Damping vibration analysis of a dual-axis precision force sensor based on passive eddy current

Abstract

High precision force sensors usually include flexible structures, which are prone to cause unnecessary mechanical vibrations, due to their low stiffness and high sensitivity. Aimed at the adverse problem, this paper proposes a novel two-degree-of-freedom passive damping system dedicated to the vibration suppression of a dual-axis precision force sensor. The damping system consists of two identical eddy current dampers (ECDs), each of which utilizes a double-layer Halbach-array permanent magnet structure and a middle-layer copper plate to generate a large damping force. Analytical models are established to predict the damping characteristic and dynamic behavior of the sensor system, with further verification through finite element simulation. Experiments are implemented to demonstrate the effectiveness of the damping design to suppress the sensor vibration in comparison with three different configurations (without ECD, with a single ECD, and dual ECDs). The results indicate the excellent damping characteristics of the developed ECD. This feature can be also extended to the vibration suppression of the planar XY positioning stages.