Controlled hybrid system safety verification: advanced life support system testbed

In this paper we demonstrate the use of barrier certificates as a method to verify safe performance of a hybrid variable configuration CO/sub 2/ removal (VCCR) system. We designed a simple nonlinear feedback controller that tracks a desired CO/sub 2/ profile, while ensuring that the CO/sub 2/ and O/sub 2/ concentrations stay within acceptable limits. Though the controller and its switching rules are simple, we do not have a closed form expression for the equilibrium sets of the closed loop hybrid system, and hence Lyapunov stability analysis and computation of region of attraction are impossible. We used sum-of-squares programming approach to construct and verify that our control law provides safe functionality of VCCR system.