Method for measuring deformation of wing of large maneuvering and high overload based on binocular vision

Abstract

The application provides a large-maneuvering high-overload wing deformation measurement method based on binocular vision, which comprises the following steps: setting wing surface feature identification points; calibrating wing binocular cameras and obtaining wing binocular camera parameters; obtaining a plurality of wing images in the process of large-maneuvering high-overload flight of an airplane based on the wing binocular cameras; and calculating wing deformation data in the process of large-maneuvering high-overload flight of the airplane based on the wing images. The application considers the step change of the gray scale of the wing surface feature identification points between continuous frames, constructs a wing surface feature identification point identification model based on a frame difference method, and constructs a wing surface feature identification point stereo matching model with the aid of binocular stereo vision, so that the deficiency of the prior art in wing deformation measurement under a large-maneuvering high-overload environment can be overcome, high-precision, real-time and stable measurement of wing deformation can be realized, and the method has practical application value.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aeronautical engineering measurement, and particularly relates to a wing deformation measurement method based on binocular vision for large maneuverability and high overload. BACKGROUND

[0002] With the development of aviation technology, the wing of a modern aircraft will bear large aerodynamic loads and inertial forces during high-speed and large maneuverability flight, resulting in complex deformation of the wing. Accurate measurement of the wing deformation is of great significance for performance evaluation, structural optimization design, flight safety assurance and aeroelasticity research of the aircraft.

[0003] Traditional wing deformation measurement methods, such as strain gauge measurement, can reflect the local strain of the wing to a certain extent, but have the disadvantages of limited measurement points, difficulty in obtaining comprehensive wing deformation information, and certain invasiveness to the wing structure. The method based on optical measurement, such as laser interference measurement, has high requirements for the measurement environment and poor stability in complex flight environments. The binocular vision measurement technology, as a non-contact optical measurement method, has the advantages of wide measurement range and the ability to obtain three-dimensional information, but in the large maneuverability and high overload flight environment, the camera calibration is prone to failure, the image matching accuracy is reduced, and the measurement accuracy is difficult to guarantee. At present, there is no perfect solution that can effectively meet the actual engineering needs. Therefore, in order to overcome the shortcomings of the prior art in wing deformation measurement in the large maneuverability and high overload environment, it is very urgent and necessary to seek a wing deformation measurement method based on binocular vision for large maneuverability and high overload, so as to realize high-precision, real-time and stable measurement of wing deformation in complex flight environments. SUMMARY

[0004] In view of the defects in the prior art, the application provides a wing deformation measurement method based on binocular vision for large maneuverability and high overload. The method comprises the following steps: setting wing surface feature identification points; calibrating wing binocular cameras and obtaining wing binocular camera parameters; obtaining a plurality of wing images during large maneuverability and high overload flight of an aircraft based on the wing binocular cameras; and calculating wing deformation data during large maneuverability and high overload flight of the aircraft based on the wing images. The application considers the step change of the gray level of the wing surface feature identification points between consecutive frames, constructs a wing surface feature identification point recognition model based on frame difference method, and constructs a wing surface feature identification point stereo matching model by means of binocular stereo vision, so as to overcome the shortcomings of the prior art in wing deformation measurement in the large maneuverability and high overload environment, realize high-precision, real-time and stable measurement of wing deformation, and have practical application value.

[0005] The application provides a wing deformation measurement method based on binocular vision for large maneuverability and high overload, which comprises the following steps:

[0006] S1, set wing surface feature identification points: set several high reflectivity wing surface feature identification points in the wing to be measured area;

[0007] S2, calibrate the wing binocular camera and obtain the wing binocular camera parameters: in the static state of the aircraft, calibrate the wing binocular camera based on Zhang Dingyou calibration method, and obtain the wing binocular camera parameters;

[0008] S3, obtain several wing images in the process of large aircraft maneuvering and high overload flight based on the wing binocular camera: in the process of aircraft flight, for the large aircraft maneuvering and high overload flight stage, synchronously shoot several wing images based on the wing binocular camera and store them;

[0009] S31, set the wing binocular camera on the aircraft body;

[0010] S32, determine the power supply source and data transmission of the wing binocular camera;

[0011] S33, set wing master-slave camera considering the synchronous shooting requirements of the camera: the wing master-slave camera includes a wing master camera and a wing slave camera, the wing master camera is internally provided with a synchronous signal generation module, and a synchronous pulse signal is generated by means of the synchronous signal generation module, and the synchronous pulse signal is sent to the wing slave camera through a connecting cable;

