Nissan Motor Company Limited

Masaharu Satoh

Naoto Fukushima

Yohsuke Akatsu

Yukio Fukunaga

Itaru Fujimura

Sunao Hano

Kensuke Fukuyama

Masahiro Tsukamoto

Kenro Takahashi

Yukio Fukanaga

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 suspension control system employs a first lateral acceleration sensor for monitoring a lateral acceleration at a first point on a vehicular body and a second lateral acceleration sensor for monitoring lateral acceleration at a second point on the vehicular body, which second point is provided at a longitudinally offset position from the first point. A controller derives a lateral shifting of vehicular load at the front suspension systems on the basis of a first lateral acceleration monitored by the first lateral acceleration sensor, and a lateral shifting of the vehicular load at a rear suspension system on the basis of a second lateral acceleration monitored by the second lateral acceleration sensor. Control for front and rear suspension systems is performed independently on the basis of the lateral load shifting at the front and rear suspension systems.

Suspension control system with variable steering characteristics

An actively controlled suspension system employs a lateral acceleration sensor for monitoring lateral acceleration exerted on the vehicular body. The lateral acceleration is shifted frontwardly from a gravity center of the vehicle body at the neutral position or non-rolling condition. The magnitude of frontward offset of the lateral acceleration sensor is so selected as to cancel influence of phase delay when the lateral acceleration sensor is oriented at the position of the neutral gravity sensor.

Anti-rolling control for actively controlled automobile suspension

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

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

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 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.

Actively controller suspension system for automotive vehicle for

An actively controlled automotive suspension system employs a factor representative of self-induced attitude change creative factor as a correction factor in attitude regulating suspension control. Suspension characteristics is controlled on the basis of rolling and/or pitching energy representing parameter. The correction factor representative of self-induced attitude change is derived on the basis of vehicular attitude change velocity for canceling the self-induced rolling and/or pitching. By canceling the self-induced rolling and/or pitching creative component from the rolling and/or pitching acceleration factor, higher rolling and/or pitching response characteristics can be provided so as to satisfactory high driving stability and riding comfort.

Actively controlled automotive suspension system with acceleration and

A suspension control system for an automotive vehicle is designed for effectively suppressing pitching motion and whereby regulating vehicular attitude. The suspension control system monitors pitching moment to be exerted on the vehicle for adjusting response characteristics in pitching-suppressive control depending upon the magnitude of the pitching moment to be exerted. The suspension control system adjusts the response characteristics of the front and rear suspensions independently of each other according to preset pitching-suppressive control coefficients respectively for the front and rear suspensions, which are set depending upon the suspension characteristics and/or suspension geometory of the vehicle, to which the suspension control system is to be applied.

Acitively controlled automotive suspension system with adjustable

An actively controlled suspension system includes an anti-roll control loop which is responsive to lateral acceleration to be exerted on a vehicle, to adjust suspension characteristics. The control loop employed suspension system is variable of response characteristics to vehicular rolling depending upon the vehicle speed for varying anti-rolling suspension control characteristics. In a range of the vehicle speed, in which the greater loop gain of the control loop, causes significant and unacceptable level of self-induced lateral vibration, the gain is varied to be the smaller value than that in other vehicle speed range. Namely, since the greater gain may affect for causing self-induced lateral vibration in substantially low vehicle speed range, the gain may be adjusted to smaller value while vehicle speed is lower than a given value.

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Kanagawa, Japan

Masaharu Satoh