing drag, thereby improving the overall propeller propulsion efficiency. This precise jet slit 8 configuration, in conjunction with the dual-rotor variable-pitch motor 2, the variable-pitch mechanism 52, and the control surface deflection mechanism 51, enables the entire system to achieve fine-grained control of the propeller blade angle 15° and the deflection of the movable control surface 7 according to different flight stages and aerodynamic requirements, and further optimizes aerodynamic performance through circulation control, thus ensuring both high lift and high efficiency.

[0046] The jet slit 8 has a double slit structure. The first slit 81 is located on the back of the movable control surface 7, and the second slit 82 is located on the back of the fixed blade 6.

[0047] The double-slit structure refers to having two independent jet slits 8 on the propeller blade 15, rather than a single slit. This structure provides more flexible circulation control, allowing airflow to be applied at different positions on the blade to adapt to different aerodynamic requirements. For example, the two slits can be arranged in parallel or staggered at different chordal positions on the blade; they can also have different geometries to optimize their respective jet characteristics. The first slit 81 is located on the back of the movable control surface 7. Its function is to enhance the deflection effect of the control surface by applying a jet to the back of the movable control surface 7, or to provide additional circulation control when the control surface deflects, thereby more effectively controlling boundary layer separation near the control surface and improving the aerodynamic efficiency of the control surface. For example, the first slit 81 can extend along the spanwise direction of the movable control surface 7 and be located near its trailing edge, or it can be integrated into the structure of the movable control surface 7 and communicate with the airflow cavity through an internal channel. The second slit 82 is located on the back of the fixed blade 6. Its function is to apply a jet to the back of the fixed blade 6, providing circulation control independently of the movable control surface 7. This is used to suppress boundary layer separation in the main body of the fixed blade 6, or to provide basic circulation control when the movable control surface 7 returns to center, thereby improving the lift or efficiency of the entire blade. For example, the second slit 82 can be located near the chordal center or leading edge of the fixed blade 6 to affect a larger portion of the blade surface, and can be controlled independently of the first slit 81 for finer circulation adjustment. The first slit 81 is located on the back of the movable control surface 7, allowing direct manipulation of the airflow on the control surface, thereby enhancing its effectiveness, especially at large yaw angles or when rapid changes in lift are required. This helps maintain the attached flow and prevent separation on high-load control surfaces. The second slit 82, located on the back of the fixed blade 6, provides an independent control point for the blade body. It can be used to optimize overall lift distribution, reduce drag, or suppress boundary layer separation in the fixed airfoil section, even when the movable control surface 7 is in a neutral position or performing its own control function. This arrangement enables a more distributed and refined application of circulation control. For example, when high lift is required, both slits can be activated simultaneously to maximize lift; during cruise, one slit may be used for fine-tuning efficiency while the other remains inactive. This independently placed slit allows for customized airflow control strategies, addressing separation at different locations on the airfoil profile more effectively than a single slit, thus significantly improving the propeller system's ability to adapt to different aerodynamic conditions and optimize performance across various flight phases.

[0048] Through the above technical solution, the system can achieve more precise and flexible control of the airflow over the surface of the propeller blade 15. The double-slit structure, particularly the placement of the first slit 81 on the back of the movable control surface 7 and the second slit 82 on the back of the fixed blade 6, enables the system to more effectively suppress boundary layer separation, especially when the movable control surface 7 is deflected or the blade is at a high angle of attack. This not only improves the propeller's lift coefficient and efficiency but also enhances its adaptability and stability under different flight conditions, thereby optimizing the aerodynamic performance of the entire propeller system.

[0049] The system includes a mechanical limit device and a limit switch 4 for detecting the limit status. The mechanical limit device 3 is set to limit the minimum blade angle when the propeller changes pitch. Specifically, the mechanical limit device 3 is a mechanism that limits the range of motion of mechanical parts through physical contact or structural obstruction. Its function is to prevent the moving parts from exceeding the preset safety or working range, thereby protecting the equipment from damage and ensuring the stability of system operation. This device can use a cam mechanism in conjunction with a limit block. When the propeller blade angle reaches the minimum set value, the cam contacts the limit block, preventing further pitch change. Alternatively, a physical stop or stop screw can be used. When the pitch change mechanism 52 moves to the preset position, the stop or stop screw contacts the moving parts of the pitch change mechanism 52, thereby limiting its continued movement. The limit switch 4 is a sensor for detecting the position or motion status of mechanical parts. When the mechanical parts move to the preset position, the limit switch 4 is triggered, sending an electrical signal for the system's logical judgment or subsequent operation. The switch can be a mechanical limit switch 4, triggered by the contact of mechanical components, such as a microswitch; or a non-contact limit switch 4, such as a photoelectric switch or proximity switch, which determines the position by detecting the presence or distance of an object, thus avoiding mechanical wear. The mechanical limit device 3 is set to limit the minimum blade angle during propeller pitch change. This setting ensures that the propeller blade 15 will not fall below the preset minimum blade angle during pitch change, preventing structural interference, aerodynamic performance abnormalities, or damage to the pitch change mechanism 52 due to an excessively small blade angle. The mechanical limit device 3 can cooperate with a moving component of the pitch change mechanism 52 (such as a slider 522 or a connecting rod). When the moving component reaches the position corresponding to the minimum blade angle, the mechanical limit device 3 intervenes to prevent further movement; or, the mechanical limit device 3 can also act directly on the root of the propeller blade 15 or its connecting structure, limiting the blade rotation angle through physical obstruction, thereby ensuring the setting of the minimum blade angle.

