Water forced landing test system and test method

Abstract

The invention relates to a water forced landing test system and a test method. The test system comprises an ejection device for ejecting an aircraft scaling model, a water pool for the scaling model to perform a dampening test, and a first data acquisition module for acquiring motion characteristic information of the scaling model in a dampening process, the second data acquisition module is used for acquiring the stress characteristic information of the scaling model in the dampening process; the data processing module is used for analyzing the change relation between the motion characteristic information and the stress characteristic information; the ejection device comprises an ejection sliding rail, an ejection trolley in sliding fit with the ejection sliding rail, a locking and releasing mechanism and an ejection action mechanism. The ejection action mechanism comprises a driving assembly and an intercepting assembly, wherein the driving assembly applies different ejection forces to the ejection trolley at different speeds, and the intercepting assembly is used for intercepting the ejection trolley so that the scale model can be ejected and separated. According to the invention, the relation among the motion characteristic, the fluid dynamic characteristic and the strength characteristic of the aircraft in the landing process can be tested and analyzed.

Description

Technical Field

[0001] The invention relates to the field of forced landing of aircraft on water, and in particular to a forced landing test system and a test method. Background Art

[0002] Advanced air traffic that uses unmanned low-altitude aircraft to transport people and goods is seen as an emerging strategic track around the world. In areas with developed water systems, unmanned low-altitude wading aircraft will usher in huge development opportunities. In addition, as global cross-sea flights become more and more frequent, water landing performance, as one of the aircraft safety performance indicators, has gradually been valued by governments of various countries. Therefore, it is very necessary to conduct water landing airworthiness compliance tests on aircraft.

[0003] Issues that need to be focused on in the study of forced landings include whether the aircraft's posture is optimal at the moment of entry into the water, whether the integrity of the aircraft can be guaranteed at the moment of impact and after it stops gliding on the water, and whether the aircraft has enough floating time to wait for rescue after stopping on the water.

[0004] There are clear regulations on forced landing in water in my country's civil aviation standards, but there is a lack of specific research results close to reality, such as water entry posture, optimal control and structural damage. The cost of using real aircraft and actual test flights is too high, and safety is difficult to guarantee; the current domestic CFD calculations and water tank drag test distance simulations are also far from the actual situation.

[0005] Therefore, the industry is in urgent need of developing a test system that can test and analyze the relationship between the motion characteristics, fluid dynamic characteristics and strength characteristics of the aircraft during the water landing process, and provide a safe flight test verification environment for some water-related aircraft, so as to carry out water-related performance verification, extreme conditions testing, and fault simulation testing, and improve the safety and reliability of aircraft design. Summary of the invention

[0006] The present invention solves the problem that the industry currently urgently needs to develop a test system that can test and analyze the relationship between the motion characteristics, fluid dynamics characteristics and strength characteristics of the aircraft during the water landing process, and provide a safe test flight verification environment for some water-related aircraft. A water ditching test system and a test method are provided to solve the technical problem. The system can test and analyze the relationship between the motion characteristics, fluid dynamics characteristics and strength characteristics of the aircraft during the water landing process, and provide a safe test flight verification environment for some water-related aircraft, so as to carry out water-related performance verification, extreme condition tests, and fault simulation tests, thereby improving the safety and reliability of aircraft design.

[0007] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0008] A water landing test system, comprising a launching device for launching a scaled model of an aircraft, a water pool for the scaled model to perform a water landing test, a first data acquisition module for collecting motion characteristic information of the scaled model during the water landing process, a second data acquisition module for collecting force characteristic information of the scaled model during the water landing process, and a data processing module for analyzing the change relationship between the motion characteristic information and the force characteristic information, wherein the motion characteristic information includes the water entry attitude angle and the water entry speed of the scaled model;

[0009] The ejection device comprises a mounting seat with a horizontal reference surface, an ejection slide rail movably connected below the mounting seat and with one end facing the pool, an ejection trolley for carrying a scaled model slidably matched with the ejection slide rail, a locking release mechanism for locking the ejection trolley before the ejection operation and unlocking the ejection trolley at the beginning of the ejection operation, and an ejection action mechanism for driving the ejection trolley to perform the ejection operation, wherein the ejection action mechanism comprises a driving component for applying different ejection forces to the ejection trolley to give different speeds and an interception component for stopping the ejection trolley to eject the scaled model away, wherein:

[0010] The ejection slide rail comprises two hinge points directly or indirectly hinged to the mounting seat, the hinge axis of each hinge point is a horizontal line perpendicular to the sliding track of the ejection trolley, and at least one hinge point is hinged to the mounting seat through a telescopic module with controlled telescopicity;

[0011] The ejection trolley includes a body that slides with the ejection slide rail and a bracket for supporting the scaled model. The bracket is rotatably connected to the body, and the rotation axis between the bracket and the body is parallel to the sliding trajectory of the body. The bracket and the body are configured such that when the bracket supporting the scaled model is not subjected to external force, the bracket and the body remain relatively still.

