Design of Tuneable Damping for Precision Positioning of a Two-Body System

Abstract

Mechanical decoupling poses a limit to the achievable positioning precision of a two-body system actuated by a single Lorentz actuator. To control such a system, the damping between the two bodies needs to be adjusted to a trade-off value, which allows both high control bandwidth of the directly actuated body and good isolation from environmental vibration. In this paper, hydraulic shock absorbers are employed to tune the damping. An experimental setup of a two-body system is built, with the shock absorbers mounted between the bodies. A higher level of damping of the decoupling mode is observed by using fluids with higher dynamic viscosity. The effectiveness of the proposed solution is confirmed by comparing the theoretical and experimental values of the damping coefficient for different values of the dynamic viscosity.