On-line multiobjective automatic control system generation by evolutionary algorithms

Evolutionary algorithms are applied to the on- line generation of servo-motor control systems. In this paper, the evolving population of controllers is evaluated at run-time via hardware in the loop, rather than on a simulated model. Disturbances are also introduced at run-time in order to pro- duce robust performance. Multiobjective optimisation of both PI and Fuzzy Logic controllers is considered. Finally an on-line implementation of Genetic Programming is presented based around the Simulink standard blockset. The on-line designed controllers are shown to be robust to both system noise and ex- ternal disturbances while still demonstrating excellent steady- state and dvnamic characteristics

Improvement of flight simulator feeling using adaptive fuzzy backlash compensation

In this paper we addressed the problem of improving the control of DC motors used for the specific application of a 3 degrees of freedom moving base flight simulator. Indeed the presence of backlash in DC motors gearboxes induces shocks and naturally limits the flight feeling. In this paper, dynamic inversion with Fuzzy Logic is used to design an adaptive backlash compensator. The classification property of fuzzy logic techniques makes them a natural candidate for the rejection of errors induced by the backlash. A tuning algorithm is given for the fuzzy logic parameters, so that the output backlash compensation scheme becomes adaptive. The fuzzy backlash compensator is first validated using a realistic model of the mechanical system and is actually tested on the real flight simulator

Performance comparison between PID and fuzzy logic controller in position control system of dc servomotor

The objective of this paper is to compare the time specification performance between conventional controller and artificial intelligence controller in position control system of a DC motor. This will include design and development of a GUI software using Microsoft Visual Basic 6.0 for position control system experiment. The scope of this research is to apply direct digital control technique in position control system. Two types of controller namely PID and fuzzy logic controller will be used to control the output response. An interactive software will be developed to visualize and analyze the system. This project consists of hardware equipment and software design. The hardware parts involve in interfacing MS150 Modular servo System and Data Acquisition System with a personal computer. The software part includes programming real-time software using Microsoft Visual Basic 6.0. Finally, the software will be integrated with hardware to produce a GUI position control system

Fuzzy efficiency optimization of AC induction motors

This paper describes the early states of work to implement a fuzzy logic controller to optimize the efficiency of AC induction motor/adjustable speed drive (ASD) systems running at less than optimal speed and torque conditions. In this paper, the process by which the membership functions of the controller were tuned is discussed and a controller which operates on frequency as well as voltage is proposed. The membership functions for this dual-variable controller are sketched. Additional topics include an approach for fuzzy logic to motor current control which can be used with vector-controlled drives. Incorporation of a fuzzy controller as an application-specific integrated circuit (ASIC) microchip is planned

Intelligent active force control of a three-link manipulator using fuzzy logic

The paper presents a novel approach to estimate the inertia matrix of a robot arm using a fuzzy logic (FL) mechanism in order to trigger the active force control (AFC) strategy. A comprehensive study is performed on a rigid three-link manipulator subjected to a number of external disturbances. The robustness and effectiveness of the proposed control scheme are investigated considering the trajectory track performance of the robotic arm taking into account the application of external disturbances and that the arm is commanded to describe a reference trajectory given a number of initial and operating conditions. The results show that the FL mechanism used in the study successfully computes appropriate estimated inertia matrix value to execute the control action. The proposed scheme exhibits a high degree of robustness and accuracy as the track error is bounded within an acceptable range of value even under the influence of the introduced disturbances

Torque Ripple Minimization in a Switched Reluctance Drive by Neuro-Fuzzy Compensation

Simple power electronic drive circuit and fault tolerance of converter are specific advantages of SRM drives, but excessive torque ripple has limited its use to special applications. It is well known that controlling the current shape adequately can minimize the torque ripple. This paper presents a new method for shaping the motor currents to minimize the torque ripple, using a neuro-fuzzy compensator. In the proposed method, a compensating signal is added to the output of a PI controller, in a current-regulated speed control loop. Numerical results are presented in this paper, with an analysis of the effects of changing the form of the membership function of the neuro-fuzzy compensator.Comment: To be published in IEEE Trans. on Magnetics, 200

Alone Self-Excited Induction Generators

In recent years, some converter structures and analyzing methods for the voltage regulation of stand-alone self-excited induction generators (SEIGs) have been introduced. However, all of them are concerned with the three-phase voltage control of three-phase SEIGs or the single-phase voltage control of single-phase SEIGs for the operation of these machines under balanced load conditions. In this paper, each phase voltage is controlled separately through separated converters, which consist of a full-bridge diode rectifier and one-IGBT. For this purpose, the principle of the electronic load controllers supported by fuzzy logic is employed in the two-different proposed converter structures. While changing single phase consumer loads that are independent from each other, the output voltages of the generator are controlled independently by three-number of separated electronic load controllers (SELCs) in two different mode operations. The aim is to obtain a rated power from the SEIG via the switching of the dump loads to be the complement of consumer load variations. The transient and steady state behaviors of the whole system are investigated by simulation studies from the point of getting the design parameters, and experiments are carried out for validation of the results. The results illustrate that the proposed SELC system is capable of coping with independent consumer load variations to keep output voltage at a desired value for each phase. It is also available for unbalanced consumer load conditions. In addition, it is concluded that the proposed converter without a filter capacitor has less harmonics on the currents

Nov i jednostavan hibridni neizraziti/PI regulator za istosmjerne motore bez četkica

A novel speed controller for the trapezoidal three--phase Brushless DC (BLDC) Motor Drive is proposed using a hybrid fuzzy logic and proportional plus integral (PI) control. The fuzzy logic control structure is different from conventional fuzzy logic implementations such that it only uses three simple rules based on speed error being either in the positive, negative or zero regions. The controller outputs a reference current, that is enforced through the motor phases by pulsewidth modulation (PWM) control. The proposed fuzzy logic controller can be used individually in applications requiring lower computation load and accepting small steady state offset. For high performance applications requiring offset free tracking, a PI controller is augmented with the fuzzy logic controller and a simple switching scheme is devised based on error variance to switch the active controller based on operating conditions. The response of the drive system under the proposed composite control structure is compared with the conventional PI based and the sliding mode controllers to demonstrate its improved performance. Simulations studies using detailed models in MATLAB/Simulink\u27s Simpowersystems toolbox are carried out to show the validity of proposed control.U ovome radu predlaže se nov regulator brzine za trapezoidalne trofazne istosmjerne motore bez četkica zasnovan na hibridnom regulatoru. Hibridni regulator sastoji se od dijela s neizrazitom logikom i proporcionano-integracijskog regulatora. Struktura neizrazitog regulatora razlikuje se od konvencionalnih implementacija neizrazitih regulatora po tome što koristi samo tri jednostavna pravila zasnovana na pogrešci brzine u pozitivnom, negativnom ili nultom području. Izlaz regulatora čini referentna struja, koja se šalje na faze motora pomoću širinsko-impulsne modulacije. Predloženi neizraziti regulator može se koristiti i zasebno u primjenama koje zahtijevaju manju računsku složenost i toleriraju malu pogrešku u stacionarnom stanju. Za slučajeve kada je potrebna visoka učinkovitost bez pogreške u stacionarnom stanju, s neizrazitim dijelom proširuje se PI regulator te je razvijen jednostavan postupak promijene regulatora zasnovan na varijanci pogreške. Odziv razmatranog sustava uspoređen je s konvencionalnim PI regulatorom i regulatorom u kliznom režimu rada kako bi se pokazala njegova učinkovitost. Izvršene su simulacije u Matlab/Simulinkovom SimPowerSystems alatu kako bi se pokazala ispravnost predloženog postupka