[0012] Preferably, the first data acquisition module includes an underwater robot for photographing the image of the scaled model landing in water from underwater and / or a camera unit for photographing the image of the scaled model landing in water from outside the pool, and an analysis and processing unit for identifying the motion characteristic information of the scaled model according to the image of the landing process;

[0013] When the camera unit is used to capture the image of the scaled model landing in water, the camera unit is arranged on one side of the scaled model landing track or on both sides of the scaled model landing track, and the lens of the camera unit is flush with the water surface in the pool, the pool wall and the water surface in the pool are both above the ground, and the pool wall is configured as follows:

[0014] The pool wall of the pool is a transparent wall plate, or

[0015] The pool wall of the water pool is provided with a through hole for a camera to shoot an image of the scaled-down model entering the water, and the through hole is installed with a transparent window.

[0016] Preferably, the camera unit includes at least two lenses for capturing images of the scaled model's water landing process in a binocular or multi-eye shooting manner. When binocular shooting is performed, the two lenses perform binocular shooting at an angle of 90°.

[0017] Preferably, the first data acquisition module also includes a light source for providing supplementary light to the water-impacting position of the scaled model.

[0018] Preferably, the first data acquisition module includes a gyroscope and an acceleration sensor built into the scaled model.

[0019] Preferably, the surface of the scaled model in contact with the water surface during landing is defined as a force-bearing surface, and the second data acquisition module includes a thin film sensor attached to the force-bearing surface to monitor pressure distribution information of the force-bearing surface.

[0020] Preferably, the force-bearing surface of the scaled model includes the regional surface corresponding to the belly of the aircraft to be tested, the lower surface of the wing and the position of the engine nacelle.

[0021] Preferably, the two ends of the ejection rail are defined as a near-water end and a far-water end, respectively, and the locking and releasing mechanism is arranged at the far-water end of the ejection rail;

[0022] The driving component of the ejection action mechanism includes an elastic rope for pulling the ejection vehicle to slide from the far water end to the near water end of the ejection slide rail, a servo winch for winding up the elastic rope, and a winding mechanism for driving the servo winch to rotate, and the servo winch rotates in coordination with the ejection slide rail; the intercepting component of the ejection action mechanism includes an arresting rope connected to the ejection slide rail, and the arresting rope is located on the sliding trajectory of the ejection vehicle along the ejection slide rail.

[0023] Preferably, two first support blocks for supporting the two wings of the scaled model respectively and a second support block for supporting the tail are provided above the bracket, each of the support blocks is connected to a supporting rod parallel to the pitch axis of the scaled model, and a connecting block is provided below the scaled model, with the forward direction of the scaled model during ejection as the front side and the other side as the rear side, and a supporting groove adapted to the supporting rod is provided on the rear side of the connecting block.

[0024] Preferably, the connecting block is detachably connected to the scaled model.

[0025] Preferably, the support block is also provided with a spring pin assembly for preventing the scaled model from sliding off the support block, the spring pin assembly comprising a pin structure which abuts against the scaled model to prevent the scaled model from sliding off the ejection trolley, and a spring which pushes the pin structure to maintain abutment with the scaled model, one end of the pin structure is an inclined surface, and the pin structure abuts against the scaled model through the inclined surface.

[0026] Preferably, when the bracket supports the scaled model, the rotation axis between the bracket and the vehicle body coincides with the roll axis of the scaled model.

[0027] Preferably, the water pool further comprises a wave-making mechanism for simulating the generation of waves.

[0028] A water landing test method based on the water landing test system comprises the following steps:

[0029] S1. Using the telescopic module to adjust the inclination angle of the ejection rail and the horizontal reference plane of the mounting seat, and adjusting the ejection force through the drive assembly to adjust the attitude angle and / or ejection speed of the scaled model carried on the ejection vehicle;

[0030] S2. Release the lock release mechanism from the ejection trolley, so that the ejection trolley slides along the ejection rail until the ejection trolley is stopped by the interception assembly, and the scaled model flies into the pool from the ejection trolley;

[0031] S3. The two data acquisition modules respectively collect the motion characteristic information and the force characteristic information of the scaled model during the water landing process, and record them as the measured data of the scaled model;

[0032] S4. Repeat steps S1 to S3 until a predetermined amount of test data is obtained. After the predetermined amount of test data is obtained, the relationship between the motion characteristic information and the force characteristic information of the scaled model during the water landing is sorted out and analyzed.

[0033] Preferably, the method further comprises the following steps:

[0034] S5. Perform fluid-solid coupling dynamics simulation on the water landing process of the scaled model based on XFlow software;

[0035] S6. The measured data of the scaled model and the simulation results of the XFlow software are mutually verified and integrated;

[0036] S7. Repeat steps S1 to S3, iteratively modify the XFlow software simulation model and parameters based on the measured data of the scaled model collected again, until the XFlow software simulation model reaches the expected accuracy range, and then output the simulation model.

