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New Software Verification Package Developed for ACAS X

Robust Software Engineering researcher Ritchie Lee and collaborator Dr. Mykel Kochenderfer (Stanford University) developed a new software package to help in the verification of the next-generation Aircraft Collision Avoidance System (ACAS X). ACAS X has been developed by the Federal Aviation Administration (FAA, POC: Neal Suchy) and teams from the Massachusetts Institute of Technology Lincoln Lab and the Johns Hopkins Lab. The new software package implements a flexible and scalable method to efficiently search for the highest probability trajectory for an event of interest when given only a black box simulator of the system. The method involves a variation of the Monte Carlo Tree Search algorithm.

This software will be used by the FAA in development of ACAS X and will identify the most likely failure conditions, which will then inform potential revisions to the control logic and build confidence in the safety of the system. This verification software package is being delivered under a newly signed Software Usage Agreement with the FAA. We are working towards additional verification and validation software packages for ACAS X and are committed to supporting the FAA in its development of ACAS X.

BACKGROUND: In response to a series of midair collisions involving commercial airliners, the Federal Aviation Administration authorized development of an onboard collision avoidance system. In its current manifestation, the Traffic Alert and Collision Avoidance System (TCAS) is mandated worldwide on all large aircraft and has significantly improved the safety of air travel. But major changes to the airspace planned over the coming years require substantial modification to the system. Recently, the Massachusetts Institute of Technology Lincoln Lab and the Johns Hopkins Lab have pioneered development of a new approach to collision avoidance systems, the next-generation Aircraft Collision Avoidance System (ACAS X), that completely rethinks how such systems are engineered, allowing the system to provide a higher degree of safety without interfering with normal, safe operations.

NASA PROGRAM FUNDING: Safe Autonomous System Operations (SASO) project, Airspace Operations and Safety Program (AOSP), Aeronautics Research Mission Directorate (ARMD)

Contact: Ritchie Lee

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