Fences

ArduPilot supports failsafes generated by several types of Fences (boundaries described by latitude/longitude and/or altitude) to prevent the vehicle from traveling higher or further than desired, or into unwanted areas. Types of Fences supported varies by vehicle. Upon Fence breach, selectable actions are taken.

For Copter, the Cylindrical Geo-Fence is a simple “tin-can” centered around HOME. In addition, there can also be inclusion and exclusion fences drawn, either circular or polygonal, or both, at various locations.

Inclusion and Exclusion Fences are defined easily in Mission Planner under the PLAN screen and loaded to the autopilot, using the FENCES item in the drop down box, just like Missions or Rally Points are planned.

TYPE OF FENCE FENCE_TYPE bit PLANE COPTER ROVER
Cylindrical (“TinCan”)
  • Center is HOME
  • Parameters for radius, height
1 “Circle” X X X
Inclusion/Exclusion Zones
  • Abritrary Locations
  • Polygonal or Circular
  • Inclusion or Exclusion
  • Defined by list, like missions
  • No height/altitude restriction
2 “Polygonal” X X X
Global Maximum Altitude
  • FENCE_ALT_MAX defines max altitude
0 “Max altitude” X X  
Global Minimum Altitude
  • FENCE_ALT_MIN defines min altitude
3 “Min altitude” X