Multirotor, multicopter and quadcopter discussion - The Drone thread

DJMK4 · 8 Jun 2015 at 14:28

Cool, I think I will do some testing in the field, take my car park up and take my laptop with me.

Take a snap shot of all my defaults so I know what they were.

Im using baseflight.

If I can get rid of the throttle punch vibes first, then I will look at tuning to lock it in more and make it a little more snappier and tuned for the stick controls.

if im going the right way about it

gandhi · 8 Jun 2015 at 14:47

P.S. The Naze does work out of the box, but it works better with larger, less well powered quads. Clean-flight copes better than Baseflight in my experience.

Django x2 · 8 Jun 2015 at 14:48

Freefaller said:
Starting to get some cool footage from our drone (skip to 2:15 for the best bit) only some bits were filmed with the drone:

The BBC did some drone flying too with our media team and the guys we've been working with which is pretty cool:

http://www.bbc.co.uk/news/business-31817098

Poor editing of the drone seeing it's shadow, but I guess it's ok for amatuer stuff

Freefaller · 8 Jun 2015 at 14:52

We're good at engineering at least!

I wasn't flying just watching

else it would have been a lot worse!

gandhi · 8 Jun 2015 at 15:25

DJMK4 said:
Cool, I think I will do some testing in the field, take my car park up and take my laptop with me.

Take a snap shot of all my defaults so I know what they were.

Im using baseflight.

If I can get rid of the throttle punch vibes first, then I will look at tuning to lock it in more and make it a little more snappier and tuned for the stick controls.

if im going the right way about it

Might be worth giving cleanflight a try. It's much more refined now, has a better configurator, more options, all sorts of goodness.

PID tuning theory:

All in Acro/Rate mode....

1) Increase P on one axis until the quad starts to oscillate at hover - reduce P gradually until the oscillation stops

2) Do the same for I

3) Do the same for D, then go back and see if you can increase P and I a bit

You should get to a point where the quad feels like it moves at a 1:1 feel with the sticks and doesn't "ring" at the end of a movement.

Then you can start to increase Rates/Reduce expo.

Alternatively, have a look for Boris B on youtube (or similar) and steal his PID's as a starting point!

DJMK4 · 8 Jun 2015 at 16:25

Cool will have a look

I hear a lot of people switching over to cleanflight, then moaning and coming back to baseflight (heard it multiple times in this thread)

How true is this? I will get a tuning session going, will do it one step at a time and eventually I should get somewhere.

Dont get me wrong its great now, this is how iv been flying it, but I want it locked down to how you guys have it in your videos, nice, snappy, locked in, responsive.

You can tell the difference when I do rolls and loops to when you guys do

Genoma · 8 Jun 2015 at 20:55

You can get a lot of that locked in feel by increasing your rates too, the quad just feels much more responsive that way.

I'm not an expert in PID theory, so this may be all balls... but my understanding is that it is a self correcting algorithm; the P is essentially how fast the corrections are applied, too high and you overshoot what the FC is aiming for, it then overcorrects and ends up in a wobble loop. Dropping the P on the default settings isn't loosing performance, it's performance tuning for your craft.

TPA could be the answer if it's high P at full throttle as mentioned. It *could* be something totally different having said that. Oh and ignore d_b he is indeed strange if he likes WOT shudder :-)

Have a look at the profile settings in cleanflight (I'm pretty sure baseflight does too but haven't used it for a while) because that way you can keep your existing settings in say profile 1 - and create two other independent profiles with some test P settings that you can select with stick combos before you fly. There are 3 profiles to play with that way (I did this to tryout different rates).

DJMK4 · 8 Jun 2015 at 21:01

Cool profiles sounds like a good shout then I can have default on one and test two out

Will let you know once iv had a play!

d_brennen · 8 Jun 2015 at 21:04

Maybe I am strange, but I do like the shudder. 99% of the time my ZMR is locked in and stable as any, a tiny amount of TPA resolves it... It feels like POWA though

Rilot · 9 Jun 2015 at 08:49

Love the drone shots of Crossrail Freefaller. Filmed with a Phantom 2?

DJMK4 · 9 Jun 2015 at 09:16

Ahh I seen that artical and video a while back, thats your companies?

Phantom 2 ? I thought you got an inspire? im sure I seen that when you took a pic and posted it here

So shall I try cleanflight?

Tackle_Berry · 9 Jun 2015 at 09:51

Be interested to see how you get on with cleanflight I tried it a few months back and ran into countless problems so switched back to baseflight. I think it was just a buggy version, it was the latest version at the time (non beta) but when I looked online it seemed a lot of people were having issues.

I have thought about trying it again but at the moment it's flying perfect on baseflight so not going to risk messing it up. Maybe once I change ESC's or something.

DJMK4 · 9 Jun 2015 at 09:56

Thats why I am hazardous, I may stick to baseflight for the time being, and read up a bit more on cleanflight and its current releases

Rilot · 9 Jun 2015 at 10:30

Using Cleanflight on 3 craft at the moment (250mm quad, 180mm quad, and 300mm hex). It's fine. No issues at all.

gandhi · 9 Jun 2015 at 11:04

DJMK4 said:
So shall I try cleanflight?

Back up your baseflight settings, do a dump/copy/paste of the CLI. If it doesn't work for you, you can then flash back to baseflight and load up your old settings

CF did go through a phase of having one or two issues when they introduced the various different PID controllers but they all seem to be ironed out now. all the various controllers work well on their base settings so they shouldn't need too much tweaking.

