Robust Adaptive Control of Multivariable Nonlinear Systems
Abstract
Our research is focused on defining robust adaptive control architectures that can be completely characterized with their performance bounds and robustness/stability margins. Research in this direction over the past several years has led to a powerful set of tools, known as L1 adaptive control theory. This new paradigm for design of adaptive control systems embeds the robustness specification explicitly into the control problem formulation (control objective) and allows for decoupling adaptation from robustness, limiting the speed of adaptation only by available hardware (CPU). The performance bounds can be predicted a priori based on the conservative bounds of uncertainty, and the time-delay margin of it can be tuned systematically. The results of this research have been leveraged into different programs across the country, including WP AFRL's Certification of Advanced Flight Critical Systems: Challenge Problem Integration and NASA s Integrated Resilient Aircraft Control . We also revealed some similarities with the disturbance observer (DOB) controllers and identified the main features in the difference between them. The key feature of this difference is that the estimation loop of the L1 adaptive architectures reconstructs the inverse map of the DOB architecture by fast estimation and with that avoids the number of challenges of DOB related to the plant inversion. Insights from this comparison were used towards modification of DOB with improved transient performance.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 28, 2011
- Accession Number
- ADA565190
Entities
People
- Naira Hovakimyan
Organizations
- University of Illinois Urbana–Champaign