[0050] The solution in this application introduces a mechanical limit device 3 and a limit switch 4. During the propeller pitch change process, when the propeller blade angle 15 reaches the preset minimum blade angle, the mechanical limit device 3 provides a physical block, effectively limiting the further movement of the pitch change mechanism 52, thereby preventing structural interference or damage to the pitch change mechanism 52 caused by an excessively small propeller blade angle 15. Simultaneously, the limit switch 4 is configured to detect the limiting status of the mechanical limit device 3. Once the minimum blade angle is reached and mechanically limited, the limit switch 4 is triggered and sends a corresponding positioning signal to the propeller control module 1. Upon receiving this signal, the propeller control module 1 can confirm that the propeller blade 15 has safely reached the minimum blade angle position and adjust subsequent control strategies accordingly, such as stopping the power supply to the corresponding rotor of the dual-rotor pitch change motor 2, or activating other functional modules. This combination of mechanical and electronic control limiting provides dual protection for the safe operation of the propeller system, ensuring that the propeller can operate stably and reliably at the minimum blade angle during extreme or specific flight phases (such as takeoff), laying the foundation for subsequent high-lift propeller mode switching.

[0051] The movable control surface 7 is made of composite material or metal, and has an internal cavity to form part of the airflow cavity; the fixed blade 6 is made of composite material. Specifically, the movable control surface 7 can be made of composite material, such as carbon fiber reinforced resin matrix composite or glass fiber reinforced resin matrix composite. These materials have advantages such as high specific strength, high specific stiffness, and corrosion resistance, which helps to achieve lightweight design and meet structural strength requirements. Alternatively, the movable control surface 7 can also be made of metal, such as aluminum alloy or titanium alloy. These metal materials have excellent strength, toughness, and processing performance, and can withstand large loads and harsh environments. The movable control surface 7 has an internal cavity, which is part of the airflow cavity and is used to guide high-pressure gas to the jet slit 8. The design of this cavity allows the airflow channel to be integrated inside the movable control surface 7, avoiding the additional resistance from external pipelines. The fixed blade 6 is made of composite material, such as carbon fiber reinforced resin matrix composite or glass fiber reinforced resin matrix composite, to achieve lightweight design, reduce the overall rotational inertia of the propeller, improve response speed, and ensure sufficient structural strength and fatigue life.

[0052] By employing the aforementioned technical solutions, the movable control surface 7 is designed to be made of composite material or metal, with an internal cavity forming part of the airflow cavity. Simultaneously, the fixed blade 6 is designed to be made of composite material, significantly optimizing the structural performance and functional integration of the propeller blade 15. Specifically, the application of composite materials effectively reduces the overall weight and moment of inertia of the blade, improving the response speed and efficiency of propeller pitch control and control surface deflection. The cavity design within the movable control surface 7 cleverly integrates the airflow channel within the blade structure, avoiding the additional resistance and complexity of external piping. This ensures that high-pressure gas can be efficiently and smoothly delivered to the jet slit 8, providing a solid foundation for circulation control. This combination of material selection and structural design allows the propeller system to achieve efficient circulation control while maintaining excellent lightweight characteristics and structural integrity, enhancing the overall performance and reliability of the system.

[0053] like Figure 8 As shown, a control method for a compound variable-pitch propeller system based on circulation control includes the following control steps during flight: Takeoff Phase Control: The propeller control module connects the first and second rotors of the dual-rotor variable-pitch motor, controlling the variable-pitch mechanism to adjust the propeller blade angle to the minimum blade angle. When the propeller blade angle reaches the minimum blade angle position, the mechanical limit device performs a mechanical limit, the limit switch is turned on, and a position signal is sent to the propeller control module. After receiving the position signal, the propeller control module disconnects the circuit of the first rotor, keeping only the second rotor powered. The second rotor drives the control surface deflection mechanism through the external worm gear, which drives the movable control surface to deflect to the maximum deflection angle through the transmission mechanism, causing the propeller to switch to high-lift propeller mode. The propeller control module controls the high-pressure gas source to supply gas to the airflow cavity and controls the circulation control module to connect the plasma exciter electrodes, forming a plasma jet at the jet slit.

[0054] In one embodiment, the propeller control module connects the circuit of the dual rotor variable pitch motor to control its pitch change; the dual rotor variable pitch motor drives the pitch change and control surface deflection mechanism to move through the inner and outer worm gears, changing the propeller blade angle to the minimum blade angle; when the propeller blade angle reaches the minimum blade angle position, the mechanical limit device limits the movement, and the limit switch is activated at the same time; the propeller control module receives the information from the limit switch, disconnects the motor rotor circuit of the inner worm gear, and only connects the motor rotor of the outer worm gear; the dual rotor variable pitch motor continues to drive the control surface deflection mechanism to move through the outer worm gear; the control surface deflection mechanism drives the movable control surface of the propeller blade to deflect to the maximum through the transmission mechanism, switching to high lift propeller mode.

