Incremental Fuzzy Logic Controller Research Articles

A robust FACTS based fuzzy control scheme for dynamic stabilization of generator station

Abstract The paper presents a Flexible Alternating Current Transmission Systems (FACTS) based dynamic stabilization scheme using a modified series–parallel switched filter compensation (MSPFC). The proposed dynamic scheme is controlled by an Incremental Fuzzy Logic controller (MIFLC) to ensure fast response dynamic voltage stabilization and efficient energy utilization. The MIFLC employs a multi loop dynamic error driven time-descaled regulation to ensure the fast response of the dynamic controller. A second Weighted Modified PID controller with fixed gains is assessed with the proposed MIFLC controller. The modified control schemes are validated under normal and fault operating situations to ensure fast dynamic control, ac power quality, feeder loss reduction, efficient energy utilization and dynamic AC voltage stabilization regulation. The performance of the proposed controllers is assessed using statistical studies and qualitative comparison that prove the high ability of the proposed MIFLC compared with modified PID controller.

Online Position Control Performance Improving Applying Incremental Fuzzy Logic Controller

This paper presents the online control system application for improving the DC motor performance. DC motor widely used in industries and many appliances. For this aim fuzzy logic controller is applied. The type of fuzzy controller use is an incremental fuzzy logic controller (IFLC). The IFLC is developed by using MATLAB Simulink Software and implemented in online position control system applying RAPCON board as a platform. The experimental results produced the best gains of the IFLC are 1.785, 0.0056955 and 0.01 for error gain (GE), gain of change error (GCE) and gain of output (GCU) respectively. Its produce smaller rise time, peak time, 0% overshoot and smaller settling time. Beside that the IFLC response also able to follow the set point. The controller response parameters values are also acceptable. It means that the IFLC suitable to be use for improving the position control system performance.

Design of an advanced incremental fuzzy logic controller for laser surface heat treatments

This work presents an innovative incremental PI fuzzy logic controller developed specifically to laser surface heat treatments, analyzing the specific issues related to the monitoring and control of the process. This real time control system improves considerably the treatment uniformity, reducing the rejection rate and increasing the productivity and final quality of the obtained products. An interesting contribution of this work is the characterization of the developed control strategy in terms of several quantitative criteria not usually analyzed, specially the design time and the experience and knowledge needed to develop and tune the control algorithm, without forgetting the classical validation criteria, such as the rise and settling time, the overshoot, and the steady state error, etc.

Fuzzy Control for Pneumatic Muscle Tracking Via Evolutionary Tuning

Abstract This paper studies the evolutionazy design of a fuzzy P+ID controller for an actual pneumatic muscle actuator system. The control of pneumatic muscles is a challenging problem because of their high degree of nonlineazity, time-varying parameters, and uncertainty. A fuzzy P+ID controller is constructed using an incremental fuzzy logic controller in place of the proportional term in a conventional PID controller. Several controller parameters are optimized via an evolutionary algorithm. The optimization is performed using a recurrent neuro-fuzzy dynamic model of the muscle rather than the muscle itself. Control results are presented, where the control objective is to force muscle length to follow a reference signal under a load. After evolutionary design, excellent tracking performance is obtained with the real muscle without the need for further tuning of controller pazameters. The tracking performance is compared to that of another fuzzy controller.

Application of hybrid fuzzy logic proportional plus conventional integral-derivative controller to combustion control of stoker-fired boilers

Combustion control of an industrial stoker-fired boiler is to provide a continuous supply of steam at the desired condition of pressure. Because no efficient mathematical model of the stoker-fired boiler is available, it would be very hard to design its controller by using any traditional model-based method. Therefore, the most widely used controller for the boiler system is a conventional PID-type controller due to its simple control structure and ease of design. However, control performance of the PID-type controller suffers greatly from high uncertainty and nonlinearity of the system, large disturbances and so on. This paper presents a hybrid fuzzy logic proportional plus conventional integral-derivative (FUZZY P+ID) controller to improve the control performance yielded by the PID-type controller. The proposed FUZZY P+ID controller is constructed by using an incremental fuzzy logic controller in place of the proportional term in the conventional PID controller. The basic idea of this study is to reduce the parameters of a fuzzy controller to be tuned so that, in comparison with the PID-type controller, only one additional parameter should be adjusted. The proposed hybrid FUZZY P+ID controller is applied to several stoker-fired boilers. In order to demonstrate the effectiveness of the hybrid controller, the real application results on control of the stoker-fired boilers are reported and analyzed.

Damping multimodal power system oscillation using a hybrid fuzzy controller for series connected FACTS devices

The paper presents a simple hybrid fuzzy logic proportional plus conventional integral controller for FACTS devices in a multi-machine power system. This controller is designed by using an incremental fuzzy logic controller in place of a proportional term in a conventional PI controller and provides a wide variation of controller gains in a nonlinear manner. This controller is well suited to series connected FACTS devices like UPFC, TCSC and TCPST, etc., in damping multi-modal oscillations in a multi-machine environment. Digital simulations of a multi-machine power system subjected to a wide variety of disturbances validate the efficiency of the new approach.

Design of a hybrid fuzzy logic proportional plus conventional integral-derivative controller

Presents approaches to the design of a hybrid fuzzy logic proportional plus conventional integral-derivative (fuzzy P+ID) controller in an incremental form. This controller is constructed by using an incremental fuzzy logic controller in place of the proportional term in a conventional PID controller, By using the bounded-input/bounded-output small gain theorem, the sufficient condition for stability of this controller is derived. Based on the condition, we modify the Ziegler and Nichols' approach to design the fuzzy P+ID controller. In this case, the stability of a system remains unchanged after the PID controller is replaced by the fuzzy P+ID controller without modifying the original controller parameters. When a plant can be described by any modeling method, the fuzzy P+ID controller can be determined by an optimization technique. Finally, this controller is used to control a nonlinear system. Numerical simulation results demonstrate the effectiveness of the fuzzy P+ID controller in comparison with the conventional PID controller, especially when the controlled object operates under uncertainty or in the presence of a disturbance.

Robust Control of Nonlinear Systems Using ‘Self-Adaptive’ Methods and Decoupling Theory

This paper reports on two robust control methods for nonlinear systems based on decoupling theory.Given a plant described by a nonlinear state equation x= f(x) + g(x)u we design a linearizing feedback/decoupling law. Subsequently, for the resulting sub-systems we propose either an incremental fuzzy logic controller or a so. called ‘saturation element’ about an operating point. The emphasize is on the application and comparison of these methods.