Casestudie Breakdown prediction Contell PILOT - Transumo

information of typical frictional behavior (e.g. linear friction vs. non linear friction).
([Sick00], p. 5-7)
Besides these specific knowledge models, there are artificial neural networks. These
networks adopt the general functioning of a human brain. This means that an artificial
neural network has to be trained with sample or historical data in advance, so that it
is able to acquire knowledge. After this training, such a network is able to judge
situations as regular or irregular like a human brain. ([Hagen97], p. 5-6)
As this approach is able to learn on its own due to training data or past behavior, it is
much more flexible, than a predefined knowledge model. 32 Both, knowledge models
and trained artificial neural networks can be used as a knowledge basis for expert
systems, which have the task to decide in an automated way (e.g. [Krems94],
[Heuer97]).
4.3 Current State within the Setting of Measurement Data Analysis
The last section 4.2 already introduced the current state of research within the setting
of machinery condition monitoring, which was faced with similar requirements, like
sensor based temperature monitoring. This section will now focus on settings, in
which analysis of time dependent data is used to detect changes and to predict
upcoming behavior. The main focus lies on a generalized approach from Frank
Daßler, which promises an early prediction of upcoming malfunctions without
additional knowledge of the underlying setting ([Daßler95], p. 8).
4.3.1 Basic Approaches
Basic approaches are based on statistical methods. Descriptive statistical measures
are used to get an aggregated overview of a datasets characterization (e.g. mean). In
addition to that, these measures ease a comparison of different datasets (or different
parts of a dataset) ([Eckey02], p. 41).
Within many settings, time series analysis is applied to measurement data. Its main
task is to discover structures and irregularities within a time sequence. By detecting
structures, the time series analysis is not only able to describe regular behavior but
also to predict the near future. 33 ([Chatfield04] p. 73-105)
32 A detailed description of the functioning of an artificial neural network will be given in section 5.9.2.
33 See section 5.5 for details
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