[0012] S34, wing master-slave camera synchronous shooting and obtaining several wing images: in the process of aircraft flight, for the large aircraft maneuvering and high overload flight stage, the wing slave camera starts to shoot several wing images synchronously with the wing master camera according to the received synchronous pulse signal;

[0013] S4, calculate and obtain the wing deformation data in the process of large aircraft maneuvering and high overload flight for the wing images: for the corresponding wing images obtained by the wing master-slave camera, by means of wing image preprocessing and wing surface feature identification point stereo matching, combined with the wing binocular camera parameters, set a deformation calculation module to calculate the three-dimensional coordinate change of the wing surface feature identification points, and obtain the wing deformation data in the process of large aircraft maneuvering and high overload flight;

[0014] S41, respectively obtain the wing foreground images of the wing master-slave camera including the wing surface feature identification points by means of wing image preprocessing: by means of the step change of the gray scale of the wing surface feature identification points between frames, a wing surface feature identification point recognition model is constructed based on frame difference method, and for the corresponding wing images obtained by the wing master-slave camera, preprocessing operation is performed through the wing surface feature identification point recognition model, and the wing foreground images of the wing master-slave camera including the wing surface feature identification points are respectively obtained;

[0015] S42, respectively, acquire the wing surface feature marker edge profile of the wing master-slave camera by means of the edge operator: respectively, for the wing foreground image of the wing master-slave camera, by means of the edge operator, the wing surface feature marker edge profile is extracted, and the wing surface feature marker edge profile of the wing master-slave camera is acquired respectively;

[0016] S43, respectively, acquire the wing surface feature marker center point pixel coordinates of the wing master-slave camera by means of the least square method: respectively, based on the pixel coordinates of all pixel points on the wing surface feature marker edge profile of the wing master-slave camera, the wing surface feature marker edge profile overdetermined equation set of the wing master-slave camera is constructed by means of the least square method, combined with singular value decomposition, the wing surface feature marker center point pixel coordinates of the wing master-slave camera are calculated and obtained respectively;

[0017] S44, acquire the wing surface feature marker center point world coordinates by means of wing surface feature marker stereo matching: based on the wing binocular camera parameters, a wing surface feature marker stereo matching model is constructed, and based on the wing surface feature marker center point pixel coordinates of the wing master-slave camera, the wing surface feature marker center point world coordinates are obtained through the wing surface feature marker stereo matching model; wherein the wing surface feature marker stereo matching model is:

[0018]

[0019]

[0020] Wherein, u1, v1 respectively represent the pixel coordinates of the wing surface feature marker center point in the horizontal and vertical axes of the wing master camera pixel coordinate system; u2, v2 respectively represent the pixel coordinates of the wing surface feature marker center point in the horizontal and vertical axes of the wing slave camera pixel coordinate system; Z C1 ,Z C2 respectively represent the depth values of the wing surface feature marker center point in the camera coordinate system of the wing master camera and the wing slave camera respectively; dx1, dy1 respectively represent the physical size of each pixel in the horizontal and vertical axes of the internal parameters of the wing master camera; dx2, dy2 respectively represent the physical size of each pixel in the horizontal and vertical axes of the internal parameters of the wing slave camera; f x1 ,f y1 respectively represent the components of the focal length in the horizontal and vertical axes of the internal parameters of the wing master camera; f x2 ,f y2 respectively represent the components of the focal length in the horizontal and vertical axes of the internal parameters of the wing slave camera; X W ,Y W ,Z Wrespectively represent the coordinate values of the center point of the wing surface feature marker point in the world coordinate system in the left-right, front-back and vertical directions respectively; R and T represent the rotation matrix and translation matrix of the wing binocular camera respectively;

[0021] S45, set up a deformation calculation module to calculate the three-dimensional coordinate changes of all wing surface feature marker points in the process of large aircraft maneuvering and high overload flight, and obtain wing deformation data in the process of large aircraft maneuvering and high overload flight.

