Aircraft structure outer surface strain measurement point positioning method and device

Abstract

The invention belongs to the technical field of aircraft test measurement, and particularly relates to an aircraft structure outer surface strain measurement point positioning method and device. The method comprises the following steps: S1, acquiring coordinates of a first measuring device and coordinates of a second measuring device under an overall coordinate system of an aircraft; s2, controlling lenses on the two measuring devices to deflect so as to lock a positioning point of a to-be-determined coordinate on the surface of the machine body, acquiring a deflection angle and a pitch angle of the first measuring device, and acquiring a deflection angle and a pitch angle of the second measuring device; and S3, respectively constructing function relations between the two measuring devices and the positioning point, and solving the coordinates of the positioning point by combining the two function relations. According to the invention, the method can achieve the precise positioning of the surface point of the airplane, and improves the positioning measurement efficiency.

Description

Technical Field

[0001] The present application belongs to the technical field of aircraft test measurement, and in particular relates to a method and device for locating strain measurement points on the outer surface of an aircraft structure. Background Art

[0002] In the static / fatigue test of full-size aircraft, a large number of strain gauges need to be pasted to detect the mechanical properties of the fuselage structure. Before the strain gauges are pasted, it is necessary to find the position coordinates in the overall coordinate system of the aircraft marked in the plan and test task book. The accuracy of the strain gauge position pasting directly affects the validity of the strain gauge measurement data and the validity of the full-aircraft test results. Therefore, in the full-aircraft test, the accuracy of the positioning of the points on the surface of the aircraft body plays a vital role in the results of the full-aircraft test. In current aircraft tests, the measurement and positioning of aircraft body points are indirectly obtained by manually measuring the relative positions of the precise coordinates of key positions around the fuselage. This method is time-consuming, labor-intensive, and inefficient. There are certain errors in the positioning results obtained. In addition, there will be certain effects on the fuselage structure during the measurement process. Summary of the invention

[0003] In order to solve at least one of the above technical problems, the present application provides a method and device for locating strain measurement points on the outer surface of an aircraft structure, so as to realize rapid positioning and measurement of points on the surface of an aircraft body during full-aircraft testing or aircraft maintenance.

[0004] The first aspect of the present application provides a method for locating strain measurement points on the outer surface of an aircraft structure, mainly comprising:

[0005] Step S1, obtaining the coordinates (x0, y0, z0) of the first measuring device and the coordinates (x1, y1, z1) of the second measuring device in the overall coordinate system of the aircraft;

[0006] Step S2, controlling the lens deflection of the two measuring devices to lock the positioning point of the body surface whose coordinates are to be determined, obtaining the deflection angle α0 and the pitch angle θ0 of the first measuring device, and obtaining the deflection angle α1 and the pitch angle θ2 of the second measuring device;

[0007] Step S3: construct functional relationships between the two measuring devices and the positioning points respectively, and combine the two functional relationships to solve the coordinates of the positioning points.

[0008] Preferably, step S2 further comprises:

[0009] Step S21, determining a conversion matrix between an installation positioning center and an imaging center of each measuring device based on a deflection angle and a pitch angle of each measuring device;

[0010] Step S22: Correct the coordinates of each measuring device based on the transformation matrix.

[0011] Preferably, step S3 further comprises:

[0012] Step S31, respectively constructing functional relationships of x-axis data between two measuring devices and the positioning point, wherein both functional relationships use z-axis data of each measuring device as a variable, and jointly solving the two functional relationships to obtain the first z-axis coordinate of the positioning point. Meanwhile, respectively constructing functional relationships of y-axis data between two measuring devices and the positioning point, wherein both functional relationships use z-axis data of each measuring device as a variable, and jointly solving the two functional relationships to obtain the second z-axis coordinate of the positioning point.

