For a linear controllable & observable system [A, B, C, D] , Different controllers can lead to same closed-loop System Matrix (A-BK).

Do you think there will be differences in system performance?

For example, controllers with and without integral feedback term show different performances under constant external disturbance. Yet they can have same (A-BK) .

Does that mean someting important is missing in closed-loop System Matrix (A-BK)? How can we fix that?

Thank you for reading!

Curiously,

Li