Model predictive control suitable for closed-loop re-identification

• A new MPC suitable for closed-loop re-identification is proposed.
• A re-identification needs to be developed in a closed-loop fashion, since the process cannot be stopped.
• The main problem is the conflict between the control and identification objectives.
• A generalization, from punctual stability to (invariant) set stability, is done to avoid the conflict.
• The proposal could be potentially applied to real processes.

The main problem of a closed-loop re-identification procedure is that, in general, the dynamic control and identification objectives are conflicting. In fact, to perform a suitable identification, a persistent excitation of the system is needed, while the control objective is to stabilize the system at a given equilibrium point. However, a generalization of the concept of stability, from punctual stability to (invariant) set stability, allows for a flexibility that can be used to avoid the conflict between these objectives. Taking into account that an invariant target set includes not only a stationary component, but also a transient one, the system could be excited without deteriorating the stability of the closed-loop. In this work, a MPC controller is proposed that ensures the stability of invariant sets at the same time that a signal suitable for closed-loop re-identification is generated. Several simulation results show the propose controller formulation properties.