Tracking Control of a Maglev Vibration Isolation System Based on a High-Precision Relative Position and Attitude Model

Abstract

The maglev vibration isolation system exhibits excellent micro-vibration isolation performance (0.01 Hz to 100 Hz band) in the space environment. However, a collision between the base and the floating platform may occur in an ultra-low frequency range (≤0.01 Hz). To avoid collision, the relative position and attitude between the base and the floating platform needs to be accurately tracked and controlled. In this study, a novel measurement method with four groups of two-dimensional position-sensitive detectors equipped with four laser light sources was proposed. A high-precision relative position and attitude measurement model was established based on the geometric relationship of space coordinates. A proportional-differential (PD) fixed-point control algorithm was adopted to realize tracking control. The control performance of the system was evaluated through simulation. Experiments were also carried out to verify the stability of the system and the precision of the control algorithm. A maglev vibration isolation system prototype was constructed and a test system was established. The proposed relative position and attitude measurement model was verified and the six degrees of freedom relative position and attitude response of the system was tested. Based on the measurement model, the tracking control of the system was proven to have high precision.

Analysis of the requirements for microaccelerations and the design appearance of a small spacecraft for technological purposes

“…[6,7]) and graphs of the desired and achievable values of microaccelerations (Figures 1-3), which are available in the literature [8][9][10][11][12][13][14][15][16][17][18]. MGIM on the MIR space station [14]; c) at ISS [15]; d) MAIS on Tiangong-2 [16]; e) MAIS on Tiangong [17] Numerous studies (for example, [1,3,9,13,14,[19][20][21][22]) show that during directed crystallization, the field of microaccelerations of the internal environment of the spacecraft creates motion of convective type. They contribute to the capture of non-metallic impurities in melts and the formation of several crystallization centers.…”

Design and Analysis of a 2-DOF Electromagnetic Actuator with an Improved Halbach Array for the Magnetic Suspension Platform

“…Without physical contact, the vibration of the base cannot be directly transmitted to the object, which is an effective approach to the isolation of micro-vibration in space [ 11 , 12 , 13 ]. It restricts the performance improvement for the vibration isolation platforms with multiple single DOF electromagnetic actuators due to the large size and mass, complex structure and control system, difficulty to miniaturize and compact [ 14 , 15 ]. While the 2-DOF electromagnetic actuators have obvious merits in the system cost and weight, layout optimization, and so on [ 16 , 17 , 18 ].…”

Design of Active Vibration Isolation Controller with Disturbance Observer-Based Linear Quadratic Regulator for Optical Reference Cavities

“…Wang et al designed an active vibration isolation system with multiple degrees of freedom based on three isolators and achieved an average attenuation rate of 94.8% in three directions using sky-hook damping with absolute velocity feedback [ 21 ]. Wu et al designed a separated maglev vibration isolation system, achieving a high-accuracy displacement and attitude control by measuring four groups of two-dimensional position sensors and four laser sources and using proportional derivative (PD) tracking control [ 22 ]. Beijen et al designed an active vibration isolator with a Steward platform; they used the filtered-error least mean squares (FeLMS) algorithm to design the feedforward controller and experimentally demonstrated vibration suppression under the isolator up to 40 dB at 2–300 Hz [ 23 ].…”