Motor control device, motor control method, motor module, and electric power steering device

Patent metadata

Field	Value
Publication number	US-12172706-B2
Application number	US-202217949348-A
Country	US
Kind code	B2
Filing date	Sep 21, 2022
Priority date	Sep 29, 2021
Publication date	Dec 24, 2024
Grant date	Dec 24, 2024

Abstract

A motor control device includes a model following controller to generate a correction torque based on an output from a control target that is a motor, and correct an input to the control target with the correction torque. A model following controller includes a high-pass filter with a first cutoff frequency and a low-pass filter with a second cutoff frequency larger than the first cutoff frequency, and is configured or programmed so that a transfer function of a control target is constrained to a nominal model in a frequency band in which a gain in a gain characteristic of Q(s)·HPF(s) is 1 where Q(s) is a transfer function of the low-pass filter and HPF(s) is a transfer function of the high-pass filter.

First claim

What is claimed is:

1. A control device usable in an electric power steering device including a motor to control the motor, the control device comprising:
a model following controller to generate a correction torque based on an output from a control target that is the motor and that correct an input to the control target with the correction torque; wherein
the model following controller:
includes a high-pass filter with a first cutoff frequency and a low-pass filter with a second cutoff frequency higher than the first cutoff frequency; and
is configured or programmed so that a transfer function of the control target is constrained to a nominal model in a frequency band in which a gain in a gain characteristic of Q(s)·HPF(s) is 1 where Q(s) is a transfer function of the low-pass filter and HPF(s) is a transfer function of the high-pass filter.

2. The control device according to claim 1 , wherein the first cutoff frequency is about 2 Hz or more and about 10 Hz or less.

3. The control device according to claim 2 , wherein the second cutoff frequency is about 3 Hz or more.

4. A motor module comprising:
a motor; and
the control device according to claim 1 .

5. An electric power steering device comprising the motor module according to claim 4 .

6. A computer-implemented method for controlling a motor of an electric power steering device including the motor, the method comprising:
generating a correction torque based on an output from a control target and correcting an input to the control target with the correction torque using a model following controller that constrains a transfer function of the control target that is the motor to a nominal model in a frequency band in which a gain in a gain characteristic of Q(s)·HPF(s) is 1, the model following controller including a high-pass filter with a first cutoff frequency and a low-pass filter with a second cutoff frequency larger than the first cutoff frequency, where Q(s) is a transfer function of the low-pass filter and HPF(s) is a transfer function of the high-pass filter.

Assignees

• Nidec Corp

Inventors

• Endo Shuji
• Miyake Sohei

Classifications

• B62D5/046

  Controlling the motor · CPC title

• B62D5/0424

  the axes of motor and final driven element of steering gear, e.g. rack, being parallel · CPC title

• B62D5/0409

  Electric motor acting on the steering column · CPC title

• B62D6/008

  Control of feed-back to the steering input member, e.g. simulating road feel in steer-by-wire applications · CPC title

• B62D5/0472

  for damping vibrations · CPC title