Method of data compression and apparatus for its use in monitoring machinery
First Claim
1. A method for monitoring machinery comprising the steps of:
- a. collecting sensor signals from said machinery, said sensor signals each having a time stamp;
b. converting said sensor signals into digital time domain data;
c. transforming said digital time domain data into frequency domain data, which both together comprise processed data;
d. comparing said processed data against alarm threshold values to determine an alarm condition;
e. forming data records of said processed data and said time stamps;
f. comparing said processed data to data retention rules which increase the density of data storable as said sensor signals approach said alarm threshold;
g. storing said data records in memory storage means; and
h. selectively removing certain of said stored data records in order to permit greater spacing between data records of lower level signals than that of higher level signals.
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Accused Products
Abstract
The present invention relates to a method and apparatus for monitoring machinery in which data is collected and stored based on application specific retention rules. Based on an alarm value, data records are adjusted by reducing the spectral resolution, coefficient precision and time intervals between records. An alarm is activated when the data value is greater than a predetermined alarm threshold value. Memory management can compare the memory availability to projected requirements. If the projected memory requirements exceeds memory availability, the data records can be interactively decimated. When decimation cannot make available sufficient memory for projected requirements within the retention rules, an alarm is issued. Collected data can be transferred with a removable nonvolatile memory or infrared communications with a computer device.
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Citations
24 Claims
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1. A method for monitoring machinery comprising the steps of:
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a. collecting sensor signals from said machinery, said sensor signals each having a time stamp; b. converting said sensor signals into digital time domain data; c. transforming said digital time domain data into frequency domain data, which both together comprise processed data; d. comparing said processed data against alarm threshold values to determine an alarm condition; e. forming data records of said processed data and said time stamps; f. comparing said processed data to data retention rules which increase the density of data storable as said sensor signals approach said alarm threshold; g. storing said data records in memory storage means; and h. selectively removing certain of said stored data records in order to permit greater spacing between data records of lower level signals than that of higher level signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for managing memory in a monitoring system comprising the steps of:
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determining a series of data records containing said processed data; determining a daily average of said data records; storing said daily average of said data records in accordance with a predetermined time interval determined by a set of retention rules, wherein said retention rules which increase the density of data storable as said data records approach an alarm value are based on a comparison of the value of said series of data records to said alarm value. - View Dependent Claims (16, 17, 18)
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19. An apparatus for monitoring machinery comprising:
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sensor means attached to said machinery for providing sensor signals; means for converting said sensor signals into digital time domain data; digital processing means for converting said time domain data into processed data; means for comparing said processed data to an alarm threshold to determine an alarm condition; means for creating a data record of said processed data; means for adjusting said data record in accordance with a set of retention criteria corresponding to said alarm band; means for comparing the memory availability, MAj, of said storage means against a projected memory requirement PRj and deleting certain of said stored data records; and means for issuing an alarm when said memory availability is less than said projected memory requirement, PRj. - View Dependent Claims (20, 21, 22, 23, 24)
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Specification