Position error predictions of a hard disk drive undergoing a large seeking motion with shock excitations

In this digest, we present a numerical simulation to predict position errors of a hard disk drive undergoing a long seeking-and-settling process while experiencing a shock excitation. The seeking-and-settling process consists of four segments: acceleration, coasting, deceleration, and settling. A 2-ms shock excitation is applied to each segment of the seeking-and-settling process respectively to evaluate the severity of the shock excitations to position errors. Simulation results lead to two significant conclusions. First, shock excitations occurring near the end of the seeking-and-settling process are more detrimental causing larger position errors. Second, the ability to rapidly reduce the position errors relies on performance and properties of fluid-dynamic spindle motors.