Helicopter wind tunnel test based electromagnetic follow-up restraint system

Abstract

This application discloses an electromagnetic servo restraint system based on helicopter wind tunnel testing, relating to the field of helicopter wind tunnel testing technology. It includes a platform and multiple servo buffer devices. The platform is positioned above the wind tunnel foundation and has a mounting position for the helicopter under test. The servo buffer devices are arranged in a ring array in a horizontal plane, with their lower ends connected to the foundation and their upper ends tilted towards the center of the mounting position and connected to the platform. Each servo buffer device provides restraint force to the helicopter under test and maintains it in a preset posture through extension and retraction. According to the electromagnetic servo restraint system based on helicopter wind tunnel testing disclosed in this application, the helicopter under test can perform realistic large-amplitude attitude and vertical movements within a safe range, providing richer testing scenarios and pushing wind tunnel testing beyond static and small-amplitude dynamic load measurements to a new level of research on flight dynamics, control law verification, and complex aerodynamic phenomena.

Description

Technical Field

[0001] This application belongs to the field of helicopter wind tunnel testing technology, specifically an electromagnetic servo constraint system based on helicopter wind tunnel testing. Background Technology

[0002] Helicopter wind tunnel testing is a key step in verifying the performance of its flight dynamics model and control system. Its technical challenge stems from the fundamental contradiction between the helicopter's motion characteristics and safety requirements in the wind tunnel. That is, it is necessary to allow or even simulate the dynamic attitude changes of the helicopter in routine tests, while applying precise and compliant constraints when its motion tends to dangerous boundaries.

[0003] In traditional helicopter wind tunnel testing, the helicopter is fixed to a point in the wind tunnel by a rigid support rod, with force sensors installed at the connection between the support rod and the helicopter. However, the inherent static constraint characteristics of traditional rigid support systems, which limit the degrees of freedom of motion, severely restrict the study of the helicopter's dynamic response in real flight environments. With the deepening research into high-risk conditions such as complex helicopter maneuvers, runaway prevention, and recovery, there is an urgent need for a new type of constraint system that can provide a safe, dynamic, and realistic testing environment for helicopters in a wind tunnel. Summary of the Invention

[0004] The purpose of this application is to provide an electromagnetic servo constraint system based on helicopter wind tunnel testing, which enables the helicopter under test to approach a more realistic flight state within a limited range in the wind tunnel, ensuring that the performance test of the helicopter is more realistic and effective.

[0005] To achieve the above objectives, this application provides the following technical solution: This application provides an electromagnetic servo restraint system based on helicopter wind tunnel testing, including a platform and multiple servo buffer devices. The platform is set above the foundation of the wind tunnel and has a work position for placing the helicopter under test. Each follow-up buffer device is arranged in a ring array in the horizontal plane. The lower end is used to connect to the foundation, and the upper end is inclined towards the center of the work station and connected to the platform. Each follow-up buffer device provides a constraint force to the helicopter under test and keeps the helicopter under test in a preset position by extending and retracting.

[0006] As a further embodiment of this application, each follower buffer device is connected to the foundation and platform at both ends via spherical hinges.

[0007] As a further embodiment of this application, the follower buffer device includes a stator mechanism and a mover mechanism, wherein the lower end of the stator mechanism is used to connect to the foundation, and the upper end extends toward one side of the platform. The moving part is mounted on the stator along the extension direction of the stator and its upper end is connected to the platform.

[0008] As a further embodiment of this application, the moving part mechanism includes a permanent magnet and a piston rod, wherein the permanent magnet is movably disposed on the stator mechanism along the extension direction of the stator mechanism; The upper end of the permanent magnet has a piston cavity arranged along the extension direction of the stator mechanism, the lower end of the piston rod has a piston head that matches the piston cavity, the piston head is movably disposed in the piston cavity, and the upper end of the piston rod is connected to the platform.

[0009] As a further embodiment of this application, the actuator mechanism also includes two buffer regions disposed on the permanent magnet, the two buffer regions being located above and below the piston chamber, respectively; When the piston head moves into the buffer zone, it performs buffer braking.

[0010] As a further embodiment of this application, the stator mechanism includes a stator assembly and a magnetic brake assembly, with the magnetic brake assembly located at the bottom of the stator assembly; When the lower end of the permanent magnet moves to the vicinity of the magnetic brake assembly, it is braked by eddy current.

[0011] As a further improvement in this application, both the permanent magnet and the piston rod are equipped with detection elements to detect real-time position and instantaneous speed.

[0012] As a further embodiment of this application, it also includes: a controller electrically connected to each follower buffer device to control the extension and retraction of each follower buffer device.

