Synchronized Modal Control for Active Vibration Isolation.

This paper deals with control methods and the stability of synchronized active control for machinery vibration isolation. It shows that the instability of the coupled control of the multi actuator system is caused by changes in the sensitivity of sensors, gains of actuators and the natural frequencies of the system. To adapt the system to these changes, the modal control method for the rigid body mode of the machine is proposed, through which the transfer functions between the control signals and the residual vibrations can be obtained by one excitation of actuators. The instability of the coupled control and the effectiveness of the modal control are demonstrated experimentally, using a machinery model supported by 4 piezoelectric actuators. Furthermore, applicable frequency ranges of the modal control, coupled control and independnt control of each actuator are clarified by calculating the convergence properties of the experimental model.