基于误差修正模型的机翼风洞试验弯扭变形测量方法

风洞试验中,机翼在高速气流下产生弯曲、扭转变形,本文提出一种基于误差修正模型的机翼弯扭变形测量方法。 首先,利用基于摄影测量的相机标定方法求得相机畸变参数,采用数字图像相关法定位与追踪荧光点的无畸变像素坐标。 然后根据摄影测量技术建立气流坐标轴系标定板,并利用气流坐标轴系标定板标定相机外参及求取机翼上荧光标记点的 Y 坐标。 最后,根据标记点已知的 Y 轴向约束,建立单双目测量系统各自的三维重建模型及弯扭变形的误差修正模型,并以模型迎角为 0°水平时为基准状态计算吹风状态下机翼弯扭变形。 经试验验证,本文提出的机翼扭转变形测量误差小于 0. 01°,机翼弯曲变形测量误差小于 0. 15 mm/ m。 该方法可为飞行器设计提供可靠及鲁棒的实验数据。

Error correction based measurement method for wing bending and torsion deformation caused by high-speed airflow in wind tunnel

In the wind tunnel experiment, high-speed airflow will cause bending deformation and torsion deformation in the wing. Thispaper proposes a method for measuring the wing bending and torsion deformation based on the error correction model. First, thecamera calibration method based on photogrammetry is used to obtain the camera distortion parameter with the use of digital imagecorrelation method to locate and track the distortion-free pixel coordinates of fluorescent points. Then an airflow calibration plate withcoordinate axis system is established based on photogrammetry technology, and the airflow coordinate axis calibration plate is used tocalibrate the external parameters of the camera and obtain the Y coordinate of the fluorescent marker point on the wing. Finally, thethree-dimensional reconstruction models of the single and binocular measurement systems and the error correction model for bendingand torsion deformation are established with the known Y-axis constraints of the marker point. When the angle of attack is 0°horizontally, the bending and torsional deformation of the wing in the blowing state is calculated as the reference state with the model.After experimental verification, the measurement error of wing torsional deformation proposed in this article is less than 0. 01°, and themeasurement error of wing bending deformation is less than 0. 15 mm / m. This method can provide reliable and robust experimentaldata for aircraft design.