CN102288164A - Non-contact measuring method for deformation of aircraft wing structure - Google Patents

Abstract

The invention discloses a non-contact measuring method for deformation of an aircraft wing structure, which comprises the following steps: respectively fixing two cameras on two leveling gauges; rotating the cameras to a suitable position and recording angular magnitude of a left inner included angle and a right inner included angle; setting numerical reading of the leveling gauges to zero; photographing and measuring an interval between the two cameras; reading parameter values of characteristic points of photographs; calculating to obtain coordinate values of the photographs; and obtaining torsion angles of wings through converting the obtained space coordinates. The method can be used for measuring on a flying airplane and cannot be affected by the limit of porthole positions of the airplane, is insensitive to influence on mechanical vibrating strength and can be used in common flying environments.

Description

A kind of non-contact measurement method of aircraft wing malformation

Technical field

The invention belongs to aviation aeroelastic analysis technical field, especially in flight course, measure the method for its wing structure distortion at aircraft.

Background technology

Bigger malformation because effect has aerodynamic loading, can take place on the wing in aircraft in flight course, this distortion at present mainly utilizes computer Simulation calculation research, and does not have relevant experiment to be verified.Because when awing measuring, the observation place is subjected to the porthole position limit bigger, and the rules of aviation simultaneously do not allow to use laser instrument, high-power electronic device and wireless telecommunications system in flight course.And all used laser in the existing non-contact measurement method as light source or need on measured object, paste sensor etc., have also be by take finish but its total system all need in 22 degree constant temperature closed systems, so these methods all can not be used in and go in the aircraft flight process to measure.The development of digital camera and computer graphics in recent years makes that regaining spatial model by camera work becomes possibility.It number is 201010223691 that a patent application is arranged, name is called a kind of reconstructing method and device of three-dimensional model of high dynamic range texture, also finish three-dimensional geometry reconstruct by taking, but should invent the capture apparatus that adopts circulating type array to arrange, recover the response curve of capture apparatus and according to the response curve of capture apparatus, to the image of taking under the different exposure time calibration that exposes, to recover the three-dimensional network model.But the capture apparatus that circulating type array is arranged can't be implemented under aircraft cruising condition environment.The quiet distortion of structure in the aircraft flight process does not all the time all have experimental data, so the quiet calculation of Deformation accuracy of aircraft aeroelasticity is difficult to effectively be verified.Therefore, from aviation aeroelastic analysis technical field, the method that develops a kind of measurement structure distortion that effectively also can implement under aircraft cruising condition environment has practical value very much.

Summary of the invention

In order to overcome the deficiency of the structure quiet distortion of prior art in measuring the aircraft flight process, the invention provides a kind of non-contact measurement method of aircraft wing malformation.Utilize two digital cameras that same model is taken pictures from different perspectives, utilize triangle geometry reconstruction method comparison film to handle the three-dimensionalreconstruction of implementation model then, obtain the distance between 2 on the model, finally can by relatively land static when cruising two different states obtain the quiet distortion of aircraft wing, thereby can effectively verify the accuracy of the quiet The deformation calculation machine of aircraft aeroelasticity analog computation.

The technical solution adopted for the present invention to solve the technical problems may further comprise the steps:

(1) two cameras is separately fixed on two level meters;

(2) rotary camera makes two interior angle α 1, α 2 between 55 ° to 75 °, described in angle be the camera lens primary optical axis (promptly by the camera lens center of circle and perpendicular to lens plane the axle) and two camera lines between angle, interior angle between left side camera lens primary optical axis and the two camera lines is α 1, and the interior angle between right camera lens primary optical axis and the two camera lines is α 2;

(3) to make its reading be zero and remain to the end of taking pictures to adjust level meter;

(4) object that will measure is taken pictures after adjusting two interior angles and level meter, and measure the distance L of two cameras this moment;

(5) choose wing wing leading edge point C slightly ₀With trailing edge point F ₀Be unique point, read the pixel coordinate value of relevant position point on the photo, the pixel coordinate of left-hand point C in the left photo (a, b), the pixel coordinate that right-hand point F is ordered be (c, d); The pixel coordinate of right photo left-hand point C ' point be (A, B), the pixel coordinate that right-hand point F ' puts be (C, D);

