Blade structure with airfoil camber capable of being steplessly regulated and control method thereof

Abstract

The invention discloses a blade structure with the airfoil camber capable of being steplessly regulated and a control method of the blade structure, and belongs to the technical field of aero-engine blades. The structure comprises an inner casing, an outer casing and a plurality of flexible blades, wherein the inner casing and the outer casing are coaxially arranged; the blade is composed of a front / rear edge framework, a flexible framework and a metal skin, and is connected with the casing and the actuating ring through a framework fixing screw rod and a deformation actuating rod. The inner actuating ring and the outer actuating ring are synchronously driven by steering engines evenly distributed in the circumferential direction, the rotating motion of the inner actuating ring and the outer actuating ring is converted into accurate deflection of the actuating rods through the coupling effect of strip-shaped driving grooves in the actuating rings and sine curve deformation track grooves in the cartridge receiver, and therefore the rear edges of the blades are driven to rotate around the front edges in a stepless mode, and continuous camber adjustment larger than or equal to + / -15 degrees is achieved. Through combination of a rigid-flexible coupling structure and closed-loop control, the problems of discontinuous adjustment, response delay, discontinuous pneumatic surface and the like in the prior art are solved, and the pneumatic efficiency and stability of the blade under different working conditions are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of aero-engine stator blade technology, specifically to a blade structure with stepless adjustable airfoil camber and its control method. Background Technology

[0002] In fluid machinery such as aero-engines and gas turbines, blades are the core components for energy conversion, and their aerodynamic performance directly determines the overall efficiency. Traditional blades employ a fixed camber design, which cannot adapt to a wide range of operating conditions, often resulting in sudden efficiency drops and stall flutter at off-design points. To improve adaptability, existing technologies have proposed various variable camber schemes, but all have inherent drawbacks: mechanical segmented adjustment (such as articulated flaps) suffers from structural discontinuities, is prone to airflow separation, generates high noise, and has complex mechanisms; hydraulic / pneumatic drive systems rely on external power sources, have slow response times, require high sealing, and exhibit poor reliability in extreme environments; smart material drives (such as SMA and piezoelectric ceramics) are limited by finite strain capacity, significant material hysteresis effects, and performance degradation at high temperatures, making it difficult to meet the demands for wide-range, high-precision control; passive adaptive structures cannot perform active control and have limited control capabilities. Therefore, there is an urgent need for an active blade camber control technology that can achieve wide-range, high-precision, continuous stepless adjustment, and possesses high reliability, lightweight design, and good aerodynamic continuity to meet the pressing needs of modern high-performance aero-engines for adaptive blades. Summary of the Invention

[0003] The present invention aims to overcome the shortcomings of the prior art and provide a blade structure and control method with stepless adjustment of airfoil camber.

[0004] The technical solution adopted in this invention is as follows: A blade structure with stepless adjustable airfoil camber, comprising: The inner and outer casings are coaxially arranged. Multiple flexible blades are arranged in a ring array between the inner and outer casings; The inner actuating ring, which is rotatably fitted inside the inner casing, and the outer actuating ring, which is rotatably fitted outside the outer casing, together constitute a ring drive assembly. The inner and outer casings are provided with sinusoidal curve deformation trajectory grooves corresponding to the number of flexible blades, and the inner and outer actuating rings are provided with strip drive grooves corresponding to the number of flexible blades. Each flexible blade includes a leading edge skeleton, a trailing edge skeleton, a flexible skeleton connecting the two, a metal skin covering the skeleton, and a skeleton fixing screw and a deformable actuating rod that are axially arranged through the blade. The frame fixing screw passes through the front edge frame and is fixed to the inner and outer casings at both ends respectively. The deformation actuating rod passes through the rear edge frame and is installed at both ends in the sinusoidal deformation trajectory groove of the inner and outer casings and the strip drive groove of the inner and outer actuating rings respectively. The drive assembly synchronously drives the inner and outer actuating rings to rotate through multiple circumferentially distributed servo motors, which in turn drive the deformation actuating rod to deflect along the sinusoidal deformation trajectory groove, thereby achieving stepless continuous adjustment of the blade airfoil camber within the range of ≥±15°.

