AUTOLAND Mode

AUTOLAND mode provides a fully automatic fixed wing landing which can also be used as an RC failsafe action.

In Mode Takeoff or during a NAV_TAKEOFF in AUTO, the takeoff direction will be captured from the GPS ground course once a GPS ground speed of 5m/s is obtained. This usually occurs early in the takeoff run of a rolling takeoff or almost immediately during a hand or bungee launch.

It will setup a parameterized base leg and final approach waypoint/altitude, based on the takeoff direction, and proceed to it and switch to an automatic landing at home. It can also be selected as a FS_LONG_ACTN for RC failsafes.

This is useful when programming a mission with a DO_LAND_START landing sequence is not convenient since it requires a GCS on a laptop or phone, such as traveling with impromptu stops to fly FPV or photograph. Simply use Mode TAKEOFF or a simple loaded before travel with a NAV_TAKEOFF waypoint. It is also useful for fields which have varying wind directions, which would prevent using a single home-loaded autolanding mission or require using the MissionSelector LUA script to slect from several missions with different approaches.

Operation

To use simply make an automatic takeoff and at any point later switch into AUTOLAND. A final approach waypoint will be created behind the HOME landing target at AUTOLAND_WP_DIST (400m by default) at AUTOLAND_WP_ALT (55m by default)using the takeoff direction plus AUTOLAND_DIR_OFF (“0” default) and land using all the parametrics of a normal autolanding. A base leg to the final approach waypoint is also created at the same altitude and 1/3 AUTOLAND_WP_DIST from the final approach waypoint as shown below:

../_images/autoland_mode.png

LAND parameter defaults are usually acceptable for most planes in the 1-2m wingspan, <2kg class) and should yeild a safe, if not optimally tuned, autolanding. LAND parameters can be optimized with test flights (See Automatic Landing).

Notes:

  • Switching out of AUTOLAND to another mode aborts the landing and returns control to that new mode.

  • Throttle aborts of the final landing sequence are not supported. (LAND_ABORT_THR)

  • If the plane has taken off not using either Mode Takeoff or NAV_LAND, the mode cannot be entered since the takeoff direction has not been captured. If it is selected as a long failsafe action (“5”), FS_LONG_ACTN, it will switch to normal RTL instead of AUTOLAND on failsafe, in this case.

  • The mode co-exists with any mission autolanding sequence, which can be used in AUTO mode, or with RTL_AUTOLAND.

  • QuadPlanes cannot use this mode unless Q_OPTIONS bit 2 (ALLOW_FW_LAND) is set and a Mode Takeoff or AUTO NAV_TAKEOFF has been used.