Considering Operating Point Variation in 3-D Analytical Charge Model Used for Design of Low-Stiffness Permanent Magnet Vibration Isolator

Vibration isolators are a key technology in ultraprecision machining and ultraprecision measurements. The increasing performance requirements of magnetic vibration isolation systems (MVISs) continue to demand improvements in the accuracy on which these devices are modeled. However, a serious constraint exists in designing MVISs, as high stiffnesses will be introduced by nonlinear force-displacement characteristics. The traditional analytic magnetic charge model assumes that the relative magnetic permeability \mu _{r} = 1, which causes the accuracy of the magnetic analytic model of the MVIS to decrease. To solve this defect, in this article, low-stiffness MVISs are designed by using the three-dimensional analytic magnetic charge model while considering the variations of the operating point. The optimized parameters of the MVIS are then obtained by combining the genetic algorithm. The feasibility of the proposed analytical charge method is verified from the results of experimental measurements and finite-element methods. The results of this article provide a powerful tool for the design of a high-performance MVIS and provide important support for the ultimate goal of ultraprecision machining and measurements.