Abstract: Touchdown between a read/write head of disk drive and a recording medium is detected based on the variance in the frequency domain of position error signals (PES), each of which is measured after incrementally positioning the read/write head closer to the recording medium, from a baseline PES. The synchronous portion of the baseline PES is quantified and removed from the baseline PES and subsequent PES measurements to remove the effect of the synchronous portion of the baseline PES. The non-synchronous portion of the PES measured at a particular read/write head position may also be removed by synchronously averaging multiple PES measurements for each read/write head position. Detection of touchdown may be based on the rate of change of the variance in the frequency domain of PES relative to a baseline PES, instead of the absolute value of the variance.

Abstract: Touchdown between a read/write head of disk drive and a recording medium is detected based on the variance in the frequency domain of position error signals (PES), each of which is measured after incrementally positioning the read/write head closer to the recording medium, from a baseline PES. The synchronous portion of the baseline PES is quantified and removed from the baseline PES and subsequent PES measurements to remove the effect of the synchronous portion of the baseline PES. The non-synchronous portion of the PES measured at a particular read/write head position may also be removed by synchronously averaging multiple PES measurements for each read/write head position. Detection of touchdown may be based on the rate of change of the variance in the frequency domain of PES relative to a baseline PES, instead of the absolute value of the variance.

Abstract: Touchdown between a read/write head of disk drive and a recording medium is detected based on the variance in the frequency domain of position error signals (PES), each of which is measured after incrementally positioning the read/write head closer to the recording medium, from a baseline PES. The synchronous portion of the baseline PES is quantified and removed from the baseline PES and subsequent PES measurements to remove the effect of the synchronous portion of the baseline PES. The non-synchronous portion of the PES measured at a particular read/write head position may also be removed by synchronously averaging multiple PES measurements for each read/write head position. Detection of touchdown may be based on the rate of change of the variance in the frequency domain of PES relative to a baseline PES, instead of the absolute value of the variance.

Abstract: Touchdown between a read/write head of disk drive and a recording medium is detected based on the variance in the frequency domain of position error signals (PES), each of which is measured after incrementally positioning the read/write head closer to the recording medium, from a baseline PES. The synchronous portion of the baseline PES is quantified and removed from the baseline PES and subsequent PES measurements to remove the effect of the synchronous portion of the baseline PES. The non-synchronous portion of the PES measured at a particular read/write head position may also be removed by synchronously averaging multiple PES measurements for each read/write head position. Detection of touchdown may be based on the rate of change of the variance in the frequency domain of PES relative to a baseline PES, instead of the absolute value of the variance.

Abstract: Touchdown is detected between an R/W head and disk by determining the variance in the frequency domain of a baseline position error signal (PES) and a PES measured after incrementally increasing the DFH control signal. To quantify the variance in the frequency domain, a discrete Fourier transform of the baseline PES and of each PES produced for a given DFH control signal is used. A band-limited PES variance is used to improve touchdown detection, but is not a requirement of this method.

Abstract: Touchdown between a read/write head of disk drive and a recording medium is detected based on the variance in the frequency domain of position error signals (PES), each of which is measured after incrementally positioning the read/write head closer to the recording medium, from a baseline PES. The synchronous portion of the baseline PES is quantified and removed from the baseline PES and subsequent PES measurements to remove the effect of the synchronous portion of the baseline PES. The non-synchronous portion of the PES measured at a particular read/write head position may also be removed by synchronously averaging multiple PES measurements for each read/write head position. Detection of touchdown may be based on the rate of change of the variance in the frequency domain of PES relative to a baseline PES, instead of the absolute value of the variance.

Abstract: Touchdown between a read/write head of disk drive and a recording medium is detected based on the variance in the frequency domain of position error signals (PES), each of which is measured after incrementally positioning the read/write head closer to the recording medium, from a baseline PES. The synchronous portion of the baseline PES is quantified and removed from the baseline PES and subsequent PES measurements to remove the effect of the synchronous portion of the baseline PES. The non-synchronous portion of the PES measured at a particular read/write head position may also be removed by synchronously averaging multiple PES measurements for each read/write head position. Detection of touchdown may be based on the rate of change of the variance in the frequency domain of PES relative to a baseline PES, instead of the absolute value of the variance.

Abstract: Touchdown is detected between an R/W head and disk by determining the variance in the frequency domain of a baseline position error signal (PES) and a PES measured after incrementally increasing the DFH control signal. To quantify the variance in the frequency domain, a discrete Fourier transform of the baseline PES and of each PES produced for a given DFH control signal is used. A band-limited PES variance is used to improve touchdown detection, but is not a requirement of this method.

Abstract: Touchdown is detected between an R/W head and disk by determining the variance in the frequency domain of a baseline position error signal (PES) and a PES measured after incrementally increasing the DFH control signal. To quantify the variance in the frequency domain, a discrete Fourier transform of the baseline PES and of each PES produced for a given DFH control signal is used. A band-limited PES variance is used to improve touchdown detection, but is not a requirement of this method.