Stability overlay for adaptive control laws applied to linear time-invariant systems

Paulo Rosa*, Jeff S. Shamma, Carlos Silvestre, Michael Athans

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

11 Scopus citations


Two broad classes of adaptive control algorithms can be found in the literature: i) stability based, with minimal assumptions on the plant; ii) performance based, with relatively more stringent assumptions on the plant. This paper proposes a solution, referred to as Stability Overlay (SO), to enable stability guarantees in performance based algorithms. In our methodology, the performance based adaptive control laws are only responsible for designating the controller that should be selected; the SO decides whether this controller should or not be used, based upon its most recent history of utilization. We argue that using two algorithms in parallel - the SO for stability purposes and any other suitable for the performance requirements - leads to higher levels of performance while guaranteeing stability of the adaptive closed-loop for bounded (but unknown) disturbances. The SO methodology is applicable to both time-invariant and time-varying, nonlinear and linear systems. However, due to space limitations, we only consider linear time-invariant (LTI) plants in this paper. The theory is illustrated with an example.

Original languageEnglish (US)
Title of host publication2009 American Control Conference, ACC 2009
Number of pages6
StatePublished - 2009
Externally publishedYes
Event2009 American Control Conference, ACC 2009 - St. Louis, MO, United States
Duration: Jun 10 2009Jun 12 2009


Other2009 American Control Conference, ACC 2009
Country/TerritoryUnited States
CitySt. Louis, MO

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


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