This paper proposes the design of linear quadratic (LQ) digital controller in Ball & Plate model in experimental environment. The non-linear mathematical model of Ball & Plate structure is presented and adequately linearized. Polynomial approach to controller design for two degrees of freedom (2DOF) controller structure is introduced as the main tool for determination of unknown parameters. This method requires placing poles of characteristic polynomial, which are semi-optimally determined using minimization of linear quadratic criterion. This criterion is minimized by spectral factorization with the aid of the Polynomial Toolbox for MATLAB. Experiments have proved that this type of controller is able to stabilize the ball in desired position on the plate, reject external disturbances and follow reference path without much effort. In addition, a simple maze was created on the plate to extend possibilities of the choice of reference signal. The algorithm is able to determine correct path through the maze and navigate the ball along this path.

A virtualization is one of the very progressive fields in information technologies. It is widely used especially in the server virtualization because it offers better usage of hardware resources by using one physical hardware for various virtual host servers. The history of the virtualization starts nearly before fifty years and the development runs from the virtualization of the mainframe to the virtualization on the hardware level. The second IT field which uses a virtualization is a testing and an education which uses a specialized software for virtualization of the operating system. The task of this contribution is to compare a desktop virtualization software from the performance and the hard-disk drive usage point of view. The practical part is focused mainly on the comparison of the VMware Player and the Oracle VM VirtualBox as one of the best-known free software for the desktop virtualization.