RST-Controller Design for Sinewave References by Means of an Auxiliary Diophantine Equation

The RST-design of discrete-time controllers is a very handsome method, that brings the solution almost automatically, once the discrete model of the process is known and a model transfer function for the closed loop has been chosen. The cancellation of steady state errors in response to reference signals has been solved a few years ago for polynomial reference signals of any order by the introduction of an auxiliary Diophantine equation. This method has now been extended to sinusoidal references as well, even to a combination of references of both types.