Wobbeling and SAS

[Warzouz]

I've noticed most of my wobbeling is due to the SAS. The SAS steers the other way only when passing the target (node, direction...), not before to smooth things down. So it steers back and so on until resonating wobbling.

To stop wobbeling, I ususally deactivate SAS or use Smart ASS from MechJeb.

I've event noticed that SAS is incapable of handling high torque vessels (such as mini-tugs). It even isn't steering at the correct target, but still "vibrates".

How do you handle wobbeling ?

Further more, I think that some landing tip over are liked to the SAS module, especially on low gravity moons. Do you share this thought ?

[TMS]

Unfortunately, the autopilot 'hold heading' buttons added in the last update don't appear to use the same algorithm or PID controller to hold a heading.

The "stability assist" button (top-left) uses an improved SAS method that was developed during 0.21 thru 0.23. The other buttons appear to behave in a manner similar to the older, pre-0.21 legacy SAS method (in that the reaction wheels and engine bells constantly over correct).

This could be because the underlying maths are different between stabilising a heading and holding to an external reference, or it could be because the dev who developed the new SAS method has since left SQUAD.

You're better off using the autopilot to achieve a heading, then switching to stability assist. This will reduce the wobble.

[Warzouz]

Yes, it over compensate, but as the ship wobble, it enters some sort of resonnance. The torque add to the wobble. Generally, in this situation, cutting the SAS stops the wobble and you only have to steer manually.

SmartAss doesn't have this issue. Steering muche smoother. Even if I have tall ships with few struts, there is nealy no wobbling.

[TMS]

Yes, it over compensate, but as the ship wobble, it enters some sort of resonnance. The torque add to the wobble. Generally, in this situation, cutting the SAS stops the wobble and you only have to steer manually.

Yep, entering resonance was pretty common on larger vessels with the old SAS algorithm.

SmartAss doesn't have this issue. Steering muche smoother. Even if I have tall ships with few struts, there is nealy no wobbling.

¯\_(ツ)_/¯

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