Closed-loop multi-rate identification with zone-MPC using constrained subspace method

In many industrial processes, process variables have different sampling intervals and they are referred to as multi-rate (MR) systems. When these systems are controlled by model predictive control which is useful to control of constrained multivariable process, model mismatch can occur because of changing in process dynamics. Thus, identification of a new model is necessary. The new model should be identified in closed-loop if the process needs to comply particular operating range for product specification or safety requirement. In this paper, the re-identification problem of a MR system in a closed-loop with a MPC controller is addressed, considering the lifted system and known dynamic characteristics. In comparison with the existing approach, the proposed identification method provides more accurate and realistic model.