Transients in reconfigurable control loops

Transient reduction in control loops in case of joint plant-controller reconfiguration

“…If the controller (C) is reconfigured, and steady-state statevariable values of the controller are different before and after switching, then a transient phenomenon will appear, unless proper initialization of the state variables is performed [4]. State adjustment is an obvious alternative in the case of processor-based digital controllers where state variables are available and can easily be modified.…”

“…This controller reconfiguration should be carried out in a way that the reconfiguration of the controller does not induce additional transients, and with the reconfiguration of controller the plant's transients are also canceled or decreased. This first goal can be reached by the adequate initialization of the new controller [4], but this technique is not powerful enough to handle the plant's transients as well. For this purpose an extra anti-transient signal is proposed, which is produced by the Transient Controller (see Fig.…”

“…• Initialize the controller's states to provide smooth transition [4], neglecting the transients possibly caused by the plant's reconfiguration.…”

“…Such systems can be characterized by a number of distinct operational modes [2], [3]. If there is an "energy content" mismatch between the subsequent modes of the dynamical system, then reconfiguration transients are unavoidable [4]. The transients may be harmful, therefore undesirable, so they should be limited, or possibly reduced.…”

“…Quite recently the case of controller reconfigurations was studied by the authors, and different solutions were proposed, e.g. choice of proper structures [5], and online transient management techniques [4]. This paper introduces novel transient control strategies for simple feedback loops, where, under certain conditions, the plant, or both the plant and the controller simultaneously, are switched to a new operational mode.…”