[0013] As a further aspect of this application, it also includes: a six-component force sensor, which is integrated on the platform and connected to the helicopter under test to measure the aerodynamic forces acting on the helicopter under test.

[0014] As a further embodiment of this application, it also includes: an inertial measurement unit, which is used to measure in real time at least one of the pitch angle, roll angle, yaw angle and three-axis angular rate of the helicopter under test.

[0015] The electromagnetic servo restraint system based on helicopter wind tunnel testing provided in this application has at least the following technical effects: the electromagnetic servo restraint system based on helicopter wind tunnel testing includes a platform and multiple servo buffer devices. The platform is set above the foundation of the wind tunnel and has a work position for placing the helicopter under test. Each servo buffer device is arranged in a ring array in the horizontal plane, with its lower end connected to the foundation and its upper end tilted towards the center of the work position and connected to the platform. Each servo buffer device provides restraint force to the helicopter under test and keeps the helicopter under test in a preset position by extending and retracting.

[0016] Therefore, according to the electromagnetic servo constraint system based on helicopter wind tunnel testing provided in this application, the helicopter under test is provided with constraint force through each servo buffer device, and the helicopter under test is kept in a preset posture by extension and retraction. This allows the helicopter under test to perform real large-amplitude attitude and vertical movement within a safe range, making the test scenarios richer. This pushes wind tunnel testing from static and small-amplitude dynamic load measurement to a new level of flight dynamics, control law verification and complex aerodynamic phenomenon research. Attached Figure Description

[0017] To facilitate understanding by those skilled in the art, the present application will be further described below with reference to the accompanying drawings.

[0018] Figure 1 A schematic diagram of an electromagnetic servo restraint system based on helicopter wind tunnel testing is provided in this application embodiment; Figure 2 for Figure 1 A top-down view of the diagram.

[0019] Figure label: 10. The helicopter to be tested; 100. Follow-up buffer device; 110. Stator mechanism; 111. Stator assembly; 112. Magnetic brake assembly; 120. Mover mechanism; 121. Permanent magnet; 122. Piston rod; 123. Buffer area; 200. Platform. Detailed Implementation

[0020] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0021] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and 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.

[0022] In the description of this application, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0023] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application; that is, the described embodiments are only a part of the embodiments of this application, and not all of them. The components of the embodiments of this application described and shown in the accompanying drawings can typically be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0026] Traditional helicopter wind tunnel testing structures, with their inherent static constraints and limited degrees of freedom, cannot simulate realistic dynamic translational motion, severely hindering research on the dynamic response of helicopters in real flight environments. Furthermore, because the support rods are exposed to airflow, they generate aerodynamic drag and eddies, which directly interfere with and contaminate measurements of the helicopter's aerodynamic characteristics. Additionally, while rigid support rods appear robust, they can withstand enormous alternating stresses under extreme conditions (such as model instability or large-amplitude oscillations), posing a risk of fatigue fracture. If a fracture occurs, the helicopter model will crash directly into the wind tunnel, resulting in low safety and significant risk.

[0027] Please see Figures 1 to 2 As shown, this application provides an electromagnetic servo constraint system based on helicopter wind tunnel testing, including a platform 200 and multiple servo buffer devices 100. The platform 200 is installed above the foundation of the wind tunnel and has a work position for placing the helicopter 10 under test.

[0028] Each follow-up buffer device 100 is arranged in a ring array in the horizontal plane, with its lower end used to connect to the foundation and its upper end tilted towards the center of the work station and connected to the platform 200.

[0029] Each follow-up buffer device 100 provides a constraint force to the helicopter 10 under test and keeps the helicopter 10 under test in a preset position by extending and retracting.

[0030] In this embodiment, the platform 200 (i.e., the follow-up platform) can be a high-rigidity lightweight alloy platform, serving as the connection hub between each follow-up buffer device 100 and the helicopter 10 under test. It has a workstation on which the helicopter 10 under test can be placed and stably fixed on the platform 200 by clamps, fastening mechanisms, etc., in preparation for testing.

[0031] In this embodiment, the follower buffer device 100 is generally elongated and has a telescopic function, such as a linear motor, pneumatic or hydraulic cylinder. The follower buffer devices 100 are arranged in a circular array in the horizontal plane, for example, as shown in... Figure 2 As shown, the three follower buffer devices 100 are arranged in a circular array in the horizontal plane. Each follower buffer device 100 has a fixed tilt angle with the vertical direction. The follower buffer devices 100 are 120° apart in the horizontal plane, which can form a stable triangular support structure.

