Van der Pol's oscillator under delayed feedback

Abstract

The effect of delayed feedback on oscillatory behaviour is investigated for the classical van der Pol oscillator. It is shown how the presence of delay can change the amplitude of limit cycle oscillations, or suppress them altogether. The result is compared to the conventional proportional-and-derivative feedback. The derivative-like effect of delay is also demonstrated in a modified equation where a delayed term provides the damping. (C) 1998 Academic Press.