Idle Stroke Detection for a Fuel Injection Control Valve

In this paper, a method for detecting the idle stroke of a piezoelectrically driven fuel injection control valve is presented. The idle stroke constitutes a small gap in the range of a few micrometers between the piezoelectric actuator and the control valve which has to be usually adjusted in the assembling process. The identification approach only relies on the analysis of the electric signals of the piezoelectric stack actuator. Neither a mathematical model of the piezoelectric actuator with its inherent nonlinear hysteresis behavior nor a model of the hybrid structure of the control valve mechanics is required. Measurement results prove the feasibility of the proposed concept.