Patent ID: 7826170

Claim:
A hard disk drive control module comprising: a feed-forward signal input port communicatively coupled with a reference model; a tracking error signal input port communicatively coupled with a magnetic transducer of said hard disk drive; an error calculator module configured for determining a difference between an estimated tracking error signal in response to a first feed-forward signal and an actual tracking error signal of said magnetic transducer in response to said first feed-forward signal, said error calculator comprising: a feed-forward signal double integrator configured for double integrating and filtering said first feed-forward signal during seeking and settling of a magnetic transducer, resulting in an estimated position of said magnetic transducer; a gain difference calculator configured for calculating a gain error from said double integrated and filtered first feed-forward signal, after seeking and settling of said magnetic transducer are completed based on said first feed-forward signal; and a phase difference calculator configured for calculating a phase error from said double integrated and filtered first feed-forward signal, after seeking and settling of said magnetic transducer are completed based on said first feed-forward signal; a feed-forward signal adjuster module configured for adjusting a gain and a phase for a second feed-forward signal based on said difference between said estimated tracking error signal in response to said first feed-forward signal and said actual tracking error signal of said magnetic transducer; a feed-forward signal adjustment output port communicatively coupled to said second feed-forward signal; an error comparator configured for comparing said gain error and said phase error from said double integrated and filtered first feed-forward signal, to an estimated tracking error waveform due to gain error and an estimated tracking error waveform due to phase error; a gain summation node configured for adding said gain error to a gain of said second feed-forward signal, based on a comparison performed by said error comparator; and a phase summation node configured for adding said phase error to a phase of said second feed-forward signal, based on a comparison performed by said error comparator.