Position Tracking With Time-Varying Desired Yaw of Quadrotors: Basics and Applications in SE(3)

Motivated by the fact that regulating yaw at zero avoids complex second order aerodynamical terms coming from cross build up of thrust vector, which looses lift and increases drag, the position control problem of quadrotors has been studied generally regulating desired yaw, which limits the scope of underactuated quadrotors because yaw is a degree of freedom. In this paper, to deal with time-varying heading, we propose a second order quaternion-based sliding mode control for the tracking of the full nonlinear position-orientation dynamics, including finite time tracking. Chattering, typical from sliding modes, does not appear and knowledge of the model and its parameters is not required to implement the controller, a novelty also in sliding modes. Some applications are explored in a simulation study to show the viability of the proposed scheme, including field-of-view targeting, aerial screw driver and aerial grasp tasks.