Onset of chaotic advection in open flows

Non peer reviewedPublisher PD

Controlled synchronization of mechanical systems with a unilateral constraint

This paper addresses the controlled synchronization problem of mechanical systems subjected to a geometric unilateral constraint as well as the design of a switching coupling law to obtain synchronization. To define the synchronization problem, we propose a distance function induced by the quotient metric, which is based on an equivalence relation using the impact map. A Lyapunov function is constructed to investigate the synchronization problem for two identical one-dimensional mechanical systems. Sufficient conditions for the individual systems and their controlled interaction are provided under which synchronization can be ensured. We present a (coupling) control law which ensures global synchronization, also in the presence of grazing trajectories and accumulation points (Zeno behavior). The results are illustrated using a numerical example.Team DeSchutte

Output regulation of hybrid linear systems: solvability conditions and structural implications

Hybrid output regulation aims at ensuring that the output of a hybrid system under control converges to a desired reference, despite the influence of unknown initial conditions and unmeasured disturbances, assuming that both references and disturbances are described as the output of an exosystem with a known model and unknown initial state. The main objective of this paper is to show how structural methods, based on tools from the geometric approach to control theory, allow a deep understanding of a plethora of surprising and unprecedented phenomena arising in output regulation problems for linear hybrid systems in the presence of time-driven periodic jumps, which do not possess any counterpart in classical output regulation