Overview

Library: libraries/AP_TECS , libraries/AR_AttitudeControl .
See Also: CRUISE for related speed settings.

The TRIM parameter group (specifically TRIM_THROTTLE or THROTTLE_CRUISE) defines the steady-state cruise values for the propulsion system.

Key Concepts

TRIM_THROTTLE: (ArduPlane/Rover) The percentage of throttle required to maintain CRUISE_SPEED in level flight.
Usage: Provides the FeedForward baseline for the speed controller. If set correctly, the drone will maintain speed perfectly when you switch from Manual to an autonomous mode.

Target percentage of throttle to apply for flight in automatic throttle modes and throttle percentage that maintains AIRSPEED_CRUISE.

This parameter sets the baseline throttle level that the autopilot will use to maintain the target cruise airspeed in level flight.

Function: It is the "Feed-Forward" term for the throttle controller. If TRIM_THROTTLE is set correctly, the drone will fly at AIRSPEED_CRUISE without the throttle PID loop having to do much work.
Tuning: Fly in FBWB or Cruise mode at your desired speed. Note the throttle percentage on your OSD or logs. Set TRIM_THROTTLE to this value.
Important: If you don't have an airspeed sensor, this parameter defines your cruise speed.