The flight controller mode determines the exact behavior of the copter (or another craft): how incoming commands and signals from the transmitter are to be interpreted.
Main article: https://dev.px4.io/en/concept/flight_modes.html
In manual mode, the pilot controls the drone directly. GPS, computer vision data, and barometer are not used. Flying in these modes requires good drone piloting skills.
MANUAL — signals from the transmitter are sent directly to the mixer and to the motors. Control of the throttle and of the front/back, right/left pairs of motors rotation speed ratio. This mode is almost never used for flying, since keeping the copter stable is too difficult.
STABILIZED — the mode with stabilized horizontal position. Control of the throttle, the copter pitch and roll, and the yaw angular velocity.
ACRO — control of throttle and the copter's pitch, roll, and yaw angular velocity. Used by drone racers and in 3D piloting shows for performing stunts.
RATTITUDE — in the center, the right stick is similar to STABILIZED, at the edges, it passes to the ACRO mode.
ALTCTL (ALTITUDE) — control of the altitude rate, pitch, roll and yaw angular velocity. The barometer is used (or another height gauge).
POSCTL (POSITION) — control of the altitude rate, forward/backward and right/left speed, and yaw angular velocity. It is the easiest flying mode. The barometer, GPS, computer vision, and other sensors are used.
In the automatic flight mode, the quadcopter ignores the control signals from the transmitter.
- AUTO.MISSION – PX4 completes the mission pre-loaded into the drone (the mission is downloaded using the QGroundControl, or from MAVLink using MAVROS.
- AUTO.RTL – the copter automatically returns to the takeoff point.
- AUTO.LAND – the copter lands automatically.
- OFFBOARD in the mode for flying at the MAVLink commands. Control from an external computer (e.g., Raspberry Pi).
The main used MAVLink packages are: