ACTIVE SUSPENSION SYSTEM WITH CONTROL TO CHANGE VARIATION IN PRESSURE OF WORKING FLUID CYLINDER BETWEEN INCREASE AND DECREASE THEREOF

摘要

An active suspension control system includes working fluid cylinders which are respectively disposed between a vehicle body and suspension members which support road wheels rotatably. The working fluid cylinder includes a piston slidably arranged therein for adjusting a relative distance between the vehicle body and the suspension member to suppress vehicle attitude change. The system includes a pressure control unit which is responsive to vehicle attitude change to control fluid pressure to be supplied to the working fluid cylinders to cause the piston to slide such that an increase in the fluid pressure is provided which is lower than a decrease in the fluid pressure. This restricts friction, caused by fluid pressure elevation in the working fluid cylinder, created between the piston and a seal ring to allow the piston to move smoothly.