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.

Abstract: 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.

Abstract: An actively controlled suspension system employs a shut-off valve which is responsive to a source pressure dropping below a predetermined level to shut-off communication between a pressure return line for returning the fluid pressure to the pressure source from a hydraulic cylinder. The shut-off valve is disposed in a drain line connecting a drain port of a spool valve assembly and the pressure source. By the presence of the shut-off valve, substantial pressure difference between the hydraulic cylinder side and pressure source side of the spool valve is not created. Therefore, no leakage through the spool valve occurs and whereby the pressure in the hydraulic cylinder can be maintained even when the source pressure becomes substantially low or zero.

Abstract: A hydraulic pressure supply system includes a discharge rate variable fluid pump. The discharge rate of the fluid pump is controlled to vary depending upon the vehicle driving condition. In the control of the discharge rate of the fluid pump, greater discharge rate is ordered while the vehicle is running, than that during vehicle stopping condition.

Abstract: A positively controlled automotive suspension system provides both of driving stability and riding comfort by adjusting damping characteristics of the suspension system according to the driving condition. The suspension system is soften in response to bounding and rebounding shock for effectively absorbing road shock. On the other hand, in response to relative displacement of the vehicle body and road wheel assembly, the suspension system serves for regulating the relative distance and whereby provides sufficient driving stability.

Abstract: A suspension system consists of a suspension rod interposed between a vehicle body side member and a wheel side member to elastically connect them. The suspension rod includes a first elastomeric member connected to the vehicle body side member and defining a first fluid chamber. A second elastomeric member is provided in the suspension rod structure to be connected to the wheel side member, defining a second fluid chamber. The first and second fluid chambers are communicated with each other through a fluid communication passage. An incompressive fluid is filled in the first and second fluid chambers and in the fluid communication passage, thereby constituting a fluid dynamic damper for suppressing resonance vibration of the suspension system.