Magnetic recording disk drive with three sensors for rotational and linear vibration compensation

Abstract

A magnetic recording disk drive has three vibration sensors mounted to the disk drive base to provide feedforward vibration compensation signals. First and second spaced-apart sensors are aligned generally parallel to a radius from the disk rotational axis to a head position on the disk between the inside diameter position (h) and outside diameter position (h) for detecting rotational vibration about the disk rotational axis and linear vibration in the cross-track direction. A third vibration sensor is aligned generally orthogonal to the primary axes of the first and second vibration sensors for detecting primarily linear vibrations in the along-the-track or track circumferential direction. The disk drive servo control processor calculates, from the signals from the three sensors, a rotational vibration feedforward signal, a radial linear vibration feedforward signal, and a circumferential linear vibration feedforward signal which are summed with the actuator control signal to compensate for the vibrations.