For me;

Tried Harakiri initially, got on well with it, yaw authority was good but never really felt "locked in"

Tried Luxfloat next. Once I'd worked out the PID's needed to be about half what they normally flew ok. The latest version is much, much better. Has very good yaw authority. In angle though, it's very stiff so I found this best for flying rate mode in FPV.

Multiwii re-write - If you read the CF thread on RCG, it's the current flavour of the month as it has been tweaked recently. Apparently very easy to tune but I have only just tried playing with this one, so can't confirm that. It works better with my spider hex than luxfloat does for some reason.

Freefaller · 9 Jun 2015 at 11:41

Rilot said:
Love the drone shots of Crossrail Freefaller. Filmed with a Phantom 2?

DJMK4 said:
Ahh I seen that artical and video a while back, thats your companies?

Phantom 2 ? I thought you got an inspire? im sure I seen that when you took a pic and posted it here

So shall I try cleanflight?

Yup we got an inspire 1 as they will be able to offer more things in terms of things like thermal imagine camera, pics4d software and so on, waypoint flying etc....

However the vids were filmed with 2 different drones. As you can see the one going up the shaft is a phantom but some of the other shots are with the inspire.

Some of our toys:

DJMK4 · 9 Jun 2015 at 12:09

gandhi said:
Back up your baseflight settings, do a dump/copy/paste of the CLI. If it doesn't work for you, you can then flash back to baseflight and load up your old settings

CF did go through a phase of having one or two issues when they introduced the various different PID controllers but they all seem to be ironed out now. all the various controllers work well on their base settings so they shouldn't need too much tweaking.

For me;

Tried Harakiri initially, got on well with it, yaw authority was good but never really felt "locked in"

Tried Luxfloat next. Once I'd worked out the PID's needed to be about half what they normally flew ok. The latest version is much, much better. Has very good yaw authority. In angle though, it's very stiff so I found this best for flying rate mode in FPV.

Multiwii re-write - If you read the CF thread on RCG, it's the current flavour of the month as it has been tweaked recently. Apparently very easy to tune but I have only just tried playing with this one, so can't confirm that. It works better with my spider hex than luxfloat does for some reason.

Cool, will give that a go, yep backup settings good call, as iv not tuned in Baseflight I will have nothing to compare it to though

Freefaller said:
Yup we got an inspire 1 as they will be able to offer more things in terms of things like thermal imagine camera, pics4d software and so on, waypoint flying etc....

However the vids were filmed with 2 different drones. As you can see the one going up the shaft is a phantom but some of the other shots are with the inspire.

Some of our toys:

That explains it

DJMK4 · 9 Jun 2015 at 19:00

Here are my default PID's in baseflight.

Default PID's in Baseflight

Name:.........Proportional........Integral......Derivative

ROLL .............4.0.................0.030.........23

PITCH.............4.030.............0.030.............23

YAW.............8.5.............0.045.............0

ALT.............5.030.............0.000.............0

VEL.............12.000.............0.045.............1

Pos.............0.11 .............0.00.............(N/A)

PosR.............2.0 .............0.08.............0.045

NavR.............1.4 .............0.20.............0.080

LEVEL.............9.00.............0.010.............100

MAG.............4.00.............N/A.............N/A

Profile
1

Roll rate (0.00)

Pitch Rate (0.00)

Yaw Rate (0.00)

TPA (0.00)

So

1) Increase P on one axis until the quad starts to oscillate at hover - reduce P gradually until the oscillation stops - Do you have to do this for ROLL / PITCH and YAW?

2) Do the same for I

3) Do the same for D, then go back and see if you can increase P and I a bit

assuming as mine is already occilating that I need to reduce the Roll pitch and yaw PIDs slightly starting with P? but not too much as it makes it sluggish? then add some TPA

Genoma · 9 Jun 2015 at 19:49

have a look at this - good explanation

http://blog.oscarliang.net/quadcopter-pid-explained-tuning/

gandhi · 9 Jun 2015 at 20:57

DJMK4 said:
1) Increase P on one axis until the quad starts to oscillate at hover - reduce P gradually until the oscillation stops - Do you have to do this for ROLL / PITCH and YAW?

Just Roll and Pitch, yaw is slightly different and one I don't understand completely but the defaults in cleanflight seem to work well.

DJMK4 said:
2) Do the same for I

3) Do the same for D, then go back and see if you can increase P and I a bit

Yep, but D won't give you oscillations so just add a bit then fly it.

DJMK4 said:
assuming as mine is already oscillating that I need to reduce the Roll pitch and yaw PIDs slightly starting with P? but not too much as it makes it sluggish? then add some TPA

That Oscar Liang post does explain it very well but you can pretty much skip all of it and go straight to the bottom of the page where he explains how to actually tune it

3 options;

1) Just add in some TPA and see if that fixes things

2) Gradually reduce the P term on roll see if it goes away, if not, reset to original value. Then repeat the same with pitch P term. If still no change, repeat the same for roll and pitch I term.

3) Flash cleanflight, use your normal settings (ppm rx, motorstop, mode switch etc) then set up 2 profiles in the PID screen - one with PID controller #1 (Multiwii re-write) and a second with #2 (Luxfloat).

Don't change any other settings like rates, expo, PID's etc. then go and fly them both and see if they solve the problem.

You can switch between the profiles by holding the left stick bottom left then use the right to select them (roll left = profile #1, Pitch forward = #2, roll right = #3)