Piezoelectric shunt damping for the read/write arm in hard disk driver

To solve the problem that the vibration of the read/write head actuating arm limits the performance improvement of hard disk diver, experimental studies on vibration suppression were performed for read/write head actuating arm using piezoelectric shunt damping technique. Taking account of the inherent structural damping of the arm, the transfer function expression of the system coupled with piezoelectric shunt damping circuit was derived based on the vibration equation and the non-dimensional mechanical impedance equation of shunt circuit. LM-BP artificial neural network was used to build the nonlinear mapping between optimization variables, and optimal frequency tuning parameter and electrical damping ratio in the transfer function were obtained by minimizing the peak value of the transfer function. Piezoelectric shunt circuit with optimized parameters was built and used in vibration suppression tests. The results showed that the transfer function peak value of the first mode of the arm was decreased by about 28.70 dB.