An electric assist steering system having an improved motor current controller with gain scheduler

摘要

A motor controller controls the operation of an electric motor (28). The motor controller includes sensors (30, 97, 102) for sensing at least one dynamic operating characteristic of the motor and for providing a signal indicative of the at least one sensed dynamic motor operating characteristic. A variable gain regulator (190) receives a current command request signal having a value and provides a motor current control signal having a value functionally related to the value of the received current command request signal and a gain control value. A gain scheduler (196) is operatively coupled to the variable gain regulator (190) and to the sensor (30, 97, 102) for providing the gain control value to the variable gain regulator (196) in response to the sensed at least one dynamic motor operating characteristic to thereby control the amount of gain of the variable gain regulator (190). The motor controller further includes a drive circuit (204, 120) operatively connected to the variable gain regulator (190) and the motor (28) for energizing the motor in response to the motor current control signal.