Two-axis Lorentz actuator for active vibration isolation system in optical payloads

Abstract

Active vibration isolation systems (AVISs) equipped with Lorentz actuators are utilized in diverse sectors to minimize vibrations transmitted to delicate payloads by offering controlled stiffness and damping. Traditional actuators in AVISs, however, are confined to a single degree of freedom (DOF). This implies that a higher number of these types of actuators is necessary to achieve vibration isolation across all six DOF in an AVIS. Consequently, this can amplify assembly errors and prolong response times, thereby compromising system performance. They also present challenges related to thrust, weight, and heat dissipation. This paper delves into the design, modeling, optimization, and validation of an innovative 6-DOF AVIS which can apply various payloads to generate various displacements and performs consistently over a range of payloads. The main feature of the proposed system is its two-axis Lorentz actuator (TALA). With identical configurations for both axes, the TALA facilitates 2-DOF in-plane motion with mutual decoupling, a novel feature in AVISs, to the best of our knowledge. Moreover, through a parametric design strategy and multi-objective optimization, it achieves a superior force constant, reduced coil weight, and minimized heat dissipation. Results from the proposed AVIS underscore its promise as a versatile tool for ultraprecision measurement instruments, including atomic force microscopes, scanning probe microscopes, and optical payloads.