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In an electric power steering system in which a torque assist command is generated for controlling a motor that provides electric power assist torque at a desired torque, a method of motor control according to the steps of: determining a voltage mode motor command responsive to the torque assist com

In an electric power steering system in which a torque assist command is generated for controlling a motor that provides electric power assist torque at a desired torque, a method of motor control according to the steps of: determining a voltage mode motor command responsive to the torque assist command, wherein the voltage mode motor command commands a first motor torque that is (a) greater than the desired torque when the desired torque is low and (b) substantially equal to the desired torque when the desired torque is high; determining a current mode motor command responsive to the torque assist command, wherein the current mode motor command commands a second motor torque that is (a) substantially equal to the desired torque when the desired torque is low and (b) greater than the desired torque when the desired torque is high; and controlling the motor responsive to the voltage and current mode motor commands, wherein the motor assist torque is equal to a lesser of the first and second motor torques.

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An electric power steering motor control method according to the steps of: determining a desired assist torque function indicating a desired assist torque in response to at least one steering system input parameter; and then sensing a steering wheel torque; responsive to the sensed steering wheel to

An electric power steering motor control method according to the steps of: determining a desired assist torque function indicating a desired assist torque in response to at least one steering system input parameter; and then sensing a steering wheel torque; responsive to the sensed steering wheel torque, determining a voltage torque command in a voltage mode, wherein the voltage torque command commands a first torque that is greater than the desired assist torque at low desired assist torques which are lower than a predetermined value, substantially equal to the desired assist torque at high desired assist torques which are higher than the predetermined value, and is substantially smooth and continuous over a range of said desired assist torques; responsive to the sensed steering wheel torque, determining a curtain torque command in a current mode, wherein the current torque command is substantially equal to the desired assist torque at said low desired assist torques, greater than the desired assist torque at said high desired assist torques, and is substantially smooth and continuous over the range of said low and high desired assist torques; and controlling an electric motor responsive to the voltage and current command torques, wherein the electric motor voltage is no greater than a voltage corresponding to the voltage torque command and the electric motor current is no greater than a current corresponding to the current torque command, wherein the motor provides torque assist to an electric power steering system and alternately operates in said current and voltage modes.