Servers by jDrones

Building RealFlight8 Models


(Peter Hall) #101

Hi all, have been using realflight to mess with the tailsittter code and I must say it works very nicely. I have been playing with the physics of my realflight FT bronco model to try and get it to be more realistic. I am having a couple of issues.

Firstly the realflight landing gear seems to do nothing, is this because I don’t have proper visual frames set up for it? This is annoying as the rounded fuselage in the CUAV TVBS graphics I am using causes the aircraft to drop a wing to one side or the other when on the ground.

I have selected the right size motors and props and the aircraft hovers at the same throttle percentage as the real one. The realfight model however reaches about 50m/s at full throttle where as the real one only gets to 25-30m/s. I need more drag. I have tried increasing fuselage frontal drag percentage to 1000%, this has no effect. Only way i could get it to slow down was increasing the wing parasitic drag to 200% this is the maximum value and this only slows the aircraft by 3 or 4 m/s. Any ideas?

Quite frustrating how linked the physics is the the visuals. I don’t really need it to look right, just fly right, although it is useful to see the control surfaces moving.


(Kisor Alaguvel) #102

Hey!
Can one import CAD models into RealFlight8 and simulate?
Just curious!


(tridge) #103

yes, unfortunately RF8 uses the visual for ground interactions.

the physics should only be linked to visuals for ground interaction, I haven’t noticed a linkage for flight.
Cheers, Tridge


(Peter Hall) #104

Thanks Tridge,

I did get it working quite well in the end, still not enough drag though


(tridge) #105

hi everyone,
KnifeEdge have now released a beta which supports up to 12 actuators for the FlightAxis protocol, which means we can build aircraft with up to 12 channels. This really helps with more complex aircraft.
See the announcement here:
http://www.knifeedge.com/forums/showthread.php?t=33513
I’ve pushed a change into master to take advantage of the extra channels. I’ve also tested to ensure that sending 12 channels doesn’t break anything with the older version of realflight.
Cheers, Tridge


(David Buzz) #106

12? Its better than 8, but I already have a design I’m working on that needs 12 for the copter, 1 for mode changes, 1 for retracts, 3 for the gimbal, 1 for a sprayer channel, 1 for arm/disarm, and probably more… why not just make it 24 or more and be done with it?


(tridge) #107

because the internal structure of RealFlight makes going to 12 easy. Going to more than 12 is a much bigger job, and not something they can take on right now.


(tridge) #108

btw, why would you need an output channel for mode changes?
This has nothing to do with input channels.


(David Buzz) #109

In the real vehicle, we passthru sbus signal out from pixhawk to another microcontroller, and it needs to be aware of mode changes and arming state, and currently gets this info via sbus signalling two servo out channels, which isn’t perfect, but works. We cant sim this at present ,but would like to


(tridge) #110

you can simulate that actually, just set one of the SERIALn_PROTOCOL channels as SBUS_OUT, and connect a real UART (see wiki) using USB serial adapter. Then the real external microcontroller can get data while flying with SITL in RealFlight.
The 12 channel limit is only on what goes into RealFlight. You can have 16 channels running with SITL, and output them all via other protocols (including SBUS).
Cheers, Tridge


(RobertWZ) #111

are there RF8 with ardupilot demo ?


(tridge) #112

There are quite a few youtube videos on the ArduPilot channel and my channel showing now it works