Towards micro air vehicle flight autonomy research on the method of horizon extraction

Recently, more and more research has been done on the Micro Air Vehicles (MAVs). Due to the limitation of the size, weight and energy of MAVs, the technologies with sensors on larger aircrafts are not currently available for MAVs. Video-based method is a feasible technique to extract the flight parameter. Pitch angle and roll angle of the MAVs can be extracted based on the horizon in the video images. In this paper, a new robust method to extracting horizon is put forward. The algorithm makes full use of the orientation information of the images. The position and orientation of horizon are obtained in the end. The method cannot only extract the horizon from the fine video images, but also applicable to those unclear images. Compared with the other horizon detection method, the algorithm has less amount of calculations and more robust to the practical situations. The experiment testified that this algorithm is feasible and effective. Our horizon extraction algorithm can correctly identify the horizon in over 99.9% of cases.