An improved auto-tuning scheme for PID controllers

Abstract

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 high-order 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.

Pressure Control for a Hydraulic Cylinder Based on a Self-Tuning PID Controller Optimized by a Hybrid Optimization Algorithm

“…One is the practical tuning method. Since 1942, when Ziegler-Nichols (Z-N) straightforward tuning was proposed, many improved methods, based on the Z-N, have been studied [29][30][31][32][33]. Another is the intelligence algorithm for tuning parameters tuning.…”

Multivariable PID Decoupling Control Method of Electroslag Remelting Process Based on Improved Particle Swarm Optimization (PSO) Algorithm

“…The self-tuning and optimization of the PID controller parameters is a very important research field [8,9]. With the rapid development of swarm intelligent theory, many PID controller parameters self-tuning methods based on the swarm intelligent theory appeared, such as genetic algorithm (GA), particle swarm algorithm (PSO), etc.…”

Intelligent control of static synchronous series compensator via an adaptive self-tuning PID controller for suppression of torsional oscillations

“…The conventional PID controller with fixed gains may usually deteriorate the controller performance. Various types of modified PID controllers have been developed such as intelligent PID controller [12], self-tuning discrete PID controller [13], self-tuning predictive PID controller [14] and fuzzy adaptive [15]. However, if severe nonlinearity is involved in the controller process, an adaptive control scheme will be more useful, particularly in the case of power systems.…”