[0037] Beneficial technical effects of the technical solution of the present invention:

[0038] (i) The ejection device is used to eject the scaled model into the water, and the first data acquisition module and the second data acquisition module collect the motion characteristic information and force characteristic information of the scaled model during the water landing process. The ejection action mechanism of the ejection device can drive the ejection trolley to slide along the length direction of the slide rail at different speeds, and then the interception component will intercept the ejection trolley, and the scaled model will be ejected into the water alone due to its own inertia.

[0039] The ejection rail of the ejection device is hinged to the mounting seat through two hinge points, one of which is hinged to the mounting seat through a controlled telescopic module. By controlling the telescopic module to extend and retract, the inclination of the ejection rail can be changed, thereby changing the pitch angle of the scaled model. The ejection trolley includes a rotatably connected body and a bracket, and the rotation axis between the bracket and the body is parallel to the sliding trajectory of the body. By rotating the bracket, the roll angle of the scaled model can be changed. By changing the sliding speed of the ejection trolley and the pitch angle and roll angle of the scaled model, various water entry speeds and water entry postures of the aircraft landing can be simulated, and then the relationship between the motion characteristic information and the force characteristic information of the scaled model during the water landing process can be fully analyzed and understood, so that the aircraft flight test verification, wading performance verification, extreme condition test, and fault simulation test can be smoothly carried out, providing guidance for the aircraft structure design and improving the safety and reliability of the aircraft design.

[0040] (ii) The glass pool wall higher than the ground is configured to facilitate observers and camera equipment to observe (shoot) the motion state of the scaled model when it lands on the water from the side, and thus accurately monitor the longitudinal motion characteristics of the aircraft such as the pitch angle and glide angle.

[0041] (III) The measurement scheme using a camera unit combined with the built-in sensor of the scaled model. The camera unit is a non-contact measurement device. Compared with the measurement scheme using only the onboard gyroscope and accelerometer, it has the advantages of high measurement accuracy, convenient measurement data transmission, and the ability to record the motion video information of the scaled model. In addition, the scheme combining the camera unit with the built-in sensor of the scaled model can support the fusion analysis of measurement data in the later stage, further improving the measurement accuracy and system reliability.

[0042] (iv) The thin film sensor is installed on the stress-bearing surface of the scaled model, which includes specific surfaces such as the belly, lower part of the wing and lower part of the engine nacelle of the scaled model. These positions are mainly selected based on the main stress-bearing parts and vulnerable parts of the scaled model during the water entry process. This can comprehensively analyze the stress and damage conditions of the scaled model during the water entry process.

[0043] (V) XFlow can calculate the dynamic pressure distribution of water on each part of the scaled model. By simulating the moment when the scaled model contacts the water surface, the impact force of water on the scaled model fuselage can be analyzed to evaluate the integrity and potential damage of the structure, which has guiding significance for the study of structural strength characteristics. Based on the indoor measured scaled model aircraft water entry data and the results of simulation by software such as XFlow, the mutual verification and fusion of test and simulation data are carried out, and the simulation model and related parameters are iteratively modified, which can improve the accuracy and reliability of the simulation model and facilitate the subsequent use of the simulation model to provide guidance for the structural design of related models. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A schematic structural diagram of a water landing test system according to an embodiment of the present invention is shown;

[0045] Figure 2 A schematic diagram of the structure of the ejection device in an embodiment of the present invention is shown;

[0046] Figure 3 A schematic diagram showing the coordination between the ejection vehicle and the scaled model in an embodiment of the present invention is shown;

[0047] Figure 4 Shows Figure 3 The enlarged view of point A in the middle;

[0048] Figure 5 A cross-sectional view of the ejection vehicle and the scaled model in an embodiment of the present invention is shown.

[0049] Markings in the accompanying drawings:

[0050] 1-mounting seat; 11-telescopic module; 2-ejection slide rail; 2a-far water end; 2b-near water end; 21-servo winch; 22-elastic rope; 23-barrier rope; 24-locking release mechanism; 3-ejection trolley; 31-carriage; 32-bracket; 321-support block; 322-support rod; 323-spring pin assembly; 4-scaled model; 41-connecting block; 411-supporting groove; 5-pool; 51-pool wall; 511-window; 52-camera unit; 53-light source. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical scheme and advantages of the present invention clearer, the following is a further detailed description of a water ditching test system and test method proposed by the present invention in combination with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structure, proportion, size, etc. illustrated in the accompanying drawings of this specification are only used to match the content disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no technical substantive significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effect that the present invention can produce and the purpose that can be achieved, should still fall within the scope of the technical content disclosed by the present invention.

[0052] The following will be combined with the attached Figures 1 to 5 The technical scheme of a water ditching test system and test method of the present invention is described in detail with specific embodiments.

