STABILITY ANALYSIS OF A RELAY FEEDBACK STRUCTURE FOR PROCESSES UNDER DISTURBANCES USING POINCARÉ MAP

Abstract

In this paper, based on Poincaré map, it is analysed the stability of a relay feedback structure that provides a stable and symmetrical oscillation for process under large static disturbances or drift. The relay feedback structure consists of a block which removes static disturbance or drift followed by a relay. The block is composed of a simple high-pass filter followed by a relay plus an integrator. In order to simplify the analysis, an equivalent relay structure is obtained. Thus, for this relay feedback structure, the conditions of existence and local stability of the limit cycle obtained by the relay feedback structure for linear time-invariant (LTI) systems with no delay time are obtained. Simulation studies illustrate the results.