[0022] Further, the construction of the wing surface feature marker point recognition model in step S41 specifically includes the following steps:

[0023] S411, considering the case that the background in the two consecutive frames of wing images is relatively static and the wing surface feature marker points change, the region where the wing surface feature marker points are located is displayed by means of two-frame difference method, and a wing difference image D is obtained t (x,y):

[0024] D t (x,y)=I t (x,y)-I t-1 (x,y) (1)

[0025] Wherein, I t (x,y), I t-1 (x,y) respectively represent the corresponding wing image frames at time t and t-1 respectively; x and y represent the pixel coordinates of the horizontal and vertical axes in the wing image respectively;

[0026] S412, set a wing surface feature threshold T, and perform binaryzation processing on the wing difference image D t (x,y) to obtain a wing foreground image f t (x,y):

[0027]

[0028] S413, for the wing foreground image f t (x,y), the wing surface feature marker points in the wing foreground image f t (x,y) are displayed by means of morphological filtering and the noise points are removed.

[0029] Preferably, the step S1 specifically includes the following steps:

[0030] S11, determine the wing region to be measured: considering the structural characteristics and deformation key positions of the wing, determine the wing region to be measured where the wing surface feature marker points need to be set;

[0031] S12, manufacturing wing surface feature identification points: considering the light environment in the flight process of the aircraft, a material with high reflectivity is selected to manufacture the wing surface feature identification points;

[0032] S13, pasting wing surface feature identification points: considering the material of the wing surface feature identification points and the characteristics of the wing surface, the wing surface feature identification points are pasted in the wing to-be-measured area;

[0033] The step S2 specifically comprises the following steps:

[0034] S21, determining a wing binocular camera calibration board: considering the specific structural features and shape and size of the wing, a corresponding size of the chessboard is selected as the wing binocular camera calibration board;

[0035] S22, acquiring a plurality of wing binocular camera calibration board images: considering different angles and distances, moving the wing binocular camera calibration board according to the specific structure and shape of the wing, and acquiring a plurality of wing binocular camera calibration board images;

[0036] S23, solving the initial value of the wing binocular camera internal parameter: based on a plurality of wing binocular camera calibration board images, a plurality of corresponding wing homography matrices are constructed, and the initial value of the wing binocular camera internal parameter is solved according to Zhang Zhengyou's calibration method;

[0037] S24, optimizing the wing binocular camera internal parameter: for the initial value of the wing binocular camera internal parameter, the nonlinear least square method is used for optimization and adjustment to obtain the optimized wing binocular camera internal parameter;

[0038] S25, solving the wing binocular camera external parameter: based on the optimized wing binocular camera internal parameter and the constructed plurality of wing homography matrices, the wing binocular camera external parameter is solved in combination with the geometric relationship of the wing binocular camera; the wing binocular camera external parameter includes the rotation matrix R and the translation matrix T of the wing binocular camera.

[0039] Preferably, the step S31 specifically comprises the following steps:

[0040] S311, considering the impact and vibration generated by large aircraft maneuvering and high overload, an installation bracket with high strength and good damping performance is prepared;

[0041] S312, the wing binocular camera is installed on the specific position of the aircraft body by means of the installation bracket, and the specific position of the aircraft body is considered to enable the field of view of the wing binocular camera to completely cover the wing to-be-measured area;

[0042] The step S32 specifically comprises the following steps:

[0043] S321, considering the power requirement of the wing binocular camera during the whole flight of the airplane, connecting the power supply port of the wing binocular camera to the power supply system of the airplane;

[0044] S322, considering the data transmission and storage requirement of the wing binocular camera during the whole flight of the airplane, connecting the data output port of the wing binocular camera to the onboard data storage device of the airplane through a data transmission line.

[0045] Preferably, in the step S33, the synchronization signal generation module generates the synchronization pulse signal based on the high-precision clock signal of itself; and in the step S34, during the shooting process, the wing master-slave camera continuously maintains the synchronization state, and the wing master-slave camera performs wing image acquisition simultaneously once receiving the synchronization pulse signal.

[0046] Preferably, in the step S2, the wing binocular camera parameters include wing binocular camera internal parameters and wing binocular camera external parameters.

[0047] Compared with the prior art, the technical effect of the present application is:

[0048] 1. The wing deformation measurement method based on binocular vision and designed by the present application considers the step change of the gray scale of the wing surface feature identification points between continuous frames, constructs a wing surface feature identification point identification model based on the frame difference method, and realizes efficient and high-precision extraction of the wing surface feature identification points; with the aid of binocular stereo vision, a wing surface feature identification point stereo matching model is constructed, which effectively guarantees the effective measurement of the wing deformation under large maneuvering and high overload.

