Steps of an automatic take-off
What ArduPilot says:
- Holding course N at N.Nm/s (N.N)
- Takeoff level-off starting at Nm
- Takeoff complete at N.Nm
“Holding course”: at first Plane only keeps the wings level; once the GPS ground speed has been above 5 m/s for 2 s it takes the direction it is moving in and holds it. The first number is that course in hundredths of a degree (27000 is west), the second the speed. “Takeoff level-off starting”: TKOFF_PLIM_SEC seconds before the target height the nose is let down gradually; the number is the height still to climb. “Takeoff complete”: the plane is above the altitude given in the mission's take-off command, and the mission moves to its next item.
Until the plane has climbed TKOFF_LVL_ALT (10 m by default) its bank is kept within LEVEL_ROLL_LIMIT (5° by default), so it cannot turn towards the first waypoint straight after the launch. Leave room ahead.
Parameters to look at
| Parameter | What it is |
|---|---|
TKOFF_PLIM_SEC | Takeoff pitch limit reduction |
TKOFF_LVL_ALT | Takeoff mode altitude level altitude |
LEVEL_ROLL_LIMIT | Level flight roll limit |
Where to do it:Mission Energy Check
The code that sends it
Holding course N at N.Nm/s (N.N)
ArduPlane/commands_logic.cpp Plane::verify_takeoff() · Open in ArduPilot Plane-4.7.1
Takeoff level-off starting at Nm
ArduPlane/takeoff.cpp Plane::get_takeoff_pitch_min_cd() · Open in ArduPilot Plane-4.7.1
Takeoff complete at N.Nm
ArduPlane/commands_logic.cpp Plane::verify_takeoff() · Open in ArduPilot Plane-4.7.1