Wide-field optical flow aided inertial navigation for unmanned aerial vehicles

Low-cost navigation can be performed for aircraft using the integration of Inertial Navigation System (INS) information in conjunction with a regulatory information source, such as Global Position System (GPS). For situations where GPS is unavailable, it is desirable to have an alternative information source in order to regulate the known drifting phenomenon experienced by INS. In this paper, the use of wide-field optical flow is explored to regulate INS drift for the purpose of GPS-denied navigation. An Unscented Information Filter (UIF) algorithm for Unmanned Aerial Vehicle (UAV) velocity and attitude estimation is proposed and evaluated with experimental flight data. The results demonstrate that the new filtering algorithm is capable of estimating the vehicle speed with approximately 1.4 m/s of error and regulating attitude errors to within 1.5 degrees standard deviation of error for both roll and pitch angles.