[0049] 2. The wing deformation measurement method based on binocular vision and designed by the present application has good adaptability, can overcome the shortcomings of the prior art in wing deformation measurement under large maneuvering and high overload, realize high-precision, real-time and stable measurement of the wing deformation, effectively meet the actual engineering requirements, provide reliable technical support for wing deformation measurement of the aircraft, and play an important role in improving the performance of the aircraft, ensuring flight safety and the like. BRIEF DESCRIPTION OF DRAWINGS

[0050] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments made with reference to the accompanying drawings.

[0051] Figure 1 is a flowchart of the wing deformation measurement method based on binocular vision and designed by the present application;

[0052] Figure 2 is a schematic diagram of the coordinate system constructed by the wing binocular camera of the present application;

[0053] Figure 3 Figure 1 is a schematic diagram of a wing deformation data acquisition process in a large maneuvering high overload flight of an aircraft according to the present application. DETAILED DESCRIPTION

[0054] The application will be further described below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related application, and are not a limitation on the application. In addition, it should be noted that only the parts related to the application are shown in the drawings for ease of description. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0055] Figure 1 The present application shows a large maneuvering high overload wing deformation measurement method based on binocular vision. The term large maneuvering in the present application refers to a measurement speed range: M = 0 ~ 1.3M; high overload refers to an overload range: < 6g. The method of the present application comprises the following steps:

[0056] S1, setting wing surface feature identification points: setting several wing surface feature identification points with high reflectivity in the wing to be measured area.

[0057] S11, determining the wing to be measured area: considering the structural characteristics and key deformation positions of the wing, determining the wing to be measured area where the wing surface feature identification points need to be set.

[0058] S12, making wing surface feature identification points: considering the light environment in the process of aircraft flight, selecting materials with high reflectivity to make wing surface feature identification points, to ensure that the camera can clearly capture the wing surface feature identification points under different light conditions, especially in the light environment during the process of aircraft flight, wherein the material with high reflectivity refers to: mainly flexible reflective material, the reflection film adopts anti-reflection film layer design, and the reflectivity is ≥ 85%.

[0059] S13, pasting wing surface feature identification points: considering the material of wing surface feature identification points and the characteristics of wing surface, pasting wing surface feature identification points in the wing to be measured area to avoid bubbles or wrinkles, and to ensure that the sticker is closely attached to the surface.

[0060] S2, calibrating the wing binocular camera and obtaining the wing binocular camera parameters: under the condition that the aircraft is in a stationary state, calibrating the wing binocular camera based on Zhang Dingyou calibration method to obtain the wing binocular camera parameters. The wing binocular camera parameters include the wing binocular camera internal parameters and the wing binocular camera external parameters.

[0061] S21, determine the wing binocular camera calibration board: considering the specific structure and shape of the wing, select the corresponding size of the checkerboard as the wing binocular camera calibration board.

[0062] S22, obtain a plurality of wing binocular camera calibration board images: considering different angles and distances, moving the wing binocular camera calibration board according to the specific structure and shape of the wing, and shooting a plurality of wing binocular camera calibration board images.

[0063] S23, solve the initial value of the wing binocular camera internal parameter: based on a plurality of wing binocular camera calibration board images, a plurality of wing homography matrices are constructed respectively, and the initial value of the wing binocular camera internal parameter is solved according to Zhang Zhengyou calibration method.

[0064] S24, optimize the wing binocular camera internal parameter: for the initial value of the wing binocular camera internal parameter, the nonlinear least square method is used for optimization and adjustment, and the optimized wing binocular camera internal parameter is obtained.

[0065] S25, solve the wing binocular camera external parameter: based on the optimized wing binocular camera internal parameter and the constructed a plurality of wing homography matrices, combined with the geometric relationship of the wing binocular camera, the wing binocular camera external parameter is solved; the wing binocular camera external parameter includes the rotation matrix R and the translation matrix T of the wing binocular camera.

[0066] S3, obtain a plurality of wing images during the large maneuvering and high overload flight of the aircraft based on the wing binocular camera: during the flight of the aircraft, a plurality of wing images are synchronously shot and stored based on the wing binocular camera during the large maneuvering and high overload flight of the aircraft.

[0067] S31, set the wing binocular camera on the aircraft body.

[0068] S311, considering the impact and vibration generated by the large maneuvering and high overload of the aircraft, prepare an installation bracket with high strength and good damping performance.

[0069] S312, set and install the wing binocular camera on the specific position of the aircraft body by means of the installation bracket, and the specific position of the aircraft body is considered to be able to completely cover the wing to be measured area.

