Memory alloy-based wing multi-modal variant driving mechanism and unmanned aerial vehicle

Abstract

This application discloses a multimodal variator wing drive mechanism based on shape memory alloy and an unmanned aerial vehicle (UAV), relating to the field of UAVs. At least three locking components are spaced apart along the motion path of the output component. Each locking component includes a shape memory alloy unlocking component and a locking pin mechanism. In the locked state, the locking pin mechanism engages with a pin hole on the output component to restrict its movement. The shape memory alloy unlocking component can actuate when heated by electricity, driving the locking pin mechanism to disengage from the pin hole, thus switching the locking components to the unlocked state. This application achieves miniaturization and weight reduction of the drive unit. Simultaneously, by using multiple locking components arranged along the path, the same drive unit can accurately and reliably lock the wing at multiple predetermined sweep angles and can reversibly fold it, meeting the requirements of multiple flight missions. A cooperative control strategy improves dynamic performance by aligning the unlocking point with the point of maximum driving force burst through a "pre-charge-re-unlock" sequence, reducing actuation impact and improving response speed.

Description

Technical Field

[0001] This application relates to the field of unmanned aerial vehicle (UAV) technology, and in particular to a multimodal variator drive mechanism for wings based on shape memory alloys and UAVs. Background Technology

[0002] In the design of mission-specific unmanned aerial vehicles (UAVs) such as long-endurance cruise platforms and high-speed maneuvering devices, variable geometry wings are a key technology for achieving wide flight envelopes and balancing optimal aerodynamic efficiency across different mission phases. These UAVs have specific requirements for wing sweep angles at different mission phases: in storage and transport mode, the wings need to be folded back close to the fuselage (nearly 90° sweep) to reduce lateral dimensions and accommodate the transport container; during high-speed transit, the wings need to be extended to an appropriate sweep angle to reduce wave drag and achieve rapid arrival; during cruise and standby, the wings need to be adjusted to a small sweep angle or even a straight state (0° sweep) to increase the aspect ratio and extend endurance; and during mission termination or recovery, the wings need to be folded back to accommodate the recovery device. Currently, the mainstream solution for achieving mode switching is pyrotechnic drive, which uses the detonation of energetic elements to generate high-pressure gas to drive the actuator. However, this solution has inherent drawbacks: the actuation impact is severe, causing not only airframe vibration and interference with attitude control, but also potentially irreversible damage to high-precision mission payloads (such as optical sensors and inertial measurement units); the pyrotechnics are single-use and cannot meet the requirements for multiple switching operations, requiring multiple independent units if multiple wing changes are needed in a single mission, resulting in system complexity, difficulty in platform reuse, and high maintenance costs; in addition, high-performance pyrotechnic actuators are expensive, which is high for equipment that pursues low cost and high efficiency. Other alternative solutions, such as hydraulic drives, require pump and valve pipelines, resulting in complex structures, large size and weight, and difficulty in integrating them into a compact space; while pure electric drives offer precise control, they require complex reduction mechanisms in high-thrust, short-stroke scenarios, also facing challenges of excessive size and weight, as well as electromagnetic compatibility.

[0003] Therefore, there is an urgent need to explore a new type of drive mechanism that is reusable, operates smoothly, has a compact structure, and is cost-controllable, in order to solve the pain points of existing solutions and meet the engineering requirements of future high-performance UAVs for multimodal variable sweep wing technology. Summary of the Invention

[0004] This application provides a shape memory alloy-based multimodal variator drive mechanism for wings and an unmanned aerial vehicle, thus solving the problems mentioned in the background art.

[0005] In a first aspect, embodiments of this application provide a multimodal variator drive mechanism for an airfoil based on shape memory alloys, comprising: a drive unit including a reciprocating output component; a shape memory alloy drive assembly connected to the drive unit, the shape memory alloy drive assembly including a first shape memory alloy drive component for driving the output component to move along a first direction, and a second shape memory alloy drive component for driving the output component to move along a second direction opposite to the first direction; both the first and second shape memory alloy drive components are configured to generate a contractile force to drive the output component to move when electrically heated; and at least three locking components are spaced apart along the movement path of the output component, each locking component having a locked state and an unlocked state; wherein, the locking... The component includes a shape memory alloy unlocking element and a locking pin mechanism. In the locked state, the locking pin mechanism engages with a pin hole provided on the output element to restrict the movement of the output element. The shape memory alloy unlocking element can be activated by heating, driving the locking pin mechanism to disengage from the pin hole, thereby switching the locking component to the unlocked state. The control unit is electrically connected to the shape memory alloy driving component and the shape memory alloy unlocking elements of each locking component. It is configured to selectively control the on / off timing of different shape memory alloy unlocking elements and the shape memory alloy driving component, so that the output element can repeatedly and orderly switch between at least three preset positions corresponding to at least three locking components and be locked, thereby driving the wing connected to the output element to repeatedly switch between modes corresponding to different sweep angles.

