  This study presents a new hardware design and control of a minimally actuated
5 control degrees of freedom (CDoF) quadrotor-based tiltrotor. The proposed
tiltrotor possesses several characteristics distinct from those found in
existing works, including: 1) minimal number of actuators for 5 CDoF, 2) large
margin to generate interaction force during aerial physical interaction (APhI),
and 3) no mechanical obstruction in thrust direction rotation. Thanks to these
properties, the proposed tiltrotor is suitable for perching-enabled APhI since
it can hover parallel to an arbitrarily oriented surface and can freely adjust
its thrust direction. To fully control the 5-CDoF of the designed tiltrotor, we
construct an asymptotically stabilizing controller with stability analysis. The
proposed tiltrotor design and controller are validated in experiments where the
first two experiments of $x,y$ position tracking and pitch tracking show
controllability of the added CDoF compared to a conventional quadrotor.
Finally, the last experiment of perching and cart pushing demonstrates the
proposed tiltrotor's applicability to perching-enabled APhI.
