ACAS Xu: Integrated Collision Avoidance and Detect and Avoid Capability for UAS

Abstract

ACAS Xu provides both a collision avoidance (CA) and detect and avoid (DAA) capability for UAS. The CA decision logic is based on Markov decision process models of the CA problem to generate both horizontal and vertical maneuver guidance to avoid collisions. DAA logic uses a rollout approach to anticipate collision risk at longer timelines to support pilot interaction and communication with air traffic controllers. System optimization and evaluation is performed using fast-time Monte-Carlo simulation environments. Compared to benchmark systems, ACAS Xu provides a significant safety benefit and alerting reduction. The algorithm specification document for ACAS Xu is slated for final approval and release in 2020.