Hi all! After some pid tuning, but require further adjustment, today i made the first real flight with my "heavy ArduXOcto", i open this thread for sharing my experience if someone else wants build a similar "heavy configuration" using ArduPiloltMega 2560, IMU, GPS and Baro, etc.
I have previously tested more expensive systems like Mikrokopter and Wookong, and unfortunately i think there is still much hard work over the code for make this electronic flight like the competition, but considering the price i would say that goes too well.
I'm still quite satisfied, even though my copter in some aggressive maneuvers tend to wobble a lot, and in the Loiter mode some circles is inevitable because I believe that the management of the accelerometers correction is not optimized or inactive.
Over the baro range i've a good altitude precision, max 20/30 cm of excursion.
This is my hardware configuration:
- APM 2560
- OilPAN IMU
- Mediatek MT3329 GPS V1.6
- XL-MaxSonar MB1200 (with active filter and "thermal mods", 4 x 10 ohm resistor around the case)
- ESC HiModel Pro 30A, in high timing mode
- Two switching BEC 6V 5A (connected to electronics through two diodes 3A, the tension output is 5.33V)
- Motor TigerMotors MT2814 710 kv (mounted with 3° inclination for increase YAV control)
- Props APC 13x6.5 "E" (X8)
- Two-Way telemetry "Mikrokopter Wi232" (890 MHz)
- Six led strip connected to APM (pins AN8<->AN13 through ULN2003), thanks to u4eake for the code
- Homebuilt frame, mixed aluminum / vetronite (by AleBS, thanks dude! :P) + homebuilt hood
- Lipo 4s2p 5000 mhA 40c
- TX Futaba T12FG
- RX Futaba R6008HS
I'm uploading the video on my youtube channel, post them soon, for now I leave you some pictures.
I enclose the parameters used for the flight test in a soft wind, but there's one error, the real "Rate Pitch I" is set to "0".
I also found out in Win 7 you must set the Arduino execution file to run as administrator. Otherwise sometimes it wont upload the code and will give an error.
Hi there, have you done any waypoint navigation with this copter? If so, would you be willing to share the Nav PIDs? I am tuning an Octo that weighs around 3kg, and its navigation is not going as well as I'd like. The desired speed is 5 m/s, but between waypoints the ground speed usually ramps up to over 10 m/s, especially after pulling out of a loiter. So I guess I'm just trying to see if my Nav PIDs are even in the right ballpark? Thank you!
glad i found this thread. having one heck of a time getting a heavy quad dialed. how much time do you think youspent getting it tuned? i spent most of the day tuning and still dont feel confident hovering. lots of wobbles. very poor yaw control.
nice sharing buddy. following eagerly
I don't yet know what the final weight will be, but very light. The original had one of Time Cops Funfly 32 boards with a DJI PPM Rx. really small and light but this one will be trying the APM 2.6. system The motors are cheap but well made Hobby King MultiStar 370 Kv. and they have the best efficiency that I have yet tested. At the estimated hover power, I am seeing 15 grams/Watt. from each motor. That is almost double what a DJI Phantom Vision can do. That figure was achieved at 3s and was slightly up on the 4s test.
The main feature that is different from the usual Tri. is the yaw control; which is what that rear vane is all about. The props. are 16.5 x4.5 Supreme from Foxtech and nothing that I tested even came close to the efficiency they showed when everything was dialled-in including the ESC 32's.
As well as being the most power efficient, Tri-copters are quite nice to fly if done right. Apart from the overall vertical lift control; the front motors run opposite directions and just create the roll stab. The pitch is done by the rear motor and the yaw comes from the vane. Importantly none of the motors have to slow down or speed up during a yaw turn. This makes for greatly improved stability in a turning descent. I may even introduce vanes to the front arms to aid fwd. flight as the model will not need to pitch down so much.
I expect this one will have almost two hours duration with li-ion battery technology.
As we are all going to find ourselves under threat from the legislators once they realize what can be done. I decided to try and get a head start in the super light trends.
Looks great Denny, you should do a blog post...
a few questions:
How much deflection do you need from the vane to fly?
Do all Tri's use opposite props on the front motors?
Interesting about the cell phone cam, easy to do?
What a brilliant idea Denny. The genius is in its simplicity. The idea that it might be possible the whole flight control can be done just using vanes is interesting .
It moves about 15 deg. each way. A point worth mentioning is that the rear motor has a built-in offset to compensate for the rear motors torque.
Most Tri-copters use all the motors running the same way. What that does is create a torque bias to remove any deadband in the yaw control. I don't seem to have that problem but if I did then a quick solution would be to fit a Gurney to the bottom of the vane. A gurney is a flat strip about 6mm wide that is glued to the trailing edge at right angles. It works like an anti flutter device that you may have seen on the rudder of high speed jets.
I will do a blog post soon when I have some more things to add to it. And of course, the flight vids.
I don't think you could do the whole FC with just vanes and have as much stability but there are a few successful coanda effect machines around that use only vanes.