Abstract: To acquire landmark's information and calculate unmanned helicopter's attitude information, a landmark recognition method based on image's contour fitting was proposed in this paper. The method judged the landmark's situation through imposing geometric constraint. If the image contained full landmark, real-time calculation of corners could obtain the helicopter's attitude information; if the image contained part of the landmark, the method could estimate the direction and size of the helicopter's movement which would make the landmark presented in the view completely. The simulations under the condition of laboratory show that the proposed method is stable and feasible.

Key words: unmanned helicopter, landmark recognition, pose estimation, autonomous landing, contour fitting

摘要： 为获取地标信息并计算无人机当前姿态，提出一种基于图像轮廓拟合的地标识别算法。所提方法通过施加几何约束判断地标。若图像中包含完整地标，实时的角点计算可以获取无人机的姿态信息；若只包含部分地标，则可估计出无人机的移动方位和平移量，以使地标完整出现在视野中。实验室条件下仿真表明了算法的稳定、可行。

关键词: 无人直升机, 地标识别, 姿态估计, 自主降落, 轮廓拟合