Yasir Saleem

Modeling and control of magnetic levitation system via fuzzy logic controller

Fuzzy logic controller (FLC) is an attractive alternative to existing classical or modern controllers for designing the challenging Non-linear control systems. It does not require any system modeling or complex mathematical equations governing the relationship between inputs and outputs. Fuzzy rules are very easy to learn and use, even by non-experts. It typically takes only a few rules to describe systems that may require several lines of conventional software code, which reduces the design complexity. By considering these advantages, this paper presents the design and analysis of a FLC controller for the magnetic levitation system. Additionally, a classical PID controller is also designed to compare the performance of both types of controllers. Results reveal that FLC found to give better transient and steady state results compare to the classical PID.

Control system design of UPFC for optimal power flow control

Electrical power system is a large interrelated set-up, which requires a cautious design in order to supply continuous electricity to consumers without any divergence. Power electronics based Flexible Alternating Current Transmission Systems (FACTS) are devices, which are used to perk up the power system reliability and stability. Unified power flow controller (UPFC), which comes under the member of FACTS devices is used for sole purpose of active power flow control on a transmission system and recuperation of power system stability. Though, a systematic design is required to attain such a functionality of UPFC. The paper illustrates a robust design of UPFC control system using state-space equations. A complete mathematical model is presented which consists of d-q representation of Shunt and Series Voltage Source Converter (VSC) of UPFC. The validation of proposed scheme is done using MATLAB/Simulink, where a complete power system was modeled and simulated with and without UPFC in order to verify the proposed scheme. The result shows that UPFC (based on our proposed control system) can faithfully manage the real power flow on a transmission system at receiving end without affecting the system stability.

Small signal stability analysis of an AC/DC hybrid power electronic system

Power electronic circuits are now widely used in latest technologies that range from automobiles to mobile phones and many more such areas encountering our day to day life. Small signal methods are widely used for modeling power electronic circuits. This modeling technique gives an exact model which is quite suitable for analyzing a circuit sampled at switching frequency. The target of this research is analysis of the accuracy of small signal method while analyzing the stability of simulated circuits. This paper presents a case study using different parameters for small signal modeling of different modules of a power electronic circuit including power source, conversion and load.

Single input fuzzy logic controller for magnetic levitation system

Fuzzy logic controller (FLC) is an attractive alternative to existing classical or modern controllers for designing the challenging Non-linear control systems. However conventional FLC (CFLC) performance is greatly dependent on its inference rules. In most cases, the more rