Nsk Corporation

Nsk Steering Systems Co., Ltd.

CaoMinh Ta

Shuji Endo

Hideyuki Kobayashi

ChunHao Jiang

Hiroaki Takase

Yuho Aoki

Masahide Saito

Disclosed herein is a method for controlling an electric power steering system, wherein a motor is controlled by vector control and driven by a current command value calculated on the basis of a parameter such as a steering torque to provide a steering assist power to a vehicle steering system, and further wherein the current command value is limited on the basis of desired output characteristics and a desired angular speed during a field-weakening control and a non-field-weakening control of the vector control.

Method and apparatus for controlling electric power steering system

A control apparatus of an electric power steering apparatus is provided in which a nonlinear element of a motor model of-the electric power steering apparatus is compensated beforehand to linearize the motor model and the back electromotive force of the motor is computed to compensate the back electromotive force for a control loop, and conduct back electromotive force compensation with no lag in order to realize a control apparatus of an electric power steering apparatus with less control error, stable controllability, small motor output torque ripple, good wheel steering feeling, and less motor noise.

Controller for electric power steering device

The invention relates to a control apparatus of an electric power steering apparatus structured such as to apply a steering assist force generated by a n-phase motor to a steering system of a vehicle, the control apparatus is provided with at least (n&#x2212;1) numbers of current detecting means for detecting a current Im in each of phases of the motor, a current command value calculating means for outputting a current command value Imref in each of the phases, and n numbers of current control means, and the control apparatus executes a current control of each of the phases by the current control means having the current command value Imref in each of the phases and the current Im in each of the phases as an input.

Control apparatus of electric power steering apparatus

The invention provides a drive control device for the motor as well as an electric power steering apparatus using the motor and the drive control device. Respective phase current command values are calculated on the basis of vector control. Pseudo-vector control for controlling respective phases separately is used as current feedback control.

Motor and drive control device therefor

A control device for electric power steering apparatus, in which when torque ripples at the time of the rotation of a motor is reduced by simple arithmetic, smooth and safe assist limitation is performed without deteriorating steering feeling, is provided. For this reason, in the control device for electric power steering apparatus adopting a vector control system for applying an assist force of a motor to a steering system, a phase delay according to an angular velocity is obtained, a corrected electric angle is calculated by adding the phase delay to an electric angle, and generation of a current command value in the vector control is compensated based on the corrected electric angle.

Control device for electric power steering apparatus

Distortions of motor voltage and current and a torque ripple of the motor are generated by dead band compensation for preventing an arm short circuit of an inverter, and a feeling of physical disorder is given in a handle operation. Therefore, the distortions of the motor voltage and current and the torque ripple of the motor are improved by using the dead band compensation for estimating the voltage distortion on the basis of a model current generated from a current command value such that no feeling of physical disorder is given in the handle operation of an electric power steering apparatus.

Device for controlling electric-motor power steering device

The invention provides a motor for a brushless DC motor, which has small torque ripple even if a trapezoidal wave current is supplied and has a small size and reduced motor noise, and a drive control device for the motor as well as an electric power steering apparatus using the motor and the drive control device. Respective phase current command values are calculated on the basis of vector control. Pseudo-vector control for controlling respective phases separately is used as current feedback control.

The present invention provides a motor drive apparatus capable of calculating an angular velocity and a rotation angle accurately in the entire rotation velocity range of a motor using a cheap Hall sensor having an inferior accuracy without using an expensive resolver having a high accuracy. The present invention includes a first angular velocity calculating means for calculating the angular velocity based on the back-EMF of the motor when it rotates at low speeds and a second angular velocity calculating means for calculating the angular velocity based on a signal from the Hall sensor when it rotates at high speeds. According to the present invention, the angular velocity and rotation angle can be calculated accurately in the entire rotation speed range using the Hall sensor under hybrid usage.

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Gunma, Japan

CaoMinh Ta