2001 Volume 67 Issue 663 Pages 3437-3444
Fast seeking in magnetic disk drives leads to residual vibration due to the mechanical resonance of the positioning system. We have therefore developed a two degree of freedom control algorithm that overcomes this problem. It has three main features. First, it generates a seeking trajectory that does not excite the primary resonance of the head actuator. Second, it calculates acceleration feed forward that assures the perfect tracking to the desired trajectory at position sampling (PTC : Perfect Tracking Control). Third, it modifies the target position trajectory, in order to reduce the modeling error, by taking into account digital control and a primary mechanical resonance. We confirmed by simulation and experiment that the control algorithm improves the track settling performance by reducing the vibration due to both the primary mechanical resonance of the head access mechanism and the slow transient response induced by tracking error in the target position trajectory. It was found that the one track seek time of a drive controlled by the algorithm is 15% faster than the conventional time.