Title: Toward global nonlinear integral action?
15:00 - 16:00
online (please contact the organizer Bayu Jayawardhana to receive login details)
Speaker: Mattia Giaccagli
Title: Toward global nonlinear integral action?
Abstract: In this presentation we focus on an output set-point tracking and constant disturbance rejection problem for a class of MIMO nonlinear systems . We allow the references and the disturbances to be arbitrarily large and the initial conditions of the system to range in the full-state space. We rely on the common approach of extending the system with an integral action processing the regulation error and we cast the problem in the contraction framework, without making explicit use of normal forms. We present sufficient conditions for the design of a state-feedback and output-feedback control laws able to make the resulting closed-loop system incrementally stable, uniformly with respect to the references and the disturbances; such property guarantees the existence of an unique attractive equilibrium on which output regulation is achieved. To this end, we develop an incremental version of forwarding control techniques. Then, we show that our assumptions are always satisfied for a class of minimum-phase systems whose zero-dynamics are incrementally stable.