Nissan Motor Company Limited

Kayaba Kogyo Kabushiki Kaisha

Yukio Fukunaga

Naoto Fukushima

Yohsuke Akatsu

Itaru Fujimura

Sunao Hano

Masaharu Satoh

Yasuji Shibahata

Yasumasa Tsubota

Kenji Nakamura

Junsuke Kuroki

Namio Irie

Masaharu Sato

Kensuke Fukuyama

Hiroshi Tsuda

Ken Kamijo

Sumitsugu Arima

Masahiro Tsukamoto

Takaaki Uno

Kenro Takahashi

Harutoshi Tsujimura

Yosuke Akatsu

Yuji Okuyama

Kenzo Shimizu

Hiroshi Yamanaka

Yoshiki Tsuda

An anti-rolling suspension control system generally derives anti-rolling control signals for controlling suspension characteristics of respective suspension systems in order to suppress vehicular rolling motion. The system is further provided means for monitoring road friction condition. The system derives distribution of rolling moment distribution ratio between front suspension systems and rear suspension systems based on the monitored road friction condition so that the derived distribution may be adapted to the road surface frictional condition.

Anti-rolling controlling system for automotive active suspension system

A pressure supply network for an active suspension system employs a strategy for predicting consumed fluid flow rate on the basis of bounding and rebounding stroke between a vehicular body and a suspension member rotatably supporting a vehicular wheel. A discharge rate of a fluid pump disposed in the pressure supply network is controlled on the basis of the predicted fluid flow rate.

Pressure supply network for active suspension system and control therefor

A fluid supply system is provided for an active vehicle suspension system, for supplying fluid pressure for a hollow working cylinder via a pressure control valve for adjusting suspension characteristics of the vehicle in order to suppress vehicular attitude changes and to absorb road shock vibration, the system having a pressurized fluid source unit for circulating a pressurized fluid through a fluid circuit extending via the pressure control valve and the working cylinder. A first sensor is provided for monitoring a relative displacement between the body of the vehicle and a suspension member rotatably supporting a road wheel thereof, for producing a relative displacement magnitude indicative signal. A second sensor is provided for monitoring a lateral acceleration exerted on the vehicle body. A predicted fluid flow amount through said fluid circuit is derived on the basis of the relative displacement indicative signal to produce a predicted fluid flow amount indicative signal. A magnitude of lateral acceleration greater than or equal to a predetermined acceleration criterion is detected to produce an acceleration detection signal. The fluid supply amount from the pressurized fluid source unit is derived of the basis of the predicted fluid flow amount for controlling the pressurized fluid source unit in order to adjust the supply amount of fluid toward the derived fluid supply amount in response to the acceleration detection signal for increasing the supply amount.

Fluid supply circuit for active suspension system with variable fluid

An active suspension system utilizes an acceleration exerted on a vehicle body and a stroke magnitude in relative displacement between the vehicle body and a suspension member as parameters for controlling discharge rate of pressure medium fluid from a pressure source unit. The pressure source unit is normally driven at limited discharge rate for minimizing driving power consumption. The pressure source unit is responsive to the vertical acceleration greater than a predetermined acceleration criterion and to vertical stroke magnitude greater than a predetermined stroke criterion to increase discharge rate for compensating pressure medium fluid amount to be consumed for suspension control.

Pressure medium fluid circuit for active suspension system with variable

An actively controlled suspension system has two hydraulic systems for generating damping force against the vibration to be transmitted between a vehicle body and a suspension member. One of the hydraulic systems is designed for absorbing relatively high frequency vibration generally input from the suspension member for preventing vibration from the suspension member from being transmitted to the vehicle body. The other hydraulic system is active on relatively low frequency of vibration generally input from the vehicle body upon change of attitude of the vehicle body. The other hydraulic system generates a fluid pressure suppressing the attitude change. A pressure control valve and a fluid pressure source may be incorporated in the second hydraulic system so that they may not be active when aforementioned one of the hydraulic system is active.

Actively controlled automotive suspension system with mutually

A vehicular height regulation system performs attitude change suppressive suspension control for equalized magnitude at respective of front and rear wheels. For performing equalized magnitude not only for the front suspension systems, the vehicular height control system includes a pair of actuator means associated with respective of rear-left and rear-right wheels, which actuator means are operable independently of each of other.

