Jean-Louis Naudin did a cool loiter comparison test of the Cheerson CX-20 (Quanum NOVA) Phantom clone with APM running ArduCopter 3.1.2 vs the DJI Phantom. Not bad!
Needless to say, newer copters with Pixhawk and more recent ArduCopter code do even better ;-)
Comments
it looks like quantum nova HK already sells.... doesn't it?
http://hobbyking.com/hobbyking/store/__55105__Quanum_Nova_FPV_GPS_W...
If the CX-20 goes mainstream, then I feel sorry for the developers here. They'll be overwhelmed with beginners questions. The kind typically found in Phantom forums.
Find another way =)
http://wltoys.en.alibaba.com/product/1492055590-212872225/WL_RC_toy...
200.000 per month
@Al Ros, re moving around in Loiter, you'll probably appreciate the "Hybrid" mode that is coming in AC3.2.
Hmm
I have been away from APM since last summers firmware and I just finished testing Loiter in firmware 3.1.5 on APM 2.5 compared to naza. Basically APM takes a more aggressive approach to position hold. So It does seem more "accurate", but NAZA is much more smooth and deliberate. Both are good understanding that their approach is a bit different. I am sure I can play with gains to smooth out APM also.
The real Problem I am having with APM loiter that I would like input on is with moving the stick while in loiter to reposition the quad. I have to say again NAZA takes a smooth approach to this as well. so that it smoothly glides to a stop and stays there. The faster you move the quad, the longer the stopping distance. It sort of models momentum.
My APM is doing something strange. It comes to a stop in "waves". When you let go the stick, it will brake more aggressively, then levels while still moving and then oscillates in a lower amplitude until it stops. It makes it unpredictable. I could not find a setting that would allow me to adjust the aggressiveness of the stop - can you point me to one?
Lastly with NAZA when you are on the sticks in loitre mode, it feels like you are in complete control just as if you are in stabilize mode with alt hold. But with AMP I am finding that it is sluggish and delayed so that you can get into pilot induced oscillation and overreaction . Again I really want My APM to work well - so please don't interpret my comparisons as any way bashing it (I have owned several of each hardware versions and have the pixhawk on order). I am looking for help to get it to fly well.
Al
Unfortunatelly, his comparison is incomplete and sorely lacking in technical analysis.
It would be interesting to compare them dynamically, as static GPS performances is different than the dynamic ones.
Some relevant things to check/compare:
- HDOP and NbSats during high angles input (eg in Alt_Hold or Hybrid mode)
- Altitude stability: is there any altitude drop when you go forward and release pitch (or pull stick back).
- Maneuverability
- Payload
- Autonomy
- ...
Randomly pointing the camera in different directions definitely helps, though they both looked awful. GPS IIF sucks.
The compass on that craft is not integrated with the GPS module. The compass is in that little tower, the GPS is inside next to the flight controller. I'm not sure anything would be gained by altering the GPS mounting. It isn't really sensitive like the compass is.
Also, the altitude hold is based more on barometer and accelerometer than GPS. So no, it is not "only a GPS module comparison".
Can we say this is only a GPS module comparison ???
Angelo
One thing I noticed in the video is the DJI kept slowly losing altitude and Jean even had to fix it once. DJI is not impressing me and it never did. I prefer the APM and PixHawk systems over DJI any day...
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