[0005] Furthermore, the flexible frame is made of multiple layers of spring steel sheets stacked together, with the layers fixed by riveting, forming a hinge shape that can be bent in both directions; the two ends of the flexible frame are respectively provided with connecting lugs, which are hinged to the front edge frame and the rear edge frame by pins.

[0006] Furthermore, the metal skin is made of multiple titanium alloy sheets spliced ​​together, with the seams of adjacent sheets using an overlapping method where the upper layer covers the lower layer, and the overlapping direction is consistent with the airflow direction. Each sheet has multiple skin sliding buckles welded to its inner side. The skin sliding buckles are T-shaped tenons that can slide and engage with corresponding T-shaped grooves on the flexible frame.

[0007] Furthermore, at least three servo mounting brackets are evenly distributed around the outer wall of the outer casing, and the servos are fixed on the servo mounting brackets; The output shaft of the servo motor is connected to a pinion via a coupling, and the outer ring of the outer actuator ring is provided with an outer gear ring that meshes with the pinion.

[0008] Furthermore, at least three servo mounting brackets are evenly distributed around the inner wall of the inner casing, and the servo is fixed on the servo mounting bracket. The output shaft of the servo motor is connected to a pinion via a coupling, and the inner ring of the inner actuator ring is equipped with an internal gear ring that meshes with the pinion.

[0009] Furthermore, the outer casing is composed of at least four arc-shaped shell segments joined together.

[0010] Furthermore, a composite material bushing is provided at the connection between the deformable actuator and the rear edge skeleton.

[0011] Furthermore, the blade structure also includes a pose sensing system, which includes: A fiber optic strain sensor embedded in the trailing edge frame is used to detect blade camber deformation. An encoder mounted on the end of the frame fixing screw is used to detect the blade deflection angle; The signal output terminals of the sensors and encoders are connected to an external controller for communication.

[0012] Furthermore, a method for controlling a blade structure with stepless adjustable airfoil camber includes the following actions: Receive command: The controller receives the target curvature angle command; Collaborative drive: The controller calculates the required rotation angle and direction of the inner and outer actuation rings based on the target curvature angle, and synchronously drives multiple circumferentially distributed servo motors to rotate the inner and outer actuation rings. Linked deformation: The rotational motion of the actuating ring is converted into the deflection motion of the deformation actuating rod along the sinusoidal deformation trajectory groove through the strip drive groove on it, so as to realize the continuous bending deformation of the blade airfoil. Closed-loop feedback: The actual curvature value of the blade is monitored in real time through the pose sensing system and fed back to the controller; Dynamic adjustment: The controller compares the actual curvature value with the target curvature value. If there is a deviation, it generates a correction command to adjust the servo motor's action until the actual curvature value matches the target curvature value, thus achieving stepless control.

[0013] Furthermore, the servo motor adopts a direct-drive closed-circuit hydraulic servo motor, and the motor speed and direction are adjusted by a servo controller.

[0014] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: It achieves high-precision, wide-range stepless continuous control: through the mechanical transmission scheme of "servo motor + actuation ring + curve groove", the rotational motion of the servo motor is accurately converted into the bending deformation of the blade. The bending adjustment range is ≥±15°, with high resolution. It can smoothly and continuously adapt to various complex working conditions, fundamentally overcoming the defects of discontinuity of mechanical segmented adjustment and limited driving range of intelligent materials.

[0015] Excellent aerodynamic performance and reliability are ensured: the blades adopt a rigid-flexible coupling structure design of "flexible skeleton + metal skin". The multi-layer spring steel flexible skeleton provides the elasticity and load-bearing capacity required for large deformations; the metal skin is slidably connected to the skeleton through T-shaped clips, maintaining a smooth and continuous aerodynamic shape under any curvature, completely avoiding airflow separation and energy loss caused by articulated structures, and improving aerodynamic efficiency. All drive mechanisms are concentrated in the casing, and the blade body is a purely mechanical structure, resistant to high temperature and high pressure environments, and highly robust.

[0016] It possesses intelligent closed-loop control capabilities: integrating a posture sensing system composed of fiber optic grating sensors and encoders, it can monitor the actual camber of the blade in real time, and perform closed-loop feedback control with the host computer through PID or fuzzy adaptive control algorithms, dynamically compensating for angle deviations caused by external factors such as airflow disturbances. It has strong anti-interference capabilities, high control precision, and realizes intelligent active control of blade camber.

