Positive use of time-delay actions in control systems

Abstract

A new type of controller, which utilizes the time-delay effect, is proposed. It is shown that the conventional P-controller equipped with an appropriate time-delay performs an averaged derivative action and thus can replace the PD-controller, and also the PI-controller equipped with an appropriate time-delay can replace the PID-controller, showing quick responses to input changes but being insensitive to high-frequency noise.