Pixhawk on 700 heli

hi set up my assault 700 flies well
but when in loiter pitch axis seams rock slightly is this normal as its corecting its gps position or is a setting too high ive tried ajusting stb-pit but made no difference
in attached log i changed head speed to get vibration levels down half way through log
if any one could check log and advise
many thanks stuart

I would start with cranking up your “I” gain in both Pitch and Roll until you see an oscillation then back it down from there.

This should help.

You should be able to start at 0.100, and go from there, maybe up to 0.500, some people even go up to 1.0. But 0.038 is certainly too low. Also increase the IMAX to 2500. This will all help with the above issue.

Typically you would run the I-term at 1 or 2 times the level of P-term on a quad. But on heli, the spread is much more. P tends to be very low, and I-term tends to be very high. This is because of the very different response characteristics of the two systems.

cheers
tried increasing rate pitch i term but when above 200 i get bounce after a stick input from trans mitter
is the imax the two on rate pitch and roll i should icrease to 2500 ?
cheers stuart

heres my present settings

Stubugs, Your P on roll and pitch are big numbers in my opinion. Your FF’s are 0 ? I’ll post my parameters a bit later for my 600.

Regards,
David R. Boulanger

Stubugs, Here is my parameter list. Not saying this is good for all heli’s but the relationship between the numbers I would think would be close. You may also try lowering your Loiter P from 1 to .8 maybe and see if that helps.

Regards,
David R. Boulanger

It won’t let my attach a parameter file!

Try this.
diydrones.com/forum/attachment/d … %3A2052803

Regards,
David R. Boulanger

Stubugs,

I looked at all your parameters and I think your main problem is all your ATC Parameters. This is the kind of stuff that Rob’s help will be missed. Your ATC RATE FF ENAB is 0 instead of 1. I think this means that your FF #'s on Rate roll and pitch are not being used. This would also explain why your Rate P’s on roll and pitch are so high. Look at my ATC parameters from my last post to you. They are pretty generic but work well. Be aware that your P’s on RATE roll and pitch will need to be lowered. They are 4 or 5 times higher than mine and once the FF #'s are used in the equation I would think you Heli is going to shake all over the place. Also compare your ATC ACCEL’s, RATE’s, and SLEW YAW to mine.

Regards,
David R. Boulanger

hi david
i looked through differences on our para and i think id be starting back at stage 1 of setting up
but before i do what head speed are you running as im running 1350 rpm which i think could make a big difference on parameter setup
stuart

Stubugs,

My head speed is 1550 with Asymmetrical Spinblades. My all up weight is 9 1/2 - 11 pounds depending on battery size and payload. I do believe the ATC parameters are very important.
Regards,
David R. Boulanger

Hi David
Does your helicopter loiter well with these settings and how does it stand up to about 17 miles an hour gusts
Stuart

Loiter is good. If the wind speed is changing a lot it will move around a little. It is set up as a camera ship so its movements are not set up to be sudden.

Regards,
David R. Boulanger

Stubugs, If you want to see some test video’s they can be seen on Youtube. The channel is SWF Drones. They are all using the parameters I posted except for the ATC video in which I was try something different.
Regards,
David R. Boulanger