Abstract
This paper studies a discretization method of continuous-time controllers taking account of the intersample behavior of the resulting sampled-data systems. First, we state how to evaluate the discretization error based on the Hilbert-Schmidt norm of the sampled-data frequency response. Second, we determine what we call the desirable frequency response of the discretized controller, and show that it can be obtained in a closed form in terms of the state-space representations of the controller and the plant. Furthermore, we propose some discretization methods of controllers based on the state-space formula about the desirable frequency response. We also demonstrate the effectiveness of these methods by numerical examples.