[0013] Step S32, taking the average value of the first z-axis coordinate and the second z-axis coordinate as the z-axis coordinate of the positioning point;

[0014] Step S33, respectively substitute the z-axis coordinate of the positioning point into the functional relationship of the two x-axis data to obtain the two x-axis coordinates of the positioning point, and take the average value as the final x-axis coordinate of the positioning point. At the same time, respectively substitute the z-axis coordinate of the positioning point into the functional relationship of the two y-axis data to obtain the two y-axis coordinates of the positioning point, and take the average value as the final y-axis coordinate of the positioning point.

[0015] Preferably, in step S1, the coordinates of the measuring device are inversely deduced by measuring the coordinates of known points on the fuselage.

[0016] The second aspect of the present application provides a device for locating strain measurement points on the outer surface of an aircraft structure, mainly comprising:

[0017] A measuring device coordinate determination module, used to obtain the coordinates (x0, y0, z0) of the first measuring device and the coordinates (x1, y1, z1) of the second measuring device in the overall coordinate system of the aircraft;

[0018] The measuring device parameter acquisition module is used to control the lens deflection of the two measuring devices to lock the positioning point of the coordinate to be determined on the body surface, obtain the deflection angle α0 and the pitch angle θ0 of the first measuring device, and obtain the deflection angle α1 and the pitch angle θ2 of the second measuring device;

[0019] The positioning point coordinate calculation module is used to respectively construct functional relationships between the two measuring devices and the positioning point, and combine the two functional relationships to solve the coordinates of the positioning point.

[0020] Preferably, the measuring device parameter acquisition module further includes:

[0021] A conversion matrix calculation unit, used to determine the conversion matrix between the installation positioning center and the imaging center of each measuring device based on the deflection angle and the pitch angle of each measuring device;

[0022] The coordinate correction unit is used to correct the coordinates of each measuring device based on the conversion matrix.

[0023] Preferably, the positioning point coordinate calculation module includes:

[0024] A separate z-axis coordinate solving unit is used to respectively construct functional relationships of x-axis data between two measuring devices and a positioning point, wherein both functional relationships use the z-axis data of each measuring device as a variable, and the two functional relationships are combined to solve the first z-axis coordinate of the positioning point. At the same time, functional relationships of y-axis data between two measuring devices and the positioning point are respectively constructed, wherein both functional relationships use the z-axis data of each measuring device as a variable, and the two functional relationships are combined to solve the second z-axis coordinate of the positioning point;

[0025] A z-axis coordinate determining unit, used to use the average value of the first z-axis coordinate and the second z-axis coordinate as the z-axis coordinate of the positioning point;

[0026] The x-axis and y-axis coordinate determination unit is used to substitute the z-axis coordinate of the positioning point into the functional relationship of the two x-axis data, obtain the two x-axis coordinates of the positioning point, and take the average value as the final x-axis coordinate of the positioning point. At the same time, the z-axis coordinate of the positioning point is substituted into the functional relationship of the two y-axis data, obtain the two y-axis coordinates of the positioning point, and take the average value as the final y-axis coordinate of the positioning point.

[0027] Preferably, in the measuring device coordinate determination module, the coordinates of the measuring device are inversely deduced by measuring the coordinates of known points on the fuselage.

[0028] The present application can achieve relatively accurate positioning of points on the aircraft surface, thereby improving the efficiency of positioning measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a flow chart of a preferred embodiment of the method for locating strain measurement points on the outer surface of an aircraft structure of the present application.

[0030] Figure 2 For this application Figure 1 Schematic diagram of the structure of the measuring device of the embodiment shown.

[0031] Figure 3 For this application Figure 1 Schematic diagram of the spatial position relationship between the measuring device and the positioning points of the illustrated embodiment.

[0032] Among them, 1-imaging unit, 2-optical zoom lens, 3-rotation axis, 4-mounting base, 5-mounting hole. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and cannot be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in combination with the drawings.

