| Hard disk drive track widths of 1 ;A magnetic hard disk drive was subjected to a number of different external vibrations tests: rotational about the center of the actuator pivot and translational in the x, y, and z directions. For a 10 tap adaptive FIR controller, experimental results display 15 dB attenuation and 89% reduction in the variance of the position error signal for the random external rotational disturbance. Similar performances were obtained in the x and y directions; while in the z direction, 15 dB attenuation and 53% reduction in the variance of the position error signal were experimentally verify for a random external disturbance. The rates of convergence of the FIR filter parameters averaged approximately 50 msec.;The hard disk drive was also subjected to external shocks about the center of rotation of the actuator bearing. Half sine waves of 3 rad/sec;Overall, the adaptive accelerometer control scheme successfully reduced the effects of external vibrations and shocks on the hard disk drive. Under these external disturbances, the hard disk drive was not able to read nor write without the utilization of the micromachined accelerometer based adaptive control scheme. |
