Patent ID: 7856963
Filing Date: 2010-12-28
Classification: F02D

Abstract:
1. A method of operating a fuel injector having a piezoelectric actuator operable by applying a drive pulse thereto, wherein the drive pulse has a frequency domain signature, the method including; determining at least one resonant frequency of an injector installation in which the injector is received, in use; and modifying the drive pulse such that a maximum of the frequency domain signature thereof does not coincide with the determined at least one resonant frequency of the injector installation, wherein modifying the drive pulse includes determining a demanded fuel volume to be delivered during the drive pulse based on an engine operating condition, determining a tuned injector on time value (TON_TUNED) based on the demanded fuel volume and the at least one resonant frequency of the injector installation, determining a peak discharge/charge current amplitude value (ITUNED) and a discharge time period (TDISCHARGE) based on the demanded fuel volume and the tuned injector on time value (TON_TUNED), and operating the fuel injector according to the determined values of the tuned injector on time value (TON_TUNED), the peak discharge/charge current amplitude value (ITUNED), and the discharge time period (TDISCHARGE).