Vibration isolation of a feedback linearized model for a contactless Electromagnetic Isolator by Virtually Varying Mass control

Two active vibration isolation methods, Virtually Increasing Mass (VIM) control and On-Off Mass (OOM) control, based on absolute acceleration feedback are proposed for a contactless Electro-Magnetic Isolator (EMI) being designed for heavy payload. They are applied to a stabilized feedback-linearized model for the vertical DOF of a candidate EMI design. The control objectives of this application are seeking, vibration isolation and force disturbance rejection. The vibration isolation performance (transmissibility) up to 1000 [Hz] is evaluated by simulation with both white noise vibrations and sweep sine vibrations. Simulation shows that the transmissibility magnitude peak is shifted to lower frequency by the proposed vibration isolation methods. The high-frequency nonlinear behaviors are analyzed. Besides, the step response to a constant force disturbance is not compromised and the seeking performance is acceptable. Above all the simulation results, the proposed control methods are feasible for the presented application.