Feedback Stabilization of Infinite-Dimensional Linear Systems with Constraints on Control and its Rate

This discussion addresses some aspects of the paper “Feedback Stabilization of Infinite-Dimensional Linear Systems with Constraints on Control and its Rate”, which investigates the design of stabilizing controllers for a certain class of systems with constrained controls. In particular, in this discussion we emphasize the importance of considering simultaneously constraints on the magnitude and rate on the control signal, by providing a review of practical examples published in the literature. It is also argued that approaches based on the Positive Invariance concepts, such as the one presented in the paper, are the very adequate for this problem, as they give a simple control structure, and make it possible to consider that many real constraints are significantly nonsymmetric by nature. Moreover, it is also emphasized in this discussion how treating infinite-dimensional systems makes the proposed technique general, and interesting for real systems that contain partial differential equations or delays.