4. Technical approach to enable autonomous assessment of the condition
Concluding the previous illustration of necessary methods and tools, the case of offshore wind turbines shows
what a particular technical solution could look like, if the previous process were implemented. The fundamental
basis, depending on condition monitoring, is the mining of relevant information from data that is related to
maintenance. It has to be stored in an on-line database for the further use. The following Fig. 1 illustrates some
possible sources using the example of wind energy and the process of data acquisition to enable unique access.
Regarding typical data warehouse applications, data from different sources aren't in general processed before being
stored in the data warehouse. The reports that are received later are responsible for transforming data into
information. Contrarily, the maintenance application, in particular in the context of condition monitoring, has a
given storage of time series. This means, that all data from sensors, ERP-systems, weather stations, etc. have to be
preprocessed to represent a tuple of key-value-pairs that consist of a time stamp and a value, e.g. a measurement, a
document, binary data, etc. The architecture follows basic principles of the architecture of the so called “Internet of
Things” applications or “Sensor Clouds”.
Fig. 1. Data mining and processing.
Marco Lewandowski and Stephan Oelker / Procedia Technology 15 ( 2014 ) 333 – 340 339
Based on the unique access of time-related data, the processing of data into information will be supported by a
wide range of methods and tools. Software services are necessary to assess the condition, trigger measures and
assign a priority based on the technical circumstances. Fig. 2 illustrates a concrete software-based architecture,
which supports this challenge with a collection of methodologies and techniques for processing the data into
information. Classification or forecast results will then be compared and arranged in order to calculate a priority.
Fig. 2. Software-based architecture for priority building.
Both previous steps enable the considered technical systems to follow their individual goal, which represents the
operation in good condition. As measures are necessary to achieve these goals, the technical systems gain the ability
to cooperate with other entities of the maintenance system in order to follow the common goal of sustainable
operation of entire wind parks