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Currently used machine diagnostic systems are based on very modern solutions based on the acquisition and recording of their operating parameters in real time. Increasingly available and high-tech sensor systems mean that the number of recorded parameters is increasing and their quality is improving. These data are mainly used to assess the technical condition of machines and the processes they perform. In mining, these data can also be used to assess and, at a later stage, improve the safety of the underground mining process. Referring to this issue, the paper presents examples of the use of diagnostic systems for powered roof supports and longwall shearers to assess the safety status of the underground hard coal mining process. In the case of the wall support, the focus was on measuring the pressures in the stands of its individual sections. Temporary changes in the values of these pressures constitute a valuable source of information regarding the interaction of the support with the rock mass. In particular, this concerns the identification of the effects of the informational impact of the rock mass on the longwall excavation protected by the support. The research results presented in the paper, especially in the case of very dangerous dynamic impacts, indicate the possibility of both diagnosing the operating condition of the section and identifying symptoms of exposure to such events. This undoubtedly significantly expands the possibilities of using the measured pressures. Diagnostic signals from a longwall shearer are also widely used. The current intensities drawn by its motors while cutting the rock mass, as well as the advance speed and its position in the wall make it possible to analyze these parameters and their changes before, during and after the occurrence of various types of events. These data enable the assessment of the effects of the rock mass on its operational efficiency and safety status. It also enables the identification of symptoms that precede the occurrence of such events. The presented examples indicate the need for a broader and more holistic approach to the use of diagnostic parameters of mining machines. In particular, this concerns the study of the cooperation between the support and the rock mass and its influence on the efficiency and safety of the rock mass mining process. The subject matter addressed relates to very important and current issues, and the developed methodology and obtained results should be applied in practice as soon as possible.

This article considers the development of a mathematical model of electrochemical grinding for processing precision components operating at varying loads. The combination of processes (for example, the mechanical and electrochemical material removal processes) significantly improves operation control capabilities by increasing the number of control inputs and selected input variables. The results of the research are presented as evaluated based on the capacity of products manufactured using this grinding method. The conducted qualitative and quantitative assessments demonstrate the adequacy of mathematical models. The difference between experimental and calculated values made up 5-10%. The electrochemical grinding helps improve the operability of components operating at varying loads compared to mechanical grinding. [ABSTRACT FROM AUTHOR]

On the stage of product design there is a problem concerning production cost estimation in the moment when elements are not yet definitely designed. Depending on the amount of the available information, more or less precise cost estimation methods are applied, i.e.: variant methods, generation methods, hybrid methods. The proposed method of cost estimation is based on a formalized description of information related to construction, manufacturing and organizational characteristics concerning the designed element, the automation method of technological processes design using methods of group technology and a model of determining production costs of machine elements based on Activity Based Costing.

The paper deals with implementation of the optimizing process into multi-axial rainflow analysis and cumulative damage calculation. It’s presented computational program FEA_FAT compiled in MATLAB. Stress analysis is realized by finite element procedure and the cumulative damage can be calculated by using two fundamental ways – critical plane approach and so called integral approach. Testing example presents random stress analysis and damage prediction of a simple FE model with non-proportional loading.

The paper deals with the conceptual design of cable-driven parallel robot which will be used for inspection and monitoring tasks in production process. The reason and need of vision based control of the production process is described in the introduction. Furthermore, mechanisms with parallel kinematic structure are described, as well as their usage in industry and sports broadcasts. On that basis, there is proposed the conceptual design of the cable driven parallel robot (CDPR) for desired task of visual monitoring of production line. Finally, there is proposed a simulation of designed robotic system and workspace shape analysis.

In this paper we are finding input-output dependencies of feed-forward neural network which usually behaves as black box. It is very important and difficult to find or evaluate those dependencies especially for multi-input/output data approximation. We will use small neural network which will be trained on a given data in MATLAB Mathworks. Network will be simulated in standalone .NET application.

The work presents the methods and solutions of the optimizing design of the truss and beam structures subjected to the cumulative fatigue damage. Two basic approaches used in the optimization of mechanical systems are presented in the paper - the so-called direct search methods and the gradient methods. A short comparative and gradient approach was made. The aim was to minimize the weight of the truss or beam structure with restrictions affecting the prescribed fatigue life. The computational model assumed only quasi-static loading with different number of cycles.

