Patent ID: 8041479
Filing Date: 2011-10-18
Classification: B60G,Y10S

Abstract:
1. A suspension system for a vehicle, comprising: (a) a suspension spring disposed between sprung and unsprung members of the vehicle; (b) a shock absorber disposed in parallel with said suspension spring; and (c) a displacement force generator disposed in parallel with said suspension spring and operable to generate a displacement force forcing the sprung and unsprung members to be displaced toward or away from each other, wherein said displacement force generator includes an elastic body connected at one of opposite end portions thereof to one of the sprung and unsprung members and an electrically-operated actuator disposed between the other of said opposite end portions of said elastic body and the other of the sprung and unsprung members and interconnecting said elastic body and the other of the sprung and unsprung members, and wherein said electrically-operated actuator includes an electric motor, and is operable to generate an actuator force based on a motor force generated by said electric motor, such that the generated actuator force acts on said elastic body so as to change an amount of deformation of said elastic body that is dependent on an amount of actuation of said actuator and such that the generated actuator force is transmitted to the sprung and unsprung members via said elastic body so as to act as the displacement force, said suspension system further comprising: (d) a displacement force controller operable to control operation of said electric motor so as to control the displacement force that is to be generated by said displacement force generator, wherein said displacement force controller performs a damping-force control for controlling the displacement force as a damping force for damping vibration of at least one of the sprung and unsprung members, wherein said displacement force controller determines, based on a target magnitude of the displacement force that is to be generated by said displacement force generator, a target amount of an electric power that is to be supplied to said electric motor of said actuator of said displacement force generator, wherein said displacement force controller performs the damping-force control based on the determined target amount of the electric power, and wherein said displacement force controller performs the damping-force control, by allowing supply of the target amount of the electric power from an electric power source to said electric motor in a process of increasing a target actuation amount defined as an amount of actuation of said actuator that corresponds to the target magnitude of the displacement force, while inhibiting supply of the electric power from said electric power source to said electric motor in a process of reduction in the target actuation amount.