[0053] Example

[0054] like Figures 1 to 5 As shown, a water landing test system of the present embodiment includes a launching device for launching a scaled model 4 of an aircraft, a water pool 5 for the scaled model 4 to perform a water landing test, a first data acquisition module for collecting motion characteristic information of the scaled model 4 during the water landing, a second data acquisition module for collecting force characteristic information of the scaled model 4 during the water landing, and a data processing module for analyzing the changing relationship between the motion characteristic information and the force characteristic information. The above-mentioned motion characteristic information includes the water entry attitude angle and the water entry speed of the scaled model 4. By simulating various water entry attitudes and water entry speeds of the aircraft landing, the relationship between the motion characteristic information and the force characteristic information of the scaled model 4 during the water landing can be fully analyzed and understood.

[0055] Specifically, the ejection device includes a mounting seat 1 having a horizontal reference surface, an ejection rail 2 movably connected to the mounting seat 1, an ejection trolley 3 for carrying a scaled model 4 that is slidably matched with the ejection rail 2, a locking release mechanism 24 for locking the ejection trolley 3 before the ejection operation and unlocking the ejection trolley 3 when the ejection operation begins, and an ejection action mechanism for driving the ejection trolley 3 to perform the ejection operation. The mounting seat 1 in this embodiment is fastened to the ceiling of the test site, and the bottom surface of the mounting seat 1 is a horizontal surface. The ejection rail 2 is movably connected to the mounting seat 1, and the ejection rail 2 can be directly controlled to swing relative to the mounting seat 1, thereby adjusting the entry attitude angle of the scaled model 4. The ejection action mechanism includes a driving component that can drive the ejection trolley 3 to slide along the length direction of the ejection rail 2 at different speeds and an interception component for stopping the ejection trolley 3 to eject the scaled model 4.

[0056] The connection relationship between the ejection slide rail 2 and the mounting seat 1 is described in detail as follows:

[0057] When testing the scaled model 4 for ejection into water, the ejection trolley 3 slides along the ejection rail 2 toward the water surface, and the scaled model 4 needs to be ejected obliquely toward the water surface. Therefore, one end of the ejection rail 2 is located lower and closer to the water surface, while the other end is located higher and farther away from the water surface. First, the end of the ejection rail 2 close to the water surface is defined as the near-water end 2b, and the end of the ejection rail 2 away from the water surface is defined as the far-water end 2a. The ejection rail 2 is provided with two hinge points that are directly or indirectly hinged to the mounting seat 1. The two hinge points are arranged along the length direction of the ejection rail 2, and the hinge axis of each hinge point is a horizontal line perpendicular to the sliding trajectory of the ejection trolley 3. In this embodiment, the two hinged points of the ejection slide 2 are connected to the mounting seat 1 by a telescopic module 11, and the two ends of the telescopic module 11 are connected to the ejection slide 2 and the mounting seat 1 in a hinged form. When the two telescopic modules 11 are not synchronously extended and retracted, the ejection slide 2 can be tilted, and the telescopic module 11 and the mounting seat 1 are hinged by adjusting at least one of the hinged points through controlled telescopic. The telescopic module 11 in this embodiment is a pneumatic cylinder, the cylinder body of the pneumatic cylinder is connected to the mounting seat 1, and the piston rod of the pneumatic cylinder is connected to the ejection slide 2. The inclination angle of the ejection slide 2 can be changed by controlling the extension and retraction of the pneumatic cylinder. It should be noted that in this embodiment, a fixed rod is also connected between the pneumatic cylinder near the water end 2b of the ejection slide 2 and the mounting seat 1, and the two ends of the fixed rod are respectively fixedly connected to the mounting seat 1 and the cylinder body of the pneumatic cylinder, thereby locking the position of the pneumatic cylinder, so that it cannot swing and can only be extended and retracted, but the two pneumatic cylinders in this embodiment can also drive the ejection slide 2 to swing.

[0058] It should be understood that in other embodiments, one hinge point of the ejection rail 2 can also be directly connected to the mounting base 1, and the other hinge point can be connected to the mounting base 1 through the telescopic module 11. Controlling the telescopic module 11 to extend and retract can also drive the ejection rail 2 to swing, thereby changing the pitch angle of the scaled model 4 and adjusting the water entry attitude angle of the scaled model 4.

[0059] The structure of the ejection car 3 is specifically described as follows:

[0060] The ejection vehicle 3 includes a body 31 that is slidably matched with the ejection rail 2 and a bracket 32 ​​for supporting the scaled model 4. The body 31 is installed below the ejection rail 2. The bracket 32 ​​is rotatably connected to the body 31, and the rotation axis between the bracket 32 ​​and the body 31 is parallel to the sliding track of the body 31. The bracket 32 ​​and the body 31 are tightly fitted against each other. When the bracket 32 ​​supporting the scaled model 4 is not subjected to external force, the friction between the bracket 32 ​​and the body 31 can keep the two relatively still, that is, the bracket 32 ​​can only rotate when the tester adjusts it. After the tester completes the angle adjustment of the bracket 32, the bracket 32 ​​supporting the scaled model 4 can no longer deviate relative to the body 31. When the bracket 32 ​​and the body 31 are controlled to rotate relative to each other, the rolling angle of the scaled model 4 can be changed, thereby adjusting the entry attitude angle of the scaled model 4.

