Control of systems with time-varying delay: A comparison study

Abstract

This contribution is focused on control of single-input single-output (SISO) systems containing harmonically time-varying delay. Three different approaches to continuous-time control are studied and compared. The first technique utilizes a modified PI-PD Smith predictor in a combination with standard forms for minimum of integral squared time error (ISTE). The second methodology exploits a Coefficient Diagram Method (CDM) for another modified Smith predictor structure. And finally, the third approach to synthesis is based on general solutions of Diophantine equations in the ring of proper and Hurwitz-stable rational functions (RPS) for a classical feedback control loop. The comparison of proposed methods is accomplished through a simple simulation example.