Review of conflict resolution methods for manned and unmanned aviation

Marta Ribeiro*, Joost Ellerbroek, Jacco Hoekstra

*Corresponding author for this work

Research output: Contribution to journalReview articlepeer-review

30 Citations (Scopus)
34 Downloads (Pure)


Current investigations into urban aerial mobility, as well as the continuing growth of global air transportation, have renewed interest in Conflict Detection and Resolution (CD&R) methods. With the new applications of drones, and the implications of a profoundly different urban airspace, new demands are placed on such algorithms, further spurring new research. This paper presents a review of current CR methods for both manned and unmanned aviation. It presents a taxonomy that categorises algorithms in terms of their approach to avoidance planning, surveillance, control, trajectory propagation, predictability assumption, resolution manoeuvre, multi-actor conflict resolution, considered obstacle types, optimization, and method category. More than a hundred CR methods were considered, showing how most work on a tactical, distributed framework. To enable a reliable comparison between methods, this paper argues that an open and ideally common simulation platform, common test scenarios, and common metrics are required. This paper presents an overview of four CR algorithms, each representing a commonly used CR algorithm category. Both manned and unmanned scenarios were tested, through fast-time simulations on an open-source airspace simulation platform.

Original languageEnglish
Article number79
Number of pages37
Issue number6
Publication statusPublished - 1 Jun 2020


  • Air traffic control (ATC)
  • Bluesky ATC simulator
  • Conflict detection and resolution (CD and R)
  • Self-separation
  • U-space
  • Velocity obstacles (VO)

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