Consider the following state space representation:
x_dot=Ax+Bu;%x_dot is the derivative of x wrt time.
If we take the Laplace transform of this expression, we will obtain
X(s) B
____ = ____
U(s) sI-A
Taking into consideration that this is a transfer function, where U(s) is input and X(s) is output, you can imagine the state variables as an output and make it track a reference signal. It can track the reference without steady state if you include an integrator in controller between reference and system. Therefore, it is possible to make state variables track a reference signal. Just by rewriting the expressions, you can obtain the necessary transfer functions. Hope this helps.
