Suspension control apparatus for vehicle and control apparatus for damping-force adjustable shock absorber

Patent metadata

Field	Value
Publication number	US-10106009-B2
Application number	US-95515310-A
Country	US
Kind code	B2
Filing date	Nov 29, 2010
Priority date	Nov 30, 2009
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A suspension control apparatus for a vehicle including a damping-force adjustable shock absorber interposed between a vehicle body and a wheel of a vehicle, and a controller for variably controlling damping-force characteristics of the damping-force adjustable shock absorber between hard and soft. The controller is configured to switch the damping-force characteristics to a soft side when a direction of a stroke of the damping-force adjustable shock absorber is reversed between an extension stroke and a contraction stroke.

First claim

What is claimed is:

1. A suspension control apparatus for a vehicle comprising:
a damping-force adjustable shock absorber interposed between a vehicle body and a wheel of a vehicle, and
a controller for variably controlling damping-force characteristics of the damping-force adjustable shock absorber between hard and soft,
the controller comprising a vibration component extracting section configured to extract a vibration component at a predetermined specific frequency from extension/contraction movement of the damping-force adjustable shock absorber,
wherein the controller is configured to determine based on a relative velocity between the vehicle body and the wheel that a direction of a stroke of the damping-force adjustable shock absorber is reversed between an extension stroke and a contraction stroke, and
when the vibration component at the predetermined specific frequency exceeds a predetermined criterion value and near the direction of the stroke of the damping-force adjustable shock absorber being reversed, the controller switches the damping-force characteristics to a soft side before the direction of the stroke of the damping-force adjustable shock absorber is reversed, and maintains the damping-force characteristics of the soft side until after the direction of the stroke is reversed.

2. A suspension control apparatus for a vehicle according to claim 1 ,
wherein the controller is configured to switch the damping-force characteristics so that the damping-force characteristics become softer as the vibration component at the predetermined specific frequency becomes larger before the direction of the stroke of the damping-force adjustable shock absorber is reversed.

3. A suspension control apparatus for a vehicle according to claim 1 , wherein the controller further comprises an emergency determination section, and
the controller is configured to temporarily interrupt the control for switching the damping-force characteristics to the soft side before the direction of the stroke of the damping-force adjustable shock absorber is reversed between the extension stroke and the contraction stroke, in case that it is determined by the emergency determination section that an emergency occurs.

4. A suspension control apparatus for a vehicle according to claim 1 , wherein the controller performs control in consideration of a time delay from output of a control amount to an actuator of the damping-force adjustable shock absorber to switching of the damping-force characteristics to the soft side.

5. A suspension control apparatus for a vehicle according to claim 1 , wherein the controller further comprises a damping-force map, and
the controller is configured to switch the damping-force characteristics to the soft side by using a damping-force estimated value obtained according to the damping-force map, only before the direction of the stroke of the damping-force adjustable shock absorber is reversed from the extension stroke to the contraction stroke.

6. A suspension control apparatus for a vehicle comprising:
a damping-force adjustable shock absorber interposed between a vehicle body and a wheel of a vehicle, and
a controller for variably controlling damping-force characteristics of the damping-force adjustable shock absorber between hard and soft,
the controller being configured to switch the damping-force characteristics to a soft side when a direction of a stroke of the damping-force adjustable shock absorber is reversed between an extension stroke and a contraction stroke, and
the suspension control apparatus further comprising a vibration component extracting section configured to extract a vibration component at a predetermined specific frequency from extension/contraction movement of the damping-force adjustable shock absorber,
wherein the controller is configured to switch the damping-force characteristics so that the damping-force characteristics become softer as the vibration component at the predetermined specific frequency becomes larger, when the vibration component at the predetermined specific frequency exceeds a predetermined criterion value and when the direction of the stroke of the damping-force adjustable shock absorber is reversed,
wherein the controller further comprises a road-surface determination section, and
wherein the controller is configured to set a smaller value as the predetermined criterion value, the smaller value being smaller than that in a normal road condition, when it is determined by the road-surface determination section that a road condition is worse in comparison with a normal road condition.

7. A suspension control apparatus for a vehicle, comprising:
a damping-force adjustable shock absorber interposed between a vehicle body and a wheel of a vehicle, and
a controller for variably controlling damping-force characteristics of the damping-force adjustable shock absorber between hard and soft,
wherein the controller comprises a damping-force map and a vibration component extracting section configured to extract a vibration component at a predetermined specific frequency from extension/contraction movement of the damping-force adjustable shock absorber by using a damping-force estimated value obtained according to the damping-force map,
wherein the controller is configured to determine based on a relative velocity between the vehicle body and the wheel that the direction of the stroke of the damping-force adjustable shock absorber is reversed between an extension stroke and a contraction stroke, and
when the vibration component at the predetermined specific frequency exceeds a predetermined criterion value and near the direction of the stroke of the damping-force adjustable shock absorber being reversed, the controller switches the damping-force characteristics to a soft side before the direction of the stroke of the damping-force adjustable shock absorber is reversed, and maintains the damping-force characteristics of the soft side until after the direction of the stroke is reversed.

8. A suspension control apparatus for a vehicle according to claim 7 ,
wherein the controller is configured to switch the damping-force characteristics so that the damping-force characteristics become softer as the vibration component at the predetermined specific frequency becomes larger before the direction of the stroke of the damping-force adjustable shock absorber is reversed.

9. A suspension control apparatus for a vehicle according to claim 7 , wherein the controller further comprises an emergency determination section, and
the controller is configured to temporarily interrupt the control for switching the damping-force characteristics to the soft side before the direction of the stroke of the damping-force adjustable shock absorber is reversed between the extension stroke and the contraction stroke, in case that it is determined by the emergency determination section that an emergency occurs.

10. A suspension control apparatus for a vehicle comprising:
a damping-force adjustable shock absorber interposed between a vehicle body and a wheel of a vehicle, and
a controller for variably controlling damping-force characteristics of the damping-force adjustable shock absorber between hard and soft,
wherein the controller comprises a damping-force map, and a vibration component extracting section configured to extract a vibration component at a predetermined specific frequency from extension/contraction movement of the damping-force adjustable shock absorber by using a damping-force estimated value obtained according to the damping-force map,
when the vibration component at the predetermined specific frequency exceeds a predetermined criterion value, the controller is configured

Assignees

• Hirao Ryusuke
• Nezu Takashi
• Ichimaru Nobuyuki
• Kobayashi Takahide
• Hitachi Automotive Systems Ltd

Inventors

• Hirao Ryusuke
• Nezu Takashi
• Ichimaru Nobuyuki
• Kobayashi Takahide

Classifications

• B60G2400/252

  vertical · CPC title

• B60G17/016

  characterised by their responsiveness, when the vehicle is travelling, to specific motion, a specific condition, or driver input {(B60G17/017 takes precedence)} · CPC title

• B60G17/08 Primary

  Characteristics of fluid dampers (adjusting fluid dampers in general F16F9/44 - F16F9/53) · CPC title

• B60G2500/10

  Damping action or damper · CPC title

• B60G2400/102

  vertical · CPC title