[0055] This application's solution utilizes the independent control capability of a dual-rotor variable-pitch motor to precisely synchronize propeller blade angle changes and movable control surface deflection, avoiding the response delay and structural complexity caused by traditional single-motor drives. Specifically, when the propeller blade angle reaches its minimum position, a mechanical limit device triggers a limit switch, and a signal feedback mechanism automatically switches the system to control surface deflection control. This design simplifies the control logic and improves reliability. Simultaneously, the application of circulation control technology effectively suppresses boundary layer separation during movable control surface deflection, maintaining a high lift coefficient. For example, when the movable control surface deflects to its maximum angle, the plasma jet formed at the jet slit delays airflow separation by changing the airfoil circulation, thereby achieving a higher lift coefficient at the same angle of attack.

[0056] The above technical solution rapidly establishes a high-lift mode during takeoff, laying the foundation for efficient transitions in subsequent flight phases. Compared to existing technologies that increase blade area or fix the torsion angle, the control method of this application enables the propeller to achieve lift performance exceeding that of traditional structures during takeoff, while avoiding aerodynamic losses caused by large blade area and large torsion angle during cruise. As a specific implementation, when the propeller control module receives the limit switch's position signal, the system immediately disconnects the first rotor circuit while keeping the second rotor energized, ensuring that the control surface deflection mechanism can independently drive the movable control surface. This timing control effectively prevents torque fluctuations and over-revving risks.

[0057] In summary, this application combines the independent control of the dual-rotor variable-pitch motor with circulation control technology in a coordinated manner, enabling rapid switching of the propeller's high-lift mode during takeoff and maintaining aerodynamic performance through plasma jets. This solves the key problem that propeller systems cannot simultaneously achieve high lift for vertical takeoff and landing and high efficiency for cruise, significantly improving the overall flight performance of tiltrotor aircraft.

[0058] In some of the aforementioned implementations, a high-lift propeller mode is proposed during takeoff by adjusting the propeller blade angle to its minimum, deflecting the movable control surfaces to their maximum deflection angle, and activating the plasma jet to provide sufficient lift. However, as the aircraft completes takeoff and enters the climb or level flight phase, a smooth transition from this high-lift, high-drag mode to a high-efficiency flight mode is required. Improper handling of the transition, such as simply and abruptly withdrawing high-lift measures, could lead to drastic fluctuations in propeller torque or even propeller over-rotation, thereby affecting the aircraft's flight stability and safety.

[0059] like Figure 9As shown, the takeoff transition phase control is as follows: The propeller control module receives the aircraft's flight speed information and outputs control quantities for the first and second rotors respectively according to the flight speed. It simultaneously performs centering deflection of the movable control surfaces and pitch adjustment of the propeller blade angle to balance the torque fluctuations caused by the change in the deflection of the movable control surfaces and prevent the propeller from over-rotating. When the takeoff transition phase ends, the movable control surfaces return to center and the propeller switches to high-efficiency propeller mode.

[0060] In one embodiment, the propeller control module receives flight speed information from the aircraft and outputs control quantities for the external and internal worm gear motors based on the flight speed. On the one hand, it centers the movable control surfaces of the propeller blades, and on the other hand, it adjusts the pitch of the propeller to balance the torque change caused by the centering of the movable control surfaces and prevents the propeller from over-spinning. The dual-rotor pitch-adjusting motor drives the control surface deflection mechanism to move through the internal and external worm gears. The control surface deflection mechanism drives the movable control surfaces of the propeller blades to deflect through the transmission mechanism, and the pitch-adjusting mechanism drives the propeller blades to adjust the pitch. At the end of the takeoff transition phase, the movable control surfaces of the propeller blades return to center, and the propeller switches to fixed-wing high-efficiency propeller mode.

[0061] In high-efficiency propeller mode, the propeller control module controls the movable control surfaces of the propeller blades to return to center; the circulation control module disconnects the plasma exciter electrode circuit; and disconnects the high-pressure gas source circuit.

[0062] The takeoff transition phase control refers to the specific control process that occurs after the aircraft completes takeoff, transitioning from high-lift propeller mode to high-efficiency propeller mode. This phase aims to ensure that the propeller system can smoothly and safely adjust its operating state as the aircraft increases speed and altitude. The propeller control module receiving aircraft flight speed information means that the propeller control module acquires the current flight speed data of the aircraft. This information can come from sensors such as the aircraft's pitot tube, inertial navigation system, or global positioning system, and is transmitted to the propeller control module via a data bus. Outputting control quantities for the first and second rotors based on flight speed means that the propeller control module calculates and generates command signals for driving the first and second rotors of the dual-rotor variable-pitch motor based on the received flight speed information. These control quantities can be voltage, current, pulse-width modulation (PWM) signals, or digital commands, used to precisely control the speed and direction of rotation of the two rotors. Synchronizing the centering deflection of the movable control surfaces and the pitch adjustment of the propeller blade angle refers to the coordinated control by the propeller control module during the takeoff transition phase. This allows the movable control surfaces to gradually return to their neutral position from their maximum deflection angle, while the propeller blade angle gradually increases from its minimum angle to adapt to the increase in flight speed and changes in lift requirements. This synchronized adjustment ensures that the propeller maintains optimal aerodynamic efficiency and stability throughout the transition. Balancing torque fluctuations caused by changes in movable control surface deflection involves precisely coordinating the centering of the movable control surfaces and the pitch adjustment of the blades to offset or mitigate instantaneous changes in propeller torque caused by changes in the deflection angle of the movable control surfaces. This helps maintain stable engine or motor operation and avoids sudden load changes. Preventing propeller over-revving means ensuring that the propeller speed remains within a safe operating range through the aforementioned synchronized adjustments and torque balancing measures, avoiding excessively high speeds caused by sudden reductions in aerodynamic load or mismatches in engine / motor power output. When the takeoff transition phase ends, the movable control surfaces return to the center, and the propeller switches to high-efficiency propeller mode. This means that after the takeoff transition phase is completed, the movable control surfaces are fully restored to the neutral position, and the propeller blade angle is adjusted to an angle suitable for cruise or efficient flight. At this time, the propeller system works with optimal propulsion efficiency.

