Method and apparatus of dual stage servo control for track following in a hard disk drive

A method of controlling a magnetic head to follow a track on a rotating disk surface in a hard disk drive, comprising the steps of:

• a micro-actuator control creating a micro-actuator control signal to stimulate a micro-actuator based upon a micro-actuator direction;
• wherein said magnetic head is positioned near said track by an effect of said micro-actuator and by an effect of a voice coil motor, both included said hard disk drive;
• a voice coil motor control creating a voice coil control signal based upon a voice coil motor direction;
• notch filtering said voice coil control signal to remove at least one significant excitation resonance to create a notch filtered voice coil control signal;
• amplifying said notch filtered voice coil control signal based upon a tuning gain to create a tuned voice coil control signal stimulating said voice coil motor;
• removing a Positional Error Signal (PES) from a track following command to create said micro-actuator direction;
• wherein said PES signal is based upon said effect of said voice coil motor and based upon said effect of said micro-actuator in positioning said magnetic head near said track;
• decoupling feedback filtering said micro-actuator control signal to create a decoupling feedback signal;
• and
• removing said PES and said decoupling feedback signal from said track following command to create said voice coil motor direction.