US 8,914,193 B2Granted

Damping force control apparatus

AssigneeToyota Jidosha Kabushiki Kaisha

InventorsAtsushi Ogawa, Motohiko Honma, Koutaro Okimura, Taisuke Hayashi, Takahito Watanabe

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Abstract

The magnitude of a linear damping coefficient Cs is set so as to decrease the greater a maximum amplitude value α of an intermediate frequency sprung acceleration is. In the case where a damping force control apparatus carries out control for dampening vibrations of a sprung member using a nonlinear H-infinity control theory, the linear damping coefficient Cs is set to a high value when the maximum amplitude value α of the intermediate frequency sprung acceleration inputted to a suspension apparatus is low. Accordingly, a requested damping force Freq also increases, which makes it possible to quickly dampen vibrations in the sprung member. Meanwhile, in the case where the maximum amplitude value α of the intermediate frequency sprung acceleration is high, the linear damping coefficient Cs is set to a low value. Accordingly, the requested damping force Freq also decreases, which makes it possible to suppress degradation in the riding quality when intermediate frequency vibrations are inputted, and particularly makes it possible to suppress riding quality degradation when the vibration speed is high.

Claims10

Dependent claims

A damping force control apparatus that controls a damping force for a vibration in a suspension apparatus including a damper and a spring interposed between a sprung member and an unsprung member, the damping force control apparatus comprising:

a nonlinear weight determination means for determining a magnitude of a nonlinear weight that is set when a nonlinear H-infinity control theory is applied to a control system designed based on the motion of the suspension apparatus;
a variable damping coefficient calculation means for calculating a variable damping coefficient which is a coefficient of a variable damping force to be generated by the damper relative to a vibration speed by applying the nonlinear H-infinity control theory to the control system in which the nonlinear weight determined by the nonlinear weight determination means has been set;
a linear damping coefficient determination means for determining a linear damping coefficient which is a coefficient of a linear damping force to be generated by the damper relative to the vibration speed based on a magnitude of a vibration in the sprung member having a frequency within a specific frequency band determined in advance as a frequency band that is greater than a sprung member resonation frequency;
a requested damping force calculation means for calculating a requested damping force which is a target damping force generated by the damper based on the variable damping coefficient and the linear damping coefficient;
and
a damping force characteristic control means for controlling a damping force characteristic of the damper based on the requested damping force,
wherein the nonlinear weight determination means determines the magnitude of the nonlinear weight based on the magnitude of the linear damping coefficient determined by the linear damping coefficient determination means so that the requested damping force corresponds to a damping force that is within a range of variation for the damping force characteristic of the damper.

4 more elements

A damping force control apparatus that controls a damping for a vibration in a suspension apparatus including a damper and a spring interposed between a sprung member and an unsprung member, the damping force control apparatus comprising:

a variable damping coefficient calculation means for calculating a variable damping coefficient which is a coefficient of a variable damping force to be generated by the damper relative to a vibration speed by applying a nonlinear H-infinity control theory to a control system designed based on the motion of the suspension apparatus;
a linear damping coefficient determination means for determining a linear damping coefficient which is a coefficient of a linear damping force to be generated by the damper relative to the vibration speed based on a magnitude of a vibration in the sprung member having a frequency within a specific frequency band determined in advance as a frequency band that is greater than a sprung member resonation frequency;
a requested damping force calculation means for calculating a requested damping force which is a target damping force generated by the damper based on the variable damping coefficient and the linear damping coefficient;
a corrected requested damping force calculation means for calculating a corrected requested damping force by correcting the requested damping force based on the magnitude of the linear damping coefficient determined by the linear damping coefficient determination means;
and
a damping force characteristic control means for controlling a damping force characteristic of the damper based on the corrected requested damping force,
wherein the corrected requested damping force calculation means calculates the corrected requested damping force so that the corrected requested damping force corresponds to a damping force within a range of variation for the damping force characteristic of the damper.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/202,879Filed 23 Feb 2009
Published: US 2012/0046829 A123 Feb 2012
Granted: 16 Dec 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

B60G 17/016
The regulating means comprising electric or electronic elements: characterised by their responsiveness, when the vehicle is travelling, to…
B60G 17/018
The regulating means comprising electric or electronic elements: characterised by the use of a specific signal treatment or control method
B60G 17/08
Characteristics of dampers , e.g. mechanical dampers: characteristics of fluid dampers
B60G 2202/24
Type of damper: fluid damper