(6) check the attribute of choosing photo, obtain horizontal, vertical pixel value (P of left photo ₁XP ₂) and equivalent 35mm egative film focal distance f ₁Horizontal, vertical pixel value (Q of right photo ₁XQ ₂) and equivalent 35mm egative film focal distance f ₂Two photo centre coordinates are respectively (X ₀, Y ₀), (X ₀₀, Y ₀₀), X wherein ₀=P ₁/ 2, Y ₀=P ₂/ 2, X ₀₀=Q ₁/ 2, Y ₀₀=Q ₂/ 2.

(7) true origin in the step (5) is moved to optical center, obtaining the new coordinate that left photo C orders by image-forming principle is (X ₀-a, b-Y ₀), the new coordinate that F is ordered is (X ₀-c, d-Y ₀); The new coordinate of right photo C ' point is (X ₀₀-A, B-Y ₀₀), the new coordinate of F ' point is (X ₀₀-C, D-Y ₀₀);

The horizontal stroke of known 35mm film, longitudinal size are (36x24) mm, (coordinate of being got is a right-handed coordinate system by calculating 2 spatial values with respect to left camera, be the initial point of volume coordinate promptly with left camera central point O, X-axis is the line direction of two cameras, Y-axis and body longitudinal axis parallel direction are upwards, Z axle and camera lens primary optical axis parallel direction are the outer normal direction of lens plane), some C ₀(X _c, Y _c, Z _c), the some F ₀(X _F, Y _F, Z _F), obtain the distance that needs at last:

$1=\sqrt{{(X_c-X_F)}^2+{(Y_c-Y_F)}^2+{(Z_c-Z_F)}^2}$

Wherein, Xc=a ₀* cos ∠ C ₀OE, Y ₀₁=a ₀* sin γ ₁, Y ₀₂=a ₁* sin γ ₂,

Z _C＝a ₀*sin∠C ₀OE；

X _F＝b ₀*cos∠F ₀OE，Y ₁₁＝b ₀*sinγ ₃、Y ₁₂＝b ₁*sinγ ₄，

Z _F＝b ₀*sin∠F ₀OE；

∠C ₀OE＝α ₁+θ ₁；∠OEC ₀＝α ₂-θ ₂；∠OC ₀E＝180°-∠C ₀OE-∠OEC ₀；

∠F ₀OE＝α ₁+θ ₃；∠OEF ₀＝α ₂-θ ₄；∠OF ₀E＝180°-∠F ₀OE-∠OEF ₀；

a ₀, a ₁Obtain by sine:

In like manner can obtain b ₀, b ₁

${\mathrm{\θ}}_1={\tan }^{-1}\frac{36*(X_0-a)/P_1}{f_1};$ ${\mathrm{\θ}}_2={\tan }^{-1}\frac{36*(X_{00}-A)/Q_1}{f_2};$ ${\mathrm{\θ}}_3={\tan }^{-1}\frac{36*(X_0-c)/P_1}{f_1};$

${\mathrm{\θ}}_4={\tan }^{-1}\frac{36*(X_{00}-C)/Q_1}{f_2};$ ${\mathrm{\γ}}_1={\tan }^{-1}\frac{24*\left({b-Y}_0\right)/P_2}{f_1};$ ${\mathrm{\γ}}_2={\tan }^{-1}\frac{24*\left({B-Y}_{00}\right)/Q_2}{f_2};$

${\mathrm{\γ}}_3={\tan }^{-1}\frac{24*\left({d-Y}_0\right)/P_2}{f_1};$ ${\mathrm{\γ}}_4={\tan }^{-1}\frac{24*\left({D-Y}_{00}\right)/Q_2}{f_2};$