[0034] The first aspect of the present application provides a method for locating strain measurement points on the outer surface of an aircraft structure, such as Figure 1 As shown, it mainly includes:

[0035] Step S1, obtaining the coordinates (x0, y0, z0) of the first measuring device and the coordinates (x1, y1, z1) of the second measuring device in the overall coordinate system of the aircraft;

[0036] Step S2, controlling the lens deflection of the two measuring devices to lock the positioning point of the body surface whose coordinates are to be determined, obtaining the deflection angle α0 and the pitch angle θ0 of the first measuring device, and obtaining the deflection angle α1 and the pitch angle θ2 of the second measuring device;

[0037] Step S3: construct functional relationships between the two measuring devices and the positioning points respectively, and combine the two functional relationships to solve the coordinates of the positioning points.

[0038] The present application acquires the parameters of the positioning point through the measuring device in the overall coordinate system of the aircraft, and constructs the functional relationship between the coordinates of each measuring device and the coordinates of the positioning point through step S3 based on the acquired parameters, and obtains the coordinates of the positioning point by joint solution. The present application provides a non-contact measurement method that can quickly acquire the coordinates of points on the aircraft body, reduce the workload of the measurement personnel, and improve work efficiency. It is suitable for non-contact measurement and positioning of surface points and specific parts in the test of civil aircraft, transport aircraft, military aircraft, unmanned aircraft, etc.

[0039] First, the overall coordinate system of the aircraft is explained. In the full aircraft test, strain gauges are pasted, displacements are measured, etc., and relevant points on the fuselage surface are measured and located as needed. Therefore, the overall coordinate system of the aircraft needs to be constructed in advance. Its coordinate origin is located at the front of the fuselage, the x-axis is located on the mid-axis plane of the fuselage, the z-axis is perpendicular to the ground and upward, and the y-axis is automatically defined by the right-hand rectangular coordinate system.

[0040] Secondly, this application uses a measuring device to obtain positioning point parameters, such as Figure 2 As shown, the device consists of three major parts: a camera system, a high-precision pan-tilt head, and a mounting base. The camera system includes an imaging unit 1, an optical zoom lens 2, a housing and other components. The main function of the camera system is to clearly image the point to be positioned on the fuselage. The high-precision pan-tilt head includes a plurality of movable components, and adjacent movable components are rotatably connected by a rotating shaft 3, which is used to rotate the camera system in the horizontal and vertical directions respectively, so that it can clearly shoot points at different positions on the fuselage. In step S2, the deflection angle and pitch angle provided by the high-precision pan-tilt head can be used to solve the coordinates of the positioning points on the fuselage. The mounting base 4 has two functions: one is to support the high-precision pan-tilt head and the camera system, and the other is to stably fix the high-precision pan-tilt head and the camera system in the installation position through the mounting hole 5 and the connector.

[0041] Before measurement and calculation, the measuring device needs to be placed in a suitable position around the fuselage and fixed, and the three-dimensional position coordinates of the center of the bottom surface of the mounting base in the overall coordinate system of the aircraft are calibrated through known coordinate points. In the measurement and positioning of points on the surface of the fuselage, two measuring devices are required. When measuring, adjust the pan-tilt rotation angle and lens focal length of the measuring device so that the point to be located is clearly imaged at the center of the image recorded by the measuring device. At this time, the three-dimensional coordinates of the points on the surface of the aircraft body in the overall coordinate system of the aircraft can be solved through the coordinates of the two measuring devices in the overall coordinate system of the aircraft and the pitch angle of the pan-tilt.

[0042] In some optional implementations, step S2 further includes:

[0043] Step S21, determining a conversion matrix between an installation positioning center and an imaging center of each measuring device based on a deflection angle and a pitch angle of each measuring device;

[0044] Step S22: Correct the coordinates of each measuring device based on the transformation matrix.

[0045] In this embodiment, since the installation positioning center of the measuring device is inconsistent with the imaging center, when the gimbal angle changes, the coordinates of the imaging center on the measuring device will change slightly. The actual equivalent position of the measuring device in the overall coordinate system of the aircraft can be calculated by the coordinates of the measuring device, the gimbal deflection angle and the size of the measuring device. The coordinate position of the measuring device A after equivalent calculation is recorded as (x0, y0, z0), and the coordinate position of the measuring device B is (x1, y1, z1).

