Patent ID: 6338016
Filing Date: 2002-01-08
Classification: B62D,H02H

Abstract:
An apparatus for controlling an electric assist motor in a vehicle steering system, said apparatus comprising:a switching circuit for connecting electrical power to the electric assist motor of the vehicle steering system, said switching circuit having a temperature condition; a temperature sensor associated with said switching circuit for providing an output signal having a value indicative of a sensed temperature condition of said switching circuit; a stall detector for determining when the electric assist motor is in a stalled condition, said stall detector being responsive to the output signal of said temperature sensor, said stall detector being effective to reduce power of the electric assist motor via a torque command to a first level in response to a determined stall condition of the electric assist motor and upon sensing that the temperature condition of said switching circuit is less than a first temperature threshold and being effective to reduce power of the electric assist motor via the torque command to a second level in response to a determined stall condition of the electric assist motor and upon sensing that the temperature condition of said switching circuit is greater than or equal to the first temperature threshold, the second level being different from the first level.