# US 11,897,550 B2 · Steering control device

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- Number: US 11,897,550 B2
- Document ID: US11897550B2
- Status: Granted
- Kind: B2
- Application number: 17/211,501
- Filed: 2021-03-24
- Published: 2021-09-30
- Granted: 2024-02-13
- Earliest claimed: 2020-03-27
- Assignees: Jtekt Corporation; Toyota Jidosha Kabushiki Kaisha
- Applicants: Jtekt Corporation; Toyota Jidosha Kabushiki Kaisha
- Inventors: Takashi Kodera; Toru Takashima; Shunsuke Yoshida
- Web page: https://patentgrep.com/patent/US11897550B2

## CPC

- B62D 5/003: {Backup systems, e.g. for manual steering (B62D5/30 takes precedence)}
- B62D 5/0484: {for reaction to failures, e.g. limp home}
- B62D 5/0481: {monitoring the steering system, e.g. failures}
- B62D 5/0487: {detecting motor faults (B62D5/0496 takes precedence)}
- B62D 5/0496: {by using a temperature sensor}
- B62D 6/007: {adjustable by the driver, e.g. sport mode}
- B62D 5/046: {Controlling the motor}
- B62D 6/002: {computing target steering angles for front or rear wheels (B62D7/159 takes precedence)}
- B62D 6/008: {Control of feed-back to the steering input member, e.g. simulating road feel in steer-by-wire applications}
- 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)

## Abstract

A steering control device configured to control a steering device includes a control unit. The control unit is configured to calculate a torque command value which is a target value of the motor torque based on execution of angle control for adjusting a convertible angle which is able to be converted to a rotation angle of the motor to a target angle; calculate the motor control signal based on the torque command value; and change a control gain which is used for the angle control based on a change of a factor influencing a behavior of a vehicle in response to steering.

## Claims

### Claim 1

A steering control device configured to control a steering device to which a motor torque is applied from an actuator with a motor as a drive source, the steering control device comprising:
a control unit configured to output a motor control signal for controlling operation of the motor;
a drive circuit configured to supply a drive electric power to the motor based on the motor control signal,
wherein the control unit is configured to:
calculate a torque command value which is a target value of the motor torque the torque command value is based on execution of angle control for adjusting a convertible angle which is able to be converted to a rotation angle of the motor;
calculate the motor control signal based on the torque command value; and
change a control gain which is used for the angle control based on a change of a factor influencing a behavior of a vehicle in response to steering, wherein:
the motor includes a plurality of coil groups with different power supply paths;
a plurality of groups each including the control unit and the drive circuit is provided such that the groups respectively correspond to the coil groups, a number of the groups being same as a number of the coil groups;
a plurality of control systems is provided between the motor and the steering control device, the control systems being configured to individually control torques generated by the coil groups; and
the factor includes a drive mode of the motor,
the drive mode includes
a cooperative mode in which torques generated by the coil groups of the control systems are controlled based on the torque command value calculated by the control unit of one of the control systems,
an independent mode in which torque generated by each of the coil groups of the control systems is controlled based on the torque command value calculated by the control unit of a corresponding one of the control systems, and
a residual mode in which, when one of the control systems is abnormal, torque generated by the coil group of a remainder of the control systems is controlled based on the torque command value calculated by the control unit of the remainder of the control systems, the remainder being normal; and
the control gain changes such that the control gain increases in order of the independent mode, the cooperative mode, and the residual mode.

### Claim 2 (depends on 1)

The steering control device according to claim 1, wherein:
the factor includes a vehicle speed; and
the control gain changes such that the control gain increases with an increase of the vehicle speed.

### Claim 3 (depends on 1)

The steering control device according to claim 1, wherein:
the factor includes an acceleration-deceleration state of the vehicle; and
the control gain changes to be smaller when the vehicle is in a deceleration state than when the vehicle is in a non-deceleration state.

### Claim 4 (depends on 1)

The steering control device according to claim 1, wherein:
the factor includes a lateral acceleration; and
the control gain changes such that the control gain increases with an increase of an absolute value of the lateral acceleration.

### Claim 5 (depends on 1)

The steering control device according to claim 1, wherein:
the factor includes at least one target temperature among a temperature of the motor, a temperature of the control unit, a temperature of the drive circuit, a temperature of the steering device, and an ambient temperature around the steering device; and
the control gain changes such that the control gain increases with a decrease of the target temperature.

### Claim 6 (depends on 1)

The steering control device according to claim 1, wherein:
the angle control includes feedback control for causing the convertible angle to conform to a target angle; and
the control gain includes a feedback gain which is used for the feedback control.

### Claim 7 (depends on 1)

The steering control device according to claim 1, wherein:
the angle control includes feedforward control based on a target angle; and
the control gain includes a feedforward gain which is used for the feedforward control.

### Claim 8 (depends on 1)

The steering control device according to claim 1, wherein:
the angle control includes damping control based on a target angular velocity which is a rate of change of a target angle; and
the control gain includes a damping gain which is used for the damping control.