Model-based estimation of piezoelectric fuel injector parameters

Fuel injection rate shaping is one path towards cleaner and more efficient diesel engines. Piezoelectrically actuated fuel injectors meet this requirement, but can exhibit improved model-based estimation performance when their internal parameters are estimated on line. To this end, this paper presents an online parameter estimation strategy for a piezoelectric fuel injector that results in improved fuel flow rate estimation when there is assumed to be some initial error in the parameter estimates. In the presence of an initial parameter error of 25%, the parameter estimator improved the model-based prediction of total injected fuel by approximately 10%.