[0046] In some optional implementations, step S3 further includes:

[0047] Step S31, respectively constructing functional relationships of x-axis data between two measuring devices and the positioning point, wherein both functional relationships use z-axis data of each measuring device as a variable, and jointly solving the two functional relationships to obtain the first z-axis coordinate of the positioning point. Meanwhile, respectively constructing functional relationships of y-axis data between two measuring devices and the positioning point, wherein both functional relationships use z-axis data of each measuring device as a variable, and jointly solving the two functional relationships to obtain the second z-axis coordinate of the positioning point.

[0048] Step S32, taking the average value of the first z-axis coordinate and the second z-axis coordinate as the z-axis coordinate of the positioning point;

[0049] Step S33, respectively substitute the z-axis coordinate of the positioning point into the functional relationship of the two x-axis data to obtain the two x-axis coordinates of the positioning point, and take the average value as the final x-axis coordinate of the positioning point. At the same time, respectively substitute the z-axis coordinate of the positioning point into the functional relationship of the two y-axis data to obtain the two y-axis coordinates of the positioning point, and take the average value as the final y-axis coordinate of the positioning point.

[0050] refer to Figure 3 , assuming that the first measuring device is located at coordinate point A, the second measuring device is located at coordinate point B, and the positioning point on the surface of the aircraft body is coordinate point C, and the coordinates of point C are (x, y, z). In step S31, the positional relationship between coordinate point A and point C on the surface of the aircraft body can be obtained according to the spatial position relationship as shown in equations 1 and 2:

[0051]

[0052] Similarly, the positional relationship between the coordinate point B and the point C on the body surface can be obtained as shown in equations 3 and 4:

[0053]

[0054] Combining equation (1) and equation (3), we can get:

[0055]

[0056] make:

[0057]

[0058] The first z-axis coordinate z of the positioning point calculated by the x-direction data of the two measuring devices is x for:

[0059]

[0060] Similarly, combining equation (2) and equation (4) we can get:

[0061]

[0062] make:

[0063]

[0064] The second coordinate z of the positioning point calculated by the y-direction data of the two measuring devices y The coordinate values ​​are:

[0065]

[0066] Then in step S32, the z-axis coordinate values ​​of the two positioning points calculated by the above formula (5) and formula (6) are averaged as the final z-axis coordinate:

[0067]

[0068] Finally, in step S33, the x-axis parameter x of the positioning point represented by the coordinate point A of the first measuring device is obtained by adding the x-axis and y-axis equations of the z-axis coordinate equations 1-4 calculated above. A and the y-axis parameter y A Similarly, the x-axis parameter x of the positioning point represented by the B coordinate point parameter of the first measuring device is obtained. B and the y-axis parameter y B , as shown in Equation 8, Equation 9, Equation 10, and Equation 11.

[0069]

[0070] Finally, the final x-axis coordinate and the final y-axis coordinate of the positioning point are calculated by averaging the following formula:

[0071]

[0072] At this point, the coordinate position (x, y, z) of the positioning point C on the surface of the aircraft body is obtained through spatial position solution of the measurement parameters of the first measurement device and the second measurement device.

[0073] In some optional implementations, in step S1, the coordinates of the measuring device are inferred by measuring the coordinates of known points on the fuselage.

[0074] In this embodiment, in actual application, the real coordinates of the measuring device cannot be directly known. It is necessary to measure the coordinates of a known point on the fuselage of the aircraft in advance, use the angle of the gimbal of the measuring device A, and use the above process to infer the position of the measuring device A (i.e., the calibration process). Then, the position of the measuring device A calculated at present is used to locate the positions of other points on the fuselage using the above process.

[0075] This application has the following advantages:

[0076] 1. Two highly integrated optical zoom cameras are used to change the measuring points through high-precision pan / tilt and lens zoom, which is simple and efficient and suitable for test site environments.