[0006] In conjunction with the first aspect, in one possible implementation, the locking mechanism includes a housing, a pin, a reset elastic element, a connecting rod, and a pressure wire element; the housing is fixed to a base; the pin is retractably disposed within the housing; the reset elastic element is disposed within the housing, with its two ends respectively connected to the inner bottom wall of the housing and the bottom of the pin, for applying an elastic force to the pin to keep it in an extended state; the connecting rod and the pressure wire element are both fixed to the base and are arranged parallel to the length direction of the output element; the shape memory alloy unlocking element... The component is a shape memory alloy wire, one end of which is connected to the pin, and the other end passes through the interior of the reset elastic component, wraps around the connecting rod, and is finally fixed to the pressure wire component. When the shape memory alloy unlocking component is not energized, the reset elastic component uses its elasticity to push the pin outward, so that the pin is inserted into the corresponding pin hole on the output component, thereby locking the output component. When the shape memory alloy unlocking component is energized and heated to shrink, the pulling force generated by it pulls the pin inward against the elasticity of the reset elastic component through the steering action of the connecting rod, so that the pin is removed from the pin hole, thereby releasing the lock on the output component.

[0007] In conjunction with the first aspect, in one possible implementation, the output component is a piston rod, and a pin hole is provided on the piston rod along its length direction; there are three locking components, which are fixedly arranged at intervals along the movement path of the piston rod, and respectively correspond to the fully folded state, the first deployed state, and the fully deployed state of the wing; wherein, when the piston rod moves to any preset position, the pin hole aligns with the corresponding locking component, so that the corresponding locking component can be inserted into the pin hole to lock the piston rod; the drive unit also includes a lever mechanism, the first end of which is hinged to the piston rod, and the second end is connected to the first shape memory alloy drive component and the second shape memory alloy drive component respectively.

[0008] In conjunction with the first aspect, in one possible implementation, the second shape memory alloy drive has a preset slack in the initial state, the slack being no less than the travel distance of the lever mechanism at the wire-threading position when the first shape memory alloy drive is driven, so as to avoid interference with the first shape memory alloy drive driving the output component to move along the first direction.

[0009] In conjunction with the first aspect, in one possible implementation, the lever mechanism includes a first link and a second link; a pin is provided on the piston rod; the first link and the second link are respectively located on both sides of the piston rod, and one end of the first link and one end of the second link are rotatably connected to the pin, such that the first link and the second link form a V-shaped structure; the other end of the first link and the other end of the second link are rotatably connected to the base, and are respectively connected to the first shape memory alloy driving member and the second shape memory alloy driving member.

[0010] In conjunction with the first aspect, in one possible implementation, the first memory alloy driving component includes two first memory alloy wires, respectively connected to the second ends of the first connecting rod and the second connecting rod; the second memory alloy driving component includes two second memory alloy wires, respectively connected to the second ends of the first connecting rod and the second connecting rod.

[0011] In conjunction with the first aspect, in one possible implementation, the control unit is configured to perform mode switching control: when it is necessary to switch from the current mode to the target mode, firstly, the shape memory alloy unlocking component of the locking assembly corresponding to the current locking position is energized to unlock; subsequently, the shape memory alloy driving assembly with the driving direction toward the target position is energized to drive until the piston rod moves to the target position, and the pin hole is aligned with and locked by the locking assembly corresponding to the target position.

[0012] In conjunction with the first aspect, in one possible implementation, the timing of controlling the energization of the shape memory alloy unlocking component is determined based on the heating state of the shape memory alloy driving component: the temperature of the shape memory alloy driving component is monitored by a temperature sensor, and when the monitored temperature reaches a preset trigger temperature, the step of controlling the energization of the shape memory alloy unlocking component is executed; wherein, the trigger temperature is lower than the austenitic phase transformation completion point of the shape memory alloy driving component material.

[0013] Secondly, embodiments of this application provide a drone, including a wing and a shape memory alloy-based multimodal variator drive mechanism as described in the first aspect or any possible implementation of the first aspect, wherein the output of the drive mechanism is connected to the wing via transmission for driving it to change its sweep angle.

[0014] One or more technical solutions provided in the embodiments of this application have at least the following technical effects: (i) It can be repetitive, breaking through the limitation of single use. The use of shape memory alloys to simultaneously achieve both driving and locking functions allows the same drive unit to complete multiple mode switching operations. Cyclic performance testing shows that the core components of the drive unit and shape memory alloy drive assembly can be reused more than five times (a single test simulates the entire mode switching process of a UAV wing under normal temperature and pressure), fully meeting the requirements for multiple variations in a single mission and UAV recovery and reuse. This solves the "operation equals scrap" problem caused by the single-use nature of pyrotechnics, reducing the total lifecycle cost.

[0015] (ii) Smooth operation, eliminating explosive impact. The deformation process of shape memory alloys is inherently smooth, and the continuous, controllable dynamic force they provide replaces the impact load generated by the instantaneous explosion of pyrotechnics. Compared to the impact overload of up to several kilograms from pyrotechnics, this application reduces the dynamic disturbance to the carrier platform to a negligible level, which helps to ensure the operational reliability of airborne precision electronic equipment (such as seekers and inertial navigation systems), and improves flight attitude stability and mission success rate.

