Active Control of Vibration Isolation System in Vehicle Using Voice Coil Motors

This paper describes active vibration control of a vibration isolation system in a vehicle. The system consists of eight rubber springs which suppor the deadload of a sprung mass and six voice coil motors for vibration control. In order that control force acts not only in the vertical direction but also in the horizontal direction, voice coil motors have been inclined 30°. To avoid mechanical interference among the motors, rubber springs have been inserted between moving coils and the sprung mass. The spring characteristics of the rubber springs and the moving coil masses produce second-order delays. The feedback control of the acceleration of the sprung mass damps the vibration isolation system. Our controllers function as integrators in a lower-frequency region, and in order to compensate the delays, they function as differentiators in a higher-frequency region.