[0061] In addition, the ejection action mechanism can also be used to change the speed at which the scaled model 4 is ejected. Based on the test equipment, the sliding speed of the ejection trolley 3, the pitch angle and the roll angle of the scaled model 4 can be changed, thereby simulating various entry postures and entry speeds of the aircraft into the water, and comprehensively analyzing and understanding the relationship between the motion characteristic information and the force characteristic information of the scaled model 4 during the landing process. The aircraft flight test verification, wading performance verification, extreme condition test, and fault simulation test can be smoothly carried out, providing guidance for the aircraft structure design and improving the safety and reliability of the aircraft design.

[0062] The locking and releasing mechanism 24 is installed at the far end 2a of the ejection slide 2, and the locking and releasing mechanism 24 switches between the state of locking the ejection trolley 3 and the state of releasing the ejection trolley 3. Before starting the ejection operation, the locking and releasing mechanism 24 is used to lock the body 31 of the ejection trolley 3 at the far end 2a of the ejection slide 2. After the ejection action mechanism is ready for ejection, the locking and releasing mechanism 24 is controlled to release the body 31 of the ejection trolley 3, and then the ejection can be started. The locking and releasing mechanism 24 can use a controlled clamp to control the clamp to clamp or release the body 31 of the ejection trolley 3, or can use an electromagnet, a vacuum suction cup or other structure to absorb the body 31 of the ejection trolley 3, lock the position of the ejection trolley 3, and release the ejection trolley 3 after releasing the adsorption of the ejection trolley 3.

[0063] In this embodiment, the driving assembly of the ejection action mechanism includes a servo winch 21 installed and rotatably connected to the ejection slide rail 2, a winding mechanism that drives the servo winch 21 to rotate, and an elastic rope 22 wound on the servo winch 21. One end of the elastic rope 22 is fixedly connected to the servo winch 21, and the other end is connected to the body 31 of the ejection vehicle 3. The servo winch 21 rotates under the control of the winding mechanism. The tension of the elastic rope 22 can be changed by winding the elastic rope 22. When the locking release mechanism 24 releases the ejection vehicle 3, the elastic ropes 22 with different tensions pull the ejection vehicle 3 to slide, so that the ejection vehicle 3 can reach different sliding speeds. In addition, it should be understood that the driving component of the ejection action mechanism needs to pull the ejection trolley 3 to slide from the far water end 2a of the ejection slide rail 2 to the near water end 2b. The driving component in this embodiment is installed at the far water end 2a of the ejection slide rail 2, and the near water end 2b of the ejection slide rail 2 is rotatably connected to a pulley. The elastic rope 22 of the driving component first passes around the pulley at the near water end 2b of the ejection slide rail 2, and then connects to the ejection trolley 3. When the ejection trolley 3 is released, the taut elastic rope 22 will inevitably slide from the far water end 2a of the ejection slide rail 2 to the near water end 2b. The intercepting assembly of the ejection action mechanism includes an arresting rope 23 on the sliding track of the vehicle body 31. Both ends of the arresting rope 23 are connected to the ejection slide rail 2. The arresting rope 23 is suspended below the ejection slide rail 2. When the ejection trolley 3 slides past the arresting rope 23, the ejection trolley 3 is blocked by the arresting rope 23 and cannot continue to slide. The scaled model 4 installed on the ejection trolley 3 will be ejected due to inertia and fly into the pool 5 to complete the ejection operation.

[0064] Specifically, three support blocks 321 are installed above the bracket 32 ​​of the ejection vehicle 3, including two first support blocks and one second support block. The two first support blocks are respectively used to support the two wings of the scaled model 4, and the second support block is used to support the tail. A through slot is opened on the top of each support block 321 and runs through the direction of the roll axis of the scaled model 4. A supporting rod 322 parallel to the pitch axis of the scaled model 4 is connected to each through slot. The scaled model 4 is also connected to three connecting blocks 41 corresponding to each supporting block 321, and the connecting blocks 41 are detachably connected to the scaled model 4. Each connecting block 41 is provided with a supporting groove 411 engaged with the supporting rod 322 on the side facing the far water end 2a of the ejection slide rail 2. The supporting groove 411 passes through the connecting block 41 along the direction of the pitch axis of the scaled model 4. When the scaled model 4 is installed on the bracket 32, each connecting block 41 is embedded in the corresponding supporting block 321 through groove, and the supporting rod 322 connected to the supporting block 321 passes through the supporting groove 411 of the corresponding connecting block 41. In the process of the ejection trolley 3 driving the scaled model 4 to slide toward the water surface, the supporting rod 322 of each supporting block 321 abuts against the groove wall of the supporting groove 411 of the corresponding connecting block 41, ensuring that the pitch angle of the scaled model 4 remains stable.