[0077] 2. High measurement accuracy, strong real-time performance and strong anti-interference ability;

[0078] 3. Accelerate detection efficiency and shorten detection cycle;

[0079] 4. Easy to install and operate;

[0080] 5. Non-contact measurement, high safety factor;

[0081] 6. Automation and real-time monitoring can be achieved through computer and program control, saving manpower and material resources.

[0082] The second aspect of the present application provides a device for locating strain measurement points on the outer surface of an aircraft structure corresponding to the above method, mainly comprising:

[0083] A measuring device coordinate determination module, used to obtain the coordinates (x0, y0, z0) of the first measuring device and the coordinates (x1, y1, z1) of the second measuring device in the overall coordinate system of the aircraft;

[0084] The measuring device parameter acquisition module is used to control the lens deflection of the two measuring devices to lock the positioning point of the coordinate to be determined on the body surface, obtain the deflection angle α0 and the pitch angle θ0 of the first measuring device, and obtain the deflection angle α1 and the pitch angle θ2 of the second measuring device;

[0085] The positioning point coordinate calculation module is used to respectively construct functional relationships between the two measuring devices and the positioning point, and combine the two functional relationships to solve the coordinates of the positioning point.

[0086] In some optional implementations, the measurement device parameter acquisition module further includes:

[0087] A conversion matrix calculation unit, used to determine the conversion matrix between the installation positioning center and the imaging center of each measuring device based on the deflection angle and the pitch angle of each measuring device;

[0088] The coordinate correction unit is used to correct the coordinates of each measuring device based on the conversion matrix.

[0089] In some optional implementations, the positioning point coordinate calculation module includes:

[0090] A separate z-axis coordinate solving unit is used to respectively construct functional relationships of x-axis data between two measuring devices and a positioning point, wherein both functional relationships use the z-axis data of each measuring device as a variable, and the two functional relationships are combined to solve the first z-axis coordinate of the positioning point. At the same time, functional relationships of y-axis data between two measuring devices and the positioning point are respectively constructed, wherein both functional relationships use the z-axis data of each measuring device as a variable, and the two functional relationships are combined to solve the second z-axis coordinate of the positioning point;

[0091] A z-axis coordinate determining unit, used to use the average value of the first z-axis coordinate and the second z-axis coordinate as the z-axis coordinate of the positioning point;

[0092] The x-axis and y-axis coordinate determination unit is used to substitute the z-axis coordinate of the positioning point into the functional relationship of the two x-axis data, obtain the two x-axis coordinates of the positioning point, and take the average value as the final x-axis coordinate of the positioning point. At the same time, the z-axis coordinate of the positioning point is substituted into the functional relationship of the two y-axis data, obtain the two y-axis coordinates of the positioning point, and take the average value as the final y-axis coordinate of the positioning point.

[0093] In some optional implementations, in the measurement device coordinate determination module, the coordinates of the measurement device are inversely deduced by measuring the coordinates of known points on the fuselage.

[0094] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for locating strain measurement points on the outer surface of an aircraft structure, characterized in that: include: Step S1, obtaining the coordinates (x0, y0, z0) of the first measuring device and the coordinates (x1, y1, z1) of the second measuring device in the overall coordinate system of the aircraft; Step S2, controlling the lens deflection of the two measuring devices to lock the positioning point of the body surface whose coordinates are to be determined, obtaining the deflection angle α0 and the pitch angle θ0 of the first measuring device, and obtaining the deflection angle α1 and the pitch angle θ2 of the second measuring device; Step S3: construct functional relationships between the two measuring devices and the positioning points respectively, and combine the two functional relationships to solve the coordinates of the positioning points.

2. The method for locating strain measurement points on the outer surface of an aircraft structure according to claim 1, characterized in that: Step S2 further includes: Step S21, determining a conversion matrix between an installation positioning center and an imaging center of each measuring device based on a deflection angle and a pitch angle of each measuring device; Step S22: Correct the coordinates of each measuring device based on the transformation matrix.

