Detailed Description
The technical scheme of the invention is as follows:
firstly, carrying out intersection imaging on a wind tunnel test model according to a stereoscopic vision measurement principle; calibrating the system before testing; in the test process, the focal length, distortion, image principal point and other internal parameters of the camera are assumed to be kept fixed; meanwhile, the postures of the observation camera and the test model are assumed to be influenced by field airflow and vibration and have offset changes relative to a test section coordinate system.
Secondly, taking the three-dimensional initial coordinates of all the characteristic mark points in the zero state of the test model in a static state as reference, regarding a test model body and a test section wall plate as two independent rigid bodies, and keeping the three-dimensional relative position coordinates of the characteristic mark points in the test process fixed and unchanged; the wing of the test model is regarded as an elastic body, and the image coordinates of the characteristic points of the wing meet the epipolar constraint condition all the time in the test process according to the stereoscopic vision measurement principle.
And thirdly, solving the optimal solution of the equation by using a beam adjustment method by taking a photogrammetric collinear equation as an observation equation, taking rigid body constraint of a model fuselage, rigid body constraint of a test section wallboard and polar line constraint of a model wing as constraint conditions, taking the real-time attitude of the camera and the real-time attitude of the model as unknown variables, taking three-dimensional coordinates of all mark points in a zero state and the initial attitude of the camera as initial values for each frame of image in the test process.
As shown in fig. 1 and fig. 2, a multi-constraint wind tunnel test model deformation video measurement vibration correction method specifically includes the following steps:
step one, arranging a video observation camera:
the method comprises the following steps that two observation cameras (marked as a 1# camera and a 2# camera) are used for carrying out intersection imaging on measurement parts of a test model, the two cameras synchronously trigger acquisition during testing, and all characteristic mark points which are arranged on a wind tunnel test section wallboard and the test model in advance can be observed by the two cameras simultaneously. The arrangement method of the characteristic mark points comprises the following steps:
using the circular characteristic mark points, regarding the body of the test model as a rigid body, arranging more than 3 characteristic mark points on the rigid body, wherein the position distribution of the mark points can not be all on the same straight line; regarding the wing of the test model as an elastic body, and arranging more than 2 characteristic mark points on each measuring section in a straight line; the bottom of the wall plate of the test section is also regarded as a rigid body, more than 3 characteristic mark points are arranged on the rigid body, and the position distribution positions of the mark points cannot be all on the same straight line.
Step two, establishing an image point projection observation equation:
in the zero state of the wind tunnel test model, the initial value image coordinates and three-dimensional coordinates of all characteristic points are collected and calculated, and the initial value of the three-dimensional coordinates of the characteristic points corresponding to the test section coordinate system is set asThe relative pose relationship matrix between the two cameras isDefining a camera coordinate system as a No. 1 camera coordinate system, and defining the initial value of the three-dimensional coordinate of the feature point in the camera coordinate system asIn the wind tunnel test process, due to the influence of field vibration, the position of the camera in the test section deviates from the initial value, and a new pose relationship between the n frame image cameras is set asThe three-dimensional coordinates of the feature points in the camera coordinate system areCorresponding to the three-dimensional coordinates under the coordinate system of the test section as
Setting the three-dimensional coordinates of any feature point P in the coordinate systems of the 1# camera and the 2# camera as P1=[X1 Y1 Z1]TAnd P2=[X2 Y2 Z2]TWhich satisfy the relationshipThe normalized image point coordinates after corresponding distortion correction are(normalized formula isWherein x and y are characteristic point image coordinates, u and v are image principal points, and fx、fyEquivalent focal length).
From the above definitions and the camera aperture imaging principle, the collinearity equation for the feature points P is simplified as follows:
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rewriting is in matrix form:
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The above equation holds for all feature points at all times:
in the zero state, the voltage of the power supply is zero,
the image of the n-th frame is processed,
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step three, establishing a rigid body and polar line constraint equation:
(1) for the three-dimensional coordinates of the feature mark points on the test model body, the three-dimensional coordinates meet rigid body constraint conditions, and for a rigid body, the rotation and translation are only 6 degrees of freedom in total. When the wind tunnel blows, the observed position and posture of the model body under the camera coordinate system change intoThe following rigid body can be obtainedConstraint equation:
wherein i represents the characteristic points of the model fuselage,and representing the three-dimensional coordinate values of all the feature points in the camera coordinate system in the zero state of the model.
