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Verifying Safety with Barriers

Complex behaviors that can be exhibited by modern engineering systems, which typically have hybrid (i.e., a mixture of continuous and discrete) dynamics, make the safety verification of such systems both critical and challenging. In principle, safety verification aims to show that system trajectories starting from a given initial set cannot reach an unsafe region in the state space. Various methods for safety verification have been developed, mostly relying on explicit computation of reachable sets. In this talk, a different approach to safety verification will be presented. Our method uses functions of state termed barrier certificates to prove safety, and does not require explicit computation of reachable sets. As a consequence, nonlinearity, uncertainty, constraints, and hybrid dynamics can be handled directly within this framework. Moreover, it is possible to treat safety verification of stochastic systems in a similar fashion. Barrier certificates can be computed using sum of squares optimization, and hence the method is computationally attractive. At the end, a converse theorem for barrier certificates will be discussed and other potential applications will be outlined.

Type of Seminar:
Public Seminar
Stephen Prajna
Control and Dynamical Systems, California Institute of Technology
Jun 08, 2004   16:00

ETH Zentrum, ETL K 25
Contact Person:

Prof. Morari
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Biographical Sketch:
Stephen Prajna received the B.Eng. degree in electrical engineering from Bandung Institute of Technology, Indonesia, and the M.S. degree in applied mathematics from University of Twente, The Netherlands, in 1998 and 2000 respectively. He is currently a Ph.D. student at the Control and Dynamical Systems option, California Institute of Technology, USA. His research includes systems analysis and synthesis using convex optimization.