Mechanics and Control
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ISSN 2083-6759
e-ISSN: 2300-7079
Issue Date
2010
Volume
Vol. 29
Number
No. 1
Description
Journal Volume
Mechanics and Control
Vol. 29 (2010)
Projects
Pages
Articles
Investigations of influence of vibration on human-operator control functions
(2010) Basista, Zygmunt; Książek, Marek A; Tarnowski, Janusz
In the paper results of experimental investigations of the system operator-handle-base have been presented. The aim of investigations was to record and analyse dynamical reactions of human operator volunteers participating in the experiments on a visual, suddenly appearing step signal. The main task of each operator was tracking of the signal as precisely as possible with a push force exerted on the tool handle. The measurements were done on an especially designed stand. The stand allows to simulate vibration of the tool with chosen frequencies with or without handle isolation. Time histories of step reference and forces realized by the operator were statistically elaborated and graphically presented.
Microstructure evaluation of Ni-Mn-Ga alloy
(2010) Flaga, Stanisław; Kata, Dariusz; Sapiński, Bogdan
This paper summarises the applications of MSMA materials, outlines the mechanism of magnetic shape memory effect and provides the procedure for microstructure evaluation of samples as well as the results of microstructure analysis using the example of the Ni-Mn-Ga alloy.
Visualization of an outflow in the radial blade passage on the basis of thermoanemometric measurements
(2010) Fortuna, Stanisław; Siwek, Tomasz; Figiel, Piotr
In this paper results of measurements of velocity distribution in the blade passage of radial rotor are presented. Construction of professional test rig with covered rotor passage and thermoanemometr usage made possible fluid flow visualization and detailed analysis of flow direction. Carried out tests showed high speed in negative pressure region. This means contrast to recently known theory about positive pressure regions. Correctness of measurements and results has been confirmed by smoke visualization and examples of computational simulations.
Control system of the hydraulic cylinders synchronization with the use of arithmetic mean of their positions
(2010) Grzybek, Dariusz; Micek, Piotr Andrzej
The aim of the control system is to ensure the effective synchronization of the cylinders motion and simultaneous minimization of volume loss in the throttling hydraulic systems. In the proposed control system, arithmetic mean of the synchronized cylinders displacements is the command value to the control subsystems where identical controllers are used. The number of the control subsystems is equal to the number of the synchronized cylinders. Developed control system enables effective motion synchronization of arbitrary number of the hydraulic cylinders with the pressure of the working liquid resulting from the current cylinders load.
Damping of the waves motion in a span by the active distributed force
(2010) Łatas, Waldemar
In the paper the problem of optimal damping of the waves - traveling along the cable in a span and reflected - by the active distributed damping force segment located near the support is analyzed. The string equation is chosen as a model of the vibrating cable. As an objective function of the optimization problem the energy dissipated by the damper force is assumed. The damping algorithm is based upon the expression for the optimal concentrated damping force. The distributed force is assumed to be proportional to the component of the cable velocity resulting from the superposed motion of the original running and the original reflected waves. The original running waves are assumed in the form of packet waves with amplitude modulation. Illustrative numerical results demonstrating the optimal damping coefficients are included.