Ultimate parameters in control technology

Ultimate parameters, i.e. the ultimate gain and the ultimate period have frequent use in the control technology. With the help of these parameters an appropriate controller can be tuned without knowledge of a plant mathematical model, or on the other side an approximate plant mathematical model can be determined on their basis. It is often assumed that the plant model includes time delay. The converse problem, i.e. the determination of the ultimate parameters, is mostly very difficult task because of the time delay existence which is represented by the transcendental function in the complex variable domain. The paper is devoted to determining and employing of ultimate parameters for the common plants with time delay. Most of the obtained results are new and they are presented in the form of transparent tables.