[0063] This application's solution, by introducing takeoff transition phase control, aims to address potential torque fluctuations and propeller overshoot issues during the transition from a high-lift takeoff mode to a high-efficiency flight mode. After the takeoff phase, the propeller control module continuously receives aircraft speed information. As the aircraft speed increases, the propeller control module synchronously outputs precise control values ​​to the first and second rotors of the dual-rotor variable-pitch motor, based on a preset control strategy or real-time calculations. Specifically, the first rotor drives the variable-pitch mechanism via an internal worm gear, gradually increasing the propeller blade angle from its minimum to accommodate higher flight speeds and reduce drag. Simultaneously, the second rotor drives the control surface deflection mechanism and transmission mechanism via an external worm gear, gradually returning the movable control surfaces to their center position from their maximum deflection angle. This synchronized and coordinated adjustment allows the aerodynamic load changes of the propeller blade angle and the movable control surfaces to compensate for each other, effectively balancing the torque fluctuations caused by changes in the movable control surface deflection. By continuously monitoring flight speed and making dynamic adjustments, this control strategy ensures that the propeller avoids overshoot due to abrupt changes in aerodynamic loads throughout the transition process. Finally, when the aircraft reaches the predetermined transition phase end conditions, the movable control surfaces return to center completely, and the propeller blade angle is adjusted to the optimal efficiency state, so that the propeller system smoothly switches to the high-efficiency propeller mode, providing stable and efficient propulsion for the subsequent flight phase.

[0064] Through the aforementioned technical solution, this application enables a smooth and safe transition from high-lift propeller mode to high-efficiency propeller mode after takeoff. This solution utilizes the propeller control module to receive and process aircraft flight speed information in real time, precisely and synchronously controlling the first and second rotors to coordinate the centering deflection of the movable control surfaces and the pitch adjustment of the propeller blade angle. This coordinated control effectively balances the aerodynamic torque fluctuations caused by changes in the deflection of the movable control surfaces, significantly reducing the risk of propeller over-rotation during the transition phase. Therefore, this application's solution not only ensures flight stability and improves flight safety during the critical transition phase but also optimizes propeller efficiency, laying a solid foundation for subsequent cruise flight.

[0065] like Figure 10 As shown, cruise phase control: The propeller control module calculates the pitch control amount based on the flight parameters input from the aircraft and controls the first rotor to drive the pitch-changing mechanism to change the propeller pitch; at the same time, it controls the second rotor to keep the control surface deflection mechanism in the center position; the propeller control module controls the disconnection of the high-pressure gas source and the plasma exciter electrode.

[0066] In one embodiment, the propeller control module receives information from the aircraft, calculates the pitch control quantity, and outputs a control signal to the dual-rotor variable-pitch motor. The dual-rotor variable-pitch motor drives the inner and outer worm gears to rotate according to the control signal. The variable-pitch and control surface deflection mechanism moves up and down following the rotation of the inner and outer worm gears. The variable-pitch mechanism drives the propeller blades to change pitch. The control surface deflection mechanism drives the movable control surface of the blade to deflect through the transmission mechanism, so that the movable control surface is always in the center position and the propeller is always in the high-efficiency mode.

[0067] Cruise phase control is an operational mode that optimizes the propeller system during the aircraft's cruise phase. Its purpose is to maximize propeller propulsion efficiency and minimize energy consumption while ensuring flight performance. This control can be automatically triggered by the flight management system based on preset flight conditions (such as reaching cruise altitude and speed) or manually activated by the crew based on the flight mission. The propeller control module calculates the pitch control value based on flight parameters input from the aircraft. This means the propeller control module receives data from the aircraft's flight control system or engine control system, such as airspeed, altitude, engine speed, thrust requirements, etc., and determines the optimal propeller blade pitch angle based on these parameters using internal algorithms or preset mapping tables. This calculation aims to ensure the propeller operates at maximum efficiency under current flight conditions. Controlling the first rotor to drive the pitch-changing mechanism for propeller pitch adjustment means the propeller control module sends commands to the first rotor of the dual-rotor pitch-changing motor, causing it to drive the internal worm and pitch-changing mechanism, thereby changing the propeller blade pitch angle. This allows for fine-tuning of propeller thrust output and efficiency to meet the needs of cruise flight. Simultaneously controlling the second rotor to keep the movable control surface in the center position means that the propeller control module sends a command to the second rotor of the dual-rotor variable-pitch motor, causing it to drive the external worm and the control surface deflection mechanism to adjust the movable control surface to a zero-deflection angle position aligned with the fixed blades. This operation aims to eliminate the additional lift and drag generated by the deflection of the movable control surface, allowing the propeller to return to its normal high-efficiency configuration. The propeller control module also controls the disconnection of the high-pressure gas source and plasma actuator electrodes. This means that the propeller control module sends a command to the high-pressure gas source and circulation control module to stop supplying high-pressure gas to the airflow cavity and cut off the power to the plasma actuator electrodes. This operation aims to shut down the circulation control system because it is generally not necessary to enhance lift or suppress boundary layer separation through plasma jets during the cruise phase, thus saving energy and reducing the complexity of system operation.

