Open AccessTrust‐region reflective adaptive controller for time varying systems
Author(s) -
Moubarak Paul M.
Publication year - 2015
Publication title -
iet control theory and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.059
H-Index - 108
eISSN - 1751-8652
pISSN - 1751-8644
DOI - 10.1049/iet-cta.2014.0380
Subject(s) - control theory (sociology) , trac , controller (irrigation) , parametric statistics , computer science , signal (programming language) , process (computing) , adaptive control , control system , time domain , heuristic , control (management) , engineering , mathematics , artificial intelligence , statistics , electrical engineering , agronomy , computer vision , biology , programming language , operating system
The new algorithm presented in this study, called TRAC (trust‐region reflective adaptive controller), performs online adaptive control of time‐varying linear or linearisable systems subject to parametric disturbances. The process of accomplishing such adaptive control consists of feeding the measured output signal back to TRAC – which occupies the outer loop of a control scheme – as well as the reference signal. Knowing the order of the closed‐loop system in the inner loop, a parametric model of the time‐varying output is derived as a function of the system's variables, such as damping and natural frequencies. Using trust‐region optimisation, these parameters are estimated in real‐time by recursively fitting the actual output into the parametric model. This allows for the location of the actual poles to be estimated in the s ‐domain after the poles have been shifted by the disturbance. Accordingly, the gains are re‐tuned in order to return the actual poles to their desired location and absorb the disturbance. The primary advantage of TRAC relative to the state‐of‐the‐art is its computational simplicity which is owed to search space restriction and heuristic approximations with trust‐region search. A video of a sample application describing real‐time TRAC‐based control can be found on the IET's Digital Library.