David F Howie

US Patent:

55436927, Aug 6, 1996

Filed:

May 31, 1994

Appl. No.:

8/251754

Inventors:

David M. Howie - Northville MI
Abbas M. Youssef - Farmington Hills MI

Assignee:

TRW Inc. - Lyndhurst OH

International Classification:

H02P 100

US Classification:

318282

Abstract:

An electric motor (20) is controlled to move a vehicle window (28) between an upper limit position and a lower limit position. The rate of change of current flow to the motor is determined during upward movement of the vehicle window toward the upper limit position. A threshold rate of change of current flow value to the motor is stored which is a function of a plurality of determinations made of the rate of change of current flow to the motor during upward movements of the vehicle window toward the upper limit position. The stored threshold rate of change of current flow value is modified on each movement of the vehicle window to the upper limit position to make the stored threshold rate of change of current flow value a function of the determinations made of the rate of change of current flow to the motor which are most current in time. The motor reverses and moves the vehicle window downward toward the lower limit position in response to a determined rate of change of current flow to the motor exceeding the threshold rate of change of current flow value during movement of the vehicle window upward toward the upper limit position.