DIAGNOSTYKA Vol. 15, No. 2 (2014)
Table of contents - SCIENTIFIC PAPERS
Mateusz LISOWSKI, Przemysław GONEK, Tadeusz UHL
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Abstract (EN)
This paper presents the method of wireless passive temperature measurement by using the
battery-free sensing platform based on RFID technology. Described platform serves as an interface
between any sensor and standard RFID reader connected to the host computer. Utilizing the RFID
technology working in high frequency band results in the possibility of providing energy from the
reader to the sensing platform via magnetic coupling between their antennas and wireless data
transmission of the measured data, even in the proximity of metal objects. Investigation related to
the wireless temperature measurements of bearing supporting a rotating shaft are presented in this
paper. Comparison with the measurements performed by using of an infrared camera shows high
compliance of data obtained by using those two methods. The result demonstrates that presented
wireless temperature measurement method could be attractive in many diagnostic purposes.

Jaroslav HOMIŠIN, Peter KAŠŠAY, Pavol ČOPAN
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Abstract (EN)
Extremal control is an optimization performed by experimenting with optimised device directly
during operation. On our department we deal with the extremal control of torsional oscillating
mechanical systems by means of pneumatic flexible shaft couplings. The torsional stiffness of
these couplings and so the natural frequencies of torsional systems can be changed by adjusting the
air pressure in their pneumatic flexible elements. The goal of this article is to confirm, by methods
of technical diagnostics, the possibility of the use of extremal control in a laboratory torsional
oscillating mechanical system built on our department and present the function of an extremal
control algorithm developed by us. The function of extremal control algorithm is presented with a
simulation on a mathematical model of a built laboratory mechanical system.

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Abstract (EN)
In diagnostics of power grids a very important role is played by vision methods. Currently, a relatively
new technique is the use of modern, autonomous devices for images acquisition, which are further
analysed. The paper presents an overall division of power grids, discussion on the most common damages
and effects of failures in these networks. Examples of currently used diagnostic methods of energy
networks are presented and examples resulting from a review of modern vision techniques (methods of
image acquisition and analysis) are listed. However, it can be noticed that there is still a need of further
developing these techniques and striving for automatisaton of the diagnosing process. The paper contains
a description of a concept of diagnostic method of energy networks, which includes the application
(usage) of an autonomous, unmanned aerial vehicle to obtain the data. Some techniques of artificial
intelligence for automated reasoning about the energy networks condition are planned to be applied.

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Abstract (EN)
The article deals with the problem of designing diagnostic systems. During this process it is
possible to use sets of requirements which are very commonly used in the software area. The
requirements may influence both on the set of possible solutions of diagnostic system as also on
the set of criteria which will be used for evaluation of these solutions. Selecting an optimal
solution is not an easy task, especially for given the nature of the diagnostic field. But this process
can be improved by using expert system. Knowledge base of this system, which contains possible
solutions of designed system can be recorded in the form of multimodal statement networks.
During the inference process, it is possible to isolate some subset of preferred solutions. This
process should be carry out based on available information about technical object, operational
conditions and imposed project limitations. The received subset of solutions should be the basis for
further analysis, which leads to get the final solution of a diagnostic system.

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Abstract (EN)
Stability studies, including damage stability and unsinkability of submarines, makes a source of
knowledge about the behavior of the ship after the flooding of the compartments. In order to carry
out research in the Naval Academy the laboratory test bed has been designed and constructed to
allow the position of laboratory immersing and emerging submarine model, enabling simulation
the damage of the hull of the submarine model, and thus better recognition of the phenomena
occurring in the operation of the ship. Brief characterization of failure of ship and submarine
accidents stressing the merits of the subject undertaken have been presented at the article.
Description of the test stand for the research over stability and unsinkability of submarines and of
possibilities of its usage in training of ship managing crew has been presented in the paper.
Presented Preliminary results of experimental tests of immersing and emerging submarine model
have been confirmed the assumption built design of the laboratory.