[0070] S32, determine the power supply source and data transmission of the wing binocular camera.

[0071] S321, considering the power requirement of the wing binocular camera during the whole flight of the aircraft, connect the power supply port of the wing binocular camera to the power supply system of the aircraft.

[0072] S322, considering the data transmission and storage requirements of the wing binocular camera in the whole flight process of the aircraft, connecting the data output port of the wing binocular camera with the on-board data storage device of the aircraft through a data transmission line.

[0073] S33, considering the synchronous shooting requirements of the camera, setting a wing master-slave camera: the wing master-slave camera includes a wing master camera and a wing slave camera, the wing master camera is internally provided with a synchronization signal generation module, and a synchronization pulse signal is generated by means of the synchronization signal generation module, and the synchronization pulse signal is sent to the wing slave camera through a connection cable. The synchronization signal generation module generates a synchronization pulse signal based on its own high-precision clock signal.

[0074] In one specific embodiment, the coordinate system constructed by the wing binocular camera is as shown in Figure 2 C1 and C2 are the wing master camera and the wing slave camera, the optical axis convergence point of which intersects with the Y axis of the space coordinate system, and the intersection point is O, L is the baseline length, and H is the distance between the epipolar line and the center of the wing to be measured.

[0075] S34, the wing master-slave camera synchronously shoots and acquires a plurality of wing images: during the flight of the aircraft, for the high overload flight stage of the large maneuver of the aircraft, the wing slave camera starts to shoot a plurality of wing images synchronously with the wing master camera according to the received synchronization pulse signal. During the shooting process, the wing master-slave camera continuously maintains a synchronous state, and each time a synchronization pulse signal is received, the wing master-slave camera simultaneously performs wing image acquisition once, so as to ensure that each group of wing images acquired is shot at the same time, and can accurately reflect the real deformation of the wing at each moment during the large maneuver high overload flight process.

[0076] S4, for the wing images, calculating and acquiring the wing deformation data in the large maneuver high overload flight process of the aircraft: for the corresponding wing images acquired by the wing master-slave camera, by means of wing image preprocessing and wing surface feature landmark point stereo matching, combining the wing binocular camera parameters, setting a deformation calculation module to calculate the three-dimensional coordinate change of the wing surface feature landmark point, and acquiring the wing deformation data in the large maneuver high overload flight process of the aircraft, as shown in Figure 3

[0077] ​S41, by means of wing image preprocessing, the wing foreground images of the wing main and slave cameras including wing surface feature marker points are respectively acquired: by means of the step change of the gray scale of the wing surface feature marker points between frames, a wing surface feature marker point identification model is constructed based on frame difference method, and the corresponding wing images acquired by the wing main and slave cameras are respectively preprocessed by the wing surface feature marker point identification model, so as to respectively acquire the wing foreground images of the wing main and slave cameras including wing surface feature marker points. In a specific embodiment, the scene is an airborne test environment, and the light interference is serious. The energy of the light from the light compensation lamp reflected by the wing surface feature marker points is submerged in sunlight, and it is extremely difficult to identify the wing surface feature marker points only by light intensity. The frame difference method uses the processing technology of image misregistration subtraction, and distinguishes the wing surface feature marker points from the strong light background by means of the step change of the gray scale of the target, so as to effectively improve the detection contrast.

[0078] The construction of the wing surface feature marker point identification model specifically includes the following steps:

[0079] S411, considering the case that the background is relatively static and the wing surface feature marker points change in the two continuous wing images, the wing surface feature marker point region is displayed by means of two-frame difference method, and a wing difference image D t (x,y) is obtained.

[0080] D t (x,y) = I t (x,y) - I t-1 (x,y) (1)

[0081] Wherein, I t (x,y), I t-1 (x,y) respectively represent the corresponding wing image frames at t and t-1 time; x and y respectively represent the pixel coordinates of the horizontal and vertical axes in the wing image.

[0082] S412, set a wing surface feature threshold T, perform binaryzation processing on the wing difference image D t (x,y), and segment the foreground and background by judging the size relationship between D t (x,y) and T, to acquire a wing foreground image f t (x,y):

[0083]

[0084] S413, for the wing foreground image f t (x,y), the wing surface feature marker points in the wing foreground image f t (x,y) are displayed by means of morphological filtering, and the noise points are removed.

