eng Science and Education Publishing Journal of Automation and Control 2372-3041 2015-12-15 3 3 79 82 10.12691/automation-3-3-8 AUTOMATION2015338 article Alexander Gmiterko 1 Ivan Virgala 1 Lubica Miková 1 Peter Frankovsky 1 Tatiana Kelemenová 1 Michal Kelemen michal.kelemen@tuke.sk 1 Department of Mechatronics, Technical University of Kosice, Faculty of Mechanical Engineering, Kosice, Slovak Republic The paper deals with in-pipe machines based on directional friction and inertial stepping principle. Both type are developed for inner pipe with diameter 11 mm. The main purpose is inspection of inner pipe wall as prevention of cracks. http://pubs.sciepub.com/automation/3/3/8/automation-3-3-8.pdf In-pipe machine locomotion insert template