Vorrichtung und Verfahren zur Feststellung einer Überlastung eines Motors in einem elektrischen Hilfskraft-Lenksystem

摘要

A vehicle electric assist steering system (10) includes a stall detector (70) for detecting a stall condition of a variable reluctance electric motor (26). The stall detector (70) monitors a torque command signal (48) which is responsive to steering torque applied by the vehicle operator to the vehicle steering wheel (12). The stall detector (70) also monitors a commutation sensor (74) which indicates motor commutation. The stall detector (70) determines the existence of a stall condition in response to the torque command signal (48) greater than a predetermined value and no motor commutation. The stall detector (70) controls the gain of an adjustable gain amplifier (52). The adjustable gain amplifier (52) controls current applied to the motor (26). The current applied to the motor (26) is limited when the stall detector (70) detects a stall condition. An over-use detector (70) determines the existence of an over-use condition by integrating the torque command signal (48).