Adaptive feedback control method for active vibration isolation based on on-line frequencies estimation

As the adaptive feedforward control method used for active control of periodic vibration has many shortcomings, an adaptive feedback control method was proposed based on on-line frequency estimation. The vibration disturbance was recovered with the error signal, and the frequencies of periodic components in disturbance were estimated using cascaded adaptive notch filters, whose parameters were adjusted with recursive least mean square algorithm. Reference signals were produced at the estimated frequencies as controller inputs, and controller weights were adjusted based on Lyapunov stability theory. Simulation and experimental results show the frequency estimation method has good estimation accuracy, the adaptive feedback control method can gain over 16 dB vibration isolation at the vibration frequency, and the controller parameters adjustment is fast.