In the exploitation of machinery and equipment, one of the most important parameters is the dynamic state of the object. Observing residual processes is the most popular method of assessing the dynamic state. In particular, dynamic residual processes are a carrier of diagnostic information. Measuring the vibrations and noise of working mini-mining machines provides knowledge about the dynamics of the assessed machinery. Many years of knowledge and experience have allowed for the creation of diagnostic procedures. Within most machines used in the industry, the procedures considered standard allow for an effective diagnostic assessment and optimal management of mini-mining machine exploitation. The applicability of these standards is quite wide. However, there are machines with parameters that prevent the application of said standards. Mini-mining machines used in subterranean mining are one of these machines. In the case of diagnostic assessment of continuous miners, chain conveyors, as well as other machinery used in the technological chain, the usage of assessment brackets consistent with adopted standards is incorrect. In the diagnostic assessment of these types of mini-mining machines, an analysis of long-term trends is often used. The determination of acceptable vibration levels is obtained heuristically through observations of the damage up to the state of emergency. In the article, methods of mini mining machines state assessment using models of machine degradation, using Weibull distribution, are presented. The presented method has been used in real results of vibration measurement of underground machinery used in a coal mine. The analyses showed a large effectiveness of the presented method. [ABSTRACT FROM AUTHOR]

The total station is the most basic geodetic measuring instrument, locally the most accurate and versatile. Its accuracy is the cornerstone of its use and is defined by the standard deviations of horizontal direction, zenith angle and slope distance measurements. These accuracy parameters are given by the manufacturer, but these are only valid under optimum measurement conditions. To ensure the credibility and reliability of the measurements, these values must be periodically ascertained or determined for atypical measurement configurations or measurement conditions. Standardised procedures are used for this purpose, but in our opinion, they do not reflect the full influence of the measuring conditions and other measuring aids. A comprehensive determination of the accuracies (variation components) from the alignment, where all possible influences in a given situation are applied, may be considered the most appropriate for determining the angular accuracy of measurements. Such atypical conditions are certainly represented by geodetic measurements in the confined spaces of an underground mine. Thus, an experimental determination of the accuracy of four different robotic total stations was carried out at the Center of experimental geotechnics in a mine Josef teaching centre (CTU in Prague), and the Frstner method was used to determine the variation components. A network of 6 stations and 8 target points was designed. The grid size was approximately 32x21 m with 4 - 31 m lengths. A network with the same configuration was also duplicated at the surface to assess whether the accuracy is different in underground and how the results will correspond to the accuracy claimed by the manufacturers. The result of the testing is that the accuracy claimed by the manufacturers is maintained even under such difficult measurement conditions in narrow corridors and with short sights. The overall evaluation also found that the accuracy achieved underground and on the surface is identical, although it varies from instrument to instrument. [ABSTRACT FROM AUTHOR]

The article deals with the preparation of simulation model of mechanism with parallel kinematic structure called hexapod as an electro-mechanical system in software MATLAB/Simulink. The simulation model is composed from functional blocks represented each part of mechanism’s kinematic structure with certain properties. The results should be used for further simulation of its behaviour as well as for generating of control algorithms for real functional prototype.

In this article, authors described selected logistics automation tools (ASLP) and briefly presentedthe PROMETHEE multi-criteria decision making method in terms of its application in assessing the implementation of ASLP in the field of production logistics. A methodology for preparing the data required toevaluate the ASLP implementation process based on modelling and simulation tools was also proposed.

In the paper basic experimental tests were carried out to compare the wear indicators of selected abrasive grinding discs in grinding process of steel. Experimental tests on the wear and efficiency of metal grinding discs were made for four types of steel (S235, NC6, Hadfield steel, WNLV + QT steel). The wear parameter included in the ISO standard (KG) of new abrasive discs from European market were examined. This paper presents an analysis of the efficiency and wear of the company’s „MOST” grinding discs using an angle grinder.

Realized measuring with the Renishaw Ballbar QC20-W on industrial robots requires a special approach to measurement and creating of a circular path. In the article, two methods of the circular path creation are compared through experimental measurements. The first method is based on creating a circle using standard program commands in the FANUC programming environment. In the second method, the circular path is created as a polygon that represents the most accurate approximation of a circle required for a Ballbar measurement. The measurement methodology, the analysis of measurement data and results are presented in the article.