𝐱̇(t)=A(t)𝐱(t)+B(t)𝐮(t)𝐲(t)=C(t)𝐱(t)+D(t)𝐮(t)\begin{eqnarray} \dot{\mathbf{x}}(t) = A(t) \mathbf{x}(t) + B(t) \mathbf{u}(t) \\ \mathbf{y}(t) = C(t) \mathbf{x}(t) + D(t) \mathbf{u}(t) \end{eqnarray}