The position and attitude change of the lower camera coordinate system of the test segment coordinate system is represented as Rn、TnThe position and posture change of the test model is expressed asThe following relationship holds:
(2) for the characteristic mark points of the wall plate of the test section, the three-dimensional coordinates under the coordinate system of the test section are kept fixed, and the three-dimensional coordinates under the corresponding camera coordinate system also meet the rigid body constraint condition:
where j represents a wallboard feature point.
(3) For a test model wing, the rigidity is relatively weak, elastic deformation occurs due to the action of aerodynamic load, and the image point coordinates meet the epipolar constraint condition:
in the formula, k represents the characteristic point of the model wing,homogeneous coordinates of normalized image points for 1# camera and 2# cameraAnd
order to Then
Step four, constructing an iterative equation:
substituting the constraint (0.3) into the observation equation (0.2) yields:
setting function
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let the objective function L1And L2The mode of (2) is minimum, a normal equation set can be obtained, and the method is rewritten into a matrix form:
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Similarly, the coordinates of the characteristic points of the wallboard satisfy the formula:
definition of RnHas a mean difference parameter of ΔTn=ΔTnAnd performing first-order Taylor expansion on the above formula to obtain an error formula:
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to make the objective function L3And L4Is minimized, can be obtainedThe system of normal equations:
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<mi>ΔT</mi>
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</msub>
</mtd>
</mtr>
<mtr>
<mtd>
<msub>
<mi>Δw</mi>
<mi>n</mi>
</msub>
</mtd>
</mtr>
<mtr>
<mtd>
<msub>
<mi>ΔT</mi>
<mi>n</mi>
</msub>
</mtd>
</mtr>
</mtable>
</mfenced>
<mo>=</mo>
<mfenced open='[' close=']'>
<mtable>
<mtr>
<mtd>
<mo>-</mo>
<mi>Δ</mi>
<msub>
<mi>F</mi>
<mn>4</mn>
</msub>
</mtd>
</mtr>
<mtr>
<mtd>
<mo>-</mo>
<mi>Δ</mi>
<msub>
<mi>F</mi>
<mn>3</mn>
</msub>
</mtd>
</mtr>
</mtable>
</mfenced>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>0.8</mn>
<mo>)</mo>
</mrow>
</mrow></math>
the above formula holds true for all the feature points j of the wall plate, wherein <math><mrow>
<msub>
<mi>J</mi>
<mn>6</mn>
</msub>
<mo>=</mo>
<mo>-</mo>
<msubsup>
<mi>R</mi>
<mi>c</mi>
<mi>n</mi>
</msubsup>
<msub>
<mrow>
<mo>|</mo>
<msubsup>
<mi>P</mi>
<mi>jc</mi>
<mn>0</mn>
</msubsup>
<mo>|</mo>
</mrow>
<mo>×</mo>
