Motor vehicle and steer control method for steerable wheel

Patent metadata

Field	Value
Publication number	US-9669869-B2
Application number	US-201214005130-A
Country	US
Kind code	B2
Filing date	Mar 1, 2012
Priority date	Mar 16, 2011
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

A vehicle suspension apparatus is constructed to improve stability and controllability. Suspension apparatus includes; a tire wheel to be equipped with a tire; a wheel hub mechanism to support the tire wheel; a first link member connecting the wheel hub mechanism and a vehicle body on a lower side of an axle in an vehicle up and down direction; a second link member connecting the wheel hub mechanism and the vehicle body on the lower side of the axle in the vehicle up and down direction and intersecting the first link member in a vehicle top view; and a steering rack moving in a vehicle widthwise direction and steering the wheel hub mechanism.

First claim

The invention claimed is:

1. A motor vehicle comprising:
a steer control apparatus to steer a steerable wheel by actuating an actuator in accordance with a steering condition of a steering wheel; and
a suspension apparatus to support the steerable wheel to a vehicle body;
wherein the suspension apparatus comprises:
a wheel hub mechanism to support the steerable wheel to be provided with a tire;
a first link member connecting the wheel hub mechanism and the vehicle body on a lower side of an axle in a vehicle up and down direction; and
a second link member connecting the wheel hub mechanism and the vehicle body on the lower side of the axle in the vehicle up and down direction and intersecting the first link member in a vehicle top view;
wherein the steer control apparatus comprises a straightness securing section to secure a straightness of the suspension apparatus, and a steer response setting section to set an early steer response characteristic at a steer response characteristic of the suspension apparatus by adjusting a straightness securing control of the straightness securing section when a steering operation of turning the steering wheel is started from a neutral position of the steering wheel,
wherein the steer response setting section comprises a delay control section to delay the straightness securing control of the straightness securing section when the steering wheel is turned from the neutral position.

2. A motor vehicle comprising:
a steer control apparatus to steer a steerable wheel by actuating an actuator in accordance with a steering condition of a steering wheel; and
a suspension apparatus to support the steerable wheel to a vehicle body;
wherein the suspension apparatus comprises:
a wheel hub mechanism to support the steerable wheel to be provided with a tire;
a first link member connecting the wheel hub mechanism and the vehicle body on a lower side of an axle in a vehicle up and down direction; and
a second link member connecting the wheel hub mechanism and the vehicle body on the lower side of the axle in the vehicle up and down direction and intersecting the first link member in a vehicle top view;
wherein the steer control apparatus comprises a straightness securing section to secure a straightness of the suspension apparatus, and a steer response setting section to set a high steer responsiveness with a steer responsiveness of the suspension apparatus in an early steer state when a steering operation of turning the steering wheel is started from a neutral position of the steering wheel, and to set a required steer responsiveness by a straightness securing control of the straightness securing section in a steer state after the early steer state,
wherein the steer response setting section comprises a delay control section to delay the straightness securing control of the straightness securing section when the steering wheel is turned from the neutral position.

3. A steer control method for a steerable wheel, comprising:
steering the steerable wheel supported by a suspension apparatus comprising: a wheel hub mechanism to support a tire wheel to be provided with the steerable wheel; a first link member connecting the wheel hub mechanism and a vehicle body of a vehicle on a lower side of an axle in a vehicle up and down direction; and a second link member connecting the wheel hub mechanism and the vehicle body on the lower side of the axle in the vehicle up and down direction and intersecting the first link member in a vehicle top view; wherein a kingpin axis of the suspension apparatus is set to pass through a tire ground contact surface at a neutral position of the steering wheel;
actuating an actuator in accordance with a steering condition of a steering wheel in a basic control mode to make use of a steer responsiveness set by intersecting arrangement of the first and second link members and setting of the kingpin axis; and
performing a straightness securing control to restrain the steer responsiveness and to secure a straightness of the vehicle by imparting a restoring force for self-aligning to the steerable wheel by actuating the actuator, wherein the straightness securing control is delayed when the steering wheel is turned from the neutral position.

4. The steer control method as recited in claim 3 , wherein the control to secure the straightness of the vehicle is performed by calculating a self-aligning torque and imparting, to the steerable wheel, the calculated self-aligning torque.

5. A steer control method for a steerable wheel, comprising:
sensing a variation of a steering angle in a steering operation turning a steering wheel, and controlling, in accordance with a sensing result, a steer actuator for steering the steerable wheel supported by a suspension apparatus comprising: a wheel hub mechanism to support a tire wheel to be provided with the steerable wheel; a first link member connecting the wheel hub mechanism and a vehicle body of a vehicle on a lower side of an axle in a vehicle up and down direction; and a second link member connecting the wheel hub mechanism and the vehicle body on the lower side of the axle in the vehicle up and down direction and intersecting the first link member in a vehicle top view; wherein a kingpin axis passing through an upper pivot point and a lower pivot point of the link members is set to pass through a tire ground contact surface at a neutral position of the steering wheel;
performing a control to secure a straightness of the vehicle by imparting a restoring force for self-aligning to the steerable wheel by actuating the actuator; and
setting a steer responsiveness set by intersecting arrangement of the first and second link members and setting of the kingpin axis of the suspension apparatus as an initial steer responsiveness at an early steer stage when the steering operation of turning the steering wheel is started from the neutral position of the steering wheel, and starting the control to secure the straightness of the vehicle with the steer actuator after an expiration of an initial set time period, wherein the straightness securing control is delayed when the steering wheel is turned from the neutral position.

6. The steer control method as recited in claim 4 , wherein the initial set time period is set equal to 0.1 sec.

7. A motor vehicle comprising:
a steer control apparatus to steer a steerable wheel by actuating an actuator in accordance with a steering condition of a steering wheel; and
a suspension apparatus to support the steerable wheel to a vehicle body;
wherein the suspension apparatus comprises:
a wheel hub mechanism to support the steerable wheel to be provided with a tire;
a first link member connecting the wheel hub mechanism and the vehicle body on a lower side of an axle in a vehicle up and down direction; and
a second link member connecting the wheel hub mechanism and the vehicle body on the lower side of the axle in the vehicle up and down direction and intersecting the first link member in a vehicle top view;
wherein a kingpin axis passing through an upper pivot point of the suspension apparatus and a lower pivot point located at an intersection point of the first link member and the second link member is set to pass through a tire ground contact surface at a neutral position of the steering wheel; and
wherein the steer control apparatus is configured to steer the steerable wheel by producing a restoring force for self-aligning in the steerable wheel by actuating the actuator and thereby to secure a straightness of the vehicle,
wherein the steer control apparatus comprises a straightness securing section to secure a straightness of the suspension apparatus, and a steer response setting section to set an early steer response characteristic at a steer re

Assignees

• Kageyama Yusuke
• Mikuriya Yutaka
• Nissan Motor

Inventors

• Kageyama Yusuke
• Mikuriya Yutaka

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

• B62D5/00

  Power-assisted or power-driven steering (for non-deflectable wheels B62D11/00; fluid-pressure servomotors in general F15B) · CPC title

• B60G2200/18

  Multilink suspensions, e.g. elastokinematic arrangements · CPC title

• B62D7/159

  characterised by computing methods or stabilisation processes or systems, e.g. responding to yaw rate, lateral wind, load, road condition · CPC title

• B62D7/18

  Steering knuckles; King pins · CPC title