[0032] The lower end of each follower buffer device 100 can be rotatably connected to the foundation via a spherical hinge, universal joint, etc. The upper end of each follower buffer device 100 is inclined toward the center of the work station and can also be rotatably connected to the platform 200 via a spherical hinge, universal joint, etc. That is, the lower end of the follower buffer device 100 can deflect in any direction in the horizontal plane, and the upper end of the follower buffer device 100 can also deflect in any direction in a plane parallel to the horizontal plane.

[0033] Specifically, such as Figure 1 As shown, turbulence is generated in the wind tunnel and blows towards the helicopter 10 under test. The airflow causes the platform 200 and the helicopter 10 under test to undergo displacement, pitch and roll oscillations together, which can be detected immediately by the corresponding sensors, such as force, torque and speed. Each follow-up buffer device 100 can provide thrust or pull to the platform 200 and the helicopter 10 under test for constraint, and can keep the platform 200 and the helicopter 10 under test in a preset position and attitude by extension and retraction, so that the helicopter 10 under test can exhibit various natural flight attitudes, simulating its real flight state, while providing protection for the helicopter 10 under test.

[0034] In this way, compared with the traditional rigid support rod structure, the application of the electromagnetic servo constraint system based on helicopter wind tunnel testing provided in this application embodiment provides constraint force to the helicopter 10 under test through each servo buffer device 100, and keeps the helicopter 10 under test in a preset posture through extension and retraction. This allows the helicopter 10 under test to perform real large-amplitude attitude and vertical movement within a safe range, and the test scenarios are richer. This pushes wind tunnel testing from static and small-amplitude dynamic load measurement to a new level of flight dynamics, control law verification and complex aerodynamic phenomenon research.

[0035] In some embodiments, each follower buffer device 100 is connected to the foundation and platform 200 at both ends via spherical hinges.

[0036] Specifically, such as Figure 1 As shown, high-precision, high-load-bearing spherical hinges are used at both ends of each follower buffer device 100, connecting it to the foundation and platform 200 respectively. This allows for multi-degree-of-freedom relative rotation between the follower buffer device 100, platform 200, and foundation, preventing the generation of huge parasitic stresses within the system due to minor asynchrony or thermal deformation, and ensuring the stable pitch and roll motion of platform 200. The specific model and specifications of the spherical hinges can be determined according to actual needs; this embodiment does not impose excessive restrictions.

[0037] In some embodiments, the follower buffer device 100 includes a stator mechanism 110 and a mover mechanism 120. The lower end of the stator mechanism 110 is connected to the foundation, and the upper end extends toward the platform 200.

[0038] The moving part 120 is movably disposed on the stator 110 along the extension direction of the stator 110, and its upper end is connected to the platform 200.

[0039] In this embodiment, the stator mechanism 110 is generally elongated and can be formed by stacking multiple electromagnetic coils. It has a mounting cavity inside, which is arranged along the length of the stator mechanism 110. The lower end of the stator mechanism 110 can be connected to the foundation via a ball joint, universal joint, or the like, while the upper end of the stator mechanism 110 extends toward the platform 200.

[0040] In this embodiment, the mover mechanism 120 is also generally elongated, and can be composed of permanent magnets. The mover mechanism 120 can be movably disposed in the mounting cavity of the stator mechanism 110, and can be connected to the stator mechanism 110 via guide rails, guide slots, guide rods, etc. (not shown in the figure). The stator mechanism 110 and the mover mechanism 120 constitute a linear motor. The upper end of the mover mechanism 120 extends out of the mounting cavity and can be connected to the platform 200 via ball joints, universal joints, etc.

[0041] In this way, the control system outputs the corresponding three-phase current to the actuator 110 through the driver to generate a precise thrust to the actuator 120, that is, to apply a reverse control force to provide a constraint force to the helicopter under test 10, and to keep the helicopter under test 10 in a preset position by extension and retraction, allowing the helicopter under test 10 to perform real movements within a safe range, expanding the test range, improving dynamic performance, making it more completely reliable, and extending its service life.

[0042] Furthermore, in this embodiment, the moving part mechanism 120 includes a permanent magnet 121 and a piston rod 122, and the permanent magnet 121 is movably disposed on the stator mechanism 110 along the extending direction of the stator mechanism 110.

[0043] The upper end of the permanent magnet 121 has a piston cavity arranged along the extension direction of the stator mechanism 110, and the lower end of the piston rod 122 has a piston head that matches the piston cavity. The piston head is movably disposed in the piston cavity, and the upper end of the piston rod 122 is connected to the platform 200.

