Variable Virtual Spring Constant and Damping Coefficient Control for Electro-Magnetic Suspension With Linear Motor

This paper proposes a linear-actuator-based active-vibration-control method with displacement feedback for an electro-magnetic suspension with a linear motor to reduce sinusoidal disturbance transmissibility. The method controls the spring constant and damping coefficient virtually, ensuring that thrust is proportional to displacement and velocity and that these values can be adjusted to both negative and positive. Therefore, it can cancel the mechanical spring, damping coefficient, and friction. A simulation and experiment were performed to verify the reduction in disturbance transmissibility using a single-degree-of-freedom mode. The experimental results confirmed that the transmissibility can be reduced via the mechanical spring constant.