Patent ID: 6138810
Filing Date: 2000-10-31
Classification: F16H

Abstract:
A method for controlling operation of an automatic transmission having a hydraulic valve that controls operation of a friction element, having a magnet fixed to a displaceable valve spool, a sensor producing a signal responsive to the sensed intensity of a field produced by the magnet representing the position of the spool in the valve, the method comprising the steps of:producing from the signal a time series record of the position of the spool;determining the desired spool position;determining a spool position error from the current spool position and desired spool position;determining a compensated spool position from said spool position error;determining a current commanded control pressure from said compensated spool position and a prior commanded control pressure;changing the magnitude of control pressure applied to the valve in response to said current commanded control pressure; andchanging the position of the spool in response to the current control pressure.