Design and implementation of multirotor aerial-underwater vehicles with experimental results

Abstract

Design and implementation of a fully-working multirotor Unmanned Aerial-Underwater Vehicle (UAUV) was successfully accomplished in the present work. The proposed prototype consists of a multirotor vehicle in an octo-quadcopter configuration, which is well suited for good transition between mediums. The mathematical model is provided by means of the Newton-Euler formalism, highlighting the impact of the drastic change in density on the vehicle dynamics. A hierarchical controller is employed for attitude tracking, utilizing a proportional control law in cascade with a body angular rate Proportional-Integral-Derivative (PID) controller. Altitude stabilization is achieved by a PID controller with compensation of the restoring forces, while a gain scheduling strategy handles the change of medium. Furthermore, the proposed platform was extensively tested in simulations and real-time experiments under real conditions, with promising results in both mediums, and seamless transition between them.