Main Site Documentation

UAV Experimental Platform


#1

I have been working on UAV/Autopilot project using the Panda for a few weeks now. I’m phasing features in one step at a time and it’s almost ready for its first flight so I thought it was a good time to show progress.

Phase 1 is about getting the hardware in the air and providing information in flight. Working features are GPS interface, on-screen display, showing basic telemetry: distance/heading to home, altitude, groundspeed, battery voltage and position.

Phase 1.5: pass-through radio PWM signals

Phase 2: add gyro stabilization

Phase 3: basic autopilot: heading hold

Phase 4: advanced autopilot: waypoints, position hold, return to home

Other features I don’t know if I’ll do yet or where to phase in: battery capacity monitoring, camera control (aim at specfic groundpoint), landing assist.

Here’s the plane ready to have the electronics mounted.

The chassis has flown before but this will be the first flight for the electronics.


#2

Interesting about how you are using that flying wing.

I have heard a lot of people saying that they don’t use flying wings for UAVs do to the “difficulty” in artificially stabilizing them. After watching my friend’s Zagi plummet from a few hundred feet in an inverted flat spin, I have a tendency to believe that.

I will also be doing a UAV, as soon as I can find a suitable aircraft.This is harder than it might sound…

  • No foam (fiberglass/covered balsa)
  • Tricycle gear
  • Electric
  • Large
  • Slow
  • Not a scale model (IE, don’t want fake antennas and junk all over it)
  • price is not much of a factor

#3

This plane body is designed for FPV/UAV work–wide flat airfoil for stability and load. Once it’s trimmed out it is very predictable. It isn’t self-stabilizing so it keeps going the way you point it. I have smaller combat wings that are much more maneuverable. I have video on one of those but I have no plans to put autopilot there. (Gyro stabilization–maybe.)

I’ll eventually get something more like a glider, but EPP foam is almost indestructible (we crash our combat wings into each other and the ground on every outing) and it has a lot of space to mount stuff. When I’m past the prototype stage, I’ll have a better idea of what I need and make a SMT board that can fit in just about anything.

My current thinking is that board would integrate USBizi, IMU, OSD, regulators and probably a small PIC processor to do whatever grunt work I can’t do in CLR.


#4

What do you think about the Easystar?

I know, it’s foam, it’s small, it doesn’t have a ton of payload, and it doesn’t have landing gear, but I’ll be damned if there aren’t a ton of them around.


#5

I hear good things about the from people flying FPV (first-person view). I also hear people using the EasyStar body with EasyGlider wings.

I have a foam plane that’s pretty close to the EasyGlider, but has a pusher prop behind the canopy. This is ideal for video. That plane is in need of some repairs after a bad-CG-induced meeting with the turf. I might move the electronics over to that plane sometime too.

But I’m also like you–looking to get something more glider-like, with fiberglass. Hobby King has a few models I’m watching, but right now I’m focusing my time and money on getting the electronics right.


#6

I saw your video on Facebook,looking good!

I am looking at two models at this point:
E-Flite Alpha Sport 450
Hanger 9 Alpha 40


#7

I had a similar plane (with a gas config) this summer. I totalled it when I had a total radio failure 20 sec after takeoff (electrical problem with a camera control system I should have done more ground testing with. :S ) (picture attached)

The advantages there is a great lifting capability, good range. Drawback is that they won’t survive a crash as well as a foamie. I moved away from the balsa/frame world and the ‘avoid crashing at all costs’ mentality to a foamie ‘embrace crashing as part of the experience’. I fully expect to have a few ugly ones before fully debug the autopilot. :wink: Be careful with gas–I hear some engines give off weird interferance.

Here’s what I’m flying now: http://www.crashtesthobby.com/index.php?p=1_16

Here are a few I have my eyes on when I’m ready for something more destructible. These are at Hobby King but there are similar planes out there:




#8

Very cool.

Is the video being transmitted back to the ground during flight? Or is it being recorded and viewed once it lands?

How did you work out the placements to keep it well balanced?


#9

Live video feed using a 1.2ghz radio and homemade transmitter antenna. I don’t have a good recording setup but you can see it roughly here as recorde by my phone:

Near future project: video distribution amp to split video to laptop for recording :slight_smile:

I was a little tail heavy to begin with so adding a couple of ounces (panda, breadboard) didn’t make a big difference. The video transmitter sits behind the CG so it balances it a bit. I’m probably a little heavy on the video TX side but it flys OK. I have yet to permanently mount the GPS and receiver antenna, so that will balance it out. One wing has all my transmitting equipment, one wing has all my receiving equipment. It helps avoid interferance from the 800mw video transmitter.

Attached is a picture of the plane’s video transmitter and antenna


#10

That is cool…What LCD screen did you used?


#11

I bought a 12" LCD TV from ebay that had a broken stand for about $60. I gutted it removing all the plastic and mounted it inside the top of a metal briefcase. The briefcase has space for batteries and I can mount my receiver antenna to it. Eventually it will be the home of another Panda that tracks signal strength and battery voltage, maybe even decodes wireless telemetry down the road.

The whole thing runs off of a 6700Mah SLA battery or a 12v ac adapter.


#12

andrejk, drop me your address and i’ll send you a 4 way video splitter :wink:

markh@ rris.com.au


#13

@ MarkH wow, thanks for offering! I should have waited… I finally realized that Amazon has them for $10 so I was wasting cycles trying to figure out how to build one. :slight_smile: I ordered it yesterday so I should have some good videos up later in the week.

I’ll use that time to add receiver diversity to my groundstation (Panda-based, of course).


#14

If you have too much of an issue with the flying wing style design you could always add vertical stabilizers.

In terms of live streaming video how are you getting a high enough data rate to dump it? Could you give more precise specs of your video system?

cheers


#15

@ FezBomb this design does pretty well. it has a thinner airfoil than the others I fly so I have small stabilizers at the wing tips. It yaws a little at low speed but it hasn’t been a problem. I have thought about building new stabilizers with integrated antennas so I can avoid the antenna sticking up from the body.

I use an analog video downlink via 1.2Ghz. I have telemetry overlaid on the video stream right now. I should be able to add a data downlink via the vertical blank interval (VBI) in the video feed.