Systematic Observer Design With Robust Global Convergence Guarantees for a Large Class of Lithium-Ion Battery Models

We present a robust nonlinear Luenberger-like observer for a class of systems that captures many of the finite-dimensional lithium-ion cell models found in the literature including electrical equivalent circuit models and electrochemical models. The observer gain is designed by solving a linear matrix inequality (LMI), which guarantees the robust, global convergence of the estimated state to the true state. We then present the main result, that is, conditions ensuring the LMI is feasible and allowing for the explicit construction of a class of suitable observer gains. These conditions are shown to be satisfied by various existing lithium-ion models thereby making the proposed observer design applicable for these models.