</msub>
<mo>.</mo>
</mrow></math>
Defining function for model wing feature pointsWhereinDefinition of <math><mrow>
<mfenced open='[' close=']'>
<mtable>
<mtr>
<mtd>
<msub>
<mi>t</mi>
<mn>1</mn>
</msub>
</mtd>
<mtd>
<msub>
<mi>t</mi>
<mn>2</mn>
</msub>
</mtd>
<mtd>
<msub>
<mi>t</mi>
<mn>3</mn>
</msub>
</mtd>
</mtr>
</mtable>
</mfenced>
<mo>=</mo>
<msub>
<mrow>
<mo>|</mo>
<msubsup>
<mi>T</mi>
<mi>c</mi>
<mi>n</mi>
</msubsup>
<mo>|</mo>
</mrow>
<mo>×</mo>
</msub>
<mo>=</mo>
<mfenced open='[' close=']'>
<mtable>
<mtr>
<mtd>
<mn>0</mn>
</mtd>
<mtd>
<msub>
<mrow>
<mo>-</mo>
<mi>t</mi>
</mrow>
<mn>3</mn>
</msub>
</mtd>
<mtd>
<msub>
<mi>t</mi>
<mn>2</mn>
</msub>
</mtd>
</mtr>
<mtr>
<mtd>
<msub>
<mi>t</mi>
<mn>3</mn>
</msub>
</mtd>
<mtd>
<mn>0</mn>
</mtd>
<mtd>
<msub>
<mrow>
<mo>-</mo>
<mi>t</mi>
</mrow>
<mn>1</mn>
</msub>
</mtd>
</mtr>
<mtr>
<mtd>
<mo>-</mo>
<msub>
<mi>t</mi>
<mn>2</mn>
</msub>
</mtd>
<mtd>
<msub>
<mi>t</mi>
<mn>1</mn>
</msub>
</mtd>
<mtd>
<mn>0</mn>
</mtd>
</mtr>
</mtable>
</mfenced>
<mo>,</mo>
</mrow></math> Function f5Is deformed into
For function f5To carry outFirst order taylor expansion, resulting in an error equation:
<math><mrow>
<msub>
<mi>Δf</mi>
<mn>5</mn>
</msub>
<mo>+</mo>
<msup>
<mrow>
<mo>(</mo>
<msubsup>
<mi>P</mi>
<mrow>
<mi>k</mi>
<mn>2</mn>
</mrow>
<mi>n</mi>
</msubsup>
<mo>)</mo>
</mrow>
<mi>T</mi>
</msup>
<mrow>
<mo>(</mo>
<msub>
<mi>J</mi>
<mn>7</mn>
</msub>
<msub>
<mi>Δw</mi>
<mi>c</mi>
</msub>
<mo>-</mo>
<msubsup>
<mi>R</mi>
<mi>c</mi>
<mi>n</mi>
</msubsup>
<msub>
<mrow>
<mo>|</mo>
<msubsup>
<mi>P</mi>
<mrow>
<mi>k</mi>
<mn>1</mn>
</mrow>
<mi>n</mi>
</msubsup>
<mo>|</mo>
</mrow>
<mo>×</mo>
</msub>
<msub>
<mi>ΔT</mi>
<mi>c</mi>
</msub>
<mo>)</mo>
</mrow>
<mo>+</mo>
<msub>
<mi>l</mi>
<mi>k</mi>
</msub>
<mo>=</mo>
<mn>0</mn>
</mrow></math>
in the formula,
<math><mrow>
<msub>
<mi>J</mi>
<mn>7</mn>
</msub>
<mo>=</mo>
<mo>-</mo>
<msub>
<mi>x</mi>
<mn>1</mn>
</msub>
<msub>
<mrow>
<mo>|</mo>
<msub>
<mi>t</mi>
<mn>1</mn>
</msub>
<mo>|</mo>
</mrow>
<mo>×</mo>
</msub>
<mo>-</mo>
<msub>
<mi>y</mi>
<mn>1</mn>
</msub>
<msub>
<mrow>
<mo>|</mo>
<msub>
<mi>t</mi>
<mn>2</mn>
</msub>
<mo>|</mo>
</mrow>
<mo>×</mo>
</msub>
<mo>-</mo>
<msub>
<mrow>
<mo>|</mo>
<msub>
<mi>t</mi>
<mn>3</mn>
</msub>
<mo>|</mo>
</mrow>
<mo>×</mo>
</msub>
<mo>=</mo>
<mfenced open='[' close=']'>
<mtable>
<mtr>
<mtd>
<mn>0</mn>
</mtd>
<mtd>
<msub>
<mi>x</mi>
<mn>1</mn>
</msub>
<msub>
<mi>t</mi>
<mn>2</mn>
</msub>
<mo>-</mo>
<msub>
<mi>y</mi>
<mn>1</mn>
</msub>
<msub>
<mi>t</mi>
<mn>1</mn>
</msub>
</mtd>
<mtd>
<msub>
<mi>x</mi>
<mn>1</mn>
</msub>
<msub>
<mi>t</mi>
<mn>3</mn>
</msub>
<mo>-</mo>
<msub>
<mi>t</mi>
<mn>1</mn>
</msub>
</mtd>
</mtr>
<mtr>
<mtd>
