A Robust Relay Feedback Structure for Processes Under Disturbances: Analysis and Applications

Journal of control, automation and electrical systems

article

da Silva, Moisés T.¹  Barros, Péricles R.¹ 

[1] Department of Electrical Engineering, Federal University of Campina Grande (UFCG)

关键词: Relay feedback;    Disturbances;    Poincaré map;    FOPTD models;   

DOI  :  10.1007/s40313-019-00512-8

学科分类：自动化工程

来源: Springer

【 摘 要 】

In this paper, a robust relay feedback structure is used to provide a stable oscillation under large static disturbances or drift. This relay structure is composed of a block to remove static disturbance or drift followed by a relay. The robust relay structure is analyzed using the describing function method. Furthermore, based on Poincaré map, the conditions for the existence and local stability of the limit cycle are obtained. In order to estimate multiple frequency points of the process, a step change and periodic square waves with frequencies lower than the ultimate frequency are applied at the process input. Thus, these frequencies information are used to identification of first-order plus time delay models over a wider frequency region. For these models, a phase adjustment is proposed from the frequencies information of the additional signal. From simulated and experimental studies, it is verified that the robust relay structure provides a symmetrical oscillation at the process output, independent of the disturbance in the process input and iterations between the loops.

【 授权许可】

CC BY