Joint Design of Model-Subspace based State-Space Identification and Control

Abstract Recently, the importance of the joint design of identification and control has been recognized, and several controller design methods based on the iteration of identification and controller re-design have been proposed. In these methods, the frequency weighted identification plays an important role. On the other hand, as a powerful identification method, subspace state-space system identification (4SID) method has been proposed. However, it is difficult to use the frequency weight in conventional 4SID methods. In this paper, we propose a new frequency weighted subspace state-space system identification method for the joint design of identification and control. First, we give a new 4SID method using not only the input-output data of the system but also the nominal model data. Second, we show how to introduce the frequency weight to our identification method, which is relevant to the cost function for control. And third, we evaluate the effectiveness of the proposed method by a numerical example using an inverted pendulum system.