Youngjoo Kim, Wooyoung Jung and Hyochoong Bang
International Journal of Aeronautical and Space Sicences, vol. 15, no. 3, pp.258-266, 2014

Abstract : We present a system for the real-time visual relative navigation of a fixed-wing unmanned aerial vehicle in a GPS-denied environment. An extended Kalman filter is used to construct a vision-aided navigation system by fusing the image processing results with barometer and inertial sensor measurements. Using a mean-shift object tracking algorithm, an onboard vision system provides pixel measurements to the navigation filter. The filter is slightly modified to deal with delayed measurements from the vision system. The image processing algorithm and the navigation filter are verified by flight tests. The results show that the proposed aerial system is able to maintain circling around a target without using GPS data.

Keyword : unmanned aerial vehicle, target tracking, relative navigation, delayed measurement, GPS-denied, vision-aided navigation, extended Kalman filter