[0016] (III) Compact structure, breaking through the space constraints of UAV platforms The drive unit and locking components are integrated into one design, eliminating the need for pumps, valves, pipelines, and seals in the hydraulic system, as well as the need for a reduction mechanism in the motor. The structure is extremely simplified, and the size and weight are less than 1 / 10 of traditional solutions, making it particularly suitable for drone platforms with stringent requirements for space and weight.

[0017] (iv) Rapid response to overcome the thermal inertia of shape memory alloys To address the technical challenge of relatively slow response in shape memory alloy (MMA) drive components, this application innovatively proposes a temperature-feedback-based "pre-charge-unlock" coordinated control sequence: before unlocking, the MMA drive component is pre-energized to store power; once the temperature reaches a preset trigger temperature (below the austenite phase transformation completion point Af) and the driving force accumulates to over 80%, the MMA unlocking component is then energized to unlock. This strategy aligns the unlocking point with the point of maximum driving force burst, enabling rapid deformation under heavy loads, optimizing the system's dynamic response, and meeting the requirements for rapid deformation in maneuvering flight scenarios.

[0018] (v) Precise switching between multiple modes to improve task adaptability By using at least three locking components positioned along the output component's motion path, the same drive unit can precisely lock the wing to multiple preset sweep angles (such as fully folded, first deployed, and fully deployed states), and supports reverse folding. This allows the UAV to flexibly adjust its aerodynamic shape according to mission phases—reducing drag during high-speed penetration, increasing lift during cruise flight, and reducing size during recovery preparation—improving the UAV platform's multi-mission adaptability and life-cycle economics.

[0019] In summary, this application uses shape memory alloy as the core component, which has the comprehensive advantages of repeatable operation, stable and controllable operation, compact structure, fast response, and precise multi-modal switching, providing a new technical solution for morphing unmanned aerial vehicles that is low-cost, highly reliable, and easy to integrate. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A schematic diagram of the structure of a shape memory alloy-based wing multimodal variator drive mechanism provided in this application embodiment; Figure 2 for Figure 1 The main view; Figure 3 This is a schematic diagram of the structure of the locking component provided in an embodiment of this application; Figure 4 A schematic diagram of the structure of the base provided in the embodiments of this application; Figure 5 for Figure 4 Enlarged view of section A in the image; Figure 6 for Figure 4 Enlarged view of section B in the image; Figure 7 This is a schematic diagram of the wing deployment structure provided in an embodiment of this application.

[0022] Reference numerals: 1-Drive unit; 11-Output component; 111-Pin; 12-Lever mechanism; 121-First link; 122-Second link; 2-Memory alloy drive assembly; 21-First memory alloy drive component; 211-First memory alloy wire; 22-Second memory alloy drive component; 221-Second memory alloy wire; 3-Locking assembly; 31-Locking pin mechanism; 311-Housing; 312-Pin; 313-Reset elastic component; 314-Connecting rod; 315-Pressing wire component; 32-Memory alloy unlocking component; 4-Base; 5-Wing; 6-Adapter rod; 7-Transmission link. Detailed Implementation

[0023] The technical solutions of 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, not all, of the embodiments of this application. 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.

[0024] In the description of the embodiments of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the embodiments of this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0025] This application provides a wing multimodal morphing drive mechanism based on shape memory alloy, such as... Figures 1 to 7As shown. The shape memory alloy-based multimodal variator wing drive mechanism includes a drive unit 1, a control unit, at least one shape memory alloy drive assembly 2, and at least three locking assemblies 3. The drive unit 1 includes a reciprocating output member 11. The shape memory alloy drive assembly 2 is connected to the drive unit 1 and includes a first shape memory alloy drive member 21 for driving the output member 11 to move along a first direction, and a second shape memory alloy drive member 22 for driving the output member 11 to move along a second direction opposite to the first direction; both the first shape memory alloy drive member 21 and the second shape memory alloy drive member 22 are configured to generate a contractile force to drive the output member 11 to move when electrically heated. At least three locking assemblies 3 are spaced apart along the movement path of the output member 11, and each locking assembly 3 has a locked state and an unlocked state. The locking assembly 3 includes a shape memory alloy unlocking member 32 and a locking pin mechanism 31. In the locked state, the locking pin mechanism 31 cooperates with a pin hole provided on the output member 11 to restrict the movement of the output member 11. The shape memory alloy unlocking component 32 can be activated when heated by electricity, driving the locking pin mechanism 31 to disengage from the pin hole, thus switching the locking component 3 to the unlocked state. The control unit is electrically connected to the shape memory alloy driving component 2 and the shape memory alloy unlocking components 32 of each locking component 3, and is configured to selectively control the on / off timing of different shape memory alloy unlocking components 32 and the shape memory alloy driving component 2, so that the output component 11 can repeatedly and orderly switch between at least three preset positions corresponding to at least three locking components 3 and be locked, thereby driving the wing 5 connected to the output component 11 to repeatedly switch between modes corresponding to different sweep angles.

