Critical Observability of a Class of Hybrid Systems and Application to Air Traffic Management

Abstract

We present a novel observability notion for switching systems that model safety–critical systems, where a set of states – called critical states – must be detected immediately since they correspond to hazards that may lead to catastrophic events. Some sufficient and some necessary conditions for critical observability are derived. An observer is proposed for reconstructing the hybrid state evolution of the switching system whenever a critical state is reached. We apply our results to the runway crossing control problem, i.e., the control of aircraft that cross landing or take-off runways. In the hybrid model of the system, five agents are present; four are humans, each modeled as hybrid systems, subject to situation awareness errors.