[0068] The proposed solution, through the coordinated action of the propeller control module, first receives flight parameters from the aircraft upon entering the cruise phase and accurately calculates the appropriate pitch control value for cruise flight. Subsequently, the propeller control module synchronously controls the first and second rotors of the dual-rotor variable-pitch motor. The first rotor drives the variable-pitch mechanism to adjust the propeller blade angle to the optimal cruise pitch, optimizing propulsion efficiency and reducing drag. Simultaneously, the second rotor drives the control surface deflection mechanism to center the movable control surfaces, eliminating the additional drag generated during takeoff to provide high lift. Furthermore, the propeller control module also controls the disconnection of the high-pressure gas source and plasma actuator electrodes, disabling circulation control to further reduce energy consumption. This multi-functional and coordinated control strategy enables the propeller system to smoothly and efficiently switch from a high-lift, high-drag takeoff mode to a low-drag, high-efficiency cruise mode, thereby significantly improving the overall cruise performance of the aircraft.

[0069] Through the aforementioned technical solution, the propeller system can smoothly switch from a high-lift mode to a high-efficiency cruise mode according to the needs of each flight phase. This switching effectively reduces aerodynamic drag during cruise flight, optimizes propeller propulsion efficiency, and reduces energy consumption of the high-pressure gas source and plasma actuator electrodes. This not only helps improve the aircraft's fuel economy and range but also ensures seamless and stable performance transitions between different flight phases, avoiding efficiency losses caused by maintaining unnecessary high-lift configurations.

[0070] like Figure 11 As shown, the landing transition phase control is as follows: The propeller control module receives the aircraft's flight speed information and outputs control quantities for the first and second rotors respectively according to the flight speed. It simultaneously performs deflection and deployment of the movable control surfaces and pitch adjustment of the propeller blade angle to balance the torque fluctuations caused by the deflection of the movable control surfaces and prevent the engine speed from being too low or the motor current from being too high. When the landing transition phase ends, the movable control surfaces deflect to the maximum angle, and the propeller switches to high-lift propeller mode.

[0071] In one embodiment, the propeller control module receives flight speed information from the aircraft and outputs control quantities for the external and internal worm gear motors based on the flight speed. On the one hand, it deflects the movable control surfaces of the propeller blades, and on the other hand, it changes the pitch of the propeller to balance the torque changes caused by the deflection of the movable control surfaces of the propeller blades and prevent the engine speed driving the propeller from being too low or the motor current from being too high. The dual-rotor variable-pitch motor drives the control surface deflection mechanism to move through the internal and external worm gears. The control surface deflection mechanism drives the movable control surfaces of the propeller blades to deflect through the transmission mechanism, and the variable-pitch mechanism drives the propeller blades to change the pitch. At the end of the landing transition phase, the movable control surfaces of the propeller blades deflect to the maximum, and the propeller switches to high-lift propeller mode. When in high-lift propeller mode, the limit switch is turned on, the propeller control module controls the high-pressure gas source circuit to be turned on, and gas is supplied to the jet slit; the circulation control module turns on the plasma exciter electrode, so that it forms a high-voltage electric field at the jet slit, generates plasma, forms a high-speed jet at the slit exit and induces the direction of the jet, suppresses the Karman vortex street and boundary layer separation behind the movable control surface, and improves the lift coefficient of the propeller blade; This application further proposes a landing transition phase control, the steps of which include: the propeller control module receives the aircraft's flight speed information, outputs control quantities for the first rotor and the second rotor respectively according to the flight speed, and simultaneously performs deflection and deployment of the movable control surfaces and pitch adjustment of the propeller blade angle to balance the torque fluctuations caused by the deflection of the movable control surfaces and prevent the engine speed from being too low or the motor current from being too high; when the landing transition phase ends, the movable control surfaces deflect to the maximum angle, and the propeller switches to high-lift propeller mode.

[0072] The propeller control module can acquire real-time aircraft speed information from various sources, including the aircraft's avionics system, pitot tube, GPS module, or inertial navigation system. This information, such as airspeed, ground speed, or relative airflow speed, is used to assess the current flight status and provide a basis for subsequent control decisions. Based on the received flight speed information and a preset control strategy or algorithm, the propeller control module calculates and generates specific control commands for the first and second rotors of the dual-rotor variable-pitch motor. These control quantities can be voltage signals, current signals, pulse width modulation (PWM) signals, or directly target speed and target position commands, used to precisely drive the first and second rotors. Synchronizing the deflection deployment of the movable control surfaces and the pitch adjustment of the propeller blade angle means that the propeller control module coordinately issues commands within the same time period, causing the deflection angle of the movable control surfaces to gradually increase (deflection deployment), while the propeller blade angle is adjusted accordingly (pitch adjustment). This synchronization can be strict time synchronization or coordinated actions based on specific control curves to ensure the coordination of both actions. The deflection and deployment of movable control surfaces alters the aerodynamic characteristics of the propeller, causing changes in the torque experienced by the propeller. The propeller control module counteracts or mitigates these torque fluctuations by precisely controlling the pitch adjustment of the blade angles, for example, by decreasing the blade angle to reduce torque or increasing the blade angle to increase torque, thus maintaining the stability of the propeller system's output torque. Excessively low engine speeds may lead to engine stall or shutdown, while excessive motor current may cause overheating, damage, or triggering of protection mechanisms. Through the aforementioned synchronization and torque balancing strategies, the propeller control module ensures that the engine or motor operating parameters remain within a safe and stable operating range throughout the descent transition phase, avoiding extreme conditions. The end of the descent transition phase is typically triggered by conditions such as reaching a preset threshold airspeed, descending to a specific altitude, or receiving a pilot command. At this moment, the propeller control module drives the movable control surfaces to the maximum deflection angle allowed by its design, while adjusting the propeller blade angle to a specific angle that matches the maximum control surface deflection angle, thereby enabling the entire propeller system to enter a high-lift propeller mode that can generate maximum lift, providing sufficient lift for the final landing.

