Active noise control using piezoelectric actuators in hard disk drives

With the increasing use of electromechanical microsystems, such as hard disk drives, CD-ROM drives, and DVD drives in the consumer electronics industry, there is a growing demand for quieter products. The noise emitted from these devices may originate from the vibration of mechanical components in operation, such as bearings, gears, and actuators. The vibration is then transmitted to other parts of the device, such as the covers, and the noise emitted may then be amplified. The objective of this article is to find a way to control seek noise in hard disk drives. Piezoelectric actuators are attached to the cover, which are used to excite the cover and suppress noise transmission of the cover of hard disk drives. A controller feedback of vibration observes through piezoelectric sensors and adjusts the voltage inputs to the actuators to minimize the radiated sound level. To get the optimal piezoelectric actuator location, genetic algorithms with immune diversity are adopted. Numerical results show that piezoelectric actuators can be effective for reducing seek noise.