Honda Motor Co., Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Hitachi Astemo Ltd.

Masaki Izawa

Takafumi Kato

Kei Oshida

Shigenobu Sekiya

Hideaki Shibue

Tsukasa Fukuzato

Yuichiro Minakuchi

Yoshio Onoe

Yasuo Shimizu

Hiromi Inagaki

Tetsuro Hamada

Katsuji Watanabe

Toshihiko Suenaga

Ryoma Kanda

Minoru Higuchi

Kazuo Matsuura

Tetsuya Koike

Yasuharu Ohyama

Takashi Furuichi

Masaru Yorita

Toshimitsu Kaji

Takuju Nakamura

Hirotada Ito

Shubham Gupta

Realized is a technique for estimating a state quantity of a vehicle, which technique is applicable to estimation of a vehicle weight and allows an increase in accuracy and speed of the estimation. A state quantity estimating device includes a data storing section (), a predictive quantity computing section (), an obtaining section (), a Kalman gain computing section (), an estimated quantity computing section () which calculates an estimated state quantity and estimated covariance, and a process noise covariance correcting section () which corrects process noise covariance. The estimated state quantity, the estimated covariance, and the process noise covariance, each of which has been calculated or corrected, are written in the data storing section () as a state quantity, state covariance, and process noise covariance, respectively, and are used in a next computation for estimating a state quantity.

State quantity estimation device, control device, and state quantity estimation method

It is an object of the present invention to improve accuracy in estimation of a state of a vehicle in order to achieve excellent ride comfort. An ECU () includes a reference vehicle model computation section (), which is configured to calculate a reference output by carrying out computation with respect to at least one of a plurality of state amounts in a planar direction and at least one of a plurality of state amounts in an up-down direction in an inseparable manner.

Suspension control device and suspension device

It is an object of the present invention to suitably estimate a state of a vehicle. A vehicle state estimation section () includes: a main computation section () configured to carry out linear computation with respect to a state amount related to a state of a vehicle; and a tire model computation section () configured to carry out nonlinear computation with direct or indirect reference to at least part of a result of the linear computation carried out by the main computation section ().

Vehicle state estimation device, control device, suspension control device, and suspension device

A suspension control system allows a state variable of a vehicle used for the damper damping force control to be computed at a high precision without regards to the caster angle given to the suspension geometry. A suspension control system for a vehicle provided with a variable damper that can adjust a damping force according to an input signal comprises a wheel rotational speed sensor for detecting a wheel rotational speed, a gain circuit for computing the unsprung load of each wheel according to the wheel rotational speed variation detected by the wheel speed sensor, a single wheel model computing unit for computing the sprung velocity and the stroke speed by inputting the unsprung load to a single wheel model representing the behavior of the vehicle, and a damper control unit for controlling a damping force of the variable damper according to the computed sprung velocity and stroke speed.

Suspension control system

A control apparatus of a variable damping force damper used to suspend a vehicle body of a vehicle is configured to set a target control quantity of the variable damping force damper based on a plurality of dynamic state quantities of the vehicle, wherein the plurality of dynamic state quantities include a vertical dynamic state quantity of the vehicle.

Control apparatus of variable damping force damper

A control system for an adjustable damping force damper of a suspension apparatus of a vehicle, includes a lateral acceleration detecting unit detecting a lateral acceleration of the vehicle at a gravity point thereof, a yaw rate detecting unit detecting a yaw rate of the vehicle and a control unit controlling a damping force of the damper. The control unit calculates a first target damping force based on an output of the lateral acceleration detecting unit, calculates a second target damping force based on a lateral acceleration at an axel position which is estimated by an output of the yaw rate detecting unit, compares an absolute value of the first target damping force with that of the second target damping force and sets a target controlling value of the damping force in accordance with the first or second target damping force which has a larger absolute value.

Control system for adjustable damping force damper

Upon searching control parameter used to adjust damping force of a damper from a map in accordance with damper speed and target damping force decided based on moving condition of the vehicle, the map sets the control parameter, which are relatively higher than the actual damping force characteristics, as map data in the area where the damper speed is less than a predetermined value, the area where the noise has the great influence on the sensor outputs. Therefore, it can be prevented that the control parameter of the damping force is varied largely or varied in a short period by the influence of noise, and the driving stability control of the vehicle can be executed exactly and the noise caused by switching the damping force of the damper can be reduced.

