Volume 24 (2016): Issue 39 (December 2016)

It is very demanding to detect fire spots under difficult conditions with high occurrence of interfering external factors such as large distances, airflow difficultly, high dustiness, high humidity, etc. Spot fire sensors do not meet the requirements due to the aforementioned conditions as well as large distances. Therefore, the detection of a fire spot via linear heat sensing cables is utilized.

The main goal of the paper is the determination of material properties from experimentally measured natural frequencies. A combination of two approaches to structural dynamics testing was applied: the experimental measurements of natural frequencies were performed by Experimental Modal Analysis (EMA) and the numerical simulations, were carried out by Finite Element Analysis (FEA). The optimization methods were used to determine the values of density and elasticity modulus of a specimen based on the experimental results.

This article deals with the management of a Freescale small robotic car along the predefined guide line. Controlling of the direction of movement of the robot is performed by neural networks, and scales (memory) of neurons are calculated by Hebbian learning from the truth tables as learning with a teacher. Reflexive infrared sensors serves as inputs. The results are experiments, which are used to compare two methods of mobile robot control - tracking lines.

The concept Industry 4.0 is a top theme of recent times. Even if it represents the so-called 4^th industrial revolution its main ideas could be used also to support the education of subjects from IT and automation. Furthermore, the basic IT and web technologies inherited by this concept are very well known to students. This paper introduces the embedded webserver of PLC and the options for its optimal utilization. The web server is essentially a simple and widely well-known technology, therefore it was chosen as an example.

Vectorization is the conversion process of a raster image representation into a vector representation. The contemporary commercial vectorization software applications do not provide sufficiently high quality outputs for such images as do mechanical engineering drawings. Line width preservation is one of the problems. There are applications which need to know the line width after vectorization because this line attribute carries the important semantic information for the next 3D model generation. This article describes the algorithm that is able to recover line width of individual lines in the vectorized engineering drawings. Two approaches are proposed, one examines the line width at three points, whereas the second uses a variable number of points depending on the line length. The algorithm is tested on real mechanical engineering drawings.

In this paper we analyze the sensitivity of solutions to a nonlinear singularly perturbed dynamical system based on different rewriting into a System of the First Order Differential Equations to a numerical scheme. Numerical simulations of the solutions use numerical methods implemented in MATLAB.

This paper deals with the use of the numerical computer oriented method for the analysis and verification of the design of workpiece clamping. The inaccuracies of the positioning in clamping locating points were simulated using the FEM software ANSYS. The influence of inaccuracies in the positions of contact locating points on the displacements of the workpiece characteristic points and their position in clamped removable jaws was examined. The reaction forces in the contact locating points were also computed and analyzed.

This paper deals with stability in the Liapunov sense of the 4-th order quasilinear differential equations with quasiderivatives. An asymptotic stability criterion is derived. An illustrative example is added.

This contribution is focused on the impact of real gearing to the dynamics of gearing and a machine aggregate system. It is shown that a mechanical reduction gearbox is the source of excitation with a large range of frequencies. The mechanical part of drives, with respect to its electrical part, is the subject of control which should ensure optimal movement modes with regards to the technological process.

Analysis of the negative impact of a mechatronic system with the flexible elements parameter error and the possibilities of impact reduction are presented in this contribution. Two advanced methods – the Model Predictive Control method and the inclusion of an LMS filter into the control process are proposed for the reduction of the insufficient effect of a double notch filter, which was initially integrated into the system for elimination of two-mass flexible joint parasitic frequencies. Simulation experiments results – response of system angular velocity and control process quality analysis confirmed the correctness of the proposition for the usage of these progressive control elements.

This contribution is focused on determining the material properties (Young modulus and shear modulus) of the testing samples. The theoretical basis for determining material properties are the knowledge of linear elasticity and strength. The starting points are dependencies among the modulus of elasticity, shear modulus, normal stress and relative strain. The relative strains of the testing samples were obtained by measuring predefined load conditions using a strain-gauge bridge and the universal measurement system Quantum X MX 840. The integration of these tasks into the teaching process enhances practical and intellectual skills of students at secondary level technical universities.

The classical non-conservative Beck’s beam, loaded by follower compressive force, is generalized by allowing an arbitrary angle of action of the follower force as well as allowing for excentric positioning of the applied force. For the corresponding boundary eigenvalue problem, the frequency equation is derived. Results of parametric studies are presented with an emphasis laid on the lowest eigenfrequencies. The characteristic shape of the computed curves indicates whether stability loss by divergence or by flutter occurs. A map of stability is presented in terms of parameters describing the excentricity and the angle under which the follower force acts on the beam.