Wherein, a ₀Be a C ₀And the distance between the left camera, a ₁Be a C ₀With the distance of right camera, θ ₁Be a C ₀With left camera line at the projection on XY plane and the angle of X-axis, θ ₂Be a C ₀With right camera line at the projection on XY plane and the angle of X-axis, γ ₁Be a C ₀With left camera line at the projection on YZ plane and the angle of Y-axis, γ ₂Be a C ₀With right camera line at the projection on YZ plane and the angle of Y-axis;

b ₀Be a C ₀And the distance between the left camera, b ₁Be a C ₀With the distance of right camera, θ ₃Be a F ₀With left camera line at the projection on XY plane and the angle of X-axis, θ ₄Be a F ₀With right camera line at the projection on XY plane and the angle of X-axis, γ ₃Be a F ₀With left camera line at the projection on YZ plane and the angle of Y-axis, γ ₄Be a F ₀With right camera line at the projection on YZ plane and the angle of Y-axis.The coordinate of being got is a right-handed coordinate system, true origin O is left camera central point, X-axis is the line direction of two cameras, and Y-axis is that parallel direction is downward with the body longitudinal axis (promptly perpendicular to that axle of the surface level), and Z axle and camera lens primary optical axis parallel direction are the outer normal direction of lens plane.Point E is right camera central point, and the XY plane is the plane of vertical Z axle, and the YZ plane is the plane of vertical X-axis.

(8) land stationary state at aircraft and carry out (1)～(7) set by step, obtain the wing wing volume coordinate (X of leading edge point slightly _C1, Y _C1, Z _C1), trailing edge F ₀Point (X _F1, Y _F1, Z _F1) and wing wing chord length slightly

$l=\sqrt{{(X_{C1}-X_{F1})}^2+{(Y_{C1}-Y_{F1})}^2+{(Z_{C1}-Z_{F1})}^2};$

Repeated execution of steps (1)～(7) when the aircraft cruising condition calculate the volume coordinate (X of wing nose of wing point _C2, Y _C2, Z _C2), trailing edge F ₀' point (X _F2, Y _F2, Z _F2) and wing wing chord length slightly

$l^{\′}=\sqrt{{(X_{C2}-X_{F2})}^2+{(Y_{C2}-Y_{F2})}^2+{(Z_{C2}-Z_{F2})}^2};$

Thereby calculate the cruising condition bottom wing slightly leading edge point y to being deformed into Δ Y ₁=| Y _C1-Y _C2|, trailing edge point y is to being deformed into Δ Y ₂=| Y _F1-Y _F2|, obtain the section torsion angle and be

In addition, it should be noted that in the aforesaid operations step:

1. owing to use 2 tests, two cameras should guarantee when taking that the body longitudinal axis (perpendicular to that axle of surface level) is parallel.

2. when suggestion is taken, adopt the high image quality of camera, maximum pixel, and use the longest burnt end to take two interior angle α ₁, α ₂All try one's best near 60 ° (55 ° to 75 °), the precision that obtains like this is the highest.

The invention has the beneficial effects as follows:

1. the present invention can measure the three-dimensional coordinate of certain point on the figure and scheme to go up any space length at 2 by two photos of taking from different perspectives;

2. because the present invention is the mode by taking pictures, adopt triangle geometry reconstruction method to come computed range, therefore the equipment that does not need laser instrument, high-power electronic device and wireless telecommunications system or sensor and so on, so without prejudice to relevant laws and regulations, and can on the aircraft of flight, measure;

3. the present invention can not be subjected to the influence of aircraft porthole position limit in force, and the influence of body y direction is little, so native system is insensitive to the intensity effect of mechanical vibration, can use in general flight environment of vehicle.

The present invention is further described below in conjunction with drawings and Examples.

Description of drawings

Fig. 1 is the synoptic diagram of the inventive method operational flowchart;

Fig. 2 is the principle schematic of calculation process of the present invention;

Among the figure, 1--left side camera; The right camera of 2--; 3--left side imaging plane; The right imaging plane of 4--; The primary optical axis of the right camera of 5--; The primary optical axis of 6--left side camera;

The geometric representation of Fig. 3 measuring machine wing twisting of the present invention angle example.

Embodiment

The present invention tests for material object, thus when survey aircraft lands stationary state and cruising condition respectively the wing of wing tip winglet slightly the distortion of front and rear edge obtain the torsion angle distortion of wing.

