Patent ID: 6966285
Filing Date: 2005-11-22
Classification: F01L,Y10T

Abstract:
1. An electrohydraulic valve actuator assembly, comprising: a movable engine valve; a movable spool valve; a spring biasing the engine valve toward a closed position; a driving channel interconnecting the spool valve and the engine valve; a first feedback channel interconnecting the engine valve, the spool valve and a first on/off valve; a second feedback channel interconnecting the engine valve, the spool valve and a second on/off valve; a feedforward plus feedback control (FPFC) operable to energize and de-energize the spool valve to selectively provide fluid flow to and from the driving channel to position the engine valve between an open position and the closed position; and a learning control (LC) operable to energize and de-energize the first and second on/off valves to selectively enable and disable the feedback channels to control the motion of the spool valve; an engine valve position locating sensor interfacing with the FPFC and LC and operative to track engine valve lift, closing timing and seating velocity from cycle to cycle; the LC having a control algorithm to calculate valve positioning error and determine corresponding trigger timings which are relayed to the on/off valves; and the LC adjusting the trigger timing of the on/off valves to alter valve lift, closing timing and seating velocity of the engine valve.