Patent attributes
In a suspension system for a vehicle, a suspension spring, an absorber for controllably changing the damping coefficient becoming the reference of amount of its own generating damping force, a displacement force generator for controllably generating a displacement force are arranged in parallel between sprung and unsprung members. A vibration damping control is executed based on a so-called skyhook damper theory by utilizing the displacement force. In execution of the vibration damping control, when a sign of sprung-member absolute velocity Vu and a sign of sprung/unsprung-members velocity difference ΔV are the same to each other, a damping-coefficient increasing control is executed to set a target damping coefficient C* of the absorber to a coefficient value C2 that is larger than a coefficient value C1 to which the target damping coefficient C* is set when the sign of sprung-member absolute velocity Vu and the sign of sprung/unsprung-members velocity difference ΔV are different from each other. Vibration of the sprung member can be effectively damped by cooperation of the absorber and the displacement force generator.
