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A robust delay‐compensation technique based on memory
Author(s) -
Inaudi José A.,
Kelly James M.
Publication year - 1994
Publication title -
earthquake engineering and structural dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.218
H-Index - 127
eISSN - 1096-9845
pISSN - 0098-8847
DOI - 10.1002/eqe.4290230905
Subject(s) - control theory (sociology) , robustness (evolution) , actuator , compensation (psychology) , group delay and phase delay , computer science , engineering , control (management) , bandwidth (computing) , artificial intelligence , psychoanalysis , gene , computer network , psychology , biochemistry , chemistry
This paper addresses the effects of time delay on actively isolated structures subjected to support excitation. A force proportional to the absolute velocity of the base of the isolated structure applied at the base of the structure (co‐located active damping) is the control scheme considered. The actuating mechanisms have some non‐zero time response. Consequently, if no compensation is provided, the performance of the system is worse than that of the ideal delay‐free controller. The dynamics of the controller‐actuator system is modelled by a delay operator on the feedback signal. Time delays producing instability of the controlled structure are investigated, and the effect of time delay on the mean square acceleration of the structure subjected to stationary random excitation is assessed. A delay‐compensation technique that requires memory of past control actions is proposed and compared with a commonly used compensation technique. By using simple numerical examples, it is shown that the proposed delay‐compensation strategy improves the performance of the system significantly. The technique is extended to other models of the actuator dynamics and modified to provide robustness to small parameter uncertainties.