Active Maglev Vibration Isolation via a Slim Halbach Array Electromagnetic Actuator

Active vibration isolation via magnetic levitation provides an effective solution to the micro-vibration problem of high-precision satellites. However, limited volume and mass constraints of the satellites demand the active vibration isolation platform to be ultra-compact yet with high thrust density. This paper presents a slim magnetically levitated actuator (thickness < 20 mm) based on modified Halbach bi-array, which intensifies air gap flux density while minimizing flux leakage. An analytical electromagnetic model of the proposed actuator is developed using an infinitesimal current element integration method, enabling accurate and efficient prediction of magnetic field distribution and thrust force. Leveraging the proposed model, an augmented FxLMS adaptive controller is implemented with its secondary path initialized via a physics-based simulation and then refined experimentally through white-noise identification. The experiment verifies that the proposed actuator produces a 11.8 N/A force constant at the nominal position and achieves an averaged 41.73 dB vibration suppression within 5–260 Hz range on a SDOF active vibration isolation platform. These results confirm the great potential of the proposed electromagnetic actuator in micro-vibration control of high-precision satellites.