Automatica, Vol.100, 82-89, 2019
Cooperative moving path following for multiple fixed-wing unmanned aerial vehicles with speed constraints
This paper is to address a cooperative moving path following (CMPF) problem, in which a fleet of fixed-wing unmanned aerial vehicles (UAVs) are required to converge to and follow a desired geometric moving path while satisfying prespecified speed and spatial constraints. A representative application of the CMPF problem is the challenging mission scenario where a group of UAVs are tasked to track a moving ground target. The proposed methodology is based on the insight that a vehicle can follow a given path only through attitude control, thus leaving its speed as an extra input to be used at the coordination level. To deal with moving path following (MPF) of a single UAV, a non-singular control law is derived to steer the vehicle along the desired moving path which avoids the singularity problem in the previous MPF strategy. For multi-UAV coordination, a pursuit strategy is employed with the introduction of a virtual leader. To account for speed constraints and collision avoidance, conditions are derived under which the combined MPF and multi-UAV coordination closed-loop system is asymptotically stable while speed and spatial constraints are satisfied. Further simulation has been performed to demonstrate the effectiveness of the proposed method. (C) 2018 Elsevier Ltd. All rights reserved.