Unmanned Aerial Vehicle Speed Estimation via Nonlinear Adaptive Observers

In this paper the problem of the speed estimation of an unmanned aerial vehicle is addressed, when acceleration, the angles and the angular speeds are available for measurement. We focus our analysis on a prototype drone - a 4 rotors helicopter robot- which is not equipped with GPS related devices and relies on the inertial measurement unit (IMU) only. A global exponential solution to this open problem is provided in the framework of adaptive observation theory when exact measurements are available. A modified estimator is presented to enhance robustness in velocity estimation in the realistic case of noisy acceleration measurements.