Vehicle steering device

Patent metadata

Field	Value
Publication number	US-10011297-B2
Application number	US-201615360552-A
Country	US
Kind code	B2
Filing date	Nov 23, 2016
Priority date	Nov 30, 2015
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

A vehicle steering device includes: a target-steered-angle setting unit configured to set a left target steered angle that is a target value of the steered angle of a left steered wheel and a right target steered angle that is a target value of the steered angle of a right steered wheel; left motor controllers configured to control a left steering motor based on a left-steered-angle deviation that is a difference between the left steered angle and the left target steered angle; right motor controllers configured to control a right steering motor based on a right-steered-angle deviation that is a difference between the right steered angle and the right target steered angle; and an abnormality determination unit configured to determine that an abnormality has occurred when an absolute value of difference between the left-steered-angle deviation and the right-steered-angle deviation is equal to or larger than a first threshold.

First claim

What is claimed is:

1. A vehicle steering device comprising:
a steering member that is operated for steering;
a left steering operation mechanism configured to turn a left steered wheel;
a right steering operation mechanism configured to turn a right steered wheel, the steering member and the left steering operation mechanism being not mechanically coupled together, the steering member and the right steering operation mechanism being not mechanically coupled together, the left steering operation mechanism being driven by a left steering motor, and the right steering operation mechanism being driven by a right steering motor;
an electronic control unit configured to set a left target steered angle that is a target value of a steered angle of the left steered wheel and a right target steered angle that is a target value of a steered angle of the right steered wheel;
a left-steered-angle acquisition device configured to acquire a left steered angle that is the steered angle of the left steered wheel;
a right-steered-angle acquisition device configured to acquire a right steered angle that is the steered angle of the right steered wheel;
a left motor controller configured to control the left steering motor so that a left-steered-angle deviation that is a difference between the left steered angle and the left target steered angle decreases; and
a right motor controller configured to control the right steering motor so that a right-steered-angle deviation that is a difference between the right steered angle and the right target steered angle decreases, wherein
the electronic control unit is further configured to determine that an abnormality has occurred when an absolute value of a difference between the left-steered-angle deviation and the right-steered-angle deviation is equal to or larger than a first threshold.

2. The vehicle steering device according to claim 1 , wherein the electronic control unit is configured to determine that the abnormality has occurred when at least one of an absolute value of a time rate of change of the left-steered-angle deviation and an absolute value of a time rate of change of the right-steered-angle deviation is smaller than a second threshold.

3. The vehicle steering device according to claim 1 , wherein the electronic control unit is configured to determine that the abnormality has occurred when an absolute value of the left-steered-angle deviation is larger than a third threshold and an absolute value of a time rate of change of the left-steered-angle deviation is smaller than a fourth threshold, or when an absolute value of the right-steered-angle deviation is larger than the third threshold and an absolute value of a time rate of change of the right-steered-angle deviation is smaller than the fourth threshold.

4. The vehicle steering device according to claim 1 , further comprising:
a vehicle-speed acquisition device configured to acquire a vehicle speed, wherein
the electronic control unit is further configured to change the first threshold in accordance with the vehicle speed acquired by the vehicle-speed acquisition device.

5. The vehicle steering device according to claim 2 , further comprising:
a vehicle-speed acquisition device configured to acquire a vehicle speed, wherein
the electronic control unit is further configured to change the first threshold in accordance with the vehicle speed acquired by the vehicle-speed acquisition device, and to change the second threshold in accordance with the vehicle speed acquired by the vehicle-speed acquisition device.

6. The vehicle steering device according to claim 3 , further comprising:
a vehicle-speed acquisition device configured to acquire a vehicle speed, wherein
the electronic control unit is further configured to change the first threshold in accordance with the vehicle speed acquired by the vehicle-speed acquisition device, to change the third threshold in accordance with the vehicle speed acquired by the vehicle-speed acquisition device, and to change the fourth threshold in accordance with the vehicle speed acquired by the vehicle-speed acquisition device.

7. The vehicle steering device according to claim 1 , wherein the abnormality is a malfunction of one of the left steering motor, the right steering motor, the left motor controller or the right motor controller.

Assignees

• Jtekt Corp

Inventors

• Oya Toshiaki
• Okada Kotaro

Classifications

• B62D5/046

  Controlling the motor · CPC title

• B62D15/022

  on or near the connection between the steering wheel and steering column · CPC title

• B62D15/0235

  by measuring or deriving directly at the electric power steering motor · CPC title

• B62D5/04 Primary

  electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear · CPC title

• B62D5/0484

  for reaction to failures, e.g. limp home · CPC title