Vision Based Navigation For Unmanned Aircraft Landing

Computer vision is of the characters of economy, passivity and information abundance.So it has became an indispensable information source in the landing of the unmanned air-craft. This article bases on the national natural and science fond projection, studies theapplication of the computer vision in the navigation for the unmanned aircraft landing onthe airport. In this article, we process the image sequence of the runway which is got froman onboard camera, estimate the attitude and position of the aircraft.At first, in the character detection, this article takes use of the directional wavelets. Thecharacters based on this method are of integrate information, accuracy and antinoise.secondly, in the lines extraction, via a technique integrating the linear and quadraticpredictors, Hough transform is utilized to detect the lines. This improves the computingspeed and the accuracy.Then we propose a new extraction method of vision-based navigation information foraircraft autonomous landing. It avoids the difficulty of feature points extraction in the tradi-tional method using points correspondence relation. It also doesn't need to set some arti?ciallandmark. It extracts the two edge lines and the threshold line on the runway only. Theselines are obviously visual and straight Then the attitude vector of aircraft is directly calcu-lated. And the position vector of aircraft is computed too if the runway width is known. Acomplete drive of the algorithm is given based on imaging geometry.In the adjustment, we try to utilize the character of the image to control the ?ying situ-ation. the Cubic Spline interpolation is used so that the adjustment is smooth and ef?cient.The theoretical analysis and the experiment result show that the extraction and conver-sion of vision-based navigation information for aircraft autonomous landing are feasible.It is very simple and has a high precision, so very suitable for a real-time navigation foraircraft landing.