Servers by jDrones

Can Arduplane fly without rc receiver? (Yet?)


(Fredrik Falkman) #1

My application requires flying in Auto or Guided. it will be exclusively BVLOS over 4G. (I know you usually shouldn’t, but I have permission and a restricted airspace.)

This means that I don’t have any use for an RC receiver. I would actually really prefer to not have a receiver, because my safety case is based on minimizing weight and since it won’t be used, it’s a liability, an unnecessary link in tha chain which could fail.

So my question is - is this possible? I know px4 has COM_RC_IN_MODE (https://dev.px4.io/en/advanced/parameter_reference.html)? where you can chose wether to use RC or not.

In my own testing on a flying wing I can happily fly with the RC transmitter turned off as long as the RC receiver is plugged in. But if I remove the receiver the elevens act strangely. The left one seems ok, while the right one is turned way up. I have tried trimming the servo outputs to a setting where on the ground in FBW it looks like the elevens are operating about right if I turn the plane about it’s axis. But when I try to fly I get a lot of turning and a lot of rolling and then inevitably crashes.

It was suggested on the developer Gitter that RC_CHANNELS_OVERRIDE might be used, but that seems to have to do with using a joystick?

I would really appreciate any suggestions or explanations!

@CraigElder @OXINARF @auturgy @tridge


(Hunt0r) #2

I’m not a dev, but I’m somewhat familiar with the code… and I don’t know of any option which supports your use case. (Someone please correct me ASAP if I’m wrong.)

Have you considered modifying the firmware to ignore real RC values and instead always provide “neutral-stick” RC-RX values? It’s a hack, but it might work. Also, since the RX is used often to change the flight mode, I am not sure if you could switch modes or not with this workaround.


(tridge) #3

yes, you can fly with no RC receiver.
The settings you need are:

  • THR_FAILSAFE=0 to disable the RC failsafe
  • STICK_MIXING=0 to disable RC stick mixing in AUTO mode.
  • FLTMODE_CH=0 to disable flight mode change by RC channel
  • INITIAL_MODE=N where N is mode number you want to start in
    You will be able to fly in the following modes:
  • AUTO
  • GUIDED
  • LOITER
  • RTL

(Fredrik Falkman) #4

@tridge you make it seem so easy! Of corse it’s the stick mixing! thanks!


(Hunt0r) #5

@tridge Thanks! @fredrikfalkman Sorry for my wrong-information…


(Fredrik Falkman) #6

I can now confirm that this did the trick. My Disco/Navio2/Arduplane/4G finally flew without the RC receiver installed. On a perfect, rainy, gusty half gale day!

Thanks!


(Brian) #7

Would Love to read and learn more details about your Disco/Navio2/Arduplane/4G setup and configuration!! Let me know if you have time to share more info and pics of your flying wing. Thanks!


(Fredrik Falkman) #8

This is the stuff that I have put inside a 3d-printed “sorta waterproof” casing along with an airspeed sensor. I run the Arduplane version supplied by Emlid. The parameter setup has taken some time - mostly because of my inexperience with this complex subject. So many things to learn!
To keep the casing water resistant I have printed a sort of Brattberg-esque rubbery conduit through which I run the servo- and power cables as well as the two airspeed hoses.
I have slung a GoPro Session 5 underneath for now. The Pi connects to the GoPro’s built-in WiFi access point to get the video stream which is then restreamed by means of ffmeg via 4G straight into QGroundcontrol. Not brilliant quality yet but working on it.