SolvedTuning & how-to

Can I dampen oscillations?

11 replies 1813 views started 14d ago

This topic has an accepted solution. Jump to solution.

#1

I use the MOZA AB9.

I have downloaded 1.3.0-beta-13 and made the adjustments from the beta release page https://ffb-bridge.com/beta in the MOZA app.

It happens now that I can induce a (sometimes very strong!) oscillation by for example letting the stick go from a deflected position.

It can become a steady oscillation, die down or increase. And it can really become a "resonance catastrophe" with the stick going forwards and backwards repeatedly at force.

To reproduce, I've been re-starting with the C172 profile. Even lowering the "Master gain" to 30% can still cause oscillations.

It can be reproduced with the Flight check → Forces → Centering spring test: Oscillations are dampened and stop after ~8 oscillations, but there is unwanted over-correcting force that leads to oscillations.

How would you dampen oscillations? Does it make sense to raise the "Dampen" setting in the MOZA app again?

I am generally a bit frightened now that I have experienced its full force :) That thing was about to destroy itself and some furniture...

Since even loading into the sim can lead to a very quick stick movement, I fear that alone could trigger that. And I am sometimes not at the sim, let alone have my hand at the joystick while it loads.

Could we detect a resonance catastrophe and limit force output?

Kind regards and happy weekend, Jonas

Report
#2

Thanks, I will immediately push an update to reduce this

Report
#3

Immediately, you can in the MOZA Cockpit set Damper back up to ~10% (try 8–15%). Leave Spring at 0.

I'm fixing the runaway oscillation issue in an update that comes out in a few minutes. Thanks for reporting this.

Report
#5

Hey,

Keep the damper at 10% in Moza Cockpit. That will be the new guidance going forward.

In addition, Beta.14 now watches the stick's own motion whenever centering is active. If it ever sees a sustained, large back-and-forth building (rather than settling), it cuts all force output within about a second and tells you in the log — disarm/re-arm resumes. I'll see if I can make this better (maybe pop up a modal).

It's tuned so normal flying, firm corrections, and the brief overshoot on release never trigger it. I validated that on my AB9. Please try your best to make it go crazy again, I don't want to see that happen at all! I will continue to build in more safety checks, but do let me know if this fixes the immediate issue.

Even with the base misconfigured, or during a sim load with nobody at the stick, it can no longer build up. Needs more testing to be 100% sure, but it's close.

Please test it out and let me know.

Report
#6

Thank you so much for your superquick reaction! I can only test it tomorrow. I am away for the night.

Report
#7

No prob, whenever is convenient :)

Report
#8Accepted solution

The new update (17) has a lot more safety related changes, along with many bugfixes. Let me know if this fixes the issues you saw.

Helpful 1Report
#9

Thank you!

I made the recommended change (10% dampen) in the MOZA software and updated to 1.3.0-beta.17.

I cannot reproduce oscillations any more. Thank you!

I experienced now while trying to oscillate that the forces were cut off (that's probably the Runaway-motion protection) and a note on the Dashboard is visible.

I think it triggers pretty easily, even when doing just some harsh flight control inputs for example when entering a snap roll. I think it would be ok to fade the forces in again after a very brief time without having to unarm/re-arm.

The 35% ceiling is a good idea to start out.

Report
#10

Yes, the safety cutoff is deliberately aggressive, I will tune it further as I get more feedback. Considering various approaches - maybe it resets automatically, as you suggest.

Report
#11
In reply to flightwusel's post
I think it triggers pretty easily, even when doing just some harsh flight control inputs for example when entering a snap roll. I think it would be ok to fade the forces in again after a very brief time without having to unarm/re-arm.
— flightwusel

Let me know what you think of 1.3 final and the new 1.3.1 beta. Lots of tuning for these strong sticks, things should be working well now.

Report
#12
In reply to FFB-Bridge's post
Let me know what you think of 1.3 final and the new 1.3.1 beta. Lots of tuning for these strong sticks, things should be working well now.
— FFB-Bridge

It works very well for me and it does not easily trigger. Thanks! I have not had the time yet to tune the profiles with the new options but I am looking forward to it!

Helpful 1Report