Getting started
« on: August 22, 2017, 04:48:38 am »
I have been flying for years and years.  I can pretty much fly anything.  I have a bunch of planes collecting dust, so why not see if I can figure out how to get them to fly way points.  I have been messing with FPV a little here and there.  Mostly on the ground as crashing does not cost much.  I have a couple quads on the shelf I have played with on and off.

Now I would like to stat using a plane with a flight control setup.  On hand I have (2) CC3D's, (2) of the real, original Open Pilot Revo Nano's.  I would like to use GPS.  I was reading that the flight modes do not work on the CC3D.  I am hoping they will work with the Revo Nano.  I have been looking for a GPS unit.  I see a handful here and there.  A couple claim to plug into the CC3D or Revolution boards.  I saw one on BG for $22.00 I may order.

Is there a setup guide I can read up on?  I have done a few searches and they are all pieces of the setup.  I guess I will have to find the one for each step as I work my way through.

Any way, I was here a while ago, well long time ago.  Got frustrated with the quads, walked away before running them over with my truck.  :)  So now I ma back looking to setup a plane and in doing this it will help with my quads.



Re: Getting started
« Reply #1 on: August 22, 2017, 06:01:13 am »
I got a feeling that it will take more than that to help the ones you ran over with your truck...

Nano can do about anything a Revo can except built in telemetry.

Set it up with a GPS / INS13 / AirspeedSensor (software) module enabled so that it has some idea of airspeed or you will have to detune the PIDs a lot to avoid oscillation.

Watch out for magnetic hatch/cowl hold downs.  My fixed wing GPS ship has them and I put the GPS/mag on top of the rudder.  :)

Make sure your failsafes (RC and/or FC) are set right to at least stop the motor and hold other controls for now.
Set your AIrspeedSettings.AirspeedSensorType to GSBWE and enable the Airspeed module in System -> Settings -> HwSettings.OptionalModules
Get it flying with Manual and INS13.  Recenter the Tx trims after each flight and adjust the linkages instead.  It is important that the tx trims be where they were during the transmitter wizard for all modes besides Manual.
I suggest a forward CG (and a little up trim so that it climbs when you add power) and set up Manual so that it flies at a leisurely cruise speed hands off.

Then add Rate mode and tune the standard PIDs up till you get an oscillation and then back them off till it completely goes away.  Rate mode should feel good, about like Manual.  Personally, on my 4 channel fixed wings, I don't stabilize yaw (leave it Manual) because I presume that forces you to coordinate your turns.

Then add Attitude mode, set FixedWingPathFollowerSettings thrust limits to something like 0.3 0.4 0.5 if that is a good range (needed for waypoint and RTB), and tune FixedWingPathFollowerSettings PIDs if needed to get it flying in Attitude mode.  Adjust FixedWingPathFollowerSettings PitchLimit Neutral to get a nice leasurely cruise speed at the correct pitch angle.

Beware that stabilization winds up (not good) in Manual and so switching from Manual to Attitude will go a bit crazy for a couple seconds.  Go to zero throttle before switching from Manual to Attitude to work around this because the default ZeroIntegralWhenThrottleLow unwinds it when throttle is zero.  Flying in Rate and switching to Attitude doesn't have this issue IIRC so that is a good way to avoid it since Rate is so similar to Manual that you can just use Rate for your base mode once you get Rate tuned.

Determine (telemetry) what your cruise speed is and set vtolpfs FWPFS min speed and max speed equal that.  Set SystemSettings.AirspeedMax and AirspeedMin to reasonable values that you should not see in gentle flight.

I suggest that you get RTB working at this point.  Always have Rate or Manual on the FMS and test RTB till you are confident in it.

To do waypoint flight, you will find that you get some atti/stab overspeed underspeed errors and it will keep jumping back to the first waypoint.  Adjust your VTOLPFS FWPFS thrust limits to keep your speed reasonable and set your waypoint "error destinations" all to -1 to ignore these speed errors if you have controlled them but can't get rid of them (e.g. GPS airspeed estimation is inaccurate?) and want to continue testing.

Beware that when you set your failsafe to RTB that switching the transmitter off first can make the motor come on!

One of my future projects is to install an FC in a fixed wing as if I were a beginner who required Attitude mode from the beginning, and see if I can do it and write about it.
« Last Edit: August 22, 2017, 06:27:42 pm by TheOtherCliff »

Re: Getting started
« Reply #2 on: August 22, 2017, 05:41:32 pm »
Well that is one heck of a reply.  Thank you for all of the information. 

I just need to pick the test plane out of my inventory.  I have one in mind, 55 inch, slow flying Cessna.  It will just hang on a breeze and fly for 30 minutes on a 2200mah 3s battery.  Or I can whip out a foam ugly one in an hour?  I have an old wing from a glider I could build a fuse and tail for.  Hm even a small foamy to mess with.  I will break out something this weekend.    I have foam and glue, watch out. 

I have (2) 550 quads on the shelf, (1) has the CC3D in it.  I have just flown around a bit.  No camera or anything.  The other has a PX4 on it, just got to the point of mounting the GPS and starting to setup up flight modes and way points.  I will get frustrated and leave it along for a while then come back and try again.  Each time I work on it I learn more and the previous steps are easier to do.