[0017] The system structure and maintainability have been optimized: the inner and outer casings and actuator rings adopt a circumferentially distributed multi-servo motor cooperative drive, forming a symmetrical load distribution, reducing local stress, and improving system stability. The outer casing adopts a segmented modular design, integrating three-dimensional grooves and lightweight perforated plates, which not only reduces the overall weight but also facilitates manufacturing, on-site assembly, and subsequent maintenance, significantly reducing the total life cycle cost. Attached Figure Description

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the overall structure of the present invention after removing the outer shell; Figure 3 This is a side cross-sectional view of the present invention; Figure 4 This is a schematic diagram of the structure of the inner casing of the present invention; Figure 5 This is a schematic diagram of the structure of the outer casing of the present invention.

[0019] Marked in the image: 1-Inner casing; 2-Outer casing; 3-Flexible blade; 4-Inner actuating ring; 5-Outer actuating ring; 6-Sine curve deformation trajectory groove; 7-Strip drive groove; 8-Leading edge frame; 9-Leading edge frame; 10-Flexible frame; 11-Metal skin; 12-Fixing screw; 13-Deformable actuating rod; 14-Servo; 15-Skin sliding buckle; 16-T-shaped slide; 17-Servo mounting base; 18-Pin gear; 19-Outer gear ring; 20-Inner gear ring. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings.

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0022] Example 1 In this embodiment, if Figure 1-5 As shown, a blade structure with stepless adjustable airfoil camber is based on a precise mechanical linkage system that enables continuous blade deformation. The structure includes a rigid inner casing and an outer casing arranged coaxially, forming the support frame of the entire system. In the annular space between these two casings, multiple flexible blades (e.g., 16 blades) are evenly distributed circumferentially, collectively forming the stator blade cascade of the turbomachinery.

[0023] The drive system consists of two independently rotatable annular components: an inner actuating ring fitted inside the inner casing and an outer actuating ring fitted outside the outer casing. On the inner and outer casing panels, corresponding to the position of each blade, sinusoidal curve deformation trajectory grooves of a specific curvature are machined. Correspondingly, the inner and outer actuating rings have strip-shaped drive grooves equal in number to the number of blades.

[0024] Each flexible blade is an independent deformation unit. Its internal skeleton consists of a leading-edge skeleton and a trailing-edge skeleton, connected by a flexible skeleton, allowing the trailing edge to bend relative to the leading edge. The entire skeleton is covered with a metal skin to form a smooth aerodynamic surface. Two key rods run through the blade: one is the skeleton fixing screw, which passes through the leading-edge skeleton and fixes its two ends (not hinged) to the inner and outer casings, thus making the leading edge of the blade the fixed rotation center of the entire blade deformation; the other is the deformation actuation rod, which passes through the trailing-edge skeleton, with its two ends inserted into the sinusoidal deformation trajectory groove of the casing and the strip drive groove of the actuation ring, respectively.

[0025] When multiple circumferentially distributed servos synchronously drive the inner and outer actuating rings to rotate relative to each other, the strip drive grooves on the actuating rings will rotate accordingly. Since one end of the deformable actuating rod is engaged in the strip drive groove, the rotational motion of the actuating ring forces the rod to displace. Furthermore, because the other end of the rod is constrained within the sinusoidal curve deformation trajectory groove of the casing, its motion trajectory is defined by this groove, ultimately converting the rotational motion of the actuating ring into the deflection motion of the deformable actuating rod along a predetermined trajectory. The actuating rod drives the trailing edge of the blade, causing it to rotate around a fixed point on the leading edge, thereby achieving continuous, stepless adjustment of the entire blade airfoil camber, with an adjustment range exceeding ±15°.

[0026] This design precisely converts the rotational motion of the drive source (servo motor) into the bending deformation of the blades through a "slot-rod" connection. The sinusoidal groove design optimizes the motion trajectory, making the camber change more linear and smooth. The fixed leading edge and driven trailing edge method simulates the bending shape of a natural airfoil to the greatest extent, effectively ensuring aerodynamic efficiency.

