How do you prevent home location being reset during arming?

ArduCopter Copter 4.0
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1

Before the drone is armed, the coordinate frames of these are identical:

  • the message to send to the drone to move it to a location of MAVLINK_MSG_SET_POSITION_TARGET_LOCAL_NED_POSITION with coordinate_frame = MAV_FRAME_LOCAL_NED. i.e. you must specify this relative to EKF origin.
  • the message sent back from the drone of its current location of MAVLINK_MSG_ID_LOCAL_POSITION_NED. i.e. the drone specifies this relative to EKF origin.

HOWEVER, once you arm the drone, MAVLINK_MSG_SET_POSITION_TARGET_LOCAL_NED_POSITION is thereafter provided relative to the arming location.

If you arm the drone in a different place to getting a GPS fix you are screwed.

Is there a way to ensure this reset of the MAVLINK_MSG_SET_POSITION_TARGET_LOCAL_NED_POSITION coordinate frame is not performed?

2

In case anyone’s reading, either of these methods will work to reset the origin of the frame for which position targets must be given to the drone:

  1. mavlink_msg_set_home_position_encode
  2. MAV_CMD_DO_SET_HOME

That said, I have an inkling that they location specified to be <50m from the EKF origin (GPS lock location). Not 100% on that though.

3

did you find any solution for this problem