[0085] S42, respectively, acquire the wing surface feature mark point edge profile of the wing master and slave cameras by means of an edge operator: respectively, for the wing foreground image of the wing master and slave cameras, edge profile extraction is performed on the wing surface feature mark point by means of an edge operator, and the wing surface feature mark point edge profile of the wing master and slave cameras is acquired respectively. In a specific embodiment, the edge operator adopts a canny operator, a Laplace operator, etc.

[0086] S43, respectively, acquire the wing surface feature mark point center point pixel coordinates of the wing master and slave cameras by means of a least square method: respectively, based on the pixel coordinates of all pixel points on the wing surface feature mark point edge profile of the wing master and slave cameras, a wing surface feature mark point edge profile overdetermined equation set of the wing master and slave cameras is constructed by means of a least square method, and the wing surface feature mark point center point pixel coordinates of the wing master and slave cameras are calculated and obtained respectively by combining singular value decomposition.

[0087] S44, acquire the wing surface feature mark point center point world coordinates by means of wing surface feature mark point stereo matching: based on the wing binocular camera parameters, a wing surface feature mark point stereo matching model is constructed, and the wing surface feature mark point center point world coordinates are obtained through the wing surface feature mark point stereo matching model based on the wing surface feature mark point center point pixel coordinates of the wing master and slave cameras; the wing surface feature mark point stereo matching model is:

[0088]

[0089]

[0090] Wherein, u1, v1 respectively represent the pixel coordinates of the wing surface feature mark point center point in the horizontal and vertical axes of the wing master camera pixel coordinate system; u2, v2 respectively represent the pixel coordinates of the wing surface feature mark point center point in the horizontal and vertical axes of the wing slave camera pixel coordinate system; Z C1 ,Z C2 respectively represent the depth values of the wing surface feature mark point center point in the camera coordinate system of the wing master camera and the wing slave camera respectively; dx1, dy1 respectively represent the physical dimensions of each pixel in the horizontal and vertical axes of the internal parameters of the wing master camera; dx2, dy2 respectively represent the physical dimensions of each pixel in the horizontal and vertical axes of the internal parameters of the wing slave camera; f x1 ,f y1 respectively represent the components of the focal length in the horizontal and vertical axes of the internal parameters of the wing master camera; f x2 ,f y2 respectively represent the components of the focal length in the horizontal and vertical axes of the internal parameters of the wing slave camera; X W ,Y W ,Z WRespectively represent the coordinate values of the center points of the wing surface feature mark points in the world coordinate system in the left, right, front and rear and vertical directions.

[0091] S45, set up a deformation calculation module to calculate the three-dimensional coordinate changes of all wing surface feature mark points in the process of high overload flight of large aircraft maneuver, and obtain the wing deformation data in the process of high overload flight of large aircraft maneuver.

[0092] The application designs a large maneuver high overload wing deformation measurement method based on binocular vision, considers the step change of the gray scale of the wing surface feature mark points between continuous frames, constructs a wing surface feature mark point identification model based on the frame difference method, realizes efficient and high-precision extraction of the wing surface feature mark points, constructs a wing surface feature mark point stereo matching model with the help of binocular stereo vision, and effectively guarantees the effective measurement of the wing deformation under large maneuver high overload.

[0093] Finally, it should be explained that: the above examples are only for illustration, not for limiting the technical solutions of the present application, although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that: the present application can still be modified or replaced equivalently without departing from the spirit and scope of the present application, any modification or partial replacement should be covered in the scope of the claims of the present application.

