I have just bought the ArduPilot Mega 2560 Full Kit... plus the Triple Axis Magnetometer HMC5883L. I should have it built over the weekend.. then i'm off to a my mates machine shop, and i'll make the splitter plate for the lower frame onto which i am going to fit the Ardupilot. the magnetometer i'll put on the tail as suggested. I am going to use my X-cell Razor 600E. For those that dont know its around the 50 size nitro heli.
Do i need to buy any other sensors i.e. the Sonar... i can fly a helicopter all day long but this is my first time flying one with stabilisation so any tips would be gratefully appreciated.
If this works well then i am going to try and use it on my x-cell gasser. i can get up to 20 minute flights with this. But i think for the time being a battery 600 is the way to go.
i'll post some pictures when i have it all together.
Hi Guy's :-) Add 1 to the team. I knew this was a long term project when I signed on.
I have available a 600efl (flybarless), 250 flybarred, and 250 flybarless, a pair of APM 2.0's (one mounted and flying in the 600, the other on the desk currently). I also have on the way once shipping a APM 2.5, ArduIM V3, and a full array of sensors plus the Ublox GPS.
I get a few hours each evening and some time each weekend for flying.
I can mount my second APM 2.0 to my 600 just to capture data if that is what you are looking for at this time?
So you have your 600 flying? Can you show your mounting, and which code are you running? Which heli? Did you do any radical balancing procedures?
I've just purchase an electronic scale, 500g, 0.01g resolution, so I can try and balance my blades better.
Very interesting, you have it running on 2.7.1. So how well does it fly?
Previously, my flybarred 600 flew like a giant Blade CX. Totally stable, predictable, easy to fly. Do you still have that? Or do you feel like you have to chase it around a bit?
Just a tip about tuning PIDS. When you tune one super tight (Values near the point of oscillation in a neutral environment) adding load, mass, or outside influence can cause the oscillation requiring you to lower the PID values.
Keys about the values to remember
P is gain, in it's purest form. This value is what you always adjust first (raise it) until you get oscillation and then back off a little bit
I is additive to P but works in the time domain. The longer the sensed position does not equal target position, this value adds to P. Thus, pure P tuning may require a backoff setting when I is tuned because I adds forcing a high value of P to reach oscillation.
That last thing you touch is D and only after extensive testing of I an P. It can remain at a lower value in most cases.
Again, be cause the over all response is rather slow, P and I are the largest factors here.
Ok, that makes good sense and would explain the behavior. You basicaly have a mechanical gain adding to any of the software gains, and thus even with good tuning, may be dificult to control.