# US 11,299,196 B2 · Failure detection device and electric power steering apparatus

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,299,196 B2
- Document ID: US11299196B2
- Status: Granted
- Kind: B2
- Application number: 16/598,379
- Filed: 2019-10-10
- Published: 2020-02-06
- Granted: 2022-04-12
- Earliest claimed: 2017-05-26
- Assignees: Hitachi Astemo, Ltd.
- Applicants: Showa Corporation
- Inventors: Hiroaki Kurihara
- Web page: https://patentgrep.com/patent/US11299196B2

## CPC

- B62D 5/0484: {for reaction to failures, e.g. limp home}
- B62D 5/049: {detecting sensor failures}
- B60R 16/02: electric {constitutive elements}
- B62D 5/0463: {calculating assisting torque from the motor based on driver input}
- G01L 25/00: Testing or calibrating of apparatus for measuring force, torque, work, mechanical power, or mechanical efficiency
- 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)
- B60R: VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G)

## Abstract

The failure detection device includes: a failure detection unit configured to detect failure of a torque detection unit, the torque detection unit detecting torque applied to a rotary shaft with plural torque sensors; and a controller configured to control drive of a motor such that the motor outputs continuous torque in an event that the failure detection unit detects failure of the torque detection unit, the continuous torque continuously generating torque that is, if at least one of the plural torque sensors is working properly, detectable by the at least one of the plural torque sensors.

## Claims

### Claim 1

A failure detection device comprising:
a failure detection unit configured to detect failure of a torque detection unit, the torque detection unit detecting torque applied to a rotary shaft with a plurality of torque sensors; and
a controller configured to control drive of a motor such that the motor outputs continuous torque in an event that the failure detection unit detects failure of the torque detection unit, the continuous torque continuously generating torque that is, if at least one of the plurality of torque sensors is working properly, detectable by the at least one of the plurality of torque sensors, wherein
the controller controls drive of the motor so as to inform the failure of the torque detection unit with vibrations caused by the continuous torque so that vibrations are given to a steering wheel of a vehicle, and
the controller sets frequency of the vibrations caused by the continuous torque in a range from 5 Hz to 7 kHz.

### Claim 2 (depends on 1)

The failure detection device according to claim 1, wherein, in an event that the controller controls drive of the motor such that the motor outputs the continuous torque, the failure detection unit detects which one of the plurality of torque sensors of the torque detection unit is having failure.

### Claim 3 (depends on 2)

The failure detection device according to claim 2, wherein, in an event that the failure detection unit detects failure of one of two torque sensors of the torque detection unit, the failure detection unit detects whether the other one of the two torque sensors is having failure, on a basis of the controller controlling drive of the motor such that the motor outputs the continuous torque.

### Claim 4 (depends on 2)

The failure detection device according to claim 2, wherein the controller controls drive of the motor so as to inform the failure of the torque detection unit with sounds of vibrations caused by the continuous torque.

### Claim 5 (depends on 2)

The failure detection device according to claim 2, wherein the controller gives a sinusoidal waveform to a current supplied to the motor to cause the motor to output the continuous torque.

### Claim 6 (depends on 2)

The failure detection device according to claim 2, wherein the controller gives any one of a rectangular waveform, a triangular waveform, and a sawtooth waveform to a current supplied to the motor to cause the motor to output the continuous torque.

### Claim 7 (depends on 1)

The failure detection device according to claim 1, wherein, in an event that the failure detection unit detects failure of one of two torque sensors of the torque detection unit, the failure detection unit detects whether the other one of the two torque sensors is having failure, on a basis of the controller controlling drive of the motor such that the motor outputs the continuous torque.

### Claim 8 (depends on 1)

The failure detection device according to claim 1, wherein the controller controls drive of the motor so as to inform the failure of the torque detection unit with sounds of vibrations caused by the continuous torque.

### Claim 9 (depends on 8)

The failure detection device according to claim 8, wherein the controller sets frequency of the sounds of vibrations caused by the continuous torque in a range from 30 Hz to 4 kHz.

### Claim 10 (depends on 1)

The failure detection device according to claim 1, wherein the controller gives a sinusoidal waveform to a current supplied to the motor to cause the motor to output the continuous torque.

### Claim 11 (depends on 1)

The failure detection device according to claim 1, wherein the controller gives any one of a rectangular waveform, a triangular waveform, and a sawtooth waveform to a current supplied to the motor to cause the motor to output the continuous torque.

### Claim 12 (depends on 1)

The failure detection according to claim 1, wherein the controller sets frequency of the vibrations given to the steering wheel on the basis of the continuous torque in a range from 5 Hz to 30 Hz.

### Claim 13 (depends on 1)

The failure detection device according to claim 1, wherein the controller varies amplitude of vibrations caused by the continuous torque depending on a lapse of time after detection of the failure of the torque detection unit by the failure detection unit.

### Claim 14 (depends on 1)

The failure detection device according to claim 1, wherein the controller lowers frequency of vibrations caused by the continuous torque depending on a lapse of time after detection of the failure of the torque detection unit by the failure detection unit.

### Claim 15 (depends on 1)

The failure detection device according to claim 1, wherein, if amplitude of vibrations caused by the continuous torque and detected by at least one of the torque sensors is below a reference amplitude, the failure detection unit determines that the at least one of the torque sensors is having failure, and
the failure detection unit makes the reference amplitude variable.

### Claim 16 (depends on 1)

The failure detection device according to claim 1, wherein, if frequency of vibrations caused by the continuous torque and detected by at least one of the torque sensors is below a reference frequency, the failure detection unit determines that the at least one of the torque sensors is having failure, and
the failure detection unit makes the reference frequency variable.

### Claim 17

An electric power steering apparatus comprising:
a torque detection unit configured to detect steering torque with a plurality of torque sensors;
a failure detection unit configured to detect failure of the torque detection unit; and
a controller configured to control drive of a motor such that the motor outputs continuous torque in an event that the failure detection unit detects failure of the torque detection unit, the continuous torque continuously generating torque that is, if at least one of the plurality of torque sensors is working properly, detectable by the at least one of the plurality of torque sensors, wherein
the controller controls drive of the motor so as to inform the failure of the torque detection unit with vibrations caused by the continuous torque so that vibrations are given to a steering wheel of a vehicle, and
the controller sets frequency of the vibrations caused by the continuous torque in a range from 5 Hz to 7 kHz.

### Claim 18

A failure detection device comprising:
a controller configured to control drive of a motor such that the motor outputs continuous torque, the continuous torque continuously generating torque detectable by a torque sensor configured to detect torque applied to a rotary shaft; and
a failure detection unit configured to detect failure of the torque sensor on a basis of whether the torque sensor detects torque applied to the rotary shaft, the torque resulting from the continuous torque in an event that the controller controls drive of the motor such that the motor outputs the continuous torque, wherein
the controller controls drive of the motor so as to inform the failure of the torque detection unit with vibrations caused by the continuous torque so that vibrations are given to a steering wheel of a vehicle, and
the controller sets frequency of the vibrations caused by the continuous torque in a range from 5 Hz to 7 kHz.