Claims

1. A method for measuring the deformation of a high-maneuverability, high-overload wing based on binocular vision, characterized in that, It includes the following steps: S1. Set up wing surface feature markers: Set up several high-reflectivity wing surface feature markers in the area to be tested on the wing. S2. Calibrate the wing-mounted binocular camera and obtain its parameters: With the aircraft stationary, calibrate the wing-mounted binocular camera based on Zhang Dingyou's calibration method and obtain its parameters. S3. Acquire several wing images during high-G flight of an aircraft based on a wing-mounted binocular camera: During the flight of an aircraft, for the high-G flight phase of an aircraft, capture and store several wing images simultaneously based on a wing-mounted binocular camera. S31. The wing-mounted binocular camera is installed on the aircraft fuselage; S32. Determine the power source and data transmission of the wing-mounted binocular camera; S33. Considering the synchronous shooting requirements of the camera, a master-slave camera for the wing is set up: the master-slave camera for the wing includes a master camera for the wing and a slave camera for the wing. The master camera for the wing is equipped with a synchronization signal generation module. The synchronization signal generation module generates a synchronization pulse signal, and the synchronization pulse signal is sent to the slave camera for the wing via a connecting cable. S34. The wing master and slave cameras synchronously capture and acquire several wing images: During the flight of the aircraft, in the high-G flight phase of high maneuverability, the wing slave camera starts to capture several wing images synchronously with the wing master camera according to the received synchronization pulse signal. S4. For the wing image, calculate and obtain wing deformation data during the high-G flight of the aircraft: For the wing image obtained by the master and slave cameras, with the help of wing image preprocessing and stereo matching of wing surface feature markers, combined with the parameters of the binocular camera of the wing, set the deformation calculation module to calculate the three-dimensional coordinate changes of the wing surface feature markers, and obtain wing deformation data during the high-G flight of the aircraft. S41. Using wing image preprocessing, obtain wing foreground images of the master and slave cameras that include the wing surface feature markers: Using the step change in grayscale of the wing surface feature markers between frames, construct a wing surface feature marker recognition model based on the frame difference method, and perform preprocessing operations on the corresponding wing images obtained by the master and slave cameras through the wing surface feature marker recognition model to obtain wing foreground images of the master and slave cameras that include the wing surface feature markers. S42. Using edge operators, obtain the edge contours of the wing surface feature markers of the master and slave cameras respectively: For the wing foreground images of the master and slave cameras respectively, use edge operators to extract the edge contours of the wing surface feature markers, and obtain the edge contours of the wing surface feature markers of the master and slave cameras respectively. S43. Using the least squares method, obtain the pixel coordinates of the center point of the wing surface feature marker of the master and slave cameras respectively: Based on the pixel coordinates of all pixels on the edge contour of the wing surface feature marker of the master and slave cameras respectively, construct the overdetermined equation system of the edge contour of the wing surface feature marker of the master and slave cameras respectively using the least squares method, and calculate the pixel coordinates of the center point of the wing surface feature marker of the master and slave cameras respectively using singular value decomposition. S44. Obtain the world coordinates of the center point of the wing surface feature markers using stereo matching: Based on the parameters of the wing binocular camera, construct a stereo matching model of the wing surface feature markers, and obtain the world coordinates of the center point of the wing surface feature markers using the stereo matching model based on the pixel coordinates of the center point of the wing surface feature markers from the master and slave cameras; wherein, the stereo matching model of the wing surface feature markers is: Where u1 and v1 represent the pixel coordinates of the center point of the wing surface feature marker on the horizontal and vertical axes of the wing's main camera pixel coordinate system, respectively; u2 and v2 represent the pixel coordinates of the center point of the wing surface feature marker on the horizontal and vertical axes of the wing's secondary camera pixel coordinate system, respectively; Z C1 Z C2 dx1 and dy1 represent the depth values ​​of the center points of the wing surface feature markers in the camera coordinate systems of the wing main camera and the wing slave camera, respectively; dx1 and dy1 represent the physical dimensions of each pixel on the horizontal and vertical axes in the intrinsic parameters of the wing main camera, respectively; dx2 and dy2 represent the physical dimensions of each pixel on the horizontal and vertical axes in the intrinsic parameters of the wing slave camera, respectively; f x1 ,f y1 These represent the components of the focal length on the horizontal and vertical axes in the intrinsic parameters of the wing's main camera; f x2 ,f y2 These represent the components of the focal length of the wing along the horizontal and vertical axes from the camera's intrinsic parameters; X W ,Y W Z W R and T represent the coordinates of the center point of the feature marker on the wing surface in the world coordinate system in the left-right, front-back, and vertical directions, respectively; R and T represent the rotation and translation matrices of the wing's binocular camera, respectively. S45. Set up a deformation calculation module to calculate the three-dimensional coordinate changes of all wing surface feature markers during the high-G maneuvering flight of the aircraft, and obtain wing deformation data during the high-G maneuvering flight of the aircraft.

