I have an Intel Aero connected to an Optitrack system in a GPS-denied environment. I am trying to make the drone take off in OFFBOARD mode using the SET_POSITION_TARGET_LOCAL_NED message.
I am building the message using dronekit.
msg = vehicle.message_factory.set_position_target_local_ned_encode(0, 0, 0, mavutil.mavlink.MAV_FRAME_LOCAL_NED,0b111111111000, north, east, down, 0, 0, 0, 0, 0, 0, 0, 0) vehicle.send_mavlink(msg)
Initially, I set north and east to 0, and down to -0.3m. I have also set north and east to the initial positions of x0 and y0 after the drone is armed.
I can successfully transition to OFFBOARD mode, and I indeed send target setpoints to the drone and it begins to take off. However, I only want the target setpoint in the Z direction to change. What ends up happening is all three directions get some change in their targets and the drone moves along the -y direction (with respect to the drone meaning always in the direction opposite the onboard camera).
I have tried masking out the north and east targets, setting them to 0, setting them to the initial positions, changing the frame from MAV_FRAME_LOCAL_NED to BODY_NED, LOCAL_OFFSET_NED, and BODY_OFFSET_NED. The behavior is always the same, a drift backwards at a very low height.