Servo-drive arrangement for opening and closing motor vehicle window

摘要

The servo-drive for the vehicle window has the current for the electric servo motor monitored as well as the rate of change of motor movement. The relative torque level w.r.t. motor movement provides a threshold level which is compared with stored levels to determine if an obstruction is in the path of the window. The threshold levels are constantly updated to generate a responsive safety cut out for the window drive. The movement of the motor is monitored by a Hall Effect device with the readings fed to a processor. The motor movement is divided into discrete segments to provide a series of threshold levels. Rises in the threshold level above preset values provides a rapid indication of an obstruction.