[0027] Furthermore, the flexible skeleton is the core component for the blade's flexible deformation. Its specific structure consists of multiple layers of high-performance spring steel sheets stacked together, with each layer fixed by riveting. This multi-layered structure gives it a hinge-like characteristic, allowing it to bend smoothly in one direction while maintaining high stiffness in other directions. Connecting lugs are machined at both ends of the flexible skeleton, forming hinged connections with corresponding lugs on the leading and trailing edge skeletons via pins.

[0028] This design creates a system of "rigid nodes + flexible linkages". The front and rear edge skeletons serve as rigid nodes, providing mounting points and aerodynamic shape, while the flexible hinge in the middle is responsible for absorbing and generating deformation. Multi-layered spring steel sheets provide the elasticity required for large deformations, while ensuring high fatigue life and load-bearing capacity, avoiding the creep and plastic deformation problems that may occur with integral flexible materials.

[0029] Furthermore, the metal skin is not a single piece, but rather composed of multiple independent titanium alloy sheets spliced ​​together. To ensure aerodynamic smoothness, all seams are overlapped, and the upper sheet is strictly guaranteed to cover the lower sheet, with the overlap direction aligned with the airflow direction, ensuring unobstructed airflow. Several skin sliding fasteners are welded to the inner side (non-aerodynamic surface) of each sheet. These fasteners are designed with T-shaped tenons, which fit precisely into corresponding T-shaped grooves on the flexible frame, forming a sliding fit.

[0030] When the blade bends, the convex skin needs to stretch, and the concave skin needs to compress. Traditional fixed connections can cause the skin to wrinkle or tear. In this embodiment, the T-shaped tenon can slide freely within the T-shaped groove, allowing relative displacement between the skin sheets to perfectly adapt to the different strain requirements at different locations during bending. This ensures that the skin always tightly covers the frame at any curvature, maintaining a perfectly smooth aerodynamic surface, which is key to improving aerodynamic efficiency.

[0031] Furthermore, the driving method of the outer actuator ring is as follows: At least three servo mounting seats are welded circumferentially on the outer wall of the outer casing. The servos are rigidly fixed to these mounting seats via flanges. The output shaft of the servo is connected to a pinion gear via a coupling. A complete external gear ring is machined on the outer ring of the outer actuator ring. The pinion gear meshes directly with the external gear ring.

[0032] This design constitutes a compact "servo-gear-ring gear" drive system. The gear meshing transmission is highly efficient, has a fast response speed, a large output torque, and can provide precise angular displacement control, making it very suitable for driving an external actuator ring for precise rotational positioning.

[0033] Furthermore, symmetrical to the driving principle of the outer actuator ring, the driving method of the inner actuator ring is as follows: At least three servo mounting brackets are welded circumferentially to the inner wall of the inner casing. The servos are fixed here, and their output shafts are connected to a pinion via a coupling. An internal gear ring is machined on the inner ring of the inner actuator ring. The pinion meshes with the internal gear ring.

[0034] The inner and outer actuating rings employ a similar gear drive scheme, ensuring the synchronicity and consistency of the drive. The drive units are arranged separately on the inner and outer casings, making full use of the structural space and resulting in a more rational and compact overall layout.

[0035] Furthermore, due to its large diameter, the outer casing adopts a split design for ease of manufacturing, transportation, and assembly, consisting of at least four arc-shaped shell sections joined together with high-strength bolts. The mating surfaces of each shell section are precision-machined to ensure the overall roundness and strength after assembly.

[0036] The segmented design solves the problems of high difficulty and cost in processing large-sized components. At the same time, this design also facilitates later maintenance. If a section of the casing or its track groove module needs to be replaced, it can be done individually without disassembling the entire system, which greatly reduces maintenance costs and time.

[0037] Furthermore, the deformable actuator does not make direct contact within the hole penetrating the trailing edge skeleton. A self-lubricating composite bushing is pressed into this hole, and the actuator passes through this bushing.

[0038] The composite material bushing acts as a bearing. It significantly reduces friction and wear between the actuator rod and the trailing edge frame, ensuring smooth and efficient transmission. Simultaneously, the bushing material possesses a degree of elasticity, absorbing minor vibrations and impacts, protecting the rod and frame holes, and improving the system's reliability and lifespan.