[0044] Specifically, such as Figure 1 As shown, the piston chamber is a closed space, with compressible buffer spaces above and below the piston head. This buffering effectively filters out the influence of airflow on the stator mechanism 110 and other supports transmitted to the helicopter under test 10, reducing support interference and resulting in higher measurement data quality. Furthermore, since the electromagnetic system requires response time to control the stator mechanism 110, the piston structure provides that time.

[0045] Furthermore, in this embodiment, the moving part mechanism 120 also includes two buffer regions 123 disposed on the permanent magnet 121, the two buffer regions 123 being located above and below the piston chamber, respectively.

[0046] When the piston head moves to the buffer zone 123, buffer braking is performed.

[0047] For example, such as Figure 1 As shown, the buffer area 123 can be a buffer oil passage on the permanent magnet 121 corresponding to the upper and lower ends of the piston cavity. In this way, when the piston head moves to the buffer area 123, the buffer oil passage can buffer the piston head until braking, thereby avoiding rigid collision and improving safety. The buffer oil passage can also be replaced by other types of buffer components, such as elastic elements, depending on actual needs. This embodiment does not impose too many restrictions.

[0048] In some embodiments, the stator mechanism 110 includes a stator assembly 111 and a magnetic brake assembly 112, the magnetic brake assembly 112 being located at the bottom of the stator assembly 111.

[0049] When the lower end of the permanent magnet 121 moves to the vicinity of the magnetic brake assembly 112, it is braked by eddy current.

[0050] Specifically, such as Figure 1As shown, multiple stator assemblies 111 are arranged sequentially in a vertical direction, and the magnetic brake assembly 123 can be arranged at the bottom of the lowest stator assembly 111. In this way, when the helicopter under test 10 moves the permanent magnet 121 down to the vicinity of the magnetic brake assembly 112, the magnetic brake assembly 112 can provide a delay-free emergency braking to the piston head through eddy current hysteresis, which greatly reduces the risk of collision and improves safety.

[0051] In this embodiment, the magnetic force of the magnetic brake assembly 123 is positively correlated with the moving speed of the piston head. Therefore, the faster the piston head moves, the greater the hysteresis force exerted by the electromagnetic brake assembly, resulting in a faster response and facilitating zero-delay emergency braking of the piston head. The specific type and specifications of the magnetic brake assembly 123 can be determined according to actual needs; this embodiment does not impose excessive restrictions.

[0052] In some embodiments, both the permanent magnet 121 and the piston rod 122 are provided with detection elements to detect real-time position and instantaneous speed.

[0053] In this way, the position, speed, and other information of the permanent magnet 121 and piston rod 122 can be detected in real time by the detection device, providing a data basis for the electromagnetic system to control the stator mechanism 110. The specific type, quantity, and installation position of the detection device can be determined according to actual needs, and this embodiment does not impose too many restrictions.

[0054] In some embodiments, the electromagnetic servo restraint system based on helicopter wind tunnel testing provided in this application further includes: a controller, which is electrically connected to each servo buffer device 100 to control the extension and retraction of each servo buffer device 100.

[0055] It is electrically connected to the stator mechanism 110 to control the lifting and lowering of the actuator mechanism 120.

[0056] In this way, the controller can control the extension and retraction of each follower buffer device 100, realizing automated control, etc. The specific type of controller can be determined according to actual needs, and this embodiment does not impose too many restrictions.

[0057] It should be noted that when the helicopter under test 10 suddenly loses control, the controller calculates in real time the reverse thrust required by each stator mechanism 110 to brake the helicopter under test 10. The driver of each stator mechanism 110 outputs saturated current and generates maximum reverse thrust to attempt braking. Due to the existence of control delay, the helicopter under test 10 still rushes past the effective control area with its huge inertia. At this moment, each piston head enters the buffer area 123, and a passive resistance is generated instantly without delay, which buys time for the electromagnetic system to respond. At the same time, the reverse thrust of each stator mechanism 110 begins to act, rapidly consuming the kinetic energy of the helicopter under test 10, thus achieving the constraint of the helicopter under test 10 and avoiding rigid impact.

[0058] Furthermore, in this embodiment, the electromagnetic servo constraint system based on helicopter wind tunnel testing provided in this application also includes: a six-component force sensor, which is integrated on the platform 200 and connected to the helicopter 10 under test to measure the aerodynamic forces acting on the helicopter 10 under test.

[0059] Specifically, the six-component force sensor can measure various component forces, torques, and other data on the helicopter 10 under test. The specific type, specifications, quantity, and installation location of the six-component force sensor can be determined according to actual needs, and no excessive restrictions are imposed in this embodiment.

