This paper explains the basics of the Linear Matrix Inequalities (LMI), with examples ofsimulations and calculations created in Matlab/Simulink programming environment wherethe controlled plant is the “Blue Lady” ship model. First chapter of this paper gives a shortoverview of publications describing the use of Linear Matrix Inequalities method. Secondchapter contains basic definitions and equations for the LMI method. Chapter three presentsthe use of LMI method for ship control by describing controller synthesis for the “BlueLady”. Chapter four compares the operation of two controllers, the first one consisting ofthree independent proper adjusted PID controllers and the second one being a multivariable LMI controller.Finally conclusions from the above comparison are drawn.
