  In this paper, we first propose a novel maneuvering technique compatible with
displacement-consensus-based formation controllers. We show that the formation
can be translated with an arbitrary velocity by modifying the weights in the
consensus Laplacian matrix. In fact, we demonstrate that the
displacement-consensus-based formation control is a particular case of our more
general method. We then uncover robustness issues with undesired steady-state
motions and resultant distorted shapes in undirected
displacement-consensus-based formation control. In particular, these issues are
triggered when neighboring agents mismeasure their relative positions, e.g.,
their onboard sensors are misaligned and have different scale factors. We will
show that if all the sensing is close to perfect but different among the
agents, then the stability of the system is compromised. Explicit expressions
for the eventual non-desired velocity and shape's distortion are given as
functions of the scale factors and misalignments for formations based on tree
graphs.