<mo>-</mo>
<msub>
<mi>x</mi>
<mn>1</mn>
</msub>
<msub>
<mi>t</mi>
<mn>2</mn>
</msub>
<mo>+</mo>
<msub>
<mi>y</mi>
<mn>1</mn>
</msub>
<msub>
<mi>t</mi>
<mn>1</mn>
</msub>
</mtd>
<mtd>
<mn>0</mn>
</mtd>
<mtd>
<msub>
<mi>y</mi>
<mn>1</mn>
</msub>
<msub>
<mi>t</mi>
<mn>3</mn>
</msub>
<mo>-</mo>
<msub>
<mi>t</mi>
<mn>2</mn>
</msub>
</mtd>
</mtr>
<mtr>
<mtd>
<mo>-</mo>
<msub>
<mi>x</mi>
<mn>1</mn>
</msub>
<msub>
<mi>t</mi>
<mn>3</mn>
</msub>
<mo>+</mo>
<msub>
<mi>t</mi>
<mn>1</mn>
</msub>
</mtd>
<mtd>
<mo>-</mo>
<msub>
<mi>y</mi>
<mn>1</mn>
</msub>
<msub>
<mi>t</mi>
<mn>3</mn>
</msub>
<mo>+</mo>
<msub>
<mi>t</mi>
<mn>2</mn>
</msub>
</mtd>
<mtd>
<mn>0</mn>
</mtd>
</mtr>
</mtable>
</mfenced>
<mo>=</mo>
<msub>
<mfenced open='|' close='|'>
<mtable>
<mtr>
<mtd>
<msub>
<mi>y</mi>
<mn>1</mn>
</msub>
<msub>
<mi>t</mi>
<mn>3</mn>
</msub>
<mo>-</mo>
<msub>
<mi>t</mi>
<mn>2</mn>
</msub>
</mtd>
</mtr>
<mtr>
<mtd>
<msub>
<mrow>
<mo>-</mo>
<mi>x</mi>
</mrow>
<mn>1</mn>
</msub>
<msub>
<mi>t</mi>
<mn>3</mn>
</msub>
<mo>+</mo>
<msub>
<mi>t</mi>
<mn>1</mn>
</msub>
</mtd>
</mtr>
<mtr>
<mtd>
<msub>
<mi>x</mi>
<mn>1</mn>
</msub>
<msub>
<mi>t</mi>
<mn>2</mn>
</msub>
<mo>-</mo>
<msub>
<mi>y</mi>
<mn>1</mn>
</msub>
<msub>
<mi>t</mi>
<mn>1</mn>
</msub>
</mtd>
</mtr>
</mtable>
</mfenced>
<mo>×</mo>
</msub>
<mo>,</mo>
</mrow></math>
rewriting is in matrix form:
<math><mrow>
<mfenced open='[' close=']'>
<mtable>
<mtr>
<mtd>
<msup>
<mrow>
<mo>(</mo>
<msubsup>
<mi>P</mi>
<mrow>
<mi>k</mi>
<mn>2</mn>
</mrow>
<mi>n</mi>
</msubsup>
<mo>)</mo>
</mrow>
<mi>T</mi>
</msup>
<msub>
<mi>J</mi>
<mn>7</mn>
</msub>
</mtd>
<mtd>
<mo>-</mo>
<msup>
<mrow>
<mo>(</mo>
<msubsup>
<mi>P</mi>
<mrow>
<mi>k</mi>
<mn>2</mn>
</mrow>
<mi>n</mi>
</msubsup>
<mo>)</mo>
</mrow>
<mi>T</mi>
</msup>
<msubsup>
<mi>R</mi>
<mi>c</mi>
<mi>n</mi>
</msubsup>
<msub>
<mrow>
<mo>|</mo>
<msubsup>
<mi>P</mi>
<mrow>
<mi>k</mi>
<mn>1</mn>
</mrow>
<mi>n</mi>
</msubsup>
<mo>|</mo>
</mrow>
<mo>×</mo>
</msub>
</mtd>
</mtr>
</mtable>
</mfenced>
<mfenced open='[' close=']'>
<mtable>
<mtr>
<mtd>
<msub>
<mi>Δw</mi>
<mi>c</mi>
</msub>
</mtd>
</mtr>
<mtr>
<mtd>
<msub>
<mi>ΔT</mi>
<mi>c</mi>
</msub>
</mtd>
</mtr>
</mtable>
</mfenced>
<mo>=</mo>
<mo>[</mo>
<msub>
<mrow>
<mo>-</mo>
<mi>Δf</mi>
</mrow>
<mn>5</mn>
</msub>
<mo>]</mo>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>0.9</mn>
<mo>)</mo>
</mrow>
</mrow></math>
the above equation holds for all the wing feature points k, so that the objective function is <math><mrow>
<msub>
<mi>L</mi>
<mn>5</mn>
</msub>
<mo>=</mo>
<mfenced open='[' close=']'>
<mtable>
<mtr>
<mtd>
<msub>
<mi>l</mi>
<mn>1</mn>
</msub>
</mtd>
</mtr>
<mtr>
<mtd>
<mo>·</mo>
</mtd>
</mtr>
<mtr>
<mtd>
<mo>·</mo>
