单相机迎角测量中振动影响研究

从描述像空间坐标与物理空间坐标关系的共线方程出发,推导出单相机迎角测量中模型迎角关于相机外方位元素的计算公式。在单相机迎角测量中模型表面标记点展向坐标Y不变的假设下,研究了2m量级风洞中,相机位于5个不同位置时,3个角外方位元素(φ,ω,κ)和模型侧滑角β在-2°～2°之间振动对迎角测量结果的影响。模拟结果表明:φ和κ的振动对迎角测量结果影响较大,且该影响对相机位置和模型迎角的变化不敏感;在相机位于法向投影位置(相机光轴与Y轴平行)时,ω与β的振动对迎角测量结果影响非常小,可以忽略,但影响量随相机位置偏离法向投影位置迅速增加。

Vibration Influence Research on Single Camera Measurement of Angle of Attack

A formula for calculating the model angle of attack with the exterior orientation elements of a camera in a single camera measurement of the angle of attack is derived from the collinearity equations which describe the relationship between the image plane coordinates and the physical space coordinates. On the assumption that spanwise coordinate Y of the targets on the model surface keeps constant in a single camera measurement of the angle of attack, the vibration influence on the model angle of attack measurement is investigated in a 2 m wind tunnel when the three angle exterior orientation elements (φ, ω, κ) and model sideslip angle β vibrated between -2° and 2° at five different camera positions. Influence simulation results show that the vibrations of φ and κ have a great influence on the angle of attack measurements, and that the influence is insensitive to the change of camera positions and model angles of attack; the vibration influence of ω and β on the angle of attack measurement is small and negligible when the camera is located at a normal projection position (i.e., the optical axis of the camera is parallel with axis Y), but the influence increases quickly as the camera location moves away from the normal projection position.