Just wondering if it is possible to upload a mission plan while the plane is in the air.
I know you can click on the screen and click fly to here while plane is in air but wondering if
One person takes off and flies the plane manually and another writes up a mission at the ground station upload it to the plane via xbee etc ,Pilot switches to auto and plane flies mission .
Is this currently possible??
yes it is possible
How is this done?
Click on the "write waypoints" button in the lower right corner of the flight planner screen.
We all load the way point file in manual mode before we fly. Isn't it. So it doesn't matter if the plane is in the air on sit on the ground.
It may be more interesting to find out if we can upload a new way point file after it had finish the mission upload earlier.
So if we send a new flight plan to the apm while the plane is flying will this overwrite the current flight plan?
Yes, whatever waypoints are in the flight planner screen will be written to the plane mid flight, replacing whatever was in the plane previously. If the plane is currently heading for waypoint 5 of 10 and you write a completely new set of 10 points, then it will head for whatever the new waypoint 5 is and go from there. I'm not sure what happens if you have less waypoints than before, but I imagine it will just RTL.
A word of warning - depending on telemetry signal strength, I have had problems where only some of the waypoints are uploaded and you get an error before all of them are up. This is usually handled gracefully by the plane (ie. it doesn't crash), but you can have trouble updating long lists of waypoints (in my case 20). Sometimes you need to hit write a few times to make it work.
It's usually better to do it on the ground to be sure they all upload.
yes, it is possible, although you have to do it carefully.
The mission planner currently sends a "wipe mission" command first, then uploads the new mission. That can take several seconds, during which time the plane has no mission. That can lead to nasty errors (the most common result is it ends up doing an RTL).
The mavlink protocol supports incremental mission updates while flying, but as yet MP doesn't do this. mavproxy can do it, and we used that capability during our OBC mission (in order to change the mission based on the results of our image recognition). If you want to do this with MP then you'll need to talk to MichaelO about adding support for incremental mission uploads. If you are using mavproxy then you can do it now.
a bit more details ...
To do an incremental mission change in flight you should use the MISSION_WRITE_PARTIAL_LIST MAVLink command. That takes a range of wp numbers to change and the APM then asks the GCS for those changed waypoints. That command is currently supported by ArduPlane, but not by ArduCopter.
This allows you to update a contiguous set of waypoints within the mission by sending just the changed waypoints. This is what mavproxy does when you drag a waypoint on the map (although mavproxy also adjusts the altitude according to the terrain model to keep the waypoint at the same altitude above ground level).
Adding new waypoints instead of adjusting existing ones is a bit trickier as you need to be careful the plane doesn't start using a waypoint that isn't uploaded yet, especially if you are using jumps. Right now mavproxy doesn't have a command line interface for doing that, although it can be done in a mavproxy module in python.
I have not yet done what I am about to say but I am planning to test running two separate missions while plane is still in air by doing the following:
On ground via 3dr telem upload/write first mission to APM using MP. Launch and run first mission. At completion of first mission switch to loiter mode using switch on tx. Upload second mission. Switch back to autopilot mode again using switch on tx. I think this will initiate the second mission and then RTL after completion.
Anyone agree or disagree from experience?