Comparison of architectures and robustness of model reference adaptive controllers and L-1 adaptive controllers

Research output: Contribution to journalArticle


The paper compares direct and indirect model reference adaptive controllers (MRAC) with the L-1 adaptive controller. The architectures of the closed-loop systems are first compared in a simple setting that clarifies the similarities and differences of the controllers. The indirect MRAC and the L-1 controller have identical state predictors, but they differ in the computation of the control signal, which in L-1 is carried out by solving a feedback loop. The special case, where the controllers only adapt to a parameter representing input disturbances, is discussed. In this case, the closed-loop system is linear, so it may not be appropriate to call the controllers adaptive. The special case does, however, give good insight into similarities and differences of the controllers and the effects of various modifications. In particular, the analysis gives good understanding of the robustness properties. Copyright (C) 2013 John Wiley & Sons, Ltd.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Control Engineering


  • L-1 adaptive control, model reference adaptive control, robust control
Original languageEnglish
Pages (from-to)633-663
JournalInternational Journal of Adaptive Control and Signal Processing
Issue number7-8
Publication statusPublished - 2014
Publication categoryResearch