</mtd>
</mtr>
<mtr>
<mtd>
<mo>·</mo>
</mtd>
</mtr>
<mtr>
<mtd>
<msub>
<mi>l</mi>
<mi>k</mi>
</msub>
</mtd>
</mtr>
</mtable>
</mfenced>
</mrow></math> The norm is the minimum, and a system of normal equations can be obtained:
<math><mrow>
<mfenced open='[' close=']'>
<mtable>
<mtr>
<mtd>
<msup>
<mrow>
<mo>(</mo>
<msubsup>
<mi>P</mi>
<mn>12</mn>
<mi>n</mi>
</msubsup>
<mo>)</mo>
</mrow>
<mi>T</mi>
</msup>
<msup>
<msub>
<mi>J</mi>
<mn>7</mn>
</msub>
<mn>1</mn>
</msup>
<mo>-</mo>
<msup>
<mrow>
<mo>(</mo>
<msubsup>
<mi>P</mi>
<mn>12</mn>
<mi>n</mi>
</msubsup>
<mo>)</mo>
</mrow>
<mi>T</mi>
</msup>
<msubsup>
<mi>R</mi>
<mi>c</mi>
<mi>n</mi>
</msubsup>
<msub>
<mrow>
<mo>|</mo>
<msubsup>
<mi>P</mi>
<mn>11</mn>
<mi>n</mi>
</msubsup>
<mo>|</mo>
</mrow>
<mo>×</mo>
</msub>
</mtd>
</mtr>
<mtr>
<mtd>
<mo>·</mo>
</mtd>
</mtr>
<mtr>
<mtd>
<mo>·</mo>
</mtd>
</mtr>
<mtr>
<mtd>
<mo>·</mo>
</mtd>
</mtr>
<mtr>
<mtd>
<msup>
<mrow>
<mo>(</mo>
<msubsup>
<mi>P</mi>
<mrow>
<mi>k</mi>
<mn>2</mn>
</mrow>
<mi>n</mi>
</msubsup>
<mo>)</mo>
</mrow>
<mi>T</mi>
</msup>
<msup>
<msub>
<mi>J</mi>
<mn>7</mn>
</msub>
<mi>k</mi>
</msup>
<mo>-</mo>
<msup>
<mrow>
<mo>(</mo>
<msubsup>
<mi>P</mi>
<mrow>
<mi>k</mi>
<mn>2</mn>
</mrow>
<mi>n</mi>
</msubsup>
<mo>)</mo>
</mrow>
<mi>T</mi>
</msup>
<msubsup>
<mi>R</mi>
<mi>c</mi>
<mi>n</mi>
</msubsup>
<msub>
<mrow>
<mo>|</mo>
<msubsup>
<mi>P</mi>
<mrow>
<mi>k</mi>
<mn>1</mn>
</mrow>
<mi>n</mi>
</msubsup>
<mo>|</mo>
</mrow>
<mo>×</mo>
</msub>
</mtd>
</mtr>
</mtable>
</mfenced>
<mfenced open='[' close=']'>
<mtable>
<mtr>
<mtd>
<msub>
<mi>Δw</mi>
<mi>c</mi>
</msub>
</mtd>
</mtr>
<mtr>
<mtd>
<msub>
<mi>ΔT</mi>
<mi>c</mi>
</msub>
</mtd>
</mtr>
</mtable>
</mfenced>
<mo>=</mo>
<msub>
<mfenced open='[' close=']'>
<mtable>
<mtr>
<mtd>
<mrow>
<mo>-</mo>
<mi>Δ</mi>
</mrow>
<msup>
<msub>
<mi>f</mi>
<mn>5</mn>
</msub>
<mn>1</mn>
</msup>
</mtd>
</mtr>
<mtr>
<mtd>
<mo>·</mo>
</mtd>
</mtr>
<mtr>
<mtd>
<mo>·</mo>
</mtd>
</mtr>
<mtr>
<mtd>
<mo>·</mo>
</mtd>
</mtr>
<mtr>
<mtd>
<mrow>
<mo>-</mo>
<mi>Δ</mi>
<msup>
<msub>
<mi>f</mi>
<mn>5</mn>
</msub>
<mi>k</mi>
</msup>
</mrow>
</mtd>
</mtr>
</mtable>
</mfenced>
<mrow>
<mi>k</mi>
<mo>×</mo>
<mn>1</mn>
</mrow>
</msub>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>0.10</mn>
<mo>)</mo>
</mrow>
</mrow></math>
assuming that the system has i model fuselage feature points, j test segment wall plate points and k model wing feature points, combining the formulas (0.7), (0.8) and (0.10), and assuming that all the formulas have the same weight, an iterative equation containing 18 adjustment variables can be obtained:
in the above formula <math><mrow>
<msup>
<msub>
<mi>J</mi>
<mn>1</mn>
</msub>
<mi>i</mi>
</msup>
<mo>=</mo>
