Ghulam Abbas

Optimal state-space controller for power switching converter

This paper describes the state-space controller for the buck converter working in Continuous Conduction Mode (CCM). The converter operates at a switching frequency of 500 KHz. Aiming to study the control of this kind of converter, some classical control techniques and the control in the state space are discussed. As an example, we present the design procedure for a dc-dc buck converter with an analog controller in s-domain, and a linear quadratic regulator (LQR). The controller is robust to the load variation and the change in supply and reference voltage. The performance of the controllers is compared and conclusions are drawn. Matlab/Simulink simulated results illustrate that the control system has good static and dynamic characteristics.

Design and analysis of fuzzy logic based robust PID controller for PWM-based switching converter

This paper presents the design and construction of a fuzzy logic based PID controller for the control of a PWM-based dc-dc buck converter working in Continuous Conduction Mode (CCM). The converter operates at a switching frequency of 500 KHz. Fuzzy Logic Toolbox from MATLAB/SIMULINK is used to fuzzify the inputs and their membership functions, express the inference rules linking the input and output variables and defuzzify the output parameter. Generally this approach expresses the advantage of simplicity as no linearized model of the buck converter is required. The simulation results from MATLAB/SIMULINK show that the fuzzy logic based PID control technique provides robust control for non-linear power electronics variable switching structure like the dc-dc buck converter and validates the design.

Fuzzy logic based robust pole-placement controller for DC-DC buck converter

This paper describes the fuzzy logic based robust pole-placement controller for the buck converter working in Continuous Conduction Mode (CCM). The converter operates at a switching frequency of 500 KHz. Pole-placement controller does not show good robustness to the load variations and the change in supply and reference voltages. In order to improve the static and dynamic properties, pole-placement controller supported by decomposed PID fuzzy algorithm is investigated. The performance of both the controllers, pole-placement and optimal pole-placement, is compared and conclusions are drawn. It will be shown that optimal control shows better dynamic performance. MATLAB/SIMULINK based simulation results validate the design.

Comparative analysis of zero order Sugeno and Mamdani fuzzy logic controllers for obstacle avoidance behavior in mobile robot navigation

This paper describes the design, implementation and comparison of zero order Takagi-Sugeno and Mamdani fuzzy logic controllers for hurdle avoidance task performed by a differentially steered mobile robot in indoor navigation. Both the controllers are two inputs, two outputs controllers. The controllers take input from two ultrasonic sensors, perform fuzzy algorithm and generate speed commands for left and right motors. The controllers are designed using fuzzy logic toolbox of MATLAB® and implemented in real time using a low cost, readily available AT89C52 microcontroller. Experimental results have revealed the validity of both the controllers for hurdle avoidance task. Finally, the controllers are compared in terms of smoothness of robot motion generated by the controllers and the memory utilized for their implementation in real time.

Corridor navigation with fuzzy logic control for sonar based mobile robots

This paper proposes and implements a simple fuzzy logic controller for mobile robot navigation in corridor environments. An error signal corresponding to the deviation of robot from the central axis of the corridor forms input to the controller which generates speed commands for the robot to keep it in centre of corridor by minimizing the error signal. The error signal is determined with the help of two ultrasonic sensors mounted on the robot. The controller is realized in real time using an inexpensive 8-bit microcontroller and is tested in a variety of corridor environments to prove its validity.

Design and FPGA implementation of 1-degree-of-freedom discrete PID controller for power switching converter

This paper describes the design, simulation, optimisation and implementation of a 1-Degree-of-Freedom (1-DOF) discrete PID controller for the buck converter working in Continuous Conduction Mode (CCM) based on Field Programmable Gate Array (FPGA) device. The converter operates at a switching frequency of 500 KHz. The elaborated PID control algorithm takes advantage of the conjugation of Xilinx ISE digital designing environment with MATLAB/Simulink simulation and testing environment, through Xilinx System Generator toolbox. This results in a faster and efficient design flow. First the PID controller is designed using Simulink Control Design Toolbox or `sisotool from MATLAB to generate the required set of compensator coefficients to meet the start-up and the transients characteristics. The controller is then realized using Xilinx System Generator (XSG) Blockset. The design example certifies the validity of the classical discrete 1-DOF PID controller as an efficient, more compact and reliable control method for rapid system prototyping for designs developed using the MATLAB/Simulink environment.

Design, low cost implementation and comparison of MIMO Mamdani Fuzzy Logic Controllers for wall tracking behavior of mobile robot

This paper describes the design, implementation and comparison of two Mamdani Fuzzy Logic Controllers for wall tracking behavior of mobile robot. Both the controllers take inputs from two ultrasonic sensors and generate motion commands for left and right motors. The controllers are designed using MATLAB and implemented in real time using an inexpensive and readily available microcontroller, AT89C52. The controllers differ in membership functions and the rule base which provides a mean for their comparison. Experimental results have validated both the controllers; however they exhibit different settling time and percentage overshoot due to the difference in the membership functions and the design of rule base.

Application of neural network based model predictive controller to power switching converters

Neural network based Model Predictive Controller (MPC) for a dc-dc buck converter working in Continuous Conduction Mode (CCM) is presented. The converter operates at a switching frequency of 500 KHz. Although neural networks (NN) have been used in problems involving knotty, non-linearity and uncertainties but here they are applied to a buck converter to control its characteristics. The neural network is trained using ‘trainlm’ method using Neural Network Toolbox. The simulation results show that the neural network model predictive controller depicts better static and dynamic characteristics. The controller is then compared with the classical lead controller. Matlab/Simulink based simulated results validate the design.

Design and implementation of a PWM-based digital controller for a high-frequency dc-dc buck converter working in CCM using classical control techniques

In this paper we describe the complete design and implementation of a digital controller for a dc-dc buck converter working in Continuous Conduction Mode (CCM) using classical control techniques. The converter operates at a switching frequency of 500 KHz. The controller is designed on the basis of digital redesign approach and standard bode plot techniques. The design is then evaluated by taking into account the computation delay. Matlab/Simulink simulated results for the fixed and variable loads are shown to validate the design.

A two loop fuzzy controller for goal directed navigation of mobile robot

This paper describes the design of a two loop fuzzy controller for goal directed navigation of a differentially driven mobile robot in unknown indoor environments. The first loop is responsible for finding a collision free path amongst obstacles while second loop uses this information to steer the mobile robot towards the target in absence of nearby obstacles. The fuzzy controller is designed and visualized with the help of Fuzzy Logic Toolbox in MATLAB environment where its membership functions and rules are tuned to have satisfactory real time results on an inexpensive test bed of two AT89C52 microcontrollers. The real time results obtained in indoor environment containing obstacles validate the proposed controller for goal directed navigation.