Decentralized position and attitude control of a vibration isolation system

Considers position and attitude control of an active vibration isolation system, which is composed of a rigid platform and supporting air springs. For isolation of the vibration from the floor, the springs should be of high compliance. However, high compliance deteriorates the positioning properties. To solve such a contradictory problem, the paper proposes to apply H_∞ control. Low compliance is achieved in the low frequency range for accurate position and attitude control of the platform, and high compliance is preserved in the high frequency range for vibration isolation. Since there are strongly coupled parts in the dynamics of position and attitude with six degrees of freedom, a decentralized control scheme compatible with the strong coupling is employed