# US 2014/0156144 A1 · Motor control apparatus and electric power steering apparatus provided with the same

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- Number: US 2014/0156144 A1
- Document ID: US20140156144A1
- Status: Published application
- Kind: A1
- Application number: 14/234,176
- Filed: 2013-03-28
- Published: 2014-06-05
- Earliest claimed: 2012-04-04
- Assignees: Nsk Ltd.
- Applicants: Nsk Ltd.
- Inventors: Yuzuru Hoshi; Toru Sakaguchi; Sachio Nakayama; Masahiro Maeda; Kenji Mori; Yousuke Imamura
- Web page: https://patentgrep.com/patent/US20140156144A1

## CPC

- H02P 29/0241: {the fault being an overvoltage}
- B62D 5/0484: {for reaction to failures, e.g. limp home}
- B62D 5/049: {detecting sensor failures}
- H02P 6/10: Arrangements for controlling torque ripple, e.g. providing reduced torque ripple
- B60T 8/1755: Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve (road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02)
- H02M 1/0009: {Devices or circuits for detecting current in a converter}
- H02M 7/5395: by pulse-width modulation
- H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- 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)
- B60T: VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL (electrodynamic brake systems for vehicle, in general B60L; brakes per se, i.e. devices where braking effect occurs, including ultimate brake actuators, F16D); ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P)

## Abstract

A motor control apparatus that is capable of making the whole control system robust not only with respect to motor parameter variations such as the temperature variation and the manufacturing unevenness but also with respect to disturbances while using a cheap and compact one-shunt type current detecting circuit and simultaneously diagnosing an estimation error and an electric power steering apparatus provide with the motor control apparatus.

## Claims

### Claim at position 1

1-6. (canceled)

### Claim 7

A motor control apparatus comprising a current detecting circuit to detect a current of a motor as a current detected-value, a drive control unit to drive and control the motor with duty based on a voltage command value determined based on at least a current command value, and a rotation detecting unit to detect an angle and an angular speed of the motor, wherein,
the motor control apparatus further comprising:
an adaptive current observer to identify parameter variations of an output model of the motor, to calculate a current estimated-value of the motor and to use the current estimated-value for a calculation of the voltage command value;
an adaptive identifying diagnosis section to diagnose an estimation error of the current estimated-value outputted from the adaptive current observer; and
a current-detection-impossible state detecting section to detect a current-detection-impossible state that a detection of the current detected-value is impossible;
wherein the adaptive identifying diagnosis section diagnoses the estimation error of the current estimated-value based on the current estimated-value, the current detected-value, the angle and the current-detection-impossible state and forcibly makes a current-detection-possible state by limiting the duty based on a diagnosis result of the adaptive identifying diagnosis section, and a control of the motor is switched to a current control based on a detected current.

### Claim 8 (depends on 7)

A motor control apparatus according to claim 7, wherein the current detecting circuit is a one-shunt current detecting type.

### Claim 9 (depends on 7)

A motor control apparatus according to claim 7, wherein the drive control unit is constructed by a vector control system of d-q axes, and the adaptive identifying diagnosis section comprising:
a q-axis current calculating section to calculate a detected q-axis current value and an estimated q-axis current value based on the current estimated-value, the current detected-value and the angle;
a current-detection-impossible state continuation watching section to watch a continuation of a current-detection-impossible state;
an estimated-current each-phase sum watching section to watch an each-phase sum based on the current estimated-value;
a q-axis difference watching section to watch a detection-estimation q-axis difference based on the current-detection-impossible state, the detected q-axis current value and the estimated q-axis current value;
an estimated q-axis-change difference watching section to watch an estimated q-axis-change difference based on the current-detection-impossible state, the estimated q-axis current value and an estimated q-axis current value just before the current-detection-impossible state; and
a synthesis judging section to synthetically judge watched results of the current-detection-impossible state continuation watching section, the estimated-current each-phase sum watching section, the q-axis difference watching section and the estimated q-axis-change difference watching section.

### Claim 10 (depends on 8)

A motor control apparatus according to claim 8, wherein the drive control unit is constructed by a vector control system of d-q axes, and the adaptive identifying diagnosis section comprising:
a q-axis current calculating section to calculate a detected q-axis current value and an estimated q-axis current value based on the current estimated-value, the current detected-value and the angle;
a current-detection-impossible state continuation watching section to watch a continuation of a current-detection-impossible state;
an estimated-current each-phase sum watching section to watch an each-phase sum based on the current estimated-value;
a q-axis difference watching section to watch a detection-estimation q-axis difference based on the current-detection-impossible state, the detected q-axis current value and the estimated q-axis current value;
an estimated q-axis-change difference watching section to watch an estimated q-axis-change difference based on the current-detection-impossible state, the estimated q-axis current value and an estimated q-axis current value just before the current-detection-impossible state; and
a synthesis judging section to synthetically judge watched results of the current-detection-impossible state continuation watching section, the estimated-current each-phase sum watching section, the q-axis difference watching section and the estimated q-axis-change difference watching section.

### Claim 11 (depends on 9)

A motor control apparatus according to claim 9, wherein the synthesis judging section outputs an observer diagnosis-abnormal flag for limiting the duty or a drive stop flag for stopping an assist.

### Claim 12 (depends on 10)

A motor control apparatus according to claim 10, wherein the synthesis judging section outputs an observer diagnosis-abnormal flag for limiting the duty or a drive stop flag for stopping an assist.

### Claim 13 (depends on 7)

A motor control apparatus according to claim 7, wherein the adaptive current observer comprises an adaptive identifying unit to identify the parameter variations of the output model of the motor, a current estimating unit to estimate a current of the motor and a voltage command value determining unit to determine the voltage command value.

### Claim 14 (depends on 9)

A motor control apparatus according to claim 9, wherein the adaptive current observer comprises an adaptive identifying unit to identify the parameter variations of the output model of the motor, a current estimating unit to estimate a current of the motor and a voltage command value determining unit to determine the voltage command value.

### Claim 15 (depends on 11)

A motor control apparatus according to claim 11, wherein the adaptive current observer comprises an adaptive identifying unit to identify the parameter variations of the output model of the motor, a current estimating unit to estimate a current of the motor and a voltage command value determining unit to determine the voltage command value.

### Claim 16 (depends on 7)

An electric power steering apparatus provided with the motor control apparatus according to claim 7.