双目视觉绳系支撑飞行器模型位姿动态测量

绳牵引并联机器人（WDPR）为风洞试验提供了一种新型支撑方式，可用于多/六自由度风洞复杂动态试验。针对该支撑下飞行器模型的大范围运动，发展了一种基于双目视觉的模型位姿动态测量方法。首先，设计了一种编码合作标志点，合理布置于模型表面，通过图像处理消除绳对标志点成像干扰，进行标志点三维重构；然后，利用绝对定姿算法求解相对位姿初值，且给出了理论误差分析，并基于双目相机重投影误差构建李代数下的无约束最小二乘优化问题，采用L-M算法进行位姿优化；最后，采用该测量系统分别进行了静态和动态精度验证试验，以及大迎角俯仰振荡等3种单/多自由度典型运动轨迹测量。试验数据显示，静态角度和位移测量精度分别优于0.02°/0.02 mm；动态测量时角度精度可达到0.1°量级，位移平均误差为0.4 mm。研究结果表明：设计的双目视觉测量系统是有效可行的，可为后续风洞试验的实际应用提供支持。

Binocular vision-based measurement of dynamic motion for aircraft model suspended by wire system

The Wire-Driven Parallel Robot (WDPR) provides a new supporting method for wind tunnel tests, and it can be used for complex and dynamic multi/six-DoF motion in wind tunnel tests. Aiming at the large-scale dynamic motion of aircraft model suspended by WDPR, a position and attitude dynamic measurement method for aircraft model based on binocular vision technique is developed. First, a type of encoded round marker is designed to be affixed on the model surface. Following the reconstruction of markers' 3D coordinates, the interference of cables to markers imaging is eliminated by image processing. Second, the initial value of relative pose is estimated by the absolute orientation algorithm, and a theoretical error analysis is given. Then the optimal result is achieved through building an unconstrained least squares optimization problem in Lie Algebra based on re-projection error, which is solved by the L-M optimization algorithm. Finally, the static and dynamic test validations and three typical dynamic single/multi-DoF motions for aircraft model such as heave/pitch oscillation are conducted. The results indicate that the precision of static angle and displacement measurement is better than 0.02°/0.02 mm respectively, and that of dynamic angle measurement can achieve the 0.1° order, and the absolute error of the dynamic displacement is 0.4 mm. The research conducted shows that the proposed binocular vision measurement system is effective and feasible, and it could provide sufficient support for the practical application in the follow-up wind tunnel tests.