Modeling and Control of a Six Degrees of Freedom Maglev Vibration Isolation System.

Bilong Liu,Hongbo Zhang,Qianqian Wu,Sifang Zhao,Ning Cui

doi:10.3390/s19163608

Abstract

The environment in space provides favorable conditions for space missions. However, low frequency vibration poses a great challenge to high sensitivity equipment, resulting in performance degradation of sensitive systems. Due to the ever-increasing requirements to protect sensitive payloads, there is a pressing need for micro-vibration suppression. This paper deals with the modeling and control of a maglev vibration isolation system. A high-precision nonlinear dynamic model with six degrees of freedom was derived, which contains the mathematical model of Lorentz actuators and umbilical cables. Regarding the system performance, a double closed-loop control strategy was proposed, and a sliding mode control algorithm was adopted to improve the vibration isolation performance. A simulation program of the system was developed in a MATLAB environment. A vibration isolation performance in the frequency range of 0.01–100 Hz and a tracking performance below 0.01 Hz were obtained. In order to verify the nonlinear dynamic model and the isolation performance, a principle prototype of the maglev isolation system equipped with accelerometers and position sensors was developed for the experiments. By comparing the simulation results and the experiment results, the nonlinear dynamic model of the maglev vibration isolation system was verified and the control strategy of the system was proved to be highly effective.

Highlights

Disturbances with different acceleration levels in a near-vacuum environment have significant effects on space missions [1,2,3,4]
The Lorentz actuator is ideal for isolating micro-vibration because of its non-contacting and linear characteristics, which have been successfully applied in satellites, spacecraft, and space stations [16,17]
A maglev vibration isolation platform with six DOF was studied in the paper

Summary

Introduction

Disturbances with different acceleration levels in a near-vacuum environment have significant effects on space missions [1,2,3,4]. A passive vibration isolation technique can provide sufficient attenuation of vibration disturbances in the high frequency range, it is not effective for isolating vibration with low and ultra-low frequencies [8,9]. Low frequency vibration cannot be isolated by these above actuators. Piezoelectric actuators are widely used in space and ground environments, but it has been proven that the piezoelectric actuator performs poorly in a frequency range below 5 Hz [13,14,15]. The Lorentz actuator is ideal for isolating micro-vibration because of its non-contacting and linear characteristics, which have been successfully applied in satellites, spacecraft, and space stations [16,17].

Objectives

Methods

Findings

Conclusion