A Formally Verified Hybrid System for the Next-Generation Airborne Collision Avoidance System

Jean-Baptiste Jeannin (1) , Khalil Ghorbal (1) , Yanni Kouskoulas (2) , Ryan Gardner (2) , Aurora Schmidt (2) , Erik Zawadzki (1) , André Platzer (1)

1 CMU - Carnegie Mellon University [Pittsburgh]
2 APL - Johns Hopkins University Applied Physics Laboratory [Laurel, MD]

The Next-Generation Airborne Collision Avoidance System (ACASX) is intended to be installed on all large aircraft to give advice to pilots and prevent mid-air collisions with other aircraft. It is currently being developed by the Federal Aviation Administration (FAA). In this paper we determine the geometric configurations under which the advice given by ACAS X is safe under a precise set of assumptions and formally verify these configurations using hybrid systems theorem proving techniques. We conduct an initial examination of the current version of the real ACAS X system and discuss some cases where our safety theorem conflicts with the actual advisory given by that version, demonstrating how formal, hybrid approaches are helping ensure the safety of ACAS X. Our approach is general and could also be used to identify unsafe advice issued by other collision avoidance systems or confirm their safety.

Domaines: Logique en informatique [cs.LO]; Théorie et langage formel [cs.FL]; Calcul formel [cs.SC]

Jean-Baptiste Jeannin, Khalil Ghorbal, Yanni Kouskoulas, Ryan Gardner, Aurora Schmidt, et al.. A Formally Verified Hybrid System for the Next-Generation Airborne Collision Avoidance System. Tools and Algorithms for the Construction and Analysis of Systems - 21st International Conference, TACAS 2015, Held as Part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2015, London, UK, April 11-18, 2015. Proceedings, 2015, London, United Kingdom. pp.21--36, ⟨10.1007/978-3-662-46681-0_2⟩. ⟨hal-01660903⟩