Electric motor control device

Abstract

A controller K calculates a command torque by correcting the required torque w with a correction based on a motor rotation speed Nm, and controls an electric motor based on the command torque T. The command torque w is regarded as one content of an outside input W to the controller K. A difference between the rotation speed of the electric motor outputted by the actual model describing an actual response of the electric motor and another rotation speed of the electric motor outputted by a reference model describing ideal performance and vibration reduction is regarded as one content Z of controlled output Z from the controller K. Moreover, a characteristic variation depending on vehicle types and so on, a torque ripple, and a sensor noise are described by weight functions wm , wm and wn. Then a pertubative output w and a sensor noise w are regarded as the remaining contents of the input W. An output of the weight function wm is regarded as the controlled output Z. The controller K is determined by solving H∞control problem that a transfer function between the outside input W and the controlled output Z is determined as an H∞norm of the transfer function to be smaller than a predetermined value.