Agnieszka WYŁOMAŃSKA, Radosław ZIMROZ
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Abstract (EN)
In the paper an automatic procedure for diagnostic signals segmentation is proposed. The
purpose of the procedures is to detect/identify part of the signal, that is related to stationary
operation regime of machine. Detection and parameterization of such events might help to
improve efficiency of machine usage, for example to minimize number of segments and their
duration for machine operation under idle mode or overload mode. It is proposed to use a
procedures that are based on statistical analysis to estimate the critical point of the division in a
structural change in a time series. Two measures have been proposed for critical points detection:
the first one is based on testing of empirical moment of order two for time subseries with length k,
second one is related to analysis of second order moment moving along the signal. These
techniques have been validated using simulations and then applied to real data acquired from on
board monitoring system developed for mobile mining machines (loaders are considered here).
Results of application are discussed in the paper.

Jakub ROEMER, Łukasz PIECZONKA, Tadeusz UHL
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Abstract (EN)
The paper investigates the application of active thermography for nondestructive testing of
welded joints. Two measurements techniques are considered: laser spot thermography and
vibrothermography. Experiments were performed on a welded carbon steel plate with welding
defects. Laser spot thermography was used to reveal welding defects and vibrothermography was
used to provide reference results. Both methods proved to be very effective and their results were
found comparable. In addition, the paper presents a semi-automatic image processing algorithm
used to facilitate laser spot thermography tests. The algorithm combines multiple thermographic
sequences captured during the test and allows for automated damage features extraction. The
algorithm allows to significantly reduce the post processing time and gives a clear information on
the damage state of a material. The paper discusses the operational principles and measurement
setup of both nondestructive testing methods.

Czesław CEMPEL
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Abstract (EN)
TRIZ methodology is a promising innovative tool to obtain various problem solutions, which
are close to so called ideal final result - IFR. There are some introductory papers of present author
like [Skoryna 10],[Cempel 12], [Cempel 14]. But it seems to be a need to make such an approach
from different sides in order to see if some new knowledge and technology will emerge. In doing
this we need at first to define the ideal final result (IFR). As a next we need to define a set of
engineering parameters to describe the problems of vibration condition monitoring (VCM) in
terms of TRIZ parameters, and also a set of inventive principles possible to apply on the way to
IFR. This means we should present the machine VCM problem by means of engineering
descriptive parameters and contradiction matrix of TRIZ. The paper undertakes this important
applicational problem and brings some new insight into system and machine VCM problems. It
follows from the paper that one can find 17 contradictions and use one set of inventive principles
to solve specified contradiction of VCM problem, and also another set of principles to enhance
obtained solution.

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Abstract (EN)
Research of a contact joint between elements fastened in a multi-bolted connection are
presented. The tests were realized with use of the INSTRON 8501 Plus servohydraulic fatigue
testing machine and the original instrumentation performed earlier in the Department of
Mechanics and Fundamentals of Machine Design at the Technical University of Szczecin [1].
A form of the normal stiffness characteristic for the studied contact joint is proposed.

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Abstract (EN)
When constructing the electric vehicle for the Shell Eco-marathon competition in Urban Concept
category , the Smart Power Team had to face the problem of choosing the perfect drivetrain. For this
purpose, two bests concepts were studied. The first concept assumed the use of high-speed BLDC motor
along with belt transmission with toothed belt. The second concept assumed the low-speed BLDC hub
motor. The research was conducted for the MuSHELLka vehicle on the roller dynamometer. The aim of
the research was to compare both concepts. The main selection criterion was the performance of both
systems, measured at constant load and speed range of 0-30 km/h. The measurements were carried using
the National Instruments hardware and software devices, the analysis of the results was performed in
MATLAB software. This article includes the accurate description of the measuring circuit, the course of
the research, data analysis and conclusions.

Davide ASTOLFI, Francesco CASTELLANI, Ludovico TERZI
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Abstract (EN)
Wind turbines, due to the distribution of the source, are an energy conversion system having
low density on the territory, whose operational behaviour and production on the short term
strongly depends on the stochastic nature of wind. They therefore need accurate assessment prior
installation and careful condition monitoring in the operative phase. In the present work, smart
post processing of Supervisory Control And Data Acquisition (SCADA) control system data sets
is employed for fault prevention and diagnosis through the analysis of the temperatures of the
machines. Automatic routines are developed for monitoring the evolution of all the temperature
SCADA channels against power production. The methods are tested on an onshore wind farm
sited in southern Italy, where nine turbines with 2 MW rated power are installed. The tests are
performed both ex post and in real time: it is shown that in the former case, a major mechanical
problem is detected, and in the latter case a significant problem to the cooling system is identified
before compromising turbine functionality.