Solid State Phenomena Vol. 208

Abstract: The project of the system to measure a child's foot pressure on the sole of a shoe is the theme of this article. The skeletal system and muscular system of human foot were discussed. The movement of the foot was also depicted. The definition of gait and gait phases were explained. In the next part of this thesis, the project of system to measure a child's foot pressure on the sole of a shoe was presented. The thesis includes: the specification of the force-sensitive resistors (FSR), their arrangement and connection method. The electronic circuit diagram of the measurement system was designed. All electronic components such as: microcontroller, analog switches, operational amplifiers, multiplexers and RS485 transceivers were discussed in detail. The project of printed circuit board was also created.

Abstract: The article presents the concept of a universal BCI system based on the detection of Steady-State Visual Evoked Potentials (SSVEP). One of the possibilities of its application involves, for example, the visual keyboard which makes it possible to enter data (alphanumeric characters) into the computer without using muscles. The first part discusses the construction and the principle of operation of BCI interfaces and next the most frequently used evoked potentials are presented. An application allowing for an analysis of the EEG signal of a person subject to effect of the photostimulator using stimuli with the frequency ranging from 1 to 40 Hz. As a result of the developed program the appropriate frequency of a stimulus in the EEG signal was detected and signalled.

Abstract: The theme of this article is the design and strength analysis for two types of rotary seals which use shape memory materials to the radial terminal. In this paper, basic types of technical seals were brought up and shape memory materials were described. Based on these pieces of information and product catalogue of Trelleborg, there were designed two types of seals with coils of wire and shape memory. After the project of building the seals was prepared, strength tests were carried out in ANSYS Workbench program. In the case of the seal type TRG two types of analysis were carried out: the first simulating the assembly of the seal, and the second, which is the extension of the first, including additionally the coil terminal of wire. For the seal type TRA, two types of analysis were conducted as well: the first including assembly and coil terminal and the second comprising additionally loading the seal with working pressure. After selecting the materials, declaring the environment and the loads with accordance to the findings of the analyses and performing computations the results were provided. As the output there were chosen: the total reduced deformation, reduced stress and reduced load.

Abstract: In the article implementation of type-2 fuzzy controller in a microprocessor Arduino is described. The interval type-2 fuzzy sets were used to shorten the cycle time of the algorithm. The type-2 fuzzy logic controller was tested experimentally by controlling position of the shape memory alloy actuator DM series produced by Miga Motor company, the worldwide leader in the field of shape memory alloys applications. The actuator despite small size distinguishes itself by its strength. The obtained results confirmed that type-2 fuzzy controller performed efficiently with difficult to control nonlinear plant. The implemented algorithm can handle uncertainties without increasing drastically the computational complexity. To reduce the response time of the control system an additional accelerating pulse was added to the algorithm.

Abstract: A truss is one of the most important parts of different structures applied in several areas of the contemporary industry. One of the most often appeared problems is the undesirable truss vibration activated, for example by the wind. The limitation of the undesired vibration is possible by the increase of the truss dimensions, but it leads to the increasing of the truss mass. The other way of the vibration damping is possible by the introduction of active elements, which generate the control forces acting on selected nodes of the truss. The piezoelectric actuators can be applicable elements to generate such control forces. Special active members are designed in order to introduce the piezoelectric actuators in the truss structure. A project of the control algorithm steering such members is a difficult task, because the truss with active members is MIMO control object. This article presents the results of the simulation research of LQG control system installed in exemplary truss with one, two or three piezoelectric active members. On the basis of the conducted simulation research one can claim that LQG control system could influence the increase of the vibration damping of such piezoelectric smart truss structure, without the increase of the truss mass.

Abstract: The aim of this paper is to present the results of laboratory research on Ionic Polymer-Metal Composite (IPMC), in context of energy harvesting applications. IPMC is a novel type of material, a smart polymer, which can work as a sensor or an actuator. One of its biggest advantages is low actuating voltage of about 4V (with 120mA current), what makes it very energy-efficient. Step response for various input amplitudes of two IPMC samples is shown. Also, a voltage generated in response to mechanical deformation of the composite is measured, and a hysteresis loop is plotted. Lastly, the changes of properties of the IPMC caused by long-term actuation are researched. These results are necessary to build an energy harvesting system utilizing IPMC. A simple gripper built with IPMC is also presented.

Abstract: In the article, three alternative models of 2S1 platform suspension system are presented. First model is based on existing construction of 2S1 platform suspension. Two next were modernized by usage of new solutions in tracked vehicles suspension technology. The solutions are especially associated with torsion spring element and idler mechanism. The authors have assumed simulation conditions for straight line driving of the vehicle models, while they overcome a single obstacle with one track. Results of all models simulations are compared and analyzed to improve stability of the vehicle while driving. There are also used a human response filter to determine less harmful driving conditions for vehicle crew.

Abstract: The article presents analytical and calculation process of shape prediction of pipe elements formed by electrodynamic forming. In the first part of the work formulation of physical phenomena arising during this method of metal forming is presented. Next, basing at developed mathematical model, with use of numerical methods prediction of the final shape of the semi-finished product during free forming was performed. Results of this stage of tests were compared with results of measurements made during experimental test.

Abstract: Multilayers of alternate Ti/TiN coatings deposited on X20Cr13 ferritic stainless steel by pulsed laser deposition (PLD) method have been tested using instrumented indentation. The effect of bilayer period and metal/ceramic thickness ratio were studied.

Abstract: In this study a fractional Brownian motion model is used to randomize integer-and fractional-order plant parameters. The analysis of these plants in systems with integer-order PID and fractional-order PI^λD^δ controllers is shown. The aim of the analysis is to compare robustness of both controllers. The quality of control system is measured by integral quality parameter. The fractional Brownian motion gives much flexibility in modeling non-stationary plants, the volatility and standard deviation of fractional Brownian motion can be easily adjusted.