[0060] In some embodiments, the electromagnetic servo constraint system based on helicopter wind tunnel testing provided in this application further includes: an inertial measurement unit, which is used to measure in real time at least one of the pitch angle, roll angle, yaw angle and three-axis angular rate of the helicopter 10 under test.

[0061] Specifically, the inertial measurement unit (IMU) is positioned at the center of gravity of the helicopter under test 10. This allows for more accurate measurement of key data such as pitch angle, roll angle, yaw angle, and three-axis angular rate of the helicopter under test 10. The specific type, specifications, and quantity of the IMU can be determined according to actual needs, and this embodiment does not impose too many restrictions.

[0062] It should be noted that the aforementioned detection components, six-component force sensors, inertial measurement units, etc., are all electrically connected to the controller to form a complete constraint system.

[0063] The above description is merely an example and illustration of the structure of this application. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the structure of the application or exceed the scope defined in the claims, they should all fall within the protection scope of this application.

Claims

1. An electromagnetic servo restraint system based on helicopter wind tunnel testing, characterized in that, It includes a platform (200) and multiple follow-up buffer devices (100), the platform (200) being installed above the foundation of the wind tunnel and having a work position for placing the helicopter (10) to be tested; Each of the following buffer devices (100) is arranged in a ring array in the horizontal plane, with the lower end for connecting to the foundation and the upper end inclined toward the center side of the work station and connected to the platform (200). Each of the following buffer devices (100) provides a constraint force on the helicopter under test (10) and keeps the helicopter under test (10) in a preset position by extending and retracting.

2. The electromagnetic servo restraint system based on helicopter wind tunnel testing according to claim 1, characterized in that, Each of the following buffer devices (100) is connected to the foundation and the platform (200) at both ends via spherical hinges.

3. The electromagnetic servo restraint system based on helicopter wind tunnel testing according to claim 1, characterized in that, The follow-up buffer device (100) includes a stator mechanism (110) and a mover mechanism (120). The lower end of the stator mechanism (110) is used to connect to the foundation, and the upper end extends toward the platform (200). The moving part (120) is movably disposed on the stator (110) along the extension direction of the stator (110), and its upper end is connected to the platform (200).

4. The electromagnetic servo constraint system based on helicopter wind tunnel testing according to claim 3, characterized in that, The moving part (120) includes a permanent magnet (121) and a piston rod (122), wherein the permanent magnet (121) is movably disposed on the stator (110) along the extending direction of the stator (110); The permanent magnet (121) has a piston cavity at its upper end arranged along the extension direction of the stator mechanism (110), and the piston rod (122) has a piston head at its lower end that matches the piston cavity. The piston head is movably disposed within the piston cavity, and the upper end of the piston rod (122) is connected to the platform (200).

5. The electromagnetic servo constraint system based on helicopter wind tunnel testing according to claim 4, characterized in that, The actuator mechanism (120) further includes two buffer regions (123) disposed on the permanent magnet (121), the two buffer regions (123) being located above and below the piston chamber, respectively; When the piston head moves to the buffer area (123), buffer braking is performed.

6. The electromagnetic servo constraint system based on helicopter wind tunnel testing according to claim 4, characterized in that, The stator mechanism (110) includes a stator assembly (111) and a magnetic brake assembly (112), the magnetic brake assembly (112) being located at the bottom of the stator assembly (111); When the lower end of the permanent magnet (121) moves to the vicinity of the magnetic brake assembly (112), it is braked by eddy current.

7. The electromagnetic servo constraint system based on helicopter wind tunnel testing according to claim 4, characterized in that, Both the permanent magnet (121) and the piston rod (122) are equipped with detection elements to detect real-time position and instantaneous speed.

8. The electromagnetic servo restraint system based on helicopter wind tunnel testing according to any one of claims 1 to 7, characterized in that, Also includes: A controller, which is electrically connected to each of the said follower buffers (100), controls the extension and retraction of each of the said follower buffers (100).

9. The electromagnetic servo restraint system based on helicopter wind tunnel testing according to claim 8, characterized in that, Also includes: A six-component force sensor, integrated on the platform (200) and connected to the helicopter under test (10), is used to measure the aerodynamic forces acting on the helicopter under test (10).

10. The electromagnetic servo restraint system based on helicopter wind tunnel testing according to claim 8, characterized in that, Also includes: An inertial measurement unit is used to measure in real time at least one of the pitch angle, roll angle, yaw angle and three-axis angular rate of the helicopter under test (10).

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