8 research outputs found
Feedback stabilization of dynamical systems with switched delays
We analyze a classification of two main families of controllers that are of
interest when the feedback loop is subject to switching propagation delays due
to routing via a wireless multi-hop communication network. We show that we can
cast this problem as a subclass of classical switching systems, which is a
non-trivial generalization of classical LTI systems with timevarying delays. We
consider both cases where delay-dependent and delay independent controllers are
used, and show that both can be modeled as switching systems with unconstrained
switchings. We provide NP-hardness results for the stability verification
problem, and propose a general methodology for approximate stability analysis
with arbitrary precision. We finally give evidence that non-trivial design
problems arise for which new algorithmic methods are needed
Converse Lyapunov theorems for discrete-time linear switching systems with regular switching sequences
We present a stability analysis framework for the general class of
discrete-time linear switching systems for which the switching sequences belong
to a regular language. They admit arbitrary switching systems as special cases.
Using recent results of X. Dai on the asymptotic growth rate of such systems,
we introduce the concept of multinorm as an algebraic tool for stability
analysis.
We conjugate this tool with two families of multiple quadratic Lyapunov
functions, parameterized by an integer T >= 1, and obtain converse Lyapunov
Theorems for each.
Lyapunov functions of the first family associate one quadratic form per state
of the automaton defining the switching sequences. They are made to decrease
after every T successive time steps. The second family is made of the
path-dependent Lyapunov functions of Lee and Dullerud. They are parameterized
by an amount of memory (T-1) >= 0.
Our converse Lyapunov theorems are finite. More precisely, we give sufficient
conditions on the asymptotic growth rate of a stable system under which one can
compute an integer parameter T >= 1 for which both types of Lyapunov functions
exist.
As a corollary of our results, we formulate an arbitrary accurate
approximation scheme for estimating the asymptotic growth rate of switching
systems with constrained switching sequences
Stability of planar switched systems under delayed event detection
This is an accepted manuscript of an article published by IEEE in 2020 59th IEEE Conference on Decision and Control (CDC), available online: https://ieeexplore.ieee.org/document/9304152
The accepted version of the publication may differ from the final published version.In this paper, we analyse the impact of delayed event detection on the stability of a 2-mode planar hybrid automata. We consider hybrid automata with a unique equilibrium point for all the modes, and we find the maximum delay that preserves stability of that equilibrium point. We also show for the class of hybrid automata treated that the instability of the equilibrium point for the equivalent hybrid automaton with delay in the transitions is equivalent to the existence of a closed orbit in the hybrid state space, a result that is inspired by the Joint Spectral Radius theorem. This leads to an algorithm for computing the maximum stable delay exactly. Other potential applications of our technique include co-simulation, networked control systems and delayed controlled switching with a state feedback control.Published versio
Feedback stabilization of dynamical systems with switched delays
We analyze a classification of two main families of controllers that are of interest when the feedback loop is subject to switching propagation delays due to routing via a wireless multi-hop communication network. We show that we can cast this problem as a subclass of classical switching systems, which is a non-trivial generalization of classical LTI systems with time-varying delays. We consider both cases where delay-dependent and delay-independent controllers are used, and show that both can be modeled as switching systems with unconstrained switchings. We provide NP-hardness results for the stability verification problem, and propose a general methodology for approximate stability analysis with arbitrary precision. We finally give evidence that non-trivial design problems arise for which new algorithmic methods are needed
Feedback stabilization of dynamical systems with switched delays
We analyze a classification of two main families of controllers that are of interest when the feedback loop is subject to switching propagation delays due to routing via a wireless multi-hop communication network. We show that we can cast this problem as a subclass of classical switching systems, which is a non-trivial generalization of classical LTI systems with time-varying delays. We consider both cases where delay-dependent and delay-independent controllers are used, and show that both can be modeled as switching systems with unconstrained switchings. We provide NP-hardness results for the stability verification problem, and propose a general methodology for approximate stability analysis with arbitrary precision. We finally give evidence that non-trivial design problems arise for which new algorithmic methods are needed