# US 12,594,984 B2 · Motor control device

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- Number: US 12,594,984 B2
- Document ID: US12594984B2
- Status: Granted
- Kind: B2
- Application number: 18/693,634
- Filed: 2021-09-28
- Published: 2024-11-28
- Granted: 2026-04-07
- Earliest claimed: 2021-09-28
- Assignees: Jtekt Corporation
- Applicants: Jtekt Corporation
- Inventors: Terutaka Tamaizumi; Yufeng Lin; Hiromasa Tamaki; Hidenori Itamoto; Muhammad Iqmal Abd Rahim; Atsuo Sakai
- Web page: https://patentgrep.com/patent/US12594984B2

## CPC

- B62D 5/046: {Controlling the motor}
- H02P 21/05: specially adapted for damping motor oscillations, e.g. for reducing hunting
- G05B 13/02: electric
- H02P 6/10: Arrangements for controlling torque ripple, e.g. providing reduced torque ripple
- H02P 21/13: Observer control, e.g. using Luenberger observers or Kalman filters
- H02P 21/20: Estimation of torque
- H02P 23/04: specially adapted for damping motor oscillations, e.g. for reducing hunting
- H02P 23/12: Observer control, e.g. using Luenberger observers or Kalman filters
- H02P 23/14: Estimation or adaptation of motor parameters, e.g. rotor time constant, flux, speed, current or voltage
- B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M)
- H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G)

## Abstract

A motor control device controls a motor of a mechanical device. The motor control device includes a command value calculation unit that calculates a command value for controlling the motor, and a disturbance observer unit for estimating a disturbance applied to the mechanical device, based on the command value and rotation information of the motor, and to correct the command value based on the disturbance that is estimated. The disturbance observer unit has parameters that are adjusted to compensate for effects of the disturbance having a specific frequency that is an object of suppression. The parameters are adjusted such that a disturbance, applied to the mechanical device after effects of the disturbance are compensated for, has frequency characteristics corresponding to antiresonance characteristics of the mechanical device.

## Claims

### Claim 1

A motor control device that controls a motor of a mechanical device, the motor control device comprising:
a first processing circuit configured to calculate a command value for controlling the motor; and
a second processing circuit configured to estimate a disturbance applied to the mechanical device, based on the command value and rotation information of the motor, and to correct the command value by reflecting the disturbance that is estimated, wherein
the second processing circuit has a parameter that is adjusted to compensate for effects of the disturbance having a specific frequency that is an object of suppression,
the disturbance that is applied to the mechanical device, after the effects of the disturbance have been compensated by reflecting the disturbance estimated by the second processing circuit, is a post-compensation disturbance, and
the parameter is adjusted such that the post-compensation disturbance has a frequency characteristic corresponding to an antiresonance characteristic that appears in control of the motor in the mechanical device.

### Claim 2 (depends on 1)

The motor control device according to claim 1, wherein the rotation information of the motor is an angular velocity of the motor.

### Claim 3 (depends on 2)

The motor control device according to claim 2, wherein the second processing circuit is configured to
calculate a differential value of the disturbance based on the command value and the angular velocity of the motor, and
calculate a first correction value for the command value by multiplying, by a gain, the differential value of the disturbance that is calculated.

### Claim 4 (depends on 3)

The motor control device according to claim 3, wherein with “J” as a coefficient of inertia of the mechanical device, “C” as a viscosity coefficient of the mechanical device, “s” as a Laplace operator, “L1” as a first observer gain of the second processing circuit, “L2” as a second observer gain of the second processing circuit, and “β” as the gain, the post-compensation disturbance has conveyance characteristics expressed by the following Expression (A) {Js2+(−L2·β)+L1·J)s+L2}/{Js2+(−L2·C+L1·J)s+L2}·Js . . . (A), and a value of “β” that is the gain is adjusted such that a value of a second term of a numerator of Expression (A) becomes zero or a value closer to zero.

### Claim 5 (depends on 2)

The motor control device according to claim 2, wherein the second processing circuit is configured to
calculate a differential value of the disturbance based on the command value and the angular velocity of the motor, and
calculate a second correction value for the command value based on the differential value of the disturbance that is calculated.

### Claim 6 (depends on 1)

The motor control device according to claim 1, wherein:
the mechanical device is configured to also operate due to torque being applied externally; and
the second processing circuit is configured to
calculate a compensation amount for compensating for the effects of the disturbance in accordance with a differential value of the torque externally applied to the mechanical device, and
calculate a third correction value for the command value based on the compensation amount that is calculated.

### Claim 7 (depends on 1)

The motor control device according to claim 1, wherein:
the mechanical device is a steering system of a vehicle; and
the motor generates a torque that is applied to the steering system.