Geofence Boundary Violation Detection in 3D Using Triangle Weight Characterization with Adjacency

Mia N. Stevens, Hossein Rastgoftar, Ella M. Atkins

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


This paper introduces a computationally efficient geofence boundary violation detection method using the Triangle Weight Characterization with Adjacency (TWCA) algorithm. The geofence is defined as a maximum and a minimum altitude, and a horizontal boundary specified as a polygon that does not self-intersect. TWCA initialization divides the horizontal component and bounding box of each geofence into a finite set of triangles, then determines the triangle containing the vehicle. During flight, each position update is checked for containment within the vertical geofence boundaries using inequalities and the horizontal geofence boundaries using TWCA. TWCA searches for the triangle containing the vehicle position using breadth-first search of the adjacency graph. The root node of the search is the triangle occupied at the previous time step. This algorithm is applicable to three-dimensional geofences containing both keep-in (inclusion) geofences and keep-out (exclusion) geofences.

Original languageEnglish (US)
Pages (from-to)239-250
Number of pages12
JournalJournal of Intelligent and Robotic Systems: Theory and Applications
Issue number1
StatePublished - Jul 15 2019
Externally publishedYes


  • Geofence
  • Safety
  • UTM
  • Unmanned aerial vehicle
  • Unmanned aircraft system

ASJC Scopus subject areas

  • Software
  • Control and Systems Engineering
  • Mechanical Engineering
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering
  • Artificial Intelligence

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