Attitude change suppressive vehicular height regulation system

A slip angle monitoring system directly compares an absolute value of lateral acceleration with an experimentarily derived given value which serves as a slip criterion to determine slip angle of a vehicle. Slip angle is set at zero while the absolute value of the lateral acceleration is smaller than or equal to the given value. On the other hand, when the absolute value is greater than the given value, the slip angle is derived by dividing the lateral acceleration by the longitudinal acceleration or by taking the minus one power of the tangent of the quotient obtained by dividing the lateral acceleration by the longitudinal acceleration, that is, the cotangent of the quotient.

System for monitoring vehicle slip angle

An active suspension control system employs a strategy minimum fluid pressure in the working chamber of an inside suspension system is reached at greater lateral acceleration than that via which at which the maximum fluid pressure in the working chamber of an outside suspension system is reached. The system also takes a strategy for adjusting the fluid pressure in the working chambers of the inside and outside suspension system inversely proportional to each other while the lateral acceleration is maintained smaller than a predetermined pressure at which the maximum fluid pressure in the working chamber of the outside suspension system is reached. This assures driving stability and riding comfort by permitting vehicular rolling in response to a lateral acceleration greater that a given lateral acceleration criterion.

Anti-rolling control system for automotive active suspension system

An an actively controlled suspension system includes a fail-safe system which is associated with a pressure control valve and detective of failure of a control circuit to perform fail-safe operation. The fail-safe system operates the pressure control valve in response to failure of the control circuit, to fix the valve position corresponding to a working fluid pressure in a working chamber defined in a suspension cylinder disposed between a vehicular body and a suspension member rotatably supporting a vehicular wheel, at a pressure value at or in the vicinity of a predetermined initial or neutral pressure.

Hydraulic circuit for actively controlled automotive suspension system

A hydraulic circuit for an active suspension system employs a pressure accumulator connected to a drain line at an orientation upstream of a pilot operated operational one-way check valve. The pressure accumulator absorbs back pressure generated in the drain line due to flow resistance in the drain line.

Active suspension system with enhanced response characteristics

An actively controlled suspension system introduces two-way mode operation in controlling suspension. A suspension control system operates in a normal mode for controlling fluid pressure in a hydraulic cylinder disposed between a vehicle body and a suspension member is adjusted depending upon the vehicle driving conditions in order to suppress vehicular attitude change, and a power OFF transition mode for controlling the fluid pressure toward a preset neutral pressure. The hydraulic circuit is constructed to maintain the pressure in the working chamber of the hydraulic cylinder at the neutral pressure while power is not supplied to control system.

Actively controlled suspension system with power supply control

An active suspension control system performs anti-rolling control in response to vehicular rolling by inducing counter rolling in a direction opposite to the vehicular body rolling direction. Magnitude of counter rolling is differentiated between front and rear suspension systems for providing desired steering characteristics. The steering characteristics is adjusted depending on the demand on stability factor in cornering.

Active suspension system for an automotive vehicle with slip angle

An actively controlled suspension system which can perform precise control of suspension characteristics with satisfactory compensation of phase delay caused in a control system. The actively controlled suspension system which can successfully avoid influence of the shifting of the gravity center of a vehicle body caused by a variation of load on the vehicle. The actively controlled suspension system employs more than one lateral acceleration sensor which are oriented at axially or longitudinally shifted positions to each other. Based on the outputs of respective lateral acceleration sensors, anti-rolling suspension control signals are produced for controlling suspension characteristics of the left- and right-sides of a suspension system.

Actively controlled suspension system with compensation of delay in

A suspension control system detects acceleration exerted on the vehicular body and close to a predetermined critical value. When the acceleration greater than the predetermined critical value, total stiffness of the suspension system is adjusted to be smaller value to allow attitude change of the vehicle body in a predetermined magnitude. Therefore, rolling or pitching is caused as a sign that traction of the suspension tends to break. This makes a driver to recognize that the vehicular driving condition is near the critical condition.

Actively controlled suspension system for suppressing attitude change of

A suspension control system introduces capability of automatically adjusting sensibility of attitude change depending upon a vehicular speed with maintaining capability of manual adjustment of the sensibility for the vehicular attitude change. The actively controlled suspension system employs a pressure control valve which is operable in response to a control signal and controls fluid pressure in the fluid chamber of a hydraulic cylinder as a replacement of the conventional hydraulic shock absorber. The pressure control valve is associated with a controller which detects bounding and rebounding acceleration and stroke speed in bounding and rebounding motion for detecting vehicular attitude change and deriving a control signal to operate the pressure control valve to suppress attitude change. The controller is response to a vehicle speed indicative parameter for adjusting sensitivity of attitude change and whereby adjusting suspension control characteristics.

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Kanagawa, Japan

Yukio Fukunaga