直升机光电助降系统的双摄影测量算法及实验研究

基于信标的摄影测量定位技术,提出了一种用于光电助降系统的双摄影测量算法.利用两台CCD 摄像机探测直升机两侧各四个信标,建立目标坐标系、摄像机坐标系和图像坐标系,根据信标、镜头中心和信标像点的共线性得到关于旋转矩阵和平移矢量的线性方程组,由此计算出直升机相对于着降点的位姿.设计了一套直升机光电助降实验系统,使用高性能DSP 系统进行实时图像处理,运用双摄影测量算法实时计算直升机着降引导信息.模拟实验结果表明,在两摄像机距离着降点8～13 m 范围内,光电助降实验系统的距离测量精度达到±5 cm,而角度测量精度达到±3°.

Theoretical and Experimental Study for Dual Camera Photogrammetry Algorithm in Photoelectric Guidance System for Helicopter Landing

Based on the positioning technology of beacon photogrammetry, Dual Camera Photogrammetry (DCP) algorithm was proposed in photoelectric guidance system for helicopter landing. Two Charge Coupled Device (CCD) cameras were used to image four beacons on both sides of the helicopter. Target coordinate systems, camera coordinate systems and image pixel coordinate systems were established. Based on the colinearity of beacon, lens center and beacon image point, a system of linear equations on rotation matrix and translation vector could be obtained. The position and posture parameters of helicopter relative to the landing point could be solved. A photoelectric guidance experiment system for helicopter landing was designed. In high performance Digital Signal Processor (DSP) system, two channels of image signal were processed in real time. The real time helicopter landing guidance information was calculated with DCP algorithm. The simulation experiments show that in the distance interval from 8 m to 13 m, the distance measurement accuracy can reach ±5 cm and the angle measurement accuracy can reach ±3° in the photoelectric guidance experiment system.