[0065] In addition, when the scaled model 4 is installed on the ejection trolley 3, since the water-proximal end 2b of the ejection rail 2 is generally lower, the scaled model 4 tends to slide downward and detach from the ejection trolley 3. In order to prevent the scaled model 4 from detaching from the ejection trolley 3 before the ejection operation begins, a spring pin assembly 323 is also installed on the support block 321 to prevent the scaled model 4 from sliding off the support block 321. The spring pin assembly 323 includes a pin structure that abuts against the connecting block 41 of the scaled model 4 to prevent the scaled model 4 from sliding off the ejection trolley 3 and a spring that pushes the pin structure to slide toward the connecting block 41 of the scaled model 4. After the scaled model 4 is installed on the ejection trolley 3, one end of the pin structure faces the connecting block 41, and the end face of the pin structure facing the connecting block 41 is an inclined surface. The spring pushes the pin structure to slide toward the connecting block 41 of the scaled model 4, so that the pin structure is against the connecting block 41 of the scaled model 4 through the above-mentioned inclined surface. Before the ejection operation begins, it is necessary to ensure that the force exerted by the pin structure on the scaled model 4 is sufficient to prevent the scaled model 4 from sliding downward; when the ejection trolley 3 is stopped by the interception assembly, the scaled model 4 will continue to move toward the pool 5 due to inertia, and at the same time, the connecting block 41 of the scaled model 4 pushes the pin structure of the spring pin assembly 323 to retract, and the spring pin assembly 323 removes the obstruction to the scaled model 4, and the scaled model 4 can be ejected into the water.

[0066] Furthermore, when the bracket 32 ​​supports the scaled model 4, the rotation axis between the bracket 32 ​​and the vehicle body 31 coincides with the roll axis of the scaled model 4, so that the rotation angle of the bracket 32 ​​corresponds to the roll angle of the scaled model 4. Therefore, by controlling the bracket 32 ​​to rotate by a specified angle, the roll angle of the scaled model 4 can be accurately adjusted.

[0067] Specifically, when collecting the motion characteristic information of the scaled model 4 during the landing process, since the entry attitude angle and the entry speed of the scaled model 4 during the actual ejection and landing cannot be accurately known, the first data acquisition module includes a camera unit 52 for shooting the image of the scaled model 4 during the landing process from the outside of the pool 5 and an analysis and processing unit for identifying the motion characteristic information of the scaled model 4 according to the image of the landing process. The camera unit 52 is used to shoot the picture of the scaled model 4 during the landing process, and then the analysis and processing unit uses video analysis technology and image analysis technology to obtain the motion characteristic information such as the entry attitude angle and the entry speed of the scaled model 4. The obtained motion characteristic information has high accuracy, which is conducive to accurately analyzing the relationship between the motion characteristic information and the force characteristic information during the landing process of the scaled model 4. Specifically, the camera unit 52 can be set on one side of the landing trajectory of the scaled model 4 or on both sides of the landing trajectory of the scaled model 4, and the lens of the camera unit 52 is flush with the water surface in the pool 5, so that the picture of the scaled model 4 during the landing process can be shot from a horizontal perspective, which is conducive to accurately knowing the entry attitude angle.

[0068] Since the camera unit 52 needs to capture images from the outside of the pool 5, the pool wall 51 of the pool 5 and the water surface in the pool 5 are configured to be higher than the ground, so that people can reach the outside of the pool 5 and the camera unit 52 can be installed. The pool wall 51 of the pool 5 in this embodiment is a concrete structure, and the pool wall 51 is also provided with a through hole for the lens to capture the image of the scaled model 4 during the water process. The through hole is installed with a transparent window 511, which is convenient for the camera unit 52 to collect images. It can be understood that the pool wall 51 of the pool 5 can also be configured as a transparent glass wall panel, which has better light transmittance and is convenient for shooting, but it is more appropriate to arrange a transparent observation window on the concrete side wall, which is not easy to break.

[0069] The camera unit 52 is a high-speed camera, including at least two lenses for capturing images of the scaled model 4 during the water landing process in the form of binocular or multi-eye photography. When binocular photography is performed, the two lenses perform binocular photography at an angle of 90°.

[0070] In order to ensure that the camera unit 52 can capture clear images, the first data acquisition module also includes a light source 53 for supplementing light to the water-impacting position of the scaled model 4 . The light source 53 in this embodiment is fixedly mounted on the bottom surface of the mounting base 1 .

[0071] In addition, the first data acquisition module may also use an underwater robot that takes underwater images of the scaled model 4 during its entry into the water. The underwater robot may be used alone or in conjunction with the camera unit 52 to take images from different angles.

