Utilization of Maximum Sensitivity in Control Quality Indication

For the needs of industrial practice a new controller parameter setting method has been presented recently. It is based on experimentally performed evaluation of excited frequency responses with the aim to achieve the recommended values of one or more control quality indicators known from course of the Nyquist plot. Unlike their linear origin, the indicators can be obtained in control loops involving nonlinearities even in the controller. In this sense, the method has philosophy similar to the popular Ziegler and Nichols method. For its implementation no mathematical model and theory is required. All processing is carried out by a program added to the control algorithm. No additional instrumentation is necessary. For a good software solution some investigation concerning choice of the indicator and processing of frequency responses need to be investigated. This is the main subject that the paper is reporting about.