Patent ID: 6807931
Filing Date: 2004-10-26
Classification: F01L,F02D

Abstract:
In a variable cam timing (VCT) system including a plurality of states indicating a set of two operational modes of the VCT system, wherein a plurality of states is provided including a first state disposed to be transferred to a second state based upon a set of conditions, the two operational modes of the VCT system consisting of open loop mode and closed loop mode, a method comprising the steps of:providing at least one phaser having a rotor and a housing, wherein the rotor is disposed to rotate within the housing; providing a closed feedback control loop for the VCT system to operate under the closed loop mode; during transferring from the first state to the second state, switching from a closed loop mode to an open loop mode, wherein the closed feedback control loop is not used; and during transferring from the second state to the first state, switching from the open loop mode to the closed loop mode, wherein the closed feedback control loop is used.