<mo>-</mo>
<msub>
<mrow>
<mo>|</mo>
<msubsup>
<mi>P</mi>
<mi>ic</mi>
<mn>0</mn>
</msubsup>
<mo>|</mo>
</mrow>
<mo>×</mo>
</msub>
<mo>,</mo>
</mrow></math> <math><mrow>
<msup>
<msub>
<mi>J</mi>
<mn>2</mn>
</msub>
<mi>i</mi>
</msup>
<mo>=</mo>
<msubsup>
<mrow>
<mo>-</mo>
<mi>R</mi>
</mrow>
<mi>c</mi>
<mi>n</mi>
</msubsup>
<msub>
<mrow>
<mo>|</mo>
<msubsup>
<mi>P</mi>
<mi>ic</mi>
<mn>0</mn>
</msubsup>
<mo>|</mo>
</mrow>
<mo>×</mo>
</msub>
<mo>,</mo>
</mrow></math> <math><mrow>
<msup>
<msub>
<mi>J</mi>
<mn>3</mn>
</msub>
<mi>i</mi>
</msup>
<mo>=</mo>
<mo>-</mo>
<msub>
<mrow>
<mo>|</mo>
<msubsup>
<mi>R</mi>
<mi>mc</mi>
<mi>n</mi>
</msubsup>
<msubsup>
<mi>P</mi>
<mi>ic</mi>
<mn>0</mn>
</msubsup>
<mo>+</mo>
<msubsup>
<mi>T</mi>
<mi>mc</mi>
<mi>n</mi>
</msubsup>
<mo>|</mo>
</mrow>
<mo>×</mo>
</msub>
<mo>,</mo>
</mrow></math> <math><mrow>
<msup>
<msub>
<mi>J</mi>
<mn>4</mn>
</msub>
<mi>j</mi>
</msup>
<mo>=</mo>
<mo>-</mo>
<msub>
<mrow>
<msubsup>
<mrow>
<mo>|</mo>
<mi>P</mi>
</mrow>
<mi>jc</mi>
<mn>0</mn>
</msubsup>
<mo>|</mo>
</mrow>
<mo>×</mo>
</msub>
<mo>,</mo>
</mrow></math> <math><mrow>
<msup>
<msub>
<mi>J</mi>
<mn>5</mn>
</msub>
<mi>j</mi>
</msup>
<mo>=</mo>
<mo>-</mo>
<msub>
<mrow>
<mo>|</mo>
<msup>
<mi>R</mi>
<mi>n</mi>
</msup>
<msubsup>
<mi>P</mi>
<mi>jc</mi>
<mn>0</mn>
</msubsup>
<mo>+</mo>
<msup>
<mi>T</mi>
<mi>n</mi>
</msup>
<mo>|</mo>
</mrow>
<mo>×</mo>
</msub>
<mo>,</mo>
</mrow></math> <math><mrow>
<msup>
<msub>
<mi>J</mi>
<mn>6</mn>
</msub>
<mi>j</mi>
</msup>
<mo>=</mo>
<msubsup>
<mrow>
<mo>-</mo>
<mi>R</mi>
</mrow>
<mi>c</mi>
<mi>n</mi>
</msubsup>
<msub>
<mrow>
<mo>|</mo>
<msubsup>
<mi>P</mi>
<mi>jc</mi>
<mn>0</mn>
</msubsup>
<mo>|</mo>
</mrow>
<mo>×</mo>
</msub>
<mo>,</mo>
</mrow></math> <math><mrow>
<msup>
<msub>
<mi>J</mi>
<mn>7</mn>
</msub>
<mi>k</mi>
</msup>
<mo>=</mo>
<msub>
<mfenced open='|' close='|'>
<mtable>
<mtr>
<mtd>
<msup>
<msub>
<mi>y</mi>
<mn>1</mn>
</msub>
<mi>k</mi>
</msup>
<msub>
<mi>t</mi>
<mn>3</mn>
</msub>
<mo>-</mo>
<msub>
<mi>t</mi>
<mn>2</mn>
</msub>
</mtd>
</mtr>
<mtr>
<mtd>
<msup>
<msub>
<mrow>
<mo>-</mo>
<mi>x</mi>
</mrow>
<mn>1</mn>
</msub>
<mi>k</mi>
</msup>
<msub>
<mi>t</mi>
<mn>3</mn>
</msub>
<mo>+</mo>
<msub>
<mi>t</mi>
<mn>1</mn>
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<mi>x</mi>
<mn>1</mn>
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<mi>k</mi>
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<mi>t</mi>
<mn>2</mn>
</msub>
<mo>-</mo>
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<mi>y</mi>
<mn>1</mn>
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<mo>×</mo>
