Mechanics
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ISSN 1734-8927
e-ISSN: 2300-7060
Issue Date
2009
Volume
Vol. 28
Number
No. 1
Description
Journal Volume
Mechanics
Vol. 28 (2009)
Projects
Pages
Articles
Teaching-playback control of electro-pneumatic servo-drive
(Wydawnictwa AGH, 2009) Dindorf, Ryszard; Takosoglu, Jakub
In paper a Fuzzy Logic Controller (FLC) of PD type to teaching playback control of electro pneumatic servo-drive are presented. The analysed fuzzy logic controller carry out a tasks: transpose control, follow-up control and teaching/play-back control. The fuzzy logic PD controller enables precise positioning of pneumatic servo-drive with the precision specified for industrial manipulators. A lot of simulation and experimental tests were carried on pneumatic servo-drive with fuzzy controller which was used for its transpose and tracking control. The designed fuzzy system is efficient, stable and resistant to disturbances and can be applied in any configurations of pneumatic servo-drive without necessity to tune the regulator, apply signal filtration or additional operations in track control or restrict the signals generated. The teaching playback control system using fuzzy logic control was constructed and practically applied in various servo pneumatic systems used in production automation.
Analysis of positioning accuracy of the effector of a triplanar manipulator
(Wydawnictwa AGH, 2009) Kuźmierowski, Tomasz; Siemieniako, Franciszek
This paper presents an analysis of positioning of the effector of a spatial parallel manipulator of the triplanar type. Computer simulation software for examining positioning accuracy and the simulation results have been described herein. The paper also contains verification of the examination through stand measurements of a manipulator of a selected configuration.
Multi-channel virtual-microphone feedback minimum-variance active noise control system
(Wydawnictwa AGH, 2009) Pawełczyk, Marek
Classical active noise control systems are designed to minimise, in a sense, the residual signal at the microphone providing information about acoustic noise and secondary sound interference. The secondary sound operates at the same time on the acoustic noise at other positions including user ears. In the worst case this can result in sound reinforcement at those positions. In many applications placing another microphone directly at the ears is not accepted. It is then justified to make efforts to design a dedicated system. The purpose is to minimise the mean-square value of the noise at the desired location while performing measurements of sound interference results at another location. This can be done by employing the general idea of Vrtual-Microphone Control systems. However, for many active noise control applications the use of a single pair of microphone and loudspeaker does not suffice to obtain satisfactory performance, i.e. generate a zone of quiet of acceptable dimensions. Moreover, for some applications, presence of an obstacle, e.g. the head in an active headrest system, constitutes a barrier for the zone of quiet at one side to propagate to the other side. Therefore, more microphones and loudspeakers are often necessary. In the most general case a coupling between subsequent pairs should be taken into account resulting in a multi-channel system. In previous papers of the author adaptive systems have been designed and analysed. In this paper a fixed parameter multi-channel Virtual-Microphone Control system, optimal in the mean- square sense, is designed. It includes non-minimum phase property of the system channels. Both the case of more inputs than outputs as well as the case of more outputs than inputs are considered. Factorization techniques have been used for the design. The system is verified by successfully controlling noise for the active headrest system.
Magnetorheological dampers in vibration control of mechanical structures
(Wydawnictwa AGH, 2009) Sapiński, Bogdan
The paper summarizes the experimental data gathered during the laboratory tests of vibration control of three mechanical structures utilizing magnetorheological (MR) dampers. The author's research program involved the investigations of the structures. The first application refers to vibration control in a driver's seat suspension (structure 1). The control objective is to reduce vertical acceleration of the driver. The second application covers vibration control in a pitch plane vehicle suspension (structure 2). The control objective is to reduce vertical and angular accelerations of the vehicle. The third application concerns vibration control of a suspended cable (structure 3). The control objective is to reduce transverse free vibrations of the cable. The obtained results demonstrate system performance improvement achieved through the control of MR damper(s).
Experimental determination of sound absorbing coefficient for selected granular materials
(Wydawnictwa AGH, 2009) Sikora, Jan; Turkiewicz, Jadwiga
The results of investigations of sound absorption coefficients for selected granular materials (potypropylene, polystyrene and garvelite granulates, high-silica sand) being often applied as sound absorbing cores in double-wall partitions are presented in the paper. The results confirmed good sound absorbing properties of granular materials, which placed them in the group of sound absorbing materials applicable in constructions limiting noises of machines and devices.