Instantiation: the quiet distortion of X1 wing aeroelasticity is photogrammetric, records actual span 14806mm, winglet wing tip chord length 180mm:

(a) state of ground:

(1) two cameras is separately fixed on two level meters;

(2) two measuring points are positioned at the 9th row and the 26th row left side porthole, and the interior angle between left camera lens primary optical axis and the two camera lines is α ₁=58 °, the interior angle between right camera lens primary optical axis and the two camera lines is α ₂=70 °;

(3) to adjust the reading make level meter be zero and remain to the end of taking pictures;

(4) object that will measure is taken pictures, measure the distance L=11900mm of two cameras;

(5) (the wing wing is the leading edge point C of winglet slightly to read on the photo point of relevant position ₀With trailing edge point F ₀) pixel coordinate value, the pixel coordinate of leading edge point C (1240,1110) in the left photo, the pixel coordinate that trailing edge point F is ordered is (1290,1140); The pixel coordinate of right photo leading edge point C ' point is (2630,1615), and the pixel coordinate of trailing edge point F ' point is (2784,1640);

(6) check the attribute of choosing photo, obtain left photo laterally, vertically pixel value (3072x2304) and equivalent 35mm egative film focal distance f ₁=102mm; Right photo laterally, vertically pixel value (3072x2304) and equivalent 35mm egative film focal distance f ₂=114mm; Two photo centre coordinates are respectively and are (1536,1152).

(7) true origin in (5) is moved to optical center, obtain the new coordinate that left photo C orders by image-forming principle and be (296 ,-42), the new coordinate that F is ordered is (246 ,-12); The new coordinate of right photo C ' point is (1094,463), and the new coordinate of F ' point is (1248,488); By calculating the little cautiously leading edge point C slightly of wing ₀With trailing edge point F ₀2 volume coordinates with respect to left camera:

Little cautiously leading edge C slightly ₀Point X _C1=8537.628mm, Y _C1=321.294mm, Z _C1=14756.5mm;

Trailing edge F ₀Point X _F1=8613.986mm, Y _F1=323.895mm, Z _F1=14593.68mm;

Winglet wing tip chord length

(b) during cruising condition, in like manner calculate:

Little cautiously leading edge C slightly ₀' some X _C2=8586.366mm, Y _C2=-281.27mm, Z _C2=14869.31mm;

Trailing edge F ₀' some X _F2=8728.913mm, Y _F2=-289.59mm, Z _F2=14765.69mm;

Winglet wing tip chord length

(8) thus can calculate under the cruising condition, little cautiously slightly leading edge point y to being deformed into: Δ Y ₁=| Y _C1-Y _C2|=602.564mm

Trailing edge point y is to being deformed into: Δ Y ₂=| Y _F1-Y _F2|=613.485mm

Obtaining the section torsion angle is:

This measured value has obtained good consistent with theoretical the analysis with the bibliographic reference value.

Claims (3)

1. the non-contact measurement method of an aircraft wing malformation is characterized in that comprising the steps:

(1) two cameras is separately fixed on two level meters;

(2) rotary camera makes two interior angle α 1, α 2 between 55 ° to 75 °, angle is the angle between camera lens primary optical axis and the two camera lines in described, interior angle between left side camera lens primary optical axis and the two camera lines is α 1, and the interior angle between right camera lens primary optical axis and the two camera lines is α 2;

(3) to make its reading be zero and remain to the end of taking pictures to adjust level meter;

(4) object that will measure is taken pictures after adjusting two interior angles and level meter, and measure the distance L of two cameras this moment;

(5) choose wing wing leading edge point C slightly ₀With trailing edge point F ₀Be unique point, read the pixel coordinate value of relevant position point on the photo, the pixel coordinate of left-hand point C in the left photo (a, b), the pixel coordinate that right-hand point F is ordered be (c, d); The pixel coordinate of right photo left-hand point C ' point be (A, B), the pixel coordinate that right-hand point F ' puts be (C, D);

(6) obtain left photo laterally, vertical pixel value (P ₁XP ₂) and equivalent 35mm egative film focal distance f ₁Horizontal, vertical pixel value (Q of right photo ₁XQ ₂) and equivalent 35mm egative film focal distance f ₂Two photo centre coordinates are respectively (X ₀, Y ₀), (X ₀₀, Y ₀₀), X wherein ₀=P ₁/ 2, Y ₀=P ₂/ 2, X ₀₀=Q ₁/ 2, Y ₀₀=Q ₂/ 2.

