Data processing: measuring – calibrating – or testing – Measurement system – Statistical measurement
Reexamination Certificate
2001-12-04
2004-04-27
Wachsman, Hal (Department: 2857)
Data processing: measuring, calibrating, or testing
Measurement system
Statistical measurement
C702S183000
Reexamination Certificate
active
06728658
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This application relates to the field of vibration analysis and more particularly to performing vibration analysis for the purpose of device monitoring.
2. Description of Related Art
The transmission of power to rotors which propel helicopters and other shafts that propel devices within the aircraft induce vibrations in the supporting structure. The vibrations occur at frequencies that correspond to the shaft rotation rate, mesh rate, bearing passing frequency, and harmonics thereof. The vibration is associated with transmission error (TE). Increased levels of TE are associated with transmission failure. Similar types of vibrations are produced by transmissions in fixed installations as well.
Parts, such as those that may be included in a helicopter transmission, may be replaced in accordance with a predetermined maintenance and parts replacement schedule. These schedules provide for replacement of parts prior to failure. The replacement schedules may indicate replacement time intervals that are too aggressive resulting in needless replacement of working parts. This may result in incurring unnecessary costs as airplane parts are expensive. Additionally, new equipment may have installed faulty or defective parts that may fail prematurely.
Thus it may be desirable to provide for an efficient technique for detecting part and device degradation without unnecessarily replacing parts. It may be desirable that this technique also provide for problem determination and detection prior to failure.
SUMMARY OF THE INVENTION
In accordance with one aspect of the invention are a method executed in a computer system and a computer program product for determining a health indicator associated with a component. A plurality of health classifications are determined. At least one condition indicator is determined quantifying a characteristic of the component. A probability associated with each of the health classifications is determined. The probability is an estimation that the component is of a particular health classification given the at least one indicator. A determination is made as to which of said health classifications is associated with said component using said probabilities associated with said health classifications for a given set of observed values.
In accordance with another aspect of the invention are a method executed in a computer system and a computer program product for determining a health status of a component. A plurality of condition indicators are selected having a value and each having a corresponding weighing factor, and at least one threshold value defining at least two classifications. A contribution to a health indicator is determined for each of the condition indicators, wherein the determining further comprises, for each of the plurality of indicators: determining which of the at least two classifications the value of each indicator belongs; and determining the contribution to the health indicator by each condition indicator in accordance with a selected one of the at least two classifications and the weighted value. The health indicator is determined in accordance with all contributions by each of the condition indicator values.
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Choate Hall & Stewart
Simmonds Precision Products Inc.
Wachsman Hal
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