200m自由飞弹道靶模型高精度视觉位姿测量技术

为精确测量弹道靶超高声速自由飞模型位姿变化参数以用于气动力参数辨识，中国空气动力研究与发展中心结合双目视觉定位技术和前光照相技术，在弹道靶上发展了超高声速自由飞模型的高精度视觉位姿测量技术。双目测量站沿模型飞行方向布置，试验前完成测量站单站标定、多站全局坐标关联等。模型进入测量站视场中心时，脉宽小于10ns的激光经扩束后照射表面带编码标记点的模型，同时双目测量站相机获得前光图像。试验后通过模型表面标记点识别解算，获得模型飞行过程的位姿参数。在解决靶室杂光滤除、前光光源出口光斑匀化、双目测量站全局关联、模型表面处理及标记点制作等技术的基础上，建立了200m自由飞弹道靶模型高精度视觉位姿测量系统。在200m自由飞弹道靶上开展了长165mm的20°锥模型的飞行试验，试验环境压力15kPa、速度2.7km/s，根据视觉位姿测量系统获得的锥模型在各测量站飞行位姿参数和激光器的出光时序，通过辨识获得锥模型的阻力系数和动导数等气动力参数，所得结果与AEDC G靶上的结果趋势基本一致。

Vision measurement technology of model poses with high accuracy on the 200m free flight ballistic range

In order to obtain the changes of model poses flying at hypervelocity accurately on the free flight ballistic range which was used for identifying the aerodynamic parameters, China Aerodynamics Research and Development Center (CARDC) developed the vision measurement technology of model poses, which combined the mature technologies of the binocular vision location and the front light photo. The binocular measurement stations were installed along the flying direction of model, which would be calibrated and correlated to the same base coordinate before model test. When the model with coded feature points on its surface entered the measurement field, it would be illuminated by the extended laser light beam with the pulse width of smaller than 10ns, meanwhile, the two front light images were obtained by the cameras of the binocular measurement station, then the model poses were obtained by identifying and calculating the coded feature points on its surface. Based on solving the key technologies of filtering the parasitic light in the chamber, homogenizing the exit facular of the front light source, correlating binocular measurement stations to the same base coordinate, dealing the model surface color and fabricating feature points, the vision measurement system of poses with high accuracy on the 200m free flight ballistic range was accomplished. The test on the 20° cone with the length of 165 mm was carried out on the ballistic range, which flew in the chamber with the pressure of 15kPa at the velocity of about 2.7km/s. According to the cone poses at different binocular measurement stations and the sequence time of lasers flashing obtained by the vision measurement system, the drag index and the dynamic derivative of the cone were obtained by identifying, the trends of which were basically in consistency with those of the AEDC G range.