Last Saturday I succeeded in damping the ETMY suspension eventually.
This means now ALL the suspensions are happily damped.
It looked like some combination of gains and control filters had made unstabie conditions.
I actually was playing with the on/off switches of the control filters and the gain values just for fun.
Then finally I found it worked when the chebyshev filters were off. This is the same situation as Yuta told me about two months before.
Other things like the input and the output matrix looked nothing is wrong, except for the sign flips at ULSEN and SDSEN as I mentioned in the last entry (see here).
So we still should take a look at the analog filters in order to make sure why the signs are flipped.