Control device for vehicle

Patent metadata

Field	Value
Publication number	US-11214303-B2
Application number	US-201916593183-A
Country	US
Kind code	B2
Filing date	Oct 4, 2019
Priority date	Nov 26, 2018
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

A vehicle of a steer-by-wire type includes: a turning device that turns a wheel by actuating a turning motor; and a reaction torque generation device that applies a reaction torque to a steering wheel by actuating a reaction motor. A control device for the vehicle is configured to control turning of the wheel by controlling the turning motor and to control the reaction torque by controlling the reaction motor, according to rotation of the steering wheel. When a power output limiting condition is satisfied, the control device executes not only power output limiting processing that limits a power output of the turning motor but also reaction torque increasing processing. In the reaction torque increasing processing, the control device controls the reaction torque to make the steering wheel harder to rotate as compared with a case where the power output limiting processing is not executed.

First claim

What is claimed is:

1. A control device for a vehicle of a steer-by-wire type,
the vehicle comprising:
a turning device configured to turn a wheel by actuating a turning motor; and
a reaction torque generation device configured to apply a reaction torque to a steering wheel by actuating a reaction motor,

the control device being configured to control turning of the wheel by controlling the turning motor and to control the reaction torque by controlling the reaction motor, according to rotation of the steering wheel, wherein
when a power output limiting condition is satisfied, the control device executes not only power output limiting processing that limits a power output of the turning motor but also reaction torque increasing processing,
in the power output limiting processing, the control device stops the turning of the wheel, or decreases the power output of the turning motor as a steering speed of the steering wheel becomes higher, and
in the reaction torque increasing processing, the control device controls the reaction torque to make the steering wheel harder to rotate as compared with a case where the power output limiting processing is not executed.

2. The control device according to claim 1 , wherein
in the power output limiting processing, the control device limits the power output of the turning motor by decreasing a current limit value being an upper limit of a motor current driving the turning motor.

3. A control device for a vehicle of a steer-by-wire type,
the vehicle comprising:
a turning device configured to turn a wheel by actuating a turning motor; and
a reaction torque generation device configured to apply a reaction torque to a steering wheel by actuating a reaction motor,

the control device being configured to control turning of the wheel by controlling the turning motor and to control the reaction torque by controlling the reaction motor, according to rotation of the steering wheel, wherein
when a power output limiting condition is satisfied, the control device executes not only power output limiting processing but also reaction torque increasing processing,
in the power output limiting processing, the control device limits a power output of the turning motor by decreasing a current limit value being an upper limit of a motor current driving the turning motor,
in the reaction torque increasing processing, the control device controls the reaction torque to make the steering wheel harder to rotate as compared with a case where the power output limiting processing is not executed,
in the power output limiting processing, the control device decreases the current limit value such that the turning of the wheel stops, and
in the reaction torque increasing processing, the control device makes the reaction torque in a case where the motor current is equal to or higher than the current limit value higher than the reaction torque in a case where the motor current is lower than the current limit value.

4. The control device according to claim 3 , wherein
a precursor start value is a current value lower than the current limit value by a first value, and
in the reaction torque increasing processing, the control device makes the reaction torque in a case where the motor current is equal to or higher than the precursor start value higher than the reaction torque in a case where the motor current is lower than the precursor start value.

5. The control device according to claim 4 , wherein
in the reaction torque increasing processing, the control device gradually increases the reaction torque as the motor current increases from the precursor start value to the current limit value.

6. The control device according to claim 3 , wherein
the power output limiting condition includes that a temperature of the turning motor exceeds a temperature threshold or a voltage supplied to the turning motor falls below a voltage threshold.

7. A control device for a vehicle of a steer-by-wire type,
the vehicle comprising:
a turning device configured to turn a wheel by actuating a turning motor; and
a reaction torque generation device configured to apply a reaction torque to a steering wheel by actuating a reaction motor,

the control device being configured to control turning of the wheel by controlling the turning motor and to control the reaction torque by controlling the reaction motor, according to rotation of the steering wheel, wherein
when a power output limiting condition is satisfied, the control device executes not only power output limiting processing but also reaction torque increasing processing,
in the power output limiting processing, the control device limits a power output of the turning motor by decreasing a current limit value being an upper limit of a motor current driving the turning motor,
in the reaction torque increasing processing, the control device controls the reaction torque to make the steering wheel harder to rotate as compared with a case where the power output limiting processing is not executed,
in the power output limiting processing, the control device decreases the current limit value as a steering speed of the steering wheel becomes higher,
a damping component of the reaction torque increases as the steering speed of the steering wheel becomes higher, and
in the reaction torque increasing processing, the control device increases the damping component as compared with a case where the reaction torque increasing processing is not executed.

8. The control device according to claim 7 , wherein
a precursor start value is a current value lower than the current limit value by a second value, and
in the reaction torque increasing processing, the control device makes the damping component in a case where the motor current is equal to or higher than the precursor start value higher than the damping component in a case where the motor current is lower than the precursor start value.

9. The control device according to claim 7 , wherein
the power output limiting condition includes that electric power of the turning motor exceeds a power threshold.

Assignees

• Toyota Motor Co Ltd

Inventors

• Shibata Kenji
• Itoh Koichi
• Sato Takafumi

Classifications

• B62D6/008 Primary

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

• B62D5/0463

  calculating assisting torque from the motor based on driver input · CPC title

• B62D5/005

  means for generating torque on steering wheel or input member, e.g. feedback · CPC title

• B62D5/046 Primary

  Controlling the motor · CPC title

• B62D5/006

  power actuated · CPC title