[0026] It should be noted that the shape memory alloy-based multimodal variator drive mechanism provided in this application embodiment achieves repeated and orderly switching and locking of the output component 11 of the drive unit 1 between multiple preset positions by selectively controlling the power-on and power-off sequence of the shape memory alloy drive component 2 and the shape memory alloy unlocking component 32 in at least three locking components 3 through the control unit. This enables the connected wing 5 to reliably and repeatedly switch between different sweep angle modes. This mechanism effectively solves the problems of high cost, non-reusability, and large impact load of existing pyrotechnic drive schemes. Using shape memory alloy as the core component for drive and locking, it has the advantages of compact structure, smooth drive, and repeatable operation. It is particularly suitable for cross-domain UAVs that need to flexibly and accurately adjust their aerodynamic shape in multiple stages such as high-speed flight, cruise flight, and mission preparation, thus improving mission adaptability and system economy.

[0027] Specifically, the first direction is the unfolding direction of the wing 5, and the second direction is the folding direction of the wing 5. This embodiment of the application, by employing a first shape memory alloy drive 21 and a second shape memory alloy drive 22 that drive the output component 11 in opposite directions, achieves bidirectional precise drive of the output component 11, providing the core power foundation for the reciprocating switching of the wing 5 between multiple sweep angle modes, and ensuring the controllability and reliability of the transformation process.

[0028] In this application, the locking mechanism 31 includes a housing 311, a pin 312, a reset elastic element 313, a connecting rod 314, and a pressure wire element 315. The housing 311 is fixed to the base 4, and the pin 312 is telescopically disposed within the housing 311. The reset elastic element 313 is disposed within the housing 311, with its two ends connected to the inner bottom wall of the housing 311 and the bottom of the pin 312, respectively, to apply an elastic force to the pin 312 to keep it in an extended state. The connecting rod 314 and the pressure wire element 315 are both fixed to the base 4, and both are arranged parallel to the length direction of the output element 11. The shape memory alloy unlocking element 32 is made of shape memory alloy wire, one end of which is connected to the pin 312, and the other end passes through the interior of the reset elastic element 313, wraps around the connecting rod 314 in a winding manner, and is finally fixed to the pressure wire element 315.

[0029] When the shape memory alloy unlocking component 32 is not energized, the reset elastic component 313 uses its elastic force to push the pin 312 outward, causing the pin 312 to insert into the corresponding pin hole on the output component 11, thereby locking the output component 11. When the shape memory alloy unlocking component 32 is energized and heated to shrink, the resulting tension, through the steering action of the connecting rod 314, pulls the pin 312 inward against the elastic force of the reset elastic component 313, causing the pin 312 to exit the pin hole, thus releasing the lock on the output component 11.

[0030] This design efficiently transforms the linear contraction motion of the shape memory alloy unlocking component 32 into the linear retraction motion of the pin 312. The structure is simple and compact, the locking is reliable, the unlocking response is rapid, and the reset process does not require additional drive, thus achieving low power consumption and high reliability operation of the locking function.

[0031] In this application, the output component 11 is a piston rod, and a pin hole is provided on the piston rod along its length. Three locking components 3 are fixedly arranged at intervals along the movement path of the piston rod, corresponding respectively to the fully folded state, the first deployed state, and the fully deployed state of the wing 5. When the piston rod moves to any preset position, the pin hole aligns with the corresponding locking component 3, allowing the corresponding locking component 3 to be inserted into the pin hole to lock the piston rod. The drive unit 1 also includes a lever mechanism 12, the first end of which is hinged to the piston rod, and the second end is connected to the first shape memory alloy drive component 21 and the second shape memory alloy drive component 22, respectively.

[0032] It should be noted that this application concretizes the output component 11 as a piston rod with a single pin hole, and sets three locking components 3 along its movement path, corresponding to the fully retracted, first deployed, and fully deployed states of the wing 5, respectively. Combined with a lever mechanism 12 that is hinged to the piston rod and transmits and converts the power between the first shape memory alloy drive component 21 and the second shape memory alloy drive component 22, a highly integrated and precisely positioned multi-position locking and driving system is constructed. In this design, the single pin hole and the three locking components 3 distributed along the path work together to achieve the function of multi-position locking. This avoids the structural strength reduction and processing complexity that may be caused by opening multiple pin holes on the piston rod, and also simplifies the logical requirements of position alignment. At the same time, the lever mechanism 12, as the core of power amplification and conversion, efficiently amplifies and converts the limited, high-load contraction displacement of the shape memory alloy element into a larger linear stroke required by the piston rod to meet the multi-mode switching of the wing 5, thereby achieving the core objective of driving the deformation of the large-scale wing 5 with a small, high-power-density shape memory alloy element.