3. The method for locating strain measurement points on the outer surface of an aircraft structure according to claim 1, characterized in that: Step S3 further comprises: Step S31, respectively constructing functional relationships of x-axis data between two measuring devices and the positioning point, wherein both functional relationships use z-axis data of each measuring device as a variable, and jointly solving the two functional relationships to obtain the first z-axis coordinate of the positioning point. Meanwhile, respectively constructing functional relationships of y-axis data between two measuring devices and the positioning point, wherein both functional relationships use z-axis data of each measuring device as a variable, and jointly solving the two functional relationships to obtain the second z-axis coordinate of the positioning point. Step S32, taking the average value of the first z-axis coordinate and the second z-axis coordinate as the z-axis coordinate of the positioning point; Step S33, respectively substitute the z-axis coordinate of the positioning point into the functional relationship of the two x-axis data to obtain the two x-axis coordinates of the positioning point, and take the average value as the final x-axis coordinate of the positioning point. At the same time, respectively substitute the z-axis coordinate of the positioning point into the functional relationship of the two y-axis data to obtain the two y-axis coordinates of the positioning point, and take the average value as the final y-axis coordinate of the positioning point.

4. The method for locating strain measurement points on the outer surface of an aircraft structure according to claim 1, characterized in that: In step S1, the coordinates of the measuring device are inversely deduced by measuring the coordinates of known points on the fuselage.

5. A device for locating strain measurement points on the outer surface of an aircraft structure, characterized in that: include: A measuring device coordinate determination module, used to obtain the coordinates (x0, y0, z0) of the first measuring device and the coordinates (x1, y1, z1) of the second measuring device in the overall coordinate system of the aircraft; The measuring device parameter acquisition module is used to control the lens deflection of the two measuring devices to lock the positioning point of the coordinate to be determined on the body surface, obtain the deflection angle α0 and the pitch angle θ0 of the first measuring device, and obtain the deflection angle α1 and the pitch angle θ2 of the second measuring device; The positioning point coordinate calculation module is used to respectively construct functional relationships between the two measuring devices and the positioning point, and combine the two functional relationships to solve the coordinates of the positioning point.

6. The device for locating strain measurement points on the outer surface of an aircraft structure according to claim 5, characterized in that: The measuring device parameter acquisition module also includes: A conversion matrix calculation unit, used to determine the conversion matrix between the installation positioning center and the imaging center of each measuring device based on the deflection angle and the pitch angle of each measuring device; The coordinate correction unit is used to correct the coordinates of each measuring device based on the conversion matrix.

7. The device for locating strain measurement points on the outer surface of an aircraft structure according to claim 5, characterized in that: The positioning point coordinate calculation module includes: A separate z-axis coordinate solving unit is used to respectively construct functional relationships of x-axis data between two measuring devices and a positioning point, wherein both functional relationships use the z-axis data of each measuring device as a variable, and the two functional relationships are combined to solve the first z-axis coordinate of the positioning point. At the same time, functional relationships of y-axis data between two measuring devices and the positioning point are respectively constructed, wherein both functional relationships use the z-axis data of each measuring device as a variable, and the two functional relationships are combined to solve the second z-axis coordinate of the positioning point; A z-axis coordinate determining unit, used to use the average value of the first z-axis coordinate and the second z-axis coordinate as the z-axis coordinate of the positioning point; The x-axis and y-axis coordinate determination unit is used to substitute the z-axis coordinate of the positioning point into the functional relationship of the two x-axis data, obtain the two x-axis coordinates of the positioning point, and take the average value as the final x-axis coordinate of the positioning point. At the same time, the z-axis coordinate of the positioning point is substituted into the functional relationship of the two y-axis data, obtain the two y-axis coordinates of the positioning point, and take the average value as the final y-axis coordinate of the positioning point.

8. The device for locating strain measurement points on the outer surface of an aircraft structure according to claim 5, characterized in that: In the measuring device coordinate determination module, the coordinates of the measuring device are inversely deduced by measuring the coordinates of known points on the fuselage.

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