[0039] Furthermore, the system integrates a pose sensing system for closed-loop control. This includes: a fiber optic strain sensor, directly embedded within the trailing edge skeleton material, capable of extremely sensitively sensing the minute strain caused by the skeleton's bending, thereby indirectly calculating the actual camber of the blade; and an absolute encoder, mounted at the end of the skeleton fixing screw, used to directly measure the absolute deflection angle of the blade. The signal outputs of all these sensors are connected to an external controller.

[0040] This sensing system provides redundant and high-precision feedback. The fiber optic sensor measures the "cause" (strain) that causes the bending, while the encoder measures the "effect" (angle). The combination of these two provides the controller with comprehensive and reliable data, forming the basis for high-precision stepless control and representing a significant advantage over traditional open-loop mechanical regulation.

[0041] Furthermore, a method for controlling a blade structure with stepless adjustable airfoil camber includes the following actions: Receive command: The controller receives the target curvature angle command; Collaborative drive: The controller calculates the required rotation angle and direction of the inner and outer actuation rings based on the target curvature angle, and synchronously drives multiple circumferentially distributed servo motors to rotate the inner and outer actuation rings. Linked deformation: The rotational motion of the actuating ring is converted into the deflection motion of the deformation actuating rod along the sinusoidal deformation trajectory groove through the strip drive groove on it, so as to realize the continuous bending deformation of the blade airfoil. Closed-loop feedback: The actual curvature value of the blade is monitored in real time through the pose sensing system and fed back to the controller; Dynamic adjustment: The controller compares the actual curvature value with the target curvature value. If there is a deviation, it generates a correction command to adjust the servo motor's action until the actual curvature value matches the target curvature value, thus achieving stepless control.

[0042] This control method is applied to the aforementioned structure, and its operational flow is as follows: The controller first receives the target camber angle command from the upper-level control system. The controller's built-in algorithm calculates the required rotation angle and direction of the inner and outer actuating rings based on the target angle. Subsequently, the controller sends synchronization commands to all servos, driving the inner and outer actuating rings to rotate. The rotation of the actuating rings is converted into the movement of the deformation actuating rod through the strip drive groove on them. The actuating rod then drives the trailing edge to deflect along the trajectory of the curved groove on the casing, realizing blade deformation. Simultaneously, the posture sensing system monitors the actual camber in real time and feeds it back to the controller. The controller continuously compares the actual value with the target value. Once a deviation occurs (such as due to airflow disturbance), it immediately calculates a correction command and adjusts the servo actions until the deviation is eliminated.

[0043] This method forms a closed-loop automatic control system of "perception-decision-execution-feedback". It enables the blades to resist external disturbances and always maintain a precise camber, thereby ensuring that the turbomachinery can operate stably and efficiently under various operating conditions.

[0044] Furthermore, the servo motor is preferably a direct-drive closed-circuit hydraulic servo motor. Its working principle is as follows: the servo controller directly adjusts the speed and direction of the drive motor, the motor drives the hydraulic pump, and the generated high-pressure oil directly drives the hydraulic motor or cylinder connected to the actuator ring, eliminating the need for complex valve groups.

[0045] Direct-drive hydraulic steering gears are compact and offer extremely fast response. By eliminating valve assemblies and lengthy piping, they suffer from minimal internal pressure loss, significantly reduced energy consumption and heat generation, and higher reliability. They are particularly suitable for complex mechanical control systems requiring high precision and rapid response.

[0046] The above description is merely a preferred embodiment of the invention and is not intended to limit the invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A blade structure with stepless adjustable airfoil camber, characterized in that, include: The inner and outer casings are coaxially arranged. Multiple flexible blades are arranged in a ring array between the inner and outer casings; A rotatable inner actuating ring fitted inside the inner casing and a rotatable outer actuating ring fitted outside the outer casing together constitute a ring drive assembly. The inner casing and the outer casing are provided with sinusoidal curve deformation trajectory grooves corresponding to the number of flexible blades, and the inner actuating ring and the outer actuating ring are provided with strip-shaped drive grooves corresponding to the number of flexible blades. Each flexible blade includes a leading edge skeleton, a trailing edge skeleton, a flexible skeleton connecting the two, a metal skin covering the skeleton, and a skeleton fixing screw and a deformable actuating rod that are axially arranged through the blade. The frame fixing screw passes through the front edge frame and is fixed at both ends to the inner and outer casings respectively. The deformation actuating rod passes through the rear edge frame and is respectively installed in the sinusoidal deformation trajectory groove of the inner and outer casings and the strip drive groove of the inner and outer actuating rings. The drive assembly synchronously drives the inner and outer actuating rings to rotate through multiple circumferentially distributed servo motors, which in turn drive the deformation actuating rod to deflect along the sinusoidal deformation trajectory groove, thereby achieving stepless continuous adjustment of the blade airfoil camber within the range of ≥±15°.

