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The article deals with development and application of snake robot for inspection pipes. The first step involves the introduction of a design of mechanical and electrical parts of the snake robot. Next, the analysis of the robot locomotion is introduced. For the curved pipe, potential field method is used. By this method, the system is able to generate path for the head and rear robot, linking the environment with obstacles, which are represented by the walls of the pipe. Subsequently, the solution of potential field method is used in inverse kinematic model, which respects tasks as obstacle avoidance, joint limit avoidance, and singularity avoidance. Mentioned approach is then tested on snake robot in provisional pipe with rectangular cross section. For this research, software Matlab (2013b) is used as the control system in cooperation with the control system of robot, which is based on microcontrollers. By experiments, it is shown that designed robot is able to pass through straight and also curved pipe.

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František Trebuňa, Dr.h.c. mult. prof. Ing. CSc. is a professor of applied mechanics, Head of the Department of Applied Mechanics and Mechatronics and Dean of the Faculty of Mechanical Engineering. He is author of 10 monographs, 12 university textbook, special book publications, 12 university notebooks and more than 300 publications in journals and conference proceedings at Slovakia abroad. He is author of important projects and engineering works. He received several prizes at home and abroad. He received three titles Doctor Honoris Causa (DHC) including two from foreign universities for the development of applied mechanics and mechatronics. Peter Frankovský, Ing. PhD. He is a senior assistant on Department of Applied Mechanics and Mechatronics. In 2010 he received PhD. in the field of applied mechanics. He works on scientific and research projects on the department and publishes the results in journals and conference proceedings at Slovakia and abroad. He made remarkable work on the building of laboratories and on publication of monographs and university textbook at the department. Jozef Bocko, doc. Ing. CSc. is an associated professor of applied mechanics on the Department of Applied Mechanics and Mechatronics, vice-dean of the Faculty of Mechanical Engineering. He is author of 1 monograph, 2 university textbooks and more than 90 publications in journals and conference proceedings at Slovakia and abroad. His research interests are oriented to the field of the finite element method, shell theory, nonlinear mechanics and application of Lie group theory in mechanics. He worked on several grant projects and research works for practice. Miroslav Pástor, Ing. Ph.D. He is a senior assistant on the Department of Applied Mechanics and Mechatronics. In 2008 he received PhD. in the field of applied mechanics. He works on scientific and research projects on the department and publishes the results. He made remarkable work on the building of laboratories and on publication of monographs and university textbook at the department.

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Anchoring parts of technical systems are often damaged due to the heavy forces acting on these systems during their operation. For that reason, various modifications are suggested and created on the anchoring screws, which should help to reduce the mechanical stress values in a place of the first load-bearing thread of a female screw. For the determination of stress fields on the surface of a plane model of a threaded joint, two non-contact optical methods were used – conventional transmission photoelasticimetry and modern digital image correlation.

This paper presents a uniquely designed device combining the hole-drilling technique with two optical systems based on the PhotoStress and digital image correlation (DIC) method, where the digital image correlation system moves with the cutting tool. The authors aimed to verify whether the accuracy of the drilled hole according to ASTM E837-13a standard and the positioning accuracy of the device were sufficient to achieve accurate results. The experimental testing was performed on a thin specimen made from strain sensitive coating PS-1D, which allowed comparison of the results obtained by both methods. Although application of the PhotoStress method allows analysis of the strains at the edge of the cut hole, it requires a lot of experimenter’s practical skills to assess the results correctly. On the other hand, the DIC method allows digital processing of the measured data. However, the problem is not only to determine the data at the edge of the hole, the results also significantly depend on the smoothing levels used. The quantitative comparison of the results obtained was performed using finite element analysis.