ANALYSIS AND CONTROL OF NON-MINIMUM PHASE LINEAR SYSTEMS

Abstract

In this dissertation, non-minimum phase linear systems are studied and analyzed for unique-time domain characteristics. The analysis is done to identify the presence of these characteristics-zero-crossings, overshoot (due to zeros) and initial undershoot in step response of both continuous-time and discrete-time non-minimum phase systems. These characteristics impede the process to reach the desired value, and thus requires special attention. For these characteristics, generalized theorems to detect the presence in the step response are discussed. In addition to this, new theorems are proposed for detection of initial undershoot in both step and impulse responses, using either the transfer function or the state-space model of the system. The utility of the theorems is elucidated using di erent practical systems, modelled in both transfer function and state-space forms. Moreover, the analysis of the percentage of initial undershoot is also done, which is aimed at serving for the design of linear controllers for such systems. The viability of this analysis is shown by its application on the design policy of classical as well as modern control techniques such as Internal Model Control (IMC), Active Disturbance Rejection Control (ADRC), etc.