2. The blade structure with stepless adjustable airfoil camber according to claim 1, characterized in that: The flexible skeleton is made of multiple layers of spring steel sheets stacked together and fixed between the layers by riveting, forming a hinge shape that can be bent in both directions. The two ends of the flexible skeleton are respectively provided with connecting lugs, which are hinged to the front edge skeleton and the rear edge skeleton by pins.

3. The blade structure with stepless adjustable airfoil camber according to claim 1, characterized in that: The metal skin is made of multiple titanium alloy sheets spliced ​​together. The seams of adjacent sheets adopt an overlapping method where the upper layer covers the lower layer, and the overlapping direction is consistent with the airflow direction. Multiple skin sliding buckles are welded to the inner side of each sheet. The skin sliding buckles are T-shaped tenons that can be slidably engaged in the corresponding T-shaped grooves opened on the flexible frame.

4. The blade structure with stepless adjustable airfoil camber according to claim 1, characterized in that: At least three servo motor mounting seats are evenly distributed around the outer wall of the outer casing, and the servo motor is fixed on the servo motor mounting seat; The output shaft of the servo motor is connected to a pinion via a coupling, and the outer ring of the outer actuator ring is provided with an outer gear ring that meshes with the pinion.

5. The blade structure with stepless adjustable airfoil camber according to claim 1, characterized in that: The inner wall of the inner casing is provided with at least three servo motor mounting seats evenly distributed around its circumference, and the servo motor is fixed to the servo motor mounting seat. The output shaft of the servo motor is connected to a pinion via a coupling, and the inner ring of the inner actuator ring is provided with an internal gear ring that meshes with the pinion.

6. The blade structure with stepless adjustable airfoil camber according to claim 1, characterized in that: The outer casing is composed of at least four arc-shaped shell segments joined together.

7. The blade structure with stepless adjustable airfoil camber according to claim 1, characterized in that: A composite material bushing is provided at the connection between the deformable actuator and the trailing edge skeleton.

8. The blade structure with stepless adjustable airfoil camber according to claim 1, characterized in that: The blade structure also includes a pose sensing system, which comprises: A fiber optic strain sensor embedded in the trailing edge frame is used to detect blade camber deformation; An encoder installed at the end of the frame fixing screw is used to detect the blade deflection angle; The signal output terminals of the sensors and encoders are connected to an external controller for communication.

9. A method for controlling a blade structure with stepless adjustable airfoil camber, applied to a blade structure with stepless adjustable airfoil camber as described in any one of claims 1-8, characterized in that, Includes the following actions: Receive command: The controller receives the target curvature angle command; Collaborative drive: The controller calculates the required rotation angle and direction of the inner and outer actuation rings based on the target curvature angle, and synchronously drives multiple circumferentially distributed servo motors to rotate the inner and outer actuation rings. Linked deformation: The rotational motion of the actuating ring is converted into the deflection motion of the deformation actuating rod along the sinusoidal deformation trajectory groove through the strip drive groove on it, so as to realize the continuous bending deformation of the blade airfoil. Closed-loop feedback: The actual curvature value of the blade is monitored in real time through the pose sensing system and fed back to the controller; Dynamic adjustment: The controller compares the actual curvature value with the target curvature value. If there is a deviation, it generates a correction command to adjust the servo motor's action until the actual curvature value matches the target curvature value, thus achieving stepless control.

10. The control method for a blade structure with stepless adjustable airfoil camber according to claim 9, characterized in that: The servo motor is a direct-drive closed-circuit hydraulic servo motor, and the motor speed and direction are adjusted by a servo controller.

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