2. The method for measuring the deformation of a high-maneuverability, high-overload wing based on binocular vision according to claim 1, characterized in that, The construction of the wing surface feature marker recognition model in step S41 specifically includes the following steps: S411. Considering the situation where the background is relatively static while the wing surface feature markers change in two consecutive wing images, the region where the wing surface feature markers are located is displayed using the two-frame difference method, thus obtaining the wing difference image D. t (x,y): D t (x,y)=I t (x,y)-I t-1 (x,y) (1) Among them, I t (x,y),I t-1 (x, y) represent the wing image frames corresponding to time t and time t-1, respectively; x, y represent the pixel coordinates of the horizontal and vertical axes in the wing image, respectively; S412. Set the wing surface feature threshold T for the wing differential image D. t Binarize (x, y) to obtain the wing foreground image f. t (x,y): S413, Regarding the foreground image f of the wing... t (x,y), the foreground image f of the wing is displayed using morphological filtering. t The wing surface feature points in (x,y) are identified and nodules are removed.

3. The method for measuring the deformation of a high-maneuverability, high-overload wing based on binocular vision according to claim 1, characterized in that, Step S1 specifically includes the following steps: S11. Determine the test area of ​​the wing: Considering the structural characteristics and key deformation parts of the wing, determine the test area of ​​the wing where feature markers need to be set on the wing surface. S12. Fabrication of wing surface feature markings: Considering the light environment during aircraft flight, select materials with high reflectivity to fabricate wing surface feature markings. S13. Affix wing surface feature markers: Considering the material of the wing surface feature markers and the characteristics of the wing surface, affix wing surface feature markers to the area of ​​the wing to be tested. Step S2 specifically includes the following steps: S21. Determine the calibration plate for the wing-mounted binocular camera calibration: Considering the specific structural characteristics and shape and size of the wing, select a checkerboard pattern of the corresponding size as the calibration plate for the wing-mounted binocular camera calibration. S22. Acquire several images of the calibration plate for the wing-mounted binocular camera calibration: Considering different angles and distances, and based on the specific structure and shape of the wing, move the calibration plate for the wing-mounted binocular camera calibration and take several images of the calibration plate for the wing-mounted binocular camera calibration. S23. Solve for the initial values ​​of the intrinsic parameters of the wing-mounted binocular camera: Based on several calibration board images used for wing-mounted binocular camera calibration, construct several corresponding wing homography matrices respectively, and solve for the initial values ​​of the intrinsic parameters of the wing-mounted binocular camera according to Zhang Zhengyou's calibration method. S24. Optimize the intrinsic parameters of the wing-mounted binocular camera: For the initial values ​​of the intrinsic parameters of the wing-mounted binocular camera, optimize and adjust them using the nonlinear least squares method to obtain the optimized intrinsic parameters of the wing-mounted binocular camera. S25. Solve for the extrinsic parameters of the wing-mounted binocular camera: Based on the optimized intrinsic parameters of the wing-mounted binocular camera and the constructed homography matrices of the wing, and in conjunction with the geometric relationship of the wing-mounted binocular camera, solve for the extrinsic parameters of the wing-mounted binocular camera; the extrinsic parameters of the wing-mounted binocular camera include the rotation matrix R and the translation matrix T of the wing-mounted binocular camera.

4. The method for measuring the deformation of a high-maneuverability, high-overload wing based on binocular vision according to claim 1, characterized in that, Step S31 specifically includes the following steps: S311. Considering the impact and vibration generated by high overload during high maneuvers of aircraft, prepare the mounting bracket; S312. The wing-mounted binocular camera is installed at a specific location on the aircraft body using the mounting bracket, wherein the specific location on the aircraft body is chosen so that the field of view of the wing-mounted binocular camera can completely cover the area to be measured on the wing. Step S32 specifically includes the following steps: S321. Considering the power requirements of the wing-mounted binocular camera during the entire flight of the aircraft, connect the power supply port of the wing-mounted binocular camera to the power supply system of the aircraft. S322. Considering the data transmission and storage requirements of the wing-mounted binocular camera during the entire flight of the aircraft, the data output port of the wing-mounted binocular camera is connected to the aircraft's onboard data storage device via a data transmission line.

5. The method for measuring the deformation of a high-maneuverability, high-overload wing based on binocular vision according to claim 1, characterized in that, In step S33, the synchronization signal generation module generates a synchronization pulse signal based on its own clock signal. In step S34, during the shooting process, the wing master and slave cameras maintain a synchronized state. Each time a synchronization pulse signal is received, the wing master and slave cameras simultaneously acquire an image of the wing.

6. The method for measuring the deformation of a high-maneuverability, high-overload wing based on binocular vision according to claim 1, characterized in that, The parameters of the wing-mounted binocular camera in step S2 include the internal parameters and external parameters of the wing-mounted binocular camera.

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