Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An actively controlled suspension system is provided with a fluid pressure device provided between a vehicle body and a suspension member for suspending the vehicle body on the suspension member. The fluid pressure member is variable at least one of damping characteristics and spring characteristics in linear fashion depending upon relative displacement of the vehicle body and the suspension member in bounding and rebounding directions.

Abstract: A suspension system for an automotive vehicle employs a active suspension control feature for actively controlling the suspension characteristics according to the vehicle driving condition. Active suspension control is performed by adjusting offset of a gravity center for adjusting load distribution at respective vehicular wheels. The load distribution is adjusted so that the suspension characteristics can be changed to over-steer characteristics when the vehicle speed demand is higher than a given level so as to allow drift of the vehicle at a corner. In order to assure driving stability, the suspension system is further adjusted to suppress vehicular rolling during drift of the vehicle.

Abstract: A hydraulic cylinder assembly to be used in an actively controlled suspension system includes a built-in pressure accumulator. The pressure accumulator employed in the hydraulic cylinder assembly has a reciprocally movable free piston for dividing a fluid chamber and a pneumatic chamber. The free piston thrustingly moves for establishing pressure balance between the fluid chamber and the pneumatic chamber and, in turn, for establishing pressure balance between the fluid chamber and an associated pressure chamber in the hydraulic cylinder so as to accumulate pressure while the fluid in the associated pressure chamber is compressed and to supply the pressure when the associated pressure chamber expands while absorbing vibration energy exerted between a vehicle body and a suspension member.

Abstract: 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.

Abstract: 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.