  Two-dimensional multilinked structures can benefit aerial robots in both
maneuvering and manipulation because of their deformation ability. However,
certain types of singular forms must be avoided during deformation. Hence, an
additional 1 Degrees-of-Freedom (DoF) vectorable propeller is employed in this
work to overcome singular forms by properly changing the thrust direction. In
this paper, we first extend modeling and control methods from our previous
works for an under-actuated model whose thrust forces are not unidirectional.
We then propose a planning method for the vectoring angles to solve the
singularity by maximizing the controllability under arbitrary robot forms.
Finally, we demonstrate the feasibility of the proposed methods by experiments
where a quad-type model is used to perform trajectory tracking under
challenging forms, such as a line-shape form, and the deformation passing these
challenging forms.