[0072] In addition, the camera unit 52 is a non-contact measurement device, and the first data acquisition module also includes a gyroscope and an accelerometer built into the scaled model 4. The gyroscope is used to measure the attitude angle of the scaled model 4, while the accelerometer can measure the acceleration and speed of the scaled model 4. The measurement scheme using the camera unit 52 combined with the built-in sensors of the scaled model 4 has the characteristics of high measurement accuracy, while the camera unit 52 has the advantages of convenient measurement data transmission and can record the motion video information of the scaled model 4. The scheme combining the camera unit 52 with the built-in sensors of the scaled model 4 can support measurement data fusion analysis in the later stage, further improving the measurement accuracy and system reliability.

[0073] In this embodiment, the surface of the scaled model 4 that contacts the water surface during the landing process is defined as the force-bearing surface, and the second data acquisition module includes a thin film sensor (not shown in the figure) attached to the force-bearing surface. When the scaled model 4 lands on the water, the thin film sensor can conveniently monitor the pressure distribution information of the force-bearing surface. In the scaled model 4, the force-bearing surface includes the surface of the area corresponding to the belly of the aircraft to be tested, the lower surface of the wing, and the position of the engine nacelle.

[0074] In addition, the water pool 5 also includes a wave-making mechanism for simulating the generation of waves, which can generate waves of a specified type in the water pool 5, thereby simulating the landing process test under different sea conditions.

[0075] A water landing test method based on the water landing test system comprises the following steps:

[0076] S1. Use the telescopic module to adjust the inclination angle of the ejection rail 2 and the horizontal reference plane of the mounting base 1, and adjust the ejection force by the drive assembly to adjust the attitude angle and / or ejection speed of the scaled model 4 carried on the ejection vehicle 3;

[0077] S2. The locking release mechanism 24 releases the lock of the ejection trolley 3, so that the ejection trolley 3 slides along the ejection rail 2 until the ejection trolley 3 is stopped by the interception assembly, and the scaled model 4 flies into the pool 5 from the ejection trolley 3;

[0078] S3. The two data acquisition modules respectively collect the motion characteristic information and force characteristic information of the scaled model 4 during the water landing process, and record them as the measured data of the scaled model 4;

[0079] S4. Repeat steps S1 to S3 until a predetermined amount of test data is obtained. After the predetermined amount of test data is obtained, the relationship between the motion characteristic information and the force characteristic information of the scaled model 4 during the water landing is sorted and analyzed;

[0080] S5. Perform fluid-solid coupling dynamics simulation on the water impaction process of scaled model 4 based on XFlow software;

[0081] S6. The measured data of the scaled model 4 is mutually verified and integrated with the simulation results of the XFlow software;

[0082] S7. Repeat steps S1 to S3, and iteratively modify the XFlow software simulation model and parameters based on the measured data of the scaled model 4 collected again, until the XFlow software simulation model reaches the expected accuracy range, and then output the simulation model.

[0083] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A water landing test system, characterized in that: It includes a launching device for launching a scaled model of an aircraft, a water pool for the scaled model to perform a water landing test, a first data acquisition module for collecting motion characteristic information of the scaled model during the water landing, a second data acquisition module for collecting force characteristic information of the scaled model during the water landing, and a data processing module for analyzing the change relationship between the motion characteristic information and the force characteristic information, wherein the motion characteristic information includes the water entry attitude angle and water entry speed of the scaled model; The ejection device comprises a mounting seat with a horizontal reference surface, an ejection slide rail movably connected below the mounting seat and with one end facing the pool, an ejection trolley for carrying a scaled model slidably matched with the ejection slide rail, a locking release mechanism for locking the ejection trolley before the ejection operation and unlocking the ejection trolley at the beginning of the ejection operation, and an ejection action mechanism for driving the ejection trolley to perform the ejection operation, wherein the ejection action mechanism comprises a driving component for applying different ejection forces to the ejection trolley to give different speeds and an interception component for stopping the ejection trolley to eject the scaled model away, wherein: The ejection slide rail comprises two hinge points directly or indirectly hinged to the mounting seat, the hinge axis of each hinge point is a horizontal line perpendicular to the sliding track of the ejection trolley, and at least one hinge point is hinged to the mounting seat through a telescopic module with controlled telescopicity; The ejection trolley includes a body that slides with the ejection slide rail and a bracket for supporting the scaled model. The bracket is rotatably connected to the body, and the rotation axis between the bracket and the body is parallel to the sliding trajectory of the body. The bracket and the body are configured such that when the bracket supporting the scaled model is not subjected to external force, the bracket and the body remain relatively still.

