摘要：AbstractOne of the difficulties of the tuning of event-based proportional-integral (PI) controllers using symmetric send-on-delta sampling (SSOD) is the appearance of a stable limit cycle, especially when rules designed for continuous control loops are applied. This oscillation is explained by the intersection in the Nyquist map of the system, that is, of the loop transfer function, with the negative reciprocal of the describing function (DF) of the SSOD sampler. However, as the DF theory is based on neglecting the high-order harmonics in the closed loop system, it introduces errors in the prediction of the oscillations. The paper presents an experimental study that establishes the boundaries of the PI controller parameters (proportional and integral gains) that avoid any limit cycle considering that a lag-dominant first order process model is used for the tuning. By taking into account the boundaries, a safety application in an event-based framework of any tuning rule designed for the classical time-driven case is possible.
