NREC

An improved auto-tuning scheme for PID controllers

متد بهینه سازی خودکار کنترلر های PID

این مقاله در خصوص بهبود و توسعه شیوه زیگلر نیکولز جهت بهینه سازی کنترلر های pid نوشته شده

An improved auto-tuning scheme is proposed for Ziegler Nichols (ZN) tuned PID controllers (ZNPIDs),
which usually provide excessively large overshoots, not tolerable in most of the situations, for high-order
and nonlinear processes. To overcome this limitation ZNPIDs are upgraded by some easily interpretable
heuristic rules through an online gain modifying factor defined on the instantaneous process states. This
study is an extension of our earlier work [Mudi RK., Dey C. Lee TT. An improved auto-tuning scheme for PI
controllers. ISA Trans 2008; 47: 45 52] to ZNPIDs, thereby making the scheme suitable for a wide range of
processes and more generalized too. The proposed augmented ZNPID (AZNPID) is tested on various highorder
linear and nonlinear dead-time processes with improved performance over ZNPID, refined ZNPID
(RZNPID), and other schemes reported in the literature. Stability issues are addressed for linear processes.
Robust performance of AZNPID is observed while changing its tunable parameters as well as the process
dead-time. The proposed scheme is also implemented on a real time servo-based position control system.
' 2009 ISA. Published by Elsevier Ltd. All rights reserved.