Closed-loop subspace model identification of dual-rate systems with input fast sampling

In this paper, we consider closed-loop identification for an unstable dual-rate system with the sampling period of the output being an integral multiple of the hold period of the input. Using the well-known lifting technique, the relation of a stack of the succeeding input samples to the output, i.e., the lifted model, is estimated using CL-MOESP, which is a closed-loop subspace model identification method. Finally, a numerical example illustrates the effectiveness of the proposed closed-loop identification method to the lifted model.