在无人机自主着陆过程中，无人机视觉导航系统利用跑道图像解算出无人机的位置姿态信息，为飞行控制系统进行自主着陆控制奠定基础。对视觉导航系统中图像处理及位置姿态解算进行了分析和研究。基于模板匹配进行跑道识别；利用 Hough变换提取跑道图像特征；采用最小二乘法对检测出的跑道边缘直线进行拟合并得出其在图像坐标系中的直线方程；基于空间的坐标关系变换，利用推导出的算法对无人机位置姿态进行了解算，并利用实际图像对所用算法进行了实验验证。

The information of position and attitude of unmanned aerial vehicle (UAV) during autonomous landing is calculated based on runway images by UAV visual navigation system, which provides a basis for flight control systems to perform the function of autonomous landing control. The calculations of image processing, position and attitude estimating in visual navigation system are analyzed and researched. Template matching mode is used to recognize the runway. Image characteristics of runway are extracted by Hough transform. The least square method is used to merger the detected edge lines of runway and their equations in the image coordinate system are achieved. Based on coordination relations in space, the algorithm is derived to calculate the position and attitude of UAV. Real images are used to verify all the algorithms in experiments.