VCT solenoid dither frequency control
DRIVE
January 2, 2004
A method that uses a dither signal (38) for reducing hysteresis effect in a variable cam timing system (10) is provided. The method includes the steps of: a) providing (82) a dither signal (38) having at least two switchable frequencies; b) determining (86) the frequency characteristics of an engine speed; c) determining (86) at least one frequency beating point in relation to a neighborhood (66) of an engine crank RPM values; and d) changing (88) the dither signal frequency when the engine is operating within the neighborhood (66) of the engine crank RPM values. Thereby frequency beating effect is reduced.
Discussion in the ATmosphere