Comparison of Several Adaptive Controllers According to Their Robustness Metrics

Research output: Contribution to conferencePaper, not in proceeding


This paper compares the performance and the robustness of several linear adaptive controllers using a linear system with time–varying disturbance in the presence of measurement noise. For the purpose of comparison we select the direct and indirect model reference adaptive controller (MRAC), the direct MRAC with σ–modification, and the L1 adaptive controller. Using tools from linear systems theory we compute the stability margins of these controllers and examine the performance of these closed–loop systems via analysis of several important transfer functions between the system’s inputs and outputs. In this paper we also investigate some properties of the piecewise constant update laws, introduced in recent L1 papers, and provide an interpretation to draw some insights. Finally, we validate the conclusions in simulations.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Control Engineering
Original languageEnglish
Publication statusPublished - 2010
Publication categoryResearch
Event2010 AIAA Guidance, Navigation and Control Conference - Toronto, Canada
Duration: 2010 Aug 22010 Aug 5


Conference2010 AIAA Guidance, Navigation and Control Conference