2. A ditching test system according to claim 1, characterized in that: The first data acquisition module includes an underwater robot for photographing the image of the scaled model landing in water from underwater and / or a camera unit for photographing the image of the scaled model landing in water from outside the pool, and an analysis and processing unit for identifying the motion characteristic information of the scaled model according to the image of the landing process; When the camera unit is used to capture the image of the scaled model landing in water, the camera unit is arranged on one side of the scaled model landing track or on both sides of the scaled model landing track, and the lens of the camera unit is flush with the water surface in the pool, the pool wall and the water surface in the pool are both above the ground, and the pool wall is configured as follows: The pool wall of the pool is a transparent wall plate, or The pool wall of the water pool is provided with a through hole for a camera to shoot an image of the scaled-down model entering the water, and the through hole is installed with a transparent window.

3. A ditching test system as claimed in claim 2, characterized in that: The camera unit includes at least two lenses for capturing images of the scaled model's water landing process in a binocular or multi-lens shooting manner. When binocular shooting is performed, the two lenses perform binocular shooting at an angle of 90°.

4. A ditching test system as claimed in claim 2, characterized in that: The first data acquisition module also includes a light source for supplementing light to the water-impacting position of the scaled model.

5. A ditching test system as claimed in claim 1, characterized in that: The first data acquisition module includes a gyroscope and an acceleration sensor built into a scaled model.

6. A ditching test system according to claim 1, characterized in that: The surface of the scaled model in contact with the water surface during the landing process is defined as a force-bearing surface, and the second data acquisition module includes a thin film sensor attached to the force-bearing surface to monitor the pressure distribution information of the force-bearing surface.

7. A ditching test system as claimed in claim 6, characterized in that: The force-bearing surfaces of the scaled model include regional surfaces corresponding to the belly, the lower surface of the wing and the position of the engine nacelle of the aircraft to be tested.

8. A ditching test system as claimed in claim 1, characterized in that: The two ends of the ejection rail are respectively defined as a near-water end and a far-water end, and the locking and releasing mechanism is arranged at the far-water end of the ejection rail; The driving component of the ejection action mechanism includes an elastic rope for pulling the ejection vehicle to slide from the far water end to the near water end of the ejection slide rail, a servo winch for winding up the elastic rope, and a winding mechanism for driving the servo winch to rotate, and the servo winch rotates in coordination with the ejection slide rail; the intercepting component of the ejection action mechanism includes an arresting rope connected to the ejection slide rail, and the arresting rope is located on the sliding trajectory of the ejection vehicle along the ejection slide rail.

9. A ditching test system as claimed in claim 1, characterized in that: Two first support blocks for supporting the two wings of the scaled model respectively and a second support block for supporting the tail are arranged above the bracket, each of the support blocks is connected to a supporting rod parallel to the pitch axis of the scaled model, a connecting block is arranged below the scaled model, with the forward direction of the scaled model during ejection as the front side and the other side as the rear side, and a supporting groove adapted to the supporting rod is opened on the rear side of the connecting block.

10. A ditching test system according to claim 9, characterized in that: The connecting block is detachably connected to the scaled model.

11. A ditching test system according to claim 9, characterized in that: The support block is also provided with a spring pin assembly for preventing the scaled model from sliding off the support block. The spring pin assembly includes a pin structure that abuts against the scaled model to prevent the scaled model from sliding off the ejection vehicle, and a spring that pushes the pin structure to maintain abutment with the scaled model. One end of the pin structure is an inclined surface, and the pin structure abuts against the scaled model through the inclined surface.

12. A ditching test system according to claim 1, characterized in that: When the bracket supports the scaled model, the rotation axis between the bracket and the vehicle body coincides with the rolling axis of the scaled model.

13. A ditching test system according to claim 1, characterized in that: The water pool also includes a wave-making mechanism for simulating the generation of waves.

14. A ditching test method based on the ditching test system according to any one of claims 1 to 13, characterized in that: The following steps are involved: S1. Using the telescopic module to adjust the inclination angle of the ejection rail and the horizontal reference plane of the mounting seat, and adjusting the ejection force through the drive assembly to adjust the attitude angle and / or ejection speed of the scaled model carried on the ejection vehicle; S2. Release the lock release mechanism from the ejection trolley, so that the ejection trolley slides along the ejection rail until the ejection trolley is stopped by the interception assembly, and the scaled model flies into the pool from the ejection trolley; S3. The two data acquisition modules respectively collect the motion characteristic information and the force characteristic information of the scaled model during the water landing process, and record them as the measured data of the scaled model; S4. Repeat steps S1 to S3 until a predetermined amount of test data is obtained. After the predetermined amount of test data is obtained, the relationship between the motion characteristic information and the force characteristic information of the scaled model during the water landing is sorted out and analyzed.

15. A ditching test method according to claim 14, characterized in that: The following steps are also included: S5. Perform fluid-solid coupling dynamics simulation on the water landing process of the scaled model based on XFlow software; S6. The measured data of the scaled model and the simulation results of the XFlow software are mutually verified and integrated; S7. Repeat steps S1 to S3, iteratively modify the XFlow software simulation model and parameters based on the measured data of the scaled model collected again, until the XFlow software simulation model reaches the expected accuracy range, and then output the simulation model.

Images