  This paper proposes a distributed guiding-vector-field (DGVF) controller for
cross-domain unmanned systems (CDUSs) consisting of heterogeneous unmanned
aerial vehicles (UAVs) and unmanned surface vehicles (USVs), to achieve
coordinated navigation whereas maneuvering along their prescribed paths. In
particular, the DGVF controller provides a hierarchical architecture of an
upper-level heterogeneous guidance velocity controller and a lower-level signal
tracking regulator. Therein, the upper-level controller is to govern multiple
heterogeneous USVs and UAVs to approach and maneuver along the prescribed paths
and coordinate the formation simultaneously, whereas the low-level regulator is
to track the corresponding desired guidance signals provided by the upper-level
module. Significantly, the heterogeneous coordination among neighboring UAVs
and USVs is achieved merely by the lightweight communication of a scalar (i.e.,
the additional virtual coordinate), which substantially decreases the
communication and computational costs. Sufficient conditions assuring
asymptotical convergence of the closed-loop system are derived in presence of
the exponentially vanishing tracking errors. Finally, real-lake experiments are
conducted on a self-established cross-domain heterogeneous platform consisting
of three M-100 UAVs, two HUSTER-16 USVs, a HUSTER-12C USV, and a WiFi 5G
wireless communication station to verify the effectiveness of the present DGVF
controller.
