T.S. Legotkina - Ph.D. (Eng.), Associate Professor, Department of Automation and Telemechanics, Perm National Research Polytechnic University. E-mail: luda@at.pstu.ac.ru Yu.N. Khizhnyakov - Ph.D. (Eng.), Professor, Department of Automation and Telemechanics, Perm National Research Polytechnic University. E-mail: luda@at.pstu.ac.ru