Ziegler-Nichols tuned PI and PID controllers are usually found to provide poor performances for high-order and nonlinear systems. In this study, an improved auto-tuning scheme is presented for Ziegler-Nichols tuned PI controllers (ZNPICs). With a view to improving the transient response, the proportional and integral gains of the proposed controller are continuously modified based on the curren...

We propose a robust non-fuzzy self-tuning scheme for fuzzy PI controllers (FPIC) for a class of systems. The output scaling factor (SF) of the proposed non-fuzzy self-tuning FPIC, termed as NF-STFPIC, is modified on-line based on the normalized change of error of the controlled variable. Performance of the proposed controller is evaluated for a pure integrating plus dead-time (IPD) and first-or...

This paper derives proportional-integral (PI) control algorithms for first-order plants with time lag. First, the effects of proportional control on overshoot and rise time are analyzed. Then these results are applied to aid in the design of PI controllers that utilize a pole-zero cancellation. New PI tuning methods are proposed for design criteria typical of those found in metal rolling mill a...

Abstract— This paper presents a comparative analysis of speed control in brushless DC motor (BLDC motor) using proportional-integral (PI) controller and Fuzzy logic controller (FLC). The controllers were analyzed under no load and loaded condition of the motor. The various parameters such as settling time, peak over shoot, steady state error, and mean square error were calculated and compared f...

In this paper we study a previously developed linearized model of TCP and AQM. We use classical control system techniques to develop controllers weU suited for the application. The controllers are shown to have better theoretical properties than the wetll known RED controller. We present gnidetines for designing stable controllers subject to network parameters tike load level, propagation delay...

In this paper we study a previously developed linearized model of TCP and AQM. We use classical control system techniques to develop controllers well suited for the application. The controllers are shown to have better theoretical properties than the well known RED controller. We present guidelines for designing stable controllers subject to network parameters like load level, propogation delay...

A new design method of fractional-order proportional-integral controllers is proposed based on fractional calculus and Bode's ideal transfer function for a first-order-plus-dead-time process model. It can be extended to be applied to various dynamic models. Tuning rules were analytically derived to cope with both set-point tracking and disturbance rejection problems. Simulations of a broad rang...

Continuous Stirred Tank Reactor (CSTR) has particular importance in chemical industry. CSTR has usually a nonlinear behavior which makes it difficult to control. The reactor has two parameters: the concentration and temperature of mixture both of which are uncertain. This case of CSTR has large disturbance in domain. In order for disturbance rejection, a controller has to be designed. In this p...

The paper addresses design, implementation and simulation of a novel type of softly switched Takagi-Sugeno fuzzy PI control system for dissolved oxygen concentration (DO) tracking at wastewater treatment plant (WWTP). The proposed control system is designed, including tuning the PI controllers, entirely based on the experimental data. This control system is validated by simulation. Copyright © ...