Nonlinearity of Maglev Actuator and Adaptive Vibration Control Using Improved FxLMS Algorithm

Maglev actuator is excellent for active vibration isolation, with non-contact form, low stiffness and rapid response. However, the actuators nonlinearity has to be restrained by the control algorithm. In this paper, the nonlinearity of maglev actuator was studied through theoretical analysis and experiment. An improved multi-channel FxLMS(filtered-x least mean square) algorithm was proposed, which considers the nonlinearity-induced harmonic frequency as extra line-spectrum excitation to control. Experiments showed that the improved FxLMS algorithm could efficiently compensate the nonlinearity of the actuators, thus had better effect when used in active vibration isolation system with non-linear actuators, compared with the traditional FxLMS method.