This article first describes the current state of the problem in the area of communication in modern factories. Next in the article is given a summary of the requirements that must be implemented for the possibility of establishing a compatible and safe communication system. In the final part of the article is given a proposal of communication model suitable for the implementation.

This article is devoted to the initial phase of data analysis of failure data from process control systems. Failure data can be used for example to detect weak spots in a production process, but also for failure prediction. To achieve these goals data mining techniques can be used. In this article, we propose a method to prepare and transform failure data from process control systems for application of data mining algorithms, especially cluster analysis.

Dealing with data from the field of medicine is nowadays very current and difficult. On a global scale, a large amount of medical data is produced on an everyday basis. For the purpose of our research, we understand medical data as data about patients like results from laboratory analysis, results from screening examinations (CT, ECHO) and clinical parameters. This data is usually in a raw format, difficult to understand, non-standard and not suitable for further processing or analysis. This paper aims to describe the possible method of data preparation and preprocessing of such raw medical data into a form, where further analysis algorithms can be applied.

The aim of this paper is to analyze and to propose an appropriate system for processing and simultaneously storing a vast volume of structured and unstructured data. The paper consists of three parts. The first part addresses the issue of structured and unstructured data. The second part provides the detailed analysis of data repositories and subsequent evaluation indicating which system would be for the given type and volume of data optimal. The third part focuses on the use of gathered information to transfer data to the proposed repository.

The aim of this paper is to propose the concept of a system that takes advantage of web technologies and integrates them into the management process and management of internal stocks which may relate to external applications and creates the conditions to transform a Computerized Control of Warehouse Stock (CCWS) in the company. The importance of implementing CCWS is in the elimination of the claims caused by the human factor, as well as to allow the processing of information for analytical purposes and their subsequent use to improve internal processes. Using CCWS in the company would also facilitate better use of the potential tools Business Intelligence and Data Mining.

Due to the increasing competitive environment in the manufacturing sector, many industries have the need for a computer integrated engineering management system. The Manufacturing Execution System (MES) is a computer system designed for product manufacturing with high quality, low cost and minimum lead time. MES is a type of middleware providing the required information for the optimization of production from launching of a product order to its completion. There are many studies dealing with the advantages of the use of MES, but little research was conducted on how to implement MES effectively. A solution to this issue are KPIs. KPIs are important to many strategic philosophies or practices for improving the production process. This paper describes a proposal for analyzing manufacturing system parameters with the use of KPIs.

To obtain the transfer equation in dynamic system theory, we need to calculate an inverse matrix. In this work we show both the classic methods and the methods used in automation theory of inverse matrix calculation. However, they are both time consuming and difficult. In the second section, we will show a simpler method. We will define how to create a graph for a given matrix and how to invert it. The matrix for the inverse graph is inverse of the original. We illustrate this method on an example and compare it to a classic solution.

Rotary ultrasonic machining (RUM) is a hybrid process that combines diamond grinding with ultrasonic machining. It is most suitable to machine hard brittle materials such as ceramics and composites. Due to its excellent machining performance, RUM is very often applied for drilling of hard machinable materials. In the final phase of drilling, the edge deterioration of the drilled hole can occur, which results in a phenomenon called edge chipping. During hole drilling, a change in the thickness of the bottom of the drilled hole occurs. Consequently, the bottom of the hole as a plate structure is exposed to the transfer through the resonance state. This resonance state can be considered as one of the important aspects leading to edge chipping. Effects of changes in the bottom thickness and as well as the fillet radius between the wall and bottom of the borehole on the stress-strain states during RUM are analyzed.

The goal of this paper is the creation of kinematic systems of the cardan shaft in the CAD/CAM/CAE system CATIA V5 and analysis of three cases of assembly to determine upon which, angular accelerations had been observed between the input driving shaft, central cardan shaft and output driven shaft. The scientific result of this paper was to confirm the presence of cardan error and how this type of error can be successfully eliminated.

In providing safety functions, the proposal of safety functions of control systems is an important part of a risk reduction strategy. In the specification of security requirements, it is necessary to determine and document individual characteristics and the desired performance level for each safety. This article presents the results of the experiment cluster analysis.

The results of the experiment prove that the methods of cluster analysis provide a suitable tool for analyzing the reliability of safety systems analysis. Regarding the increasing complexity of the systems, we can state that the application of these methods in the subject area is a good choice.