A microgravity isolation mount

Abstract

In this paper we discuss the design and preliminary testing of a system for isolating microgravity sensitive payloads from spacecraft vibrational and impulsive disturbances.The Microgravity Isolation Mount (MGIM) concept consists of a platform which floats almost freely within a limited volume inside the spacecraft, but which is constrained to follow the spacecraft in the long term by means of very weak springs.The springs are realised magnetically and form part of a six degree of freedom active magnetic suspension system.The latter operates without any physical contact between the spacecraft and the platform itself.Power and data transfer is also performed by contactless means. Specifications are given for the expected level of input disturbances and the tolerable level of platform acceleration.The structural configuration of the mount is discussed and the design of the principal elements, i.e. actuators, sensors, control loops and power/data transfer devices are described.Finally we describe the construction of a hardware model that is being used to verify the predicted performance of the MGIM.

Dynamic characteristics modeling of rotary platform installed on board of a small spacecraft

“…Later, the Vibration Isolation Mounting System was developed on the basis of the Microgravity Isolation Mount [13]. It became the basis for the Microgravity Vibration Isolation Subsystem which is part of the Fluid Science Laboratory [14].…”

Active Controller Design for Microgravity Isolation Systems

“…Grodsinsky and Whorton [7] reported a detailed survey and related discussions. Therefore, a number of researchers are working on the development of active control systems to ensure a proper acceleration environment [9,10,17]. Jones et al have presented a conservative estimate of the frequency spectrum of acceleration levels found on a spacecraft (Fig.…”

“…Jones et al [10] have developed an active microgravity isolation mount using a Lorentz type of electromagnetic actuator. Their controller is based on the classical phase lead/lag compensator and utilizes the displacement of the mass relative to the base as feedback signal because the absolute displacement of the controlled mass cannot be directly measured.…”