[0073] like Figure 12 As shown, during the landing phase, the propeller control module maintains the maximum deflection angle of the movable control surface and the propeller blade angle unchanged; it controls the high-pressure gas source to continuously supply gas and controls the circulation control module to keep the plasma exciter electrodes energized, so as to continuously form a plasma jet at the jet slit to suppress boundary layer separation.

[0074] In one embodiment, the propeller control module controls the pitch and movable control surfaces to maintain the state at the end of the descent transition phase, thus maintaining a fixed state; the propeller control module controls the high-pressure gas source to maintain the continuous ejection of gas; and the circulation control module controls the plasma exciter electrodes to form controllable plasma at the slit nozzle, maintaining the high-lift mode.

[0075] During the descent transition phase, the propeller control module continuously receives aircraft speed information to monitor the aircraft's dynamic state in real time. Based on this speed information, the propeller control module precisely calculates and outputs control quantities for the first and second rotors of the dual-rotor variable-pitch motor according to a preset control law or algorithm. These control quantities are designed to achieve simultaneous deflection and deployment of movable control surfaces and variable-pitch adjustment of the propeller blade angle. Specifically, as the flight speed decreases, the propeller control module instructs the second rotor to drive the outer worm gear, which, through the control surface deflection mechanism and transmission mechanism, gradually increases the deflection angle of the movable control surfaces to enhance the circulation control effect. At the same time, the propeller control module instructs the first rotor to drive the inner worm gear, which, through the variable-pitch mechanism, adjusts the propeller blade angle accordingly. This synchronized and coordinated adjustment mechanism is crucial because the deflection of the movable control surfaces significantly alters the aerodynamic load on the propeller; if the blade angle is not adjusted in time, it will cause drastic fluctuations in propeller torque. Through precise synchronous pitch adjustment, the propeller control module effectively balances torque fluctuations caused by changes in the deflection of the movable control surfaces, thereby maintaining the stability of the propeller system's output torque. This torque stability is crucial to preventing excessively low engine speeds or excessive motor current. When the landing transition phase ends, for example, when the aircraft reaches the preset landing speed, the propeller control module ensures that the movable control surfaces have fully deflected to their maximum angle, and that the propeller blade angle has been adjusted to a set value matching this high-lift state. This allows the propeller system to reliably switch to high-lift propeller mode, providing the necessary lift for a safe landing.

[0076] Through the aforementioned technical solution, during the aircraft's landing transition phase, the propeller control module can precisely and synchronously coordinate the deflection and deployment of the movable control surfaces and the pitch adjustment of the propeller blade angle based on real-time aircraft flight speed information. This refined synchronous control effectively balances the torque fluctuations caused by changes in the deflection of the movable control surfaces, significantly reducing the risk of excessively low engine speed or excessive motor current, thereby avoiding potential dangers such as engine stalling and motor overload, and greatly improving flight safety and system stability. Ultimately, the propeller system can smoothly and reliably switch from cruise mode to high-lift propeller mode, providing sufficient lift for safe landing and optimizing the control performance and efficiency of the landing process.

[0077] In some of the above-described embodiments, the propeller system switches to a high-lift propeller mode during the descent transition phase to prepare for the landing phase. However, in actual landing, especially at lower aircraft speeds, the boundary layer of the airflow over the propeller blade surface is prone to separation, which may lead to lift loss and reduced control efficiency, thereby affecting the aircraft's safe landing performance.

[0078] During descent, the propeller control module first ensures the propeller blades are in a high-lift mode, maintaining the movable control surfaces at their maximum deflection angle while keeping the propeller blade angle constant. This mechanical configuration provides the aircraft with basic high-lift or high-drag characteristics. Building upon this, to address potential boundary layer separation during low-speed descent, the propeller control module further activates the active circulation control system. Specifically, the propeller control module instructs a high-pressure gas source to continuously supply air to the airflow cavity inside the propeller blades, ensuring a stable high-pressure airflow at the jet slit. Simultaneously, the circulation control module is instructed to keep the plasma actuator electrodes energized, generating plasma in the region near the jet slit. The high-pressure airflow interacts with the plasma, continuously forming a plasma jet at the jet slit. This plasma jet effectively injects momentum and energy into the boundary layer on the blade surface, enhancing the boundary layer's resistance to adverse pressure gradients and thus suppressing boundary layer separation. In this way, even under low-speed descent conditions, the propeller blades maintain good aerodynamic performance, providing stable lift or drag, ensuring the aircraft's safety and controllability. This scheme provides reliable low-speed, high-lift performance for the aircraft during the landing phase through the synergistic effect of mechanical configuration and active flow field control.

