Question

The major requirement of making the output of the system small in output regulator problem is :

(a) The system must be controllable

(b) The system must be stable

(c) The system must be observable

(d) The system must be LTI

This question was posed to me in semester exam.

This intriguing question originated from Optimal Control Problems in chapter Optimal Control Systems of Control Systems

Answer 1

Correct choice is (c) The system must be observable

To elaborate: We are concerned with making the output of the output regulator problem small this is achieved when the system is observable.