Control system for adjustable damping force

A control system for a adjustable damping force damper includes a damper and a spring provided on a suspension apparatus of a vehicle, a sprung speed sensor for detecting speed of an upper member of the spring, the sprung speed is generated when the vehicle gets over steps on a road surface and a control unit for setting a gain so as to determine an damping force of the damper based on a product of the sprung speed and the gain. When an absolute value of the sprung speed exceeds a predetermined value, the control unit changes the gain in response to a positive sign or a negative sign of the sprung speed.

A damper with a controllable variable damping force, includes a piston and a cylinder provided with a magnetic viscous fluid and piston therein. An interior of the cylinder is divided by the piston into first and second fluid chambers which communicate with each other. A controller energizes a coil provided to the piston, wherein a viscosity of the magnetic viscous fluid in the fluid passage is changed when the coil is energized. When the controller fails to energize the coil, an electric current supply circuit supplies a predetermined constant electric current to the coil. Alternatively, when the controller detects an abnormality in energizing control of the coil, the controller supplies the predetermined constant electric current to the coil. Further, a sub-coil may be provided with the piston, wherein the controller supplies the sub-coil with a predetermined constant electric current whenever the coil is not operating properly.

Damper with variable damping force

In a suspension control system, accelerations detected by acceleration sensors are differentiated by a differentiator to calculate acceleration derivative values. Based on these values, a target electrical current calculating section calculates a target electrical current that is supplied to an actuator which controls a damping force of a damper. Before a rolling or pitch angle occurs in the vehicle, the change of the rolling or pitch angle is predicted to control the damping force of the damper, thereby improving the response of rolling angle and pitch angle control to achieve, simultaneously, an accurate posture control and a satisfactory riding comfort. Because the target electrical current calculating section corrects the target electrical current of the actuator based on a damper speed obtained by differentiating a damper displacement, even when a large input is applied to the damper due to an unevenness of the road surface, a proper posture control is performed.

A control device of a variable damping force damper for controlling a damping force of a damper used in a vehicle suspension system comprises: relative displacement detection means for detecting a value corresponding to a relative displacement between a vehicle body and a wheel in a vertical direction; relative speed detection means for detecting a value corresponding to a relative speed between the vehicle body and the wheel in the vertical direction; multiplying means for multiplying the value corresponding to the relative displacement and the value corresponding to the relative speed; and means for setting a damping force control target value of the damper based on the output from the multiplying means.

Control device of variable damping force damper

An active actuator is interposed between the unsprung mass and the sprung mass of a vehicle, and a controller selectively extends and retracts the actuator at a prescribed acceleration so as to selectively apply an additional contact load to the wheel by making use of the inertial force of the sprung mass and/or the unsprung mass of the vehicle. A particularly advantageous result can be achieved by increasing the tire contact load when the wheel is about to lock up when braking. The present invention can thus reduce the braking distance for the given road condition.

Tire contact load control system

An active actuator is interposed between the unsprung mass and the sprung mass of a vehicle, and a controller selectively extends and retracts the actuator at a prescribed acceleration so as to selectively apply an additional contact load to the wheel by making use of the inertial force of the sprung mass and/or the unsprung mass of the vehicle. Thus, the tire contact load of each wheel can be increased at will and independently from the other wheels so that the gripping force available to each wheel can be increased as required by appropriately operating the corresponding actuator. Therefore, the braking performance and the accelerating performance for the given road condition can be improved. Additionally, even when a frictional coefficients for the right and left wheels differ from each other, by appropriately applying an additional contact load to the wheel travelling over the more slippery part of the road surface, the stability of the vehicle can be also substantially increased.

An active actuator is interposed between the unsprung mass and the sprung mass of a vehicle, and extended and retracted in a cyclic manner so as to apply a prescribed reaction to the unsprung mass during an extending stroke of the actuator. Thus, the additional contact load is applied to the tire in a cyclic manner over a desired period of time so that the gripping force of the tire can be increased over a desired period of time. Although the increase in the tire contact load and the reduction in the tire contact load occurs in an alternating, cyclic manner, it is possible to achieve an overall advantage for instance in reducing the braking distance by intermittently increasing the tire contact load of the rear wheels by detecting the braking action of the vehicle with a suitable acceleration sensor or the like. In particular, by setting a retracting stroke of the actuator substantially longer in time duration than an extending stroke of the actuator, it is possible to reduce the degree of the contact load reduction between each consecutive phase of contact load increase, and to achieve an even better overall result.

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Saitama, Japan

Masaki Izawa