(7) true origin in the step (5) is moved to optical center, obtaining the new coordinate that left photo C orders is (X ₀-a, b-Y ₀), the new coordinate that F is ordered is (X ₀-c, d-Y ₀); The new coordinate of right photo C ' point is (X ₀₀-A, B-Y ₀₀), the new coordinate of F ' point is (X ₀₀-C, D-Y ₀₀);

Obtain 2 spatial value point C with respect to left camera ₀(X _c, Y _c, Z _c), the some F ₀(X _F, Y _F, Z _F), obtain the distance that needs at last:

Wherein, Xc=a ₀* cos ∠ C ₀OE, Y ₀₁=a ₀* sin γ ₁, Y ₀₂=a ₁* sin γ ₂,

Z _C=a ₀* sin ∠ C ₀OE;

X _F＝b ₀*cos∠F ₀OE，Y ₁₁＝b ₀*sinγ ₃、Y ₁₂＝b ₁*sinγ ₄，?

Z _F＝b ₀*sin∠F ₀OE；

∠C ₀OE＝α ₁+θ ₁；∠OEC ₀＝α ₂-θ ₂；∠OC ₀E＝180°-∠C ₀OE-∠OEC ₀；

∠ F ₀OE=α ₁+ θ ₃∠ OEF ₀=α ₂-θ ₄∠ OF ₀E=180 °-∠ F ₀OE-∠ OEF ₀a ₀, a ₁Obtain by sine:

In like manner can obtain b ₀, b ₁

Wherein, a ₀Be a C ₀And the distance between the left camera, a ₁Be a C ₀With the distance of right camera, θ ₁Be a C ₀With left camera line at the projection on XY plane and the angle of X-axis, θ ₂Be a C ₀With right camera line at the projection on XY plane and the angle of X-axis, γ ₁Be a C ₀With left camera line at the projection on YZ plane and the angle of Y-axis, γ ₂Be a C ₀With right camera line at the projection on YZ plane and the angle of Y-axis; b ₀Be a C ₀And the distance between the left camera, b ₁Be a C ₀With the distance of right camera, θ ₃Be a F ₀With left camera line at the projection on XY plane and the angle of X-axis, θ ₄Be a F ₀With right camera line at the projection on XY plane and the angle of X-axis, γ ₃Be a F ₀With left camera line at the projection on YZ plane and the angle of Y-axis, γ ₄Be a F ₀With right camera line at the projection on YZ plane and the angle of Y-axis; The coordinate of being got is a right-handed coordinate system, and true origin O is left camera central point, and X-axis is the line direction of two cameras, and Y-axis is downward with body longitudinal axis parallel direction, and Z axle and camera lens primary optical axis parallel direction are the outer normal direction of lens plane; Point E is right camera central point, and the XY plane is the plane of vertical Z axle, and the YZ plane is the plane of vertical X-axis;

(8) land stationary state at aircraft and carry out (1)～(7) set by step, obtain the wing wing volume coordinate (X of leading edge point slightly _C1, Y _C1, Z _C1), trailing edge F ₀Point (X _F1, Y _F1, Z _F1) and wing wing chord length slightly

Repeated execution of steps (1)～(7) when the aircraft cruising condition calculate the volume coordinate (X of wing nose of wing point _C2, Y _C2, Z _C2), trailing edge F ₀' point (X _F2, Y _F2, Z _F2) and wing wing chord length slightly

Thereby calculate the cruising condition bottom wing slightly leading edge point y to being deformed into Δ Y ₁=| Y _C1-Y _C2|, trailing edge point y is to being deformed into Δ Y ₂=| Y _F1-Y _F2|, obtain the section torsion angle and be

2. according to the non-contact measurement method that utilizes the described aircraft wing malformation of claim 1, it is characterized in that: described two cameras should guarantee that the body longitudinal axis is parallel when taking.

3. according to the non-contact measurement method that utilizes the described aircraft wing malformation of claim 1, it is characterized in that: described camera adopts high image quality, maximum pixel and the longest burnt end to take two interior angle α ₁, α ₂All be 60 °.

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