Method and apparatus for enhanced mechanical signature analysis

A method of analyzing a test magnitude of a test frequency associated with one or more vibrations in an operating test disc drive comprising steps of:

• (a) receiving time domain test data from the operating test disc drive;
• (b) converting the time domain test data into frequency domain test data having test frequencies with associated test magnitudes;
• (c) comparing the frequency domain test data with theoretical disc drive frequency domain data calculated based on characteristics of the test disc drive;
• and
• (d) determining whether a test magnitude of an associated test frequency in the test data is within a predetermined limit.

A method of determining a reference disc drive frequency used in analyzing vibrations in a test disc drive, the method comprising steps of:

• (a) calculating a theoretical disc drive frequency, the theoretical disc drive frequency being a function of electromechanical characteristics of a predetermined class of disc drives of which the test disc drive is a member;
• (b) searching a configuration file of reference disc drive frequency data associated with the predetermined class of disc drives, using the theoretical disc drive frequency;
• and
• (c) identifying a peak magnitude within a predetermined range of frequencies around the theoretical frequency, the peak magnitude corresponding to the reference disc drive frequency.

A computer program product readable by a computing system and encoding a computer program of instructions for executing a computer process for analyzing a test magnitude of a test frequency associated with one or more vibrations in an operating test disc drive, the computer process comprising steps of:

• (a) receiving time domain test data from the operating test disc drive;
• (b) converting the time domain test data into frequency domain test data having test frequencies with associated test magnitudes;
• (c) comparing the frequency domain test data with theoretical disc drive frequency domain data calculated based on characteristics of the test disc drive;
• and
• (d) determining whether a test magnitude of an associated test frequency in the test data is within a predetermined limit.

A disc drive mechanical signature analysis system comprising:

• a test disc drive;
• a reference disc drive data module having frequency domain data for a reference disc drive and operable to calculate theoretical frequencies having peak magnitudes, the theoretical frequencies being used to locate reference disc drive frequencies in a configuration file having reference disc drive frequency data associated with corresponding classes of disc drives;
• and
• means for analyzing vibrations in the disc drive comprising a transducer fastened to an outside surface of the test disc drive, the transducer being operable to detect the vibrations within the operating test disc drive and generate a test data signal.

A mechanical signature analysis system for analyzing frequencies and magnitudes of vibrations in an operating test disc drive, the system comprising:

• a test data acquisition module connected to the test disc drive operable to acquire time domain test data from the test disc drive and convert the time domain test data into frequency domain test data;
• a disc drive data module having frequency domain data for a reference disc drive;
• a failure analysis module connected to the disc drive data module and the test data acquisition module, wherein the failure analysis module has failure limits associated with the reference disc drive frequency domain data and is operable to determine whether the test data are within the failure limits, and generate failure analysis results;
• and
• wherein the disc drive data module is operable to calculate theoretical frequencies having peak magnitudes, the theoretical frequencies being used to locate reference disc drive frequencies in a configuration file having reference disc drive frequency data associated with corresponding classes of disc drives.