I finally ordered a Pixhawk to upgrade from the old reliable 2.5. I will be switching over from running 3.01 to 3.1 ( rc5 I think ). Am I correct that aside from some parameters that did not exist in 3.01 on my APM that my main PID’s that I have been flying very well on should all be the same? Same Helicopter just changing over to the Pixhawk.
Regards,
David R. Boulanger
Good question. I wish I could remember the answer. 
Unfortunately I spend too much time messing around with the code to remember a stable release from over a year ago. 
I think that for the most part you should be OK. But I would suggest starting out your first flight with your Rate Roll and Pitch P-term on the Ch6 knob with a suitable range, just in case.
When going from APM to Pixhawk on 3.1, I know that the I-term Leak rate happens 4-times faster than on APM which makes the I-term even less effective, so you can probably use some extra here. I plan to fix this for 3.2.
From the release notes:
[quote]3) TradHeli only fixes:
a) Drift now uses same (reduced) collective range as stabilize mode
b) AutoTune disabled (for tradheli only)
c) Landing collective (smaller than normal collective) used whenever copter is not moving[/quote]
[quote]1) Heli improvements:
a) support for direct drive tails (uses TAIL_TYPE and TAIL_SPEED parameters)
b) smooth main rotor ramp-up for those without external govenor (RSC_RAMP_TIME)
c) internal estimate of rotor speed configurable with RSC_RUNUP_TIME parameter to ensure rotor at top speed before starting missions
d) LAND_COL_MIN collective position used when landed (reduces chance copter will push too hard into the ground when landing or before starting missions)
e) reduced collective while in stabilize mode (STAB_COL_MIN, STAB_COL_MAX) for more precise throttle control
f) external gyro parameter range changed from 1000~2000 to 0~1000 (more consistent with other parameters)
g) dynamic flight detector switches on/off leaky-i term depending on copter speed[/quote]
Thanks Rob. It will probably be a week before the Pixhawk is here based on previous experience with 3DR. Good to know about the leaky I.
Regards,
David R. Boulanger
I flew my first flight with the Pixhawk and 3.1.5. Stabilize is dialed in good. Vibes are less than .15 on all axis’. Alt hold is drifting up and down a lot and loiter had a slight TBE. TBE may be being caused by the heli hunting so much for the proper altitude. Vibes are also a bit higher in Alt Hold and Loiter,but only about ± .2. I need to try to figure out how to post parameters on this forum. I’m thinking my THR_ACCEL_I is to low at .5. That’s a left over parameter from 3.01 and I noticed Sean Whitneys is at 1.5. Anybody has any comment on ideas before I try again tomorrow I would welcome feedback.
Regards
David R. Boulanger
Can you post the logs?
Here is the tlog I think. I will try there rlog next
Regards,
David R. Boulanger
let me know
Regards,
David R. Boulanger
Everything is good now. Just had to up the THR_ACCEL P and I. Flying at 4 meters high Alt Hold and Loiter looked perfect.
Regards,
David R. Boulanger
Vibes were a lot better except for a hard landing. I think I am in good shape now. I would have tried RTL and maybe some simple waypoints had the thunderstorms not come early today. Thanks for your help Rob. I think this topic can now be classified as solved. Todays log is attached
Regards,
David R. Boulanger
Do you have the flash logs? Just .log, or better yet if you’re using Pixhawk, just stick the card in your computer and take it directly as a .bin
I’ll try posting the logs from the card in the morning. Thanks again.
Regards,
David R. Boulanger
Rob, Todays flight should be attached. Just tested loiter, Alt Hold and did one RTL. Also tested how the tail would hold with sudden changes in collective. Wind was a little gusty but not more than 10MPH
Regards,
David R. Boulanger