# Missions

Note

This is a very high level introduction. For more detailed information see:

# Planning Missions

Manually planning missions is straightforward:

  • Open to the Plan View and select the Mission radio button
  • Select the Takeoff toolbar option then select the takeoff location on the map (set the takeoff altitude in the corresponding editor to a sensible value).
  • Select the Add Waypoint ("plus") toolbar icon.
  • Click on the map to add waypoints.
  • Use the waypoint list on the right to modify the waypoint parameters/type The altitude indicator on the bottom provides a sense of the relative altitude of each waypoint.
  • Once finished, click on the Upload button (top right) to send the mission to the vehicle.

You can also use the Pattern tool to automate creation of survey grids.

planning-mission

# Mission Feasibility Checks

PX4 runs some basic sanity checks to determine if a mission is feasible. For example, whether the mission is close enough to the vehicle, if the mission will conflict with a geofence, or if a mission landing pattern is required but is not present.

The checks are run when the mission is uploaded and immediately before it is run. If any of the checks fail, the user is notified and it is not possible to start the mission.

For more detail on the checks and possible actions, see: Mission Mode > Mission Feasibility Checks.

# Setting Vehicle Yaw

If set, a multi-rotor vehicle will yaw to face the Heading value specified in the target waypoint (corresponding to MAV_CMD_NAV_WAYPOINT.param4 (opens new window)).

If Heading has not been explicitly set for the target waypoint (param4=NaN) then the vehicle will yaw towards a location specified in the parameter MPC_YAW_MODE. By default this is the next waypoint.

Vehicle types that cannot independently control yaw and direction of travel will ignore yaw settings (e.g. Fixed Wing).

# Setting Acceptance/Turning Radius

The acceptance radius defines the circle around a waypoint within which a vehicle considers it has reached the waypoint, and will immediately switch to (and start turning towards) the next waypoint.

For a multi-rotor drones, the acceptance radius is tuned using the parameter NAV_ACC_RAD. By default, the radius is small to ensure that multirotors pass above the waypoints, but it can be increased to create a smoother path such that the drone starts to turn before reaching the waypoint.

The image below shows the same mission flown with different acceptance radius parameters:

acceptance radius comparison

The speed in the turn is automatically computed based on the acceptance radius (= turning radius) and the maximum allowed acceleration and jerk (see Jerk-limited Type Trajectory for Multicopters).

TIP

For more information about the impact of the acceptance radius around the waypoint see: Mission Mode > Inter-waypoint Trajectory.

# Flying Missions

Once the mission is uploaded, switch to the flight view. The mission is displayed in a way that makes it easy to track progress (it cannot be modified in this view).

flying-mission