Applied Mechanics and Materials Vol. 816

Abstract: The aim of the paper is to propose the concept of mechatronic system, which will have a good ability to overcome obstacles encountered in urban and non-urban environments. With its properties and characteristic features it should be able to adapt to diverse terrain, overcome obstacles such as stairs, slopes, rocks, but also muddy, sandy or slippery surface. The requirements and criteria imposed on this robot will depend on the mentioned properties.

Abstract: The article describes design of a drive module of a modular mobile chassis. This chassis was developed at the Department of Robotics, Faculty of Mechanical Engineering, VŠB-Technical University of Ostrava, as a part of the student grant competition “Research and development of modular robotic systems.” The article describes variants and the final mechanical construction of the drive module and also the structural analysis of this module according to the possible positioning in the whole modular system. The obtained results and possible ways of additional future development and modifications of the module are summarized in the conclusion.

Abstract: There has been a world-wide interest in the area of controlling different systems via smartphones. This paper deals with problems in the area of devices controlled by smartphone. The main objective was to produce a control unit CRC which controls some functions of the vehicle remotely by phone (either by Android application or DTMF). Following operations are supported: starting engine, opening windows, turning on heating or AC, windows defrosting, seat heating. If case of theft, telephone call is made to the owner. He can then block the engine via phone.

Abstract: Paper deals with in-pipe machine which locomotes inside pipe for inspection purpose otherwise cable drawing into pipes. It uses bristled locomotion based on friction difference principle. The friction between bristle tip and inner pipe wall has anisotropic character. Knowledge of this anisotropic friction is a key to developing and optimizing of in-pipe machine based on this principle.

Abstract: Nowadays, machine engraving of photos into solid materials such as marble or granite is becoming very popular. Relatively cheap CNC machines are available. The problem is that high quality photos are essential to obtain good results. The first part of the paper describes a model of a CNC machine used for engraving and puts down the principles of image processing applied to poor quality photos in order to get the best results, as well as the fundamental image processing methods necessary for achieving satisfactory results when using an electromagnetic diamond percussion tool for engraving. The second part of the paper describes a very simple method of data coding and the algorithm of engraving tool movement for image engraving process by means of a control system based on ATmega16 microcontroller. The quality of the engraved images is comparable, or even better, than that of manually engraved images or images engraved by other competitive CNC machines.

Abstract: The paper deals with stepper motor control using microcontroller ATmega8-16PU. In the paper are mentioned two ways of control, namely full-step mode and half-step mode control. At first, bipolar stepper motor is introduced. Next, there is created measuring stand consisting of bipolar stepper motor with one step angle 1.8° and encoder with 360 CPR. During the experiment were measured angular velocities by I/O measuring card MF624 cooperating with Matlab/Simulink. The results show differences between used two stepping modes of motor.

Abstract: Looking for new applications of the available materials, such as magnetorheological elastomers (MERs) is an important element of machine design process. To this end it is necessary to determine their fundamental mechanical properties, including Young’s modulus and shear modulus. These properties are determined experimentally by testing the material in compression, tension and shear. In the case of the analysed group of materials the above-mentioned constants depend, inter alia, on the parameters of magnetic field acting on them. Therefore, it is necessary to determine the character and the extent of variation of the mechanical properties as a function of the physical constants characterising the active magnetic field, namely magnetic flux and magnetic intensity (field strength).This paper presents the results of static compression tests carried out on magnetorheological elastomers. The parameters measured during the static compression test were force and displacement at a pre-set magnetic flux. The maximum strength of the induced magnetic field was limited by the design parameters of the test set-up. In order to determine the behaviour of the material at greater values of magnetic strength and flux the properties of a real material were modelled with a neural network. The simulation was carried out using a simple, one-layer neural network. The chosen network training approach was error backpropagation. This approach enables approximation and predicting of changes of the properties of the tested material. The output results will enable deriving an analytical model of the tested MREs.

Abstract: The aim of the thesis is to describe of building elements Bond Graph methodology for modeling dynamic systems. Technique of Bond Graph methodology for modeling dynamic systems is demonstrated and its place in the process of modeling of mechanic and electric system and its behavior is discussed. The building elements of bond graphs as source effort and flow, capacitor, resistor, inductor, gyrator and transformer are described.

Abstract: The article deals with the issue of the usage bond graphs at modeling of mechanical systems. In contrast with the classical method, where the equations for individual components are created first and then on their basis the simulation scheme is derived, here the described method uses the reverse procedure. In the introductory part of article the bond graph notation is defined and next basic types of multi-ports are explained. The last part consists of definition of port and power bond between ports that are explained on example of DC motor with separate excitation.

Abstract: The article is focused on stress analysis in PTC Creo CAD System Simulation. There is provided a methodology for evaluating the results of these analyzes and attention of the pitfalls in their evaluation in the article. The presented methodology is explained in a simple example of beam loaded by force in the middle. In the example will present the procedure how to properly evaluate the results and how to solve problems. The aplications ot the methodoly willbe presented in expamles ot twou project.