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In the process of actual engineering application, the equation can be simplified according to the actual test conditions of the wind tunnel site. For example, for missile-type test models without elastomeric components, all of the equations above may be eliminatedAndthe iterative equation can also hold; for another example, without considering the constraints of the panel points of the test segment, the coefficient matrix of the above iterative equation removes the last 4j rows and modifies the adjustment parameter to <math><mrow>
<msub>
<mfenced open='[' close=']'>
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<mtr>
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<mi>Δw</mi>
<mi>mc</mi>
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<mi>ΔT</mi>
<mi>mc</mi>
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<mi>c</mi>
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The above iterative equation is abbreviated below as:
JΔD=ΔF (0.11)
step five, iteratively solving the optimal solution of the equation set:
relative attitude between cameras at system zero state(derived from system calibration) decomposition constitutes the initial value of the iteration Taking the three-dimensional coordinates and image coordinates of all characteristic points in the zero state of the model asAnd the normalized coordinates of the image points of the wing feature points at the moment of the image frame nA deviation matrix deltaf is constructed. The correction Δ D = (J) of the current adjustment parameter D is obtained by using equation (0.11)T J)-1JTΔ F, update iteration parameter D = D0+ΔD。
Recalculating matrices J and delta F by using the new iteration parameter as an initial value, calculating the correction delta D of the new adjustment parameter D, and repeating the iteration calculation until delta FTAnd when the delta F is smaller than a given threshold value, the iterative calculation process is ended, and the obtained iterative parameter D is the optimal solution meeting all constraint conditions of the system.
And step six, reconstructing the current camera posture and the model posture. Including new pose relationships for the camera at the current timeCamera coordinate system vibration correction Rn、TnAnd model pose
And expressing the optimal solution D obtained by the calculation in the steps as follows: d = [ a ]1 b1 c1 t11 t12 t13 a2 b2 c2 t21 t22 t23 a3 b3 c3 t31 t32 t33]TAnd if so, the pose relationship between the 1# camera and the 2# camera at the current moment of the system is as follows:
wherein
The vibration correction quantity of the camera coordinate system is as follows:
wherein
The attitude of the test model in the test section coordinate system is as follows:
wherein 。