Robust Consensus of High-Order Systems Under Output Constraints: Application to Rendezvous of Underactuated UAVs

We solve output- and state-consensus problems for multiagent high-order systems in feedback form. We consider systems interconnected over arbitrary (connected) undirected-topology networks as well as directed spanning-trees and directed cycles. We assume that the systems may be subject to multiple restrictions in the form of output or state constraints, such as limited-range measurements and physical limitations. In addition, we suppose that the systems may be subject to external disturbances. Under these conditions, we present a control framework and a formal analysis that establishes robust stability in the input-to-state sense. The former relies on a modified backstepping method and the latter on multistability theory. Finally, we apply our approach to a case-study of interest in the aerospace industry: Safety-aware rendezvous control of underactuated UAVs subject to connectivity and collision-avoidance constraints.