Electromagnetic Actuator Based on Perpendicularly Magnetized Magnetic Ring Array for Large-Scale Precision Vibration Isolation

Purpose: A perpendicularly magnetized electromagnetic negative stiffness actuator (PMENSA) is introduced to generate tunable negative stiffness. It incorporates multiple layers of magnetic rings aligned axially and magnetized perpendicularly, amplifying the magnetic field. Its tunable negative stiffness is achieved by the modulation of current in coils, enabling it to adapt to variations in load mass and tune its natural frequency in response to different excitation frequencies, thereby enhancing vibration isolation. Methods: A theoretical model has been developed and successfully validated through simulations, and a multi-objective optimization method based on genetic algorithms is employed to refine structural parameters. Results and Conclusions: Experimental results confirm that PMENSA with a current of 1 A significantly reduces the natural frequency of vibration isolation from 3 to 1.375 Hz, and the peak vibration transmissibility experiences a notable decrease of 13.41 dB, representing a substantial 46.4% reduction. This performance underscores the potential applications of PMENSA in fields such as advanced lithography, space cameras and other sophisticated scientific experimental systems.