A method for determining the load exerted on a piezoelectric actuator as well as a method and apparatus for driving a piezoelectric actuator of a pump-nozzle unit of a control valve.

摘要

A method for the determination of a piezoelectric actuator (76) external load f_ext, in particular of the on a piezoelectric actuator of a control valve (22) of a pump-nozzle unit external load f exerted_ext,values of a piezo current (i_P) and a piezo voltage u_P be detected,characterized in that the method comprises the further steps of:– Determining the differential piezo capacitance δc_P as a function of values of the piezo current i_P and of the piezo voltage u_P, and– Determining the external load f_ext depending on the course of the differential piezo capacitance δc_P.