The aircraft is close to a fence
What ArduPilot says:
- … in N.Nm
The aircraft is still inside the fence but closer to it than the margin, and the line gives the distance left: “Max Alt fence in 1.5m”. It is sent only when FENCE_OPTIONS bit 2 (notify on margin breaches) is set, FENCE_NTF_FREQ times a second (1 by default; 0 means once for each approach). The margin is FENCE_MARGIN, and for the circle and the drawn fences FENCE_MARGIN_XY when that is above 0. “… cleared margin breach” follows when the aircraft is farther from the fence than the margin again.
What to do, most likely first
The flight is heading for the fence.
FixTurn back or change height now. If the distance reaches 0 the fence is breached and
FENCE_ACTIONtakes over.A planned route runs along the fence, closer to it than the margin.
CheckThe line repeats along one leg of the mission and clears on the next.
FixPlan the route farther inside, or draw the fence with more room around the route.
Parameters to look at
| Parameter | What it is |
|---|---|
FENCE_OPTIONS | Fence options |
FENCE_MARGIN | Fence Margin |
FENCE_MARGIN_XY | Fence Horizontal Margin |
FENCE_NTF_FREQ | Fence margin notification frequency in hz |
FENCE_ACTION | Fence Action |
Where to do it:Failsafe Explainer
The code that sends it
… in N.Nm
libraries/AC_Fence/AC_Fence.cpp AC_Fence::record_margin_breach() · Open in ArduPilot Copter-4.7.1