Jorge Cortés
Professor
Cymer Corporation Endowed Chair
Continuity and boundedness of minimum-norm CBF-safe
controllers
M. Alyaseen, N. Atanasov, J. Cortés
IEEE Transactions on Automatic Control, submitted
Abstract
The existence of a Control Barrier Function (CBF) for a
control-affine system provides a powerful design tool to ensure
safety. Any controller that satisfies the CBF condition and ensures
that the trajectories of the closed-loop system are well defined
makes the zero superlevel set forward invariant. Such a controller
is referred to as safe. This paper studies the regularity
properties of the minimum-norm safe controller as a stepping stone
towards the design of general continuous safe feedback controllers.
We characterize the set of points where the minimum-norm safe
controller is discontinuous and show that it depends solely on the
safe set and not on the particular CBF that describes it. Our
analysis of the controller behavior as we approach a point of
discontinuity allows us to identify sufficient conditions to ensure
it grows unbounded or it remains bounded. Examples illustrate our
results, providing insight into the conditions that lead to
(un)bounded discontinuous minimum-norm controllers.
pdf
Mechanical and Aerospace Engineering,
University of California, San Diego
9500 Gilman Dr,
La Jolla, California, 92093-0411
Ph: 1-858-822-7930
Fax: 1-858-822-3107
cortes at ucsd.edu
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jorgilliyo