[0079] Through the aforementioned technical solution, during the aircraft's descent phase, the propeller control module can precisely maintain the maximum deflection angle of the movable control surfaces and the propeller blade angle, providing the aircraft with a stable base of high lift or high drag. More importantly, by controlling the continuous supply of high-pressure gas and keeping the plasma actuator electrodes energized by the circulation control module, a continuous plasma jet is formed at the jet slit, effectively suppressing boundary layer separation that may occur on the propeller blade surface under low-speed descent conditions. This significantly enhances the propeller's aerodynamic efficiency and lift retention capability at low speeds, avoiding lift loss and control performance degradation caused by boundary layer separation, thereby ensuring the stability and safety of the aircraft during descent and improving the aircraft's low-speed handling performance.

[0080] During the transition phase, the propeller control module controls the output of pulsed airflow from the high-pressure air source based on the real-time deflection angle of the movable control surface. By adjusting the jet pulse frequency and flow rate, the circulation is dynamically adjusted under different deflection states.

[0081] The transition phase refers to the period during which an aircraft smoothly transitions from one flight state to another, such as the transition from takeoff to cruise (takeoff transition phase) or from cruise to landing (landing transition phase). During this phase, the aircraft's speed, attitude, and propeller operating status are continuously changing. For example, the transition phase can refer to the process after takeoff where the aircraft gradually accelerates from a low-speed climb to cruise speed; or it can refer to the process before landing where the aircraft gradually decelerates from cruise speed and adjusts its attitude to prepare for landing. The propeller control module is a core control unit responsible for receiving various sensor data and flight parameters, and sending control commands to the various actuators of the propeller system according to preset control strategies or algorithms. This module can be an embedded controller. The real-time deflection angle of the movable control surface refers to the actual deflection position of the movable control surface relative to the fixed propeller blade at any given time. This angle is dynamically changing and needs to be monitored in real time by sensors. For example, it can be measured in real time by an angle sensor (such as a rotary encoder or Hall effect sensor) mounted on the movable control surface shaft; or indirectly by monitoring the position feedback signal of the actuator (such as a motor or hydraulic cylinder) that drives the movable control surface deflection. A high-pressure gas source is a device that provides high-pressure gas to form a jet. The high-pressure gas source can be an engine bleed air system, utilizing the high-pressure air from the aircraft engine compressor; or it can be a separate booster pump, driven electrically or mechanically, compressing ambient air to the required pressure. Outputting pulsed airflow refers to the high-pressure gas source no longer continuously and stably supplying gas, but releasing high-pressure gas in a periodic, intermittent manner, forming a series of airflow pulses. This can be achieved by setting a high-speed switching valve (such as a solenoid valve or piezoelectric valve) at the gas source outlet to periodically open and close the airflow channel; or by adjusting the drive frequency or duty cycle of the air pump to make it operate intermittently to generate pulsed airflow. Adjusting the jet pulse frequency and flow rate refers to the precise control of the periodicity (frequency) and the amount of gas (flow rate) of each pulse of the pulsed airflow. Frequency can be adjusted by controlling the switching cycle of the switching valve, and flow rate can be adjusted by controlling the opening time of the switching valve or the pressure of the air source; alternatively, an integrated flow controller, combined with a flow sensor and regulating valve, can achieve precise control of pulse frequency and instantaneous flow rate. The goal of dynamically adjusting circulation under different deflection states is to precisely adjust the circulation effect generated by the jet based on the real-time deflection angle of the movable control surface to adapt to different aerodynamic requirements. For example, the propeller control module can look up the optimal pulse frequency and flow rate based on the movable control surface angle using a lookup table or algorithm to precisely control the circulation; or, through a closed-loop control system, it can monitor the pressure distribution or lift coefficient on the blade surface in real time and feed it back to the propeller control module, which then dynamically adjusts the jet parameters to maintain the target circulation.

[0082] During the transition phase, the propeller control module continuously monitors the real-time deflection angle of the movable control surfaces. Given that the movable control surfaces undergo synchronous return to center or deflection deployment during the transition phase, their aerodynamic characteristics are dynamically changing. To ensure the accuracy and efficiency of circulation control, the propeller control module no longer simply maintains a continuous supply of high-pressure air. Instead, it dynamically adjusts the output mode of the high-pressure air source based on the received real-time deflection angle information of the movable control surfaces. Specifically, the propeller control module controls the output of pulsed airflow from the high-pressure air source and precisely adjusts the frequency and flow rate of these pulsed airflows. This pulsed airflow output, combined with the plasma jet formed at the jet slit by the plasma actuator electrodes, allows for more precise control of the jet's influence on the blade surface boundary layer. By changing the pulse frequency, the periodicity of the jet action can be adjusted, thereby affecting the response speed and stability of the circulation effect; by changing the pulse flow rate, the intensity of each jet can be adjusted, thereby affecting the magnitude of the circulation effect. This dynamic adjustment mechanism enables circulation control to adapt in real time to the aerodynamic requirements of the movable control surface under different deflection states, avoiding control lag or overshoot that may be caused by fixed airflow parameters, thereby maintaining stable and efficient propeller operation throughout the entire transition phase.

[0083] Through the above technical solution, during the transition phase of the aircraft, the propeller control module can precisely control the output pulsed airflow of the high-pressure air source based on the real-time deflection angle of the movable control surfaces, and dynamically adjust the frequency and flow rate of the jet pulses. This refined circulation control method enables the propeller system to adapt to the aerodynamic requirements of the movable control surfaces under different deflection states in real time, effectively avoiding problems such as low circulation control efficiency or aerodynamic instability caused by airflow parameter mismatch. Therefore, this solution can significantly improve the aerodynamic efficiency and stability of the propeller during dynamic transitions, ensuring the smooth transition and safe operation of the aircraft under complex flight conditions, while optimizing energy consumption and improving the overall performance of the system.

[0084] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0085] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A compound variable-pitch propeller system based on circulation control, characterized in that, include: A dual-rotor variable-pitch motor is disposed inside a propeller hub. The dual-rotor variable-pitch motor includes a first rotor and a second rotor. The first rotor is connected to an inner worm gear, which is connected to a variable-pitch mechanism. The second rotor is connected to an outer worm gear, which is connected to a rudder deflection mechanism. The propeller hub is connected to the propeller blades. The propeller blades include fixed blades and movable control surfaces. The fixed blades are connected to the propeller hub, and the movable control surfaces are rotatably connected to the fixed blades. The propeller blades are provided with jet slits. A transmission mechanism is provided, which connects the rudder surface deflection mechanism to the movable rudder surface and is used for the deflection movement of the movable rudder surface.

2. The compound variable-pitch propeller system based on circulation control according to claim 1, characterized in that, The pitch-changing mechanism includes a slide groove and a rotatable slider, the slide groove and the rotatable slider are connected, and the rotatable slider is fixedly connected to the propeller blade; The control surface deflection mechanism includes a rack, a rotating shaft, and a rocker arm. The rack meshes with the external worm gear, and the rocker arm is connected to the movable control surface through the transmission mechanism.

3. The compound variable-pitch propeller system based on circulation control according to claim 2, characterized in that, The transmission mechanism includes a first rotating shaft and a second rotating shaft. The rocker arm is connected to the second rotating shaft via the first rotating shaft. The second rotating shaft is connected to a first gear. The first gear is connected to the second gear via a chain. The rotating shaft is fixedly connected to the second gear. The rotating shaft is fixedly connected to the movable rudder surface.

4. The compound variable-pitch propeller system based on circulation control according to claim 1, characterized in that, A propeller control module is electrically connected to the dual-rotor variable-pitch motor, limit switch, high-pressure air source and circulation control module respectively. Plasma exciter electrodes are disposed at both ends of the jet slit, and the jet slit is connected to the gas flow cavity; The high-pressure gas source is connected to the propeller gas passage connector to provide high-pressure gas to the airflow cavity; the circulation control module is connected to and controls the energization state of the plasma exciter electrodes.

5. The compound variable-pitch propeller system based on circulation control according to claim 1, characterized in that, The jet slit is located on the back of the movable control surface and / or the back of the fixed propeller blade.

6. A control method for a compound variable-pitch propeller system based on circulation control, characterized in that, Takeoff phase control: The propeller control module connects the first and second rotors of the dual-rotor variable pitch motor and controls the variable pitch mechanism to adjust the propeller blade angle to the minimum blade angle. When the propeller blade angle reaches the minimum blade angle position, the mechanical limit device performs mechanical limit, the limit switch is turned on and sends a position signal to the propeller control module. After receiving the arrival signal, the propeller control module disconnects the circuit of the first rotor, keeping only the second rotor powered on; The second rotor drives the control surface deflection mechanism through the external worm gear, and through the transmission mechanism, it drives the movable control surface to deflect to the maximum deflection angle, so that the propeller switches to high lift propeller mode. The propeller control module controls the high-pressure gas source to supply gas to the airflow cavity, and controls the circulation control module to connect the plasma exciter electrode to form a plasma jet at the jet slit.

7. The control method according to claim 6, characterized in that, This also includes takeoff transition phase control: The propeller control module receives the aircraft's flight speed information and outputs control quantities for the first and second rotors respectively according to the flight speed. It simultaneously performs centering deflection of the movable control surfaces and pitch adjustment of the propeller blade angle to balance the torque fluctuations caused by the deflection of the movable control surfaces and prevent propeller over-rotation. When the takeoff transition phase ends, the movable control surfaces return to center, and the propeller switches to high-efficiency propeller mode.

8. The control method according to claim 6, characterized in that, It also includes cruise phase control: The propeller control module calculates the pitch control amount based on the flight parameters input from the aircraft and controls the first rotor to drive the pitch-changing mechanism to change the propeller pitch. Simultaneously, the second rotor is controlled to keep the movable rudder surface in the center position by the rudder surface deflection mechanism. The propeller control module controls the disconnection of the high-pressure gas source and the plasma exciter electrodes.

9. The control method according to claim 6, characterized in that, It also includes landing transition phase control: The propeller control module receives the aircraft's flight speed information and outputs control quantities to the first and second rotors respectively according to the flight speed. It simultaneously performs deflection and deployment of the movable control surfaces and pitch adjustment of the propeller blade angle to balance the torque fluctuations caused by the deflection of the movable control surfaces and prevent the engine speed from being too low or the motor current from being too high. When the descent transition phase ends, the movable control surfaces deflect to their maximum angle, and the propeller switches to high-lift propeller mode.

10. The control method according to claim 6, characterized in that, It also includes landing phase control: The propeller control module maintains the maximum deflection angle of the movable control surfaces and the propeller blade angle unchanged. The high-pressure gas source is controlled to continuously supply gas, and the circulation control module is controlled to keep the plasma exciter electrodes energized, so that a plasma jet is continuously formed at the jet slit to suppress boundary layer separation.

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