ArduSub supports several different flight modes, some of which are only available when certain sensors are present. ArduSub always operates in exactly one flight mode at any given time. ArduSub always boots in MANUAL mode.
Manual mode passes the pilot inputs directly to the motors, with no stabilization. ArduSub (version 3.5+) always starts up in Manual mode.
Stabilize mode is like Manual mode, with heading and attitude stabilization.
Depth Hold is like Stabilize mode with the addition of depth stabilization when the pilot throttle input is zero. A depth sensor is required to use depth hold mode.
Position Enabled Modes
These modes require an external source of positioning information. A GPS will not work underwater.
Position Hold mode will stabilize the vehicle’s absolute position, attitude, and heading when the pilot control inputs are neutral. The vehicle can be maneuvered and repositioned by the pilot.
Auto mode executes the mission stored on the autopilot autonomously. Pilot control inputs are ignored in most cases. The vehicle may be disarmed, or the mode can be changed to abort the mission.
Circle mode navigates in circles with the front of the vehicle facing the center point.
Guided mode allows the vehicle’s target position to be set dynamically by a ground control station or companion computer. This allows ‘Click to Navigate Here’ interactions with a map.
Acro (Acrobatic) mode performs angular rate stabilization.