[0033] Specifically, the three key flight modes implemented in this application correspond to the geometric states of the wing 5: when the wing 5 is fully folded, its deployment angle is 0°, corresponding to a sweep angle of 90°. This mode is suitable for storage, transportation, or high-speed flight phases to minimize aerodynamic drag or space occupation; when the wing 5 is in the first deployed state, its deployment angle is 60°, corresponding to a sweep angle of 30°. This mode is suitable for transitional or cruise flight phases that balance certain lift and speed requirements; when the wing 5 is fully deployed, its deployment angle is 90°, corresponding to a sweep angle of 0°. This mode provides the maximum lift area and is specifically designed for low-speed cruise or takeoff and landing phases where lift requirements are highest. This three-state design covers the key aerodynamic configurations from fully folded to fully deployed, meeting the core aerodynamic requirements of UAVs for cross-domain flight.

[0034] In this application, the lever mechanism 12 includes a first connecting rod 121 and a second connecting rod 122. A pin 111 is provided on the piston rod.

[0035] The first connecting rod 121 and the second connecting rod 122 are located on both sides of the piston rod, and one end of the first connecting rod 121 and one end of the second connecting rod 122 are rotatably connected to the pin 111, so that the first connecting rod 121 and the second connecting rod 122 form a V-shaped structure. The other end of the first connecting rod 121 and the other end of the second connecting rod 122 are rotatably connected to the base 4, and are respectively connected to the first shape memory alloy drive member 21 and the second shape memory alloy drive member 22.

[0036] It should be noted that the lever mechanism 12 adopts a V-shaped structure formed by the first connecting rod 121 and the second connecting rod 122 hinged by the pin 111 on the piston rod, and the other ends of the connecting rods are respectively rotatably connected to the base 4 and connected to the two driving components. This symmetrical V-shaped lever layout not only efficiently couples the linear motion of the piston rod with the contraction motion of the first memory alloy driving component 21 and the second memory alloy driving component 22, but also effectively improves the force distribution through the cooperative support of the first connecting rod 121 and the second connecting rod 122, enhancing the transmission stability and structural rigidity. At the same time, it provides an ideal interface for the symmetrically arranged first memory alloy driving component 21 and the second memory alloy driving component 22, which is conducive to the balance and increase of driving force.

[0037] Specifically, such as Figure 5 As shown, to achieve flexibility and tolerance in motion transmission, both the first link 121 and the second link 122 have slotted holes on the side facing the pin 111 that match the pin 111. Through these slotted holes, the first link 121 and the second link 122 are fitted onto the pin 111, forming a combination of a sliding pair and a rotating pair. This connection method ensures that the pin 111 (and thus the piston rod) can be effectively pushed to move, while allowing the first link 121 and the second link 122 to have a slight self-adjusting capability in the plane of motion. This capability can adapt to small deviations in the motion trajectory caused by machining or assembly errors, avoiding over-constraint and thus ensuring the smoothness and reliability of the entire lever transmission mechanism.

[0038] In this application, the second memory alloy drive member 22 has a preset slack amount in the initial state. The slack amount is not less than the movement stroke of the wire threading position of the lever mechanism 12 when the first memory alloy drive member 21 is driven, so as to avoid interference with the movement of the first memory alloy drive member 21 driving the output member 11 along the first direction.

[0039] The slack amount is determined based on the travel distance of the wire-threading position of the lever mechanism 12. During the entire travel distance of the output component 11 driven by the first shape memory alloy drive 21 in the first direction, the wire-threading position of the lever mechanism 12 generates a corresponding displacement; the slack amount is set to be no less than this displacement. In one specific embodiment, the travel distance of the wire-threading position of the lever mechanism 12 is 17 mm, and the slack amount of the second shape memory alloy drive 22 is set to 18 mm, where 1 mm is a safety margin. This 1 mm margin is used to offset the slack redundancy before the lever mechanism 12 moves in the opposite direction when the second shape memory alloy drive 22 subsequently performs the folding / retracting drive, ensuring reliable triggering of the folding / retracting action and effective transmission. Based on the above principles, those skilled in the art can determine the corresponding slack amount value proportionally according to the actual lever ratio and the travel distance of the output component 11.

[0040] In this application, the first memory alloy driving component 21 includes two first memory alloy wires 211, which are respectively connected to the second ends of the first connecting rod 121 and the second connecting rod 122. The second memory alloy driving component 22 includes two second memory alloy wires 221, which are respectively connected to the second ends of the first connecting rod 121 and the second connecting rod 122.

[0041] When the two first shape memory alloy wires 211 are energized and driven into position and cooled, they will elongate to a certain extent. At this time, during the process of the two second shape memory alloy wires 221 being heated and contracted to drive the wing 5 to retract, the two first shape memory alloy wires 211 are in a relaxed state and will not hinder the movement.

[0042] The first memory alloy drive component 21 and the second memory alloy drive component 22 are symmetrically connected to the second ends of the first connecting rod 121 and the second connecting rod 122 by two first memory alloy wires 211 and two second memory alloy wires 221, respectively. This double-sided symmetrical arrangement makes the driving torque evenly applied to the lever mechanism 12, avoiding the off-center load and jamming that may be caused by single-sided driving, and improving the smoothness and synchronization of the linear motion of the piston rod.

[0043] In this implementation, the control unit is configured to perform mode switching control. Specifically, the control unit selectively controls the energization of either the first memory alloy drive member 21 or the second memory alloy drive member 22 in the memory alloy drive assembly 2 to drive the output member 11. When it is necessary to switch from the current mode to the target mode, the memory alloy unlocking member 32 of the locking assembly 3 corresponding to the current locked position is first energized to unlock. Subsequently, the memory alloy drive assembly 2 with the drive direction toward the target position (the first memory alloy drive member 21 is controlled if it is in the unfolding direction, and the second memory alloy drive member 22 is controlled if it is in the folding direction) is energized and driven until the piston rod moves to the target position, the pin hole aligns with the locking assembly 3 corresponding to the target position and is locked by it.

[0044] Specifically, the control unit can be a microcontroller, microprocessor, etc.

[0045] In this application, the timing of controlling the energization of the memory alloy unlocking component 32 is determined based on the heating state of the memory alloy driving component 2: the temperature of the memory alloy driving component 2 is monitored by a temperature sensor (not shown in the figure), and when the monitored temperature reaches the preset trigger temperature, the step of controlling the energization of the memory alloy unlocking component 32 is executed; wherein, the trigger temperature is lower than the austenite phase transformation completion point Af (Austenite Finish Temperature) of the material of the memory alloy driving component 2.

[0046] Specifically, the temperature sensor is connected to the shape memory alloy drive assembly 2.

[0047] It should be noted that this application achieves a coordinated control sequence of "pre-accumulation-re-unlocking" by setting the timing of the energization of the shape memory alloy unlocking component 32 to be based on the heating state of the shape memory alloy driving component 2 (specifically, by determining whether its temperature reaches a preset trigger temperature below Af). This control strategy precisely maps the target of "initial force required for rapid drive" to the executable parameter of "temperature threshold for triggering the unlocking action," ensuring that the shape memory alloy driving component 2 has accumulated sufficient driving force before the mechanical lock is released. When the locking component 3 unlocks at the "optimal point of force application" where the driving force has been fully accumulated but the driving material has not yet completed its phase change, the output component 11 can immediately obtain a strong initial acceleration, thereby shortening the overall time from unlocking to moving to the target position and optimizing the dynamic response process of mode switching. Through the above-mentioned coordinated control sequence of "pre-accumulation-re-unlocking," this application effectively overcomes the inherent characteristic that the linear growth of the shape memory alloy driving force may lead to a slow dynamic response, and achieves rapid and precise mode switching of the wing 5 under heavy loads. This enables the drive mechanism to reliably complete multiple cyclic actuation tasks. By further increasing the number of locking components 3, more preset positions can be locked, thereby providing more diverse wing 5 sweep angle configuration options according to the differentiated requirements of aerodynamic shape (such as high-speed flight, cruise flight, etc.) in different flight stages, greatly improving the multi-mission adaptability and comprehensive performance of the flight platform.

[0048] The multimodal variator drive mechanism for wings based on shape memory alloy provided in this application works mainly based on the synergistic effect of the controlled contraction of the shape memory alloy drive component 2 and the locking component 3, so as to realize the repeated and precise switching and locking of the output component 11 (piston rod) in at least three preset positions.

[0049] The following, in conjunction with specific implementation methods, uses three locking components 3 corresponding to three modes of wing 5: fully retracted (90° sweep angle), first deployment (30° sweep angle), and fully deployed (0° sweep angle) to illustrate its basic working principle and optimized "pre-charge-re-unlock" cooperative control timing: Initial state and basic structure: A pin hole is provided on the piston rod (output part 11). Three locking components 3 (including shape memory alloy unlocking component 32 and locking pin mechanism 31) are fixedly arranged along their movement path. Lever mechanism 12 (including first connecting rod 121 and second connecting rod 122) couples the linear motion of the piston rod with the retraction motion of the shape memory alloy drive component 2. The first shape memory alloy drive component 21 (including two first shape memory alloy wires 211) is used to drive the piston rod to move in the unfolding direction, and the second shape memory alloy drive component 22 (including two second shape memory alloy wires 221) is used to drive the piston rod to move in the folding direction. The second shape memory alloy drive component 22 has a slack in the initial state to avoid interference with the unfolding drive.

[0050] Basic working principle (taking the switch from mode one (complete folding) to mode two (first unfolding) as an example): The traditional "unlock-drive-lock" basic logic is as follows: Unlocking: The control unit first commands the memory alloy unlocking part 32 of the locking component 3 corresponding to the current locked position (corresponding to mode one) to be energized and heated to shrink, overcoming the elastic force of the reset elastic part 313, and pulling the pin 312 of the locking pin mechanism 31 out of the piston rod pin hole to release the lock.

[0051] Drive and Lock: Subsequently, the control unit commands the first shape memory alloy drive component 21 (first shape memory alloy wire 211) to be energized and heated to contract. The contraction force is amplified by the lever mechanism 12 and converted into thrust, pushing the piston rod to move in the deployment direction. When the piston rod moves to the point where the pin hole aligns with the second locking component 3 (corresponding to mode two), the reset elastic element 313 of the locking component 3 automatically ejects the pin 312 and inserts it into the pin hole, locking the piston rod, and the wing 5 is thus fixed in the first deployed state.

[0052] Optimized "pre-charge-re-unlock" coordinated control timing (taking the same switching process as an example): To overcome the relatively slow force build-up process caused by thermal inertia in shape memory alloy drives and achieve rapid response under heavy loads, the following optimized cooperative control timing can be adopted: Command reception and pre-start (pre-charge): After receiving the switching command, the control unit first controls the first shape memory alloy drive component 21 to start heating. At this time, the shape memory alloy unlocking component 32 is not energized, and the piston rod is still locked in the mode one position.

[0053] Temperature monitoring and force storage determination: During heating, the control unit monitors the temperature of the first shape memory alloy drive component 21 through a temperature sensor (not shown in the figure). The controller has a pre-stored trigger temperature threshold T_trigger, which is lower than the austenite phase transformation completion point Af of the material, but sufficient to cause it to generate significant shrinkage force (in the middle and late stages of the martensite to austenite transformation).

[0054] Triggering the unlocking action: When the monitored temperature reaches or exceeds T_trigger, it indicates that the driving force has been fully accumulated. The control unit immediately sends a power-on command to the memory alloy unlocking component 32 corresponding to mode one.

[0055] Coordinated action and rapid movement: The shape memory alloy unlocking component 32 is energized and retracts, pulling the pin 312 to unlock. Almost simultaneously with unlocking, the contraction force of the first shape memory alloy driving component 21, which is already in a "pre-charged" state, is immediately released through the lever mechanism 12, providing the piston rod with a large initial acceleration, causing it to move rapidly towards mode two.

[0056] Position locking and drive stop: During piston rod movement, the first shape memory alloy drive component 21 remains energized. When the piston rod moves to the second mode position and the pin hole is aligned, the pin 312 of the second locking component 3 automatically pops out and locks under the action of the reset elastic element 313. After locking is completed, the control unit cuts off the power supply to the first shape memory alloy drive component 21.

[0057] The principle of switching from mode two to mode three, or from mode three to other modes, is similar to the above process. The difference is that the driving source is switched to the corresponding first memory alloy driving component 21 or second memory alloy driving component 22, and the corresponding locking component 3 is unlocked.

[0058] Therefore, both the basic logic and the optimized "pre-charge-unlock" timing are achieved through selective and coordinated control of the power-on / off timing of the shape memory alloy drive assembly 2 and each locking assembly 3 by the control unit. This enables reliable, repeatable, and orderly switching of the wing 5 between multiple preset sweep angle modes. The optimized timing, through the strategy of "first driving preheating and accumulating power, and then triggering unlocking after the driving force reaches the threshold," aligns the unlocking point with the point of maximum driving force burst, improving dynamic response speed and switching reliability.

[0059] This application provides an unmanned aerial vehicle (UAV) including a wing 5 and the aforementioned shape memory alloy-based multimodal variator drive mechanism. The output component 11 of the drive mechanism is connected to the wing 5 via a transmission connection, and is used to drive the wing 5 to change its sweep angle.

[0060] Specifically, such as Figure 7 As shown, the wing 5 is rotatably connected to the UAV body via a hinge shaft; the output component 11 is fixedly connected to the adapter rod 6, and the two ends of the adapter rod 6 are rotatably connected to the corresponding transmission link 7, which is connected to the corresponding wing 5; the linear motion of the output component 11 drives the wing 5 to rotate around the hinge shaft via the adapter rod 6 and the transmission link 7 in sequence, so as to change the sweep angle of the wing 5.

[0061] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.

[0062] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A wing multimodal morphing drive mechanism based on shape memory alloy, characterized in that, include: The drive unit (1) includes a reciprocating output component (11). A shape memory alloy driving assembly (2) is connected to the driving unit (1). The shape memory alloy driving assembly (2) includes a first shape memory alloy driving member (21) for driving the output member (11) to move along a first direction, and a second shape memory alloy driving member (22) for driving the output member (11) to move along a second direction opposite to the first direction. Both the first shape memory alloy driving member (21) and the second shape memory alloy driving member (22) are configured to generate a contraction force when electrically heated to drive the output member (11) to move. At least three locking components (3) are spaced apart along the movement path of the output component (11), and each locking component (3) has a locked state and an unlocked state; The locking component (3) includes a shape memory alloy unlocking component (32) and a locking pin mechanism (31). In the locked state, the locking pin mechanism (31) cooperates with a pin hole provided on the output component (11) to restrict the movement of the output component (11). The shape memory alloy unlocking component (32) can generate an action when heated by electricity, driving the locking pin mechanism (31) to disengage from the pin hole, so that the locking component (3) switches to the unlocked state. The control unit is electrically connected to the shape memory alloy drive assembly (2) and the shape memory alloy unlocking member (32) of each of the locking assemblies (3), and is configured to selectively control the power-on and power-off sequence of different shape memory alloy unlocking members (32) and the shape memory alloy drive assembly (2), so that the output member (11) can repeatedly and orderly switch between at least three preset positions corresponding to at least three locking assemblies (3) and be locked, thereby driving the wing (5) connected to the output member (11) to repeatedly switch between modes corresponding to different sweep angles.

