Abstract: FEM is a very important tool for getting the numerical solution of many engineering
problems. It has been widely used in solving structural, mechanical, heat transfer, and fluid
dynamics’ problems as well as problems of other disciplines such as piezoelectricity. Since the
complexity of many problems leads to the formation of models of large dimension, which are
described with many degrees of freedom, their numeric solution makes for the highest demands.
The number of degrees of freedom is often unnecessarily large to represent the structural response
in a limited bandwidth and therefore, in such a case, a reduction should be conducted. The
systematic reduction of complex FE models on simple electromechanical equivalent circuit models
(with less mechanical degrees of freedom) is the subject of this paper. The aim of the work is to
make the reduction in such a way that the characteristics of the systems input/output descriptions
are approximated within a pre-selectable frequency range with sufficient accuracy. A transducerwedge-
system is used as an example for the method, to extract a state space model of the systems
piezoelectric input/output description and to derive the parameters of the electromechanical
equivalent circuit directly from the modal finite element analysis. In the present paper we describe
the general methodology as well as its application to piezoelectric transducers as used in ultrasonic
Abstract: The analysis of technological trends nanoelectromechanical systems and processes of
self-formation micro- and nanostructures in manufacturing MEMS/NEMS have been made and the
requirements have been formulated. The results of modeling geometry nanostructures and the
implementation of self-formation processes for creating new technologies of manufacturing
MEMS/NEMS have also been presented.
Abstract: This paper presents a two-channel digital control system for the hydraulic stand MZPK
100 designed for fatigue tests of cruciform specimens under biaxial tension-compression. In the
past, the fatigue test stand MZPK 100 was provided with unreliable analog control power cubicles.
Application of the computer with an analog and digital input-output signal path board,
Matlab/Simulink software and a new control box equipped with the necessary electronic subassemblies
(responsible for proper switching of the hydraulic supplier, command electrovalves,
conditioning of signals from sensors and so on) enables replacement of the old analog system by a
new two-channel digital control system. Nowadays, it is easy to modify the control system to
different requirements of material tests because the hardware (electronic) solutions have been
simplified, and the software has a friendly Simulink interface. Such an approach allows for the
implementation of different control algorithms, e.g. PID, adaptive, and fuzzy logic etc. Moreover,
this paper presents a description of how to keep the center of the specimen static under a controlled
force that is being applied by four independent actuators.
Abstract: A model of the AC induction motor, which allows us to analyze all operation modes of
motor supplied by the frequency converter, has been developed. A simulation of the inverter of the
frequency converter and the AC induction motor interaction on the basis of the developed motor
model, using software MATLAB, was performed and a motor regenerative braking mode was
investigated. The results of investigation are used for the development of fault protection of the
Abstract: An asymmetric PI (aPI) controller based on a control algorithm, which is the
modification of the PI control method, has been suggested. The principal characteristic feature of
the aPI controller is that different values of proportional and integral constants are used at positive
and at negative errors. Contrary to the classical PI controller, the proposed controller allows us to
improve the positive disturbance rejection of control systems without sacrificing the unit step
response dynamics. Results of the investigation of the concrete control systems based on the aPI
controller are also presented. Using the dynamic system simulation program Simulink performed
Abstract: The main flaws of electric arc welds and factors determining the quality of the welded
seams are considered in this paper. In practice, welding tools and their control systems are affected
by some external factors causing deviation of the weld’s quality from the specified values.
Currently used control systems of welding tools do not always satisfy the requirements for quality
of welded joints. Major principles of developing the adaptive control system of the welding tool are
considered here and the developed functional and block diagrams of microprocessor system are
presented. General equations describing the welding process are also provided and the obtained
transfer function of a closed system is described.
Abstract: The paper considers some problems of calculating major parameters and characteristics
of a mechatronic system with a linear induction motor (LIM). It has been shown that LIM operating
in the presence of traveling magnetic fields are widely used alongside other actuators. These motors
allow for modular design because inductors may be made as independent modules. Then, by
choosing the required number of inductors and their arrangement in a mechatronic system, a desired
trajectory of transverse motion may be obtained.
A theoretical model for LIM calculation, taking into account major assumptions about onedimensional
magnetic field, is offered. Complex amplitude is expressed as the exponential function
of a longitudinal coordinate of current volumetric density of the inductor. The above inductances as
the parameters of dynamic equations may be used in further investigation of dynamics of
mechatronic systems. However, in order to create optimal control systems for mechatronic systems
with linear actuators, the major parameters and characteristics of a linear motor should be known.
Therefore, the present investigation is aimed at developing methods for calculating the parameters
of mechatronic systems with linear electric drives.
Abstract: Unreliable and inflexible analog control systems of fatigue test stands applied in
laboratories are being replaced by systems enabling easy development and implementation of new
test ideas. This paper presents a digital control system applied in the fatigue test stand SHM 250b.
It is based on a new electronic system and the I/O board RT-DAQ4/PCI with the software
Matlab/Simulink used for communication with the board. The control system for the fatigue test
stand SHM 250b gives the possibility of performing fatigue tests under controlled strain ε(t), stress
σ(t) and energy parameter W(t) which is calculated from the stress and strain signals. The applied
control system is now used, depending on the performed fatigue tests, and can be developed for
specific needs of material strength analysis.
Abstract: Analysis into the effects of parametric characteristics of visual aid on the perception level
of information transmitted has led to the possibility of examining and determining the quality of the
reading level as a function of certain parameters of a digital apparatus (sensor), the distance to the
text, the size of letters and the intensity of light. Efforts have been made to evaluate the effect of the
specifications of the executor as well as the information transfer (by tactile way) speed onto the
sensory organs of the disabled person at the perception level. A choice has been made of rational
information transfer speeds and appropriate visual aid characteristics to facilitate an adequate
Abstract: A laser instrument maintains the course of the positioned gantry module. A laser beam
generator emitting a vertical beam is placed at the end of the experimental field. A laser beam
catcher with photo diodes is mounted onto a positioned gantry module replaceable support. Course
deviations were assessed in two cases: when laser, straight-course maintaining mechanism was
mounted at the same end of the spar as positioning trundle; and when it was mounted at the middle
of the spar. Furthermore, we estimated how course deviations vary when changing the interaxial
distance of laser catcher photodiodes.
An electromechanical transmitter was used in the tests. The gantry module is positioned by a
special positioning trundle and is run by a 12 V electric motor through a worm self - braking