Finite-time circular formation around a moving target with multiple underactuated ODIN vehicles

In this paper, we present a framework for achieving circular formation of a two-dimensional moving target using a team of underactuated Omni-Directional Intelligent Navigator (ODIN) vehicles. The main goal is to ensure uniform circumnavigation of the moving target with prescribed radius, velocity and inter-vehicle spacing. In the formation, part of vehicle group is capable of obtaining information from the moving target. Distributed adaptive control laws are developed for the group of vehicles by merging the techniques of command filter and backstepping control. A robust controller is designed to compensate for the effect of non-smooth actuator saturation. With the proposed control, the convergence to a circular formation performance can be ensured in a finite time. Finally, numerical simulations are presented to show the effectiveness of the proposed formation scheme.