2. The wing multimodal morphing drive mechanism based on shape memory alloy according to claim 1, characterized in that, The locking mechanism (31) includes a housing (311), a pin (312), a reset elastic element (313), a connecting rod (314), and a pressure wire element (315). The housing (311) is fixed to the base (4); The pin (312) is retractably disposed within the housing (311); The reset elastic element (313) is disposed inside the housing (311), and its two ends are respectively connected to the inner bottom wall of the housing (311) and the bottom of the pin (312), and is used to apply an elastic force to the pin (312) to keep it in an extended state; The connecting bar (314) and the pressure wire (315) are both fixed to the base (4) and are arranged parallel to the length direction of the output component (11); The memory alloy unlocking component (32) is a memory alloy wire, one end of which is connected to the pin (312), and the other end passes through the interior of the reset elastic component (313), wraps around the connecting bar (314) in a winding manner, and is finally fixed to the pressure wire component (315). When the memory alloy unlocking component (32) is not energized, the reset elastic component (313) pushes the pin (312) outward by its elastic force, so that the pin (312) is inserted into the corresponding pin hole on the output component (11) to lock the output component (11); when the memory alloy unlocking component (32) is energized and heated to shrink, the pulling force generated by it is driven by the steering action of the connecting rod (314) to pull the pin (312) to overcome the elastic force of the reset elastic component (313) and retract inward, so that the pin (312) exits the pin hole to release the lock on the output component (11).

3. The wing multimodal morphing drive mechanism based on shape memory alloy according to claim 2, characterized in that, The output component (11) is a piston rod, and a pin hole is provided on the piston rod along its length direction; The locking components (3) are three in number, fixedly arranged at intervals along the movement path of the piston rod, and respectively corresponding to the fully folded state, the first deployed state and the fully deployed state of the wing (5); When the piston rod moves to any preset position, the pin hole aligns with the corresponding locking component (3), so that the corresponding locking component (3) can be inserted into the pin hole to lock the piston rod; the drive unit (1) also includes a lever mechanism (12), the first end of the lever mechanism (12) is hinged to the piston rod, and the second end is connected to the first memory alloy drive component (21) and the second memory alloy drive component (22) respectively.

4. The wing multimodal morphing drive mechanism based on shape memory alloy according to claim 3, characterized in that, The second memory alloy drive (22) has a preset slack in the initial state. The slack is not less than the movement stroke of the wire threading position of the lever mechanism (12) when the first memory alloy drive (21) is driven, so as to avoid interference with the first memory alloy drive (21) driving the output (11) to move in the first direction.

5. The wing multimodal morphing drive mechanism based on shape memory alloy according to claim 3, characterized in that, The lever mechanism (12) includes a first link (121) and a second link (122); The piston rod is provided with a pin (111). The first connecting rod (121) and the second connecting rod (122) are located on both sides of the piston rod, and one end of the first connecting rod (121) and one end of the second connecting rod (122) are rotatably connected to the pin (111), so that the first connecting rod (121) and the second connecting rod (122) form a V-shaped structure; The other end of the first link (121) and the other end of the second link (122) are rotatably connected to the base (4) and connected to the first memory alloy drive (21) and the second memory alloy drive (22) respectively.

6. The wing multimodal morphing drive mechanism based on shape memory alloy according to claim 5, characterized in that, The first memory alloy drive component (21) includes two first memory alloy wires (211), which are respectively connected to the second ends of the first connecting rod (121) and the second connecting rod (122); the second memory alloy drive component (22) includes two second memory alloy wires (221), which are respectively connected to the second ends of the first connecting rod (121) and the second connecting rod (122).

7. The wing multimodal morphing drive mechanism based on shape memory alloy according to claim 4, characterized in that, The control unit is configured to perform mode switching control: When it is necessary to switch from the current mode to the target mode, firstly control the memory alloy unlocking part (32) of the locking component (3) corresponding to the current locking position to be energized and unlocked; then, control the memory alloy driving component (2) with the driving direction toward the target position to be energized and driven until the piston rod moves to the target position, and the pin hole is aligned with the locking component (3) corresponding to the target position and locked by it.

8. The wing multimodal morphing drive mechanism based on shape memory alloy according to claim 7, characterized in that, The timing of energizing the shape memory alloy unlocking component (32) is determined based on the heating state of the shape memory alloy driving assembly (2): The temperature of the memory alloy drive component (2) is monitored by a temperature sensor. When the monitored temperature reaches the preset trigger temperature, the step of controlling the power-on action of the memory alloy unlocking component (32) is executed. The trigger temperature is lower than the austenitic phase transformation completion point of the material of the memory alloy drive component (2).

9. A drone, characterized in that, The wing (5) includes a wing multimodal variant drive mechanism based on shape memory alloy as described in any one of claims 1 to 8, wherein the output component (11) of the drive mechanism is driveably connected to the wing (5) for driving it to change its sweep angle.

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