Mechanics
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ISSN 1734-8927
e-ISSN: 2300-7060
Issue Date
2008
Volume
Vol. 27
Number
No. 2
Description
Journal Volume
Mechanics
Vol. 27 (2008)
Projects
Pages
Articles
On experimental identification of selected dry friction model
(Wydawnictwa AGH, 2008) Furmanik, Kazimierz
The paper concerns with an identification problem of selected dry friction model on a basis of results of vibration experimental investigations of the given mechanical system. The system structure implicates a shape of its dynamics motion equations from these one can assign the friction model (function), taking under consideration the values assigned in measurements as following: displacements, velocities and accelerations meeting specified exploitation inputs (loading, velocities) of the defined friction pairs. The model can be used in mechanical systems for design and exploitation.
The effect of the modification of the bleeding method for regulation of the impeller pump efficiency
(Wydawnictwa AGH, 2008) Mikoś, Marian; Karch, Michał
In the thesis the experimental research results are presented concerning possibilities of the use of the additional angular momentum of a stream under suction as a factor enabling regulation of the impeller pump efficiency with maintaining a constant pressure value.
Predictive neural network controller for hydrostatic transmission control
(Wydawnictwa AGH, 2008) Nawrocka, Agata; Kwaśniewski, Janusz
In this paper predictive neural network controller is applied to control rotational speed of hydraulic engine hydrostatic transmission. It describes the functional structure and design principle of predictive neural network controller. This predictive neural network control method provides control linear and nonlinear systems. In this case feed forward network with one hidden layer was used. The control objective is to minimize a control cost function. Computer simulations are provided for illustration and verification. As control plant the hydrostatic transmission was chosen. The control by using the hydraulic drive is the time variant process, consequential to inconstancy parameters of hydraulic liquid (for instance: kinematic viscosity, compressibility and thickness). The efficiency of pump control is realized by use the electrohydraulic servo - system distinguish itself by a nonlinear characteristic. Finally, a predictive neural network method to control this kind of object is successfully applied.
Stability and control of the heavy solid body motion
(Wydawnictwa AGH, 2008) Rakiševa, Zaure Baânovna
The solid body motion with one fixed point under gravity action has been studied. The linear change of the variables, which reduced the initial system to the system of the non-dimensional equations with explicitly expressed linear part, had been suggested. The first integral of the norm type was found. The transformed system of the equations was investigated on stability on the first approximation. Analysis of the characteristic roots of this system was carried out. For the case of the instable by Lyapunov solution the control problem was solved. The small forces were found, by addition of which the body motion became asymptotically stable. Change of the first integrals of the controlled system was researched. Nature of the controlling forces was determined and their influence upon the body motion was revealed.
Vibration control capabilities of a cantilever beam with a magnetorheological fluid
(Wydawnictwa AGH, 2008) Sapiński, Bogdan; Snamina, Jacek
This paper presents an analysis of dynamic characteristics of a cantilever beam with a magnetorheological (MR) fluid. The beam consists of two aluminium outer layers and MR fluid layer placed between them. Due to MR fluid control capabilities both damping and stiffness of the beam can be changed simultaneously. The simple model of three-layered structure is assumed. Vibration characteristics of the beam are predicted for various magnetic field strength and a simple control algorithm based on switching of the beam stiffness is proposed. The results of calculations illustrate the vibration control capabilities of the MR adaptive beam at various level of magnetic strength.