An adaptive observer design for fuel cell hydrogen estimation

We present an observer design to estimate the partial pressure of hydrogen in the anode channel of a fuel cell. Our design makes use of a monotonic nonlinear growth property of the voltage output on hydrogen partial pressures at the inlet and at the exit of the channel. By treating the slowly-varying inlet partial pressure as an unknown parameter, an adaptive observer is developed that employs a nonlinear voltage injection term. We then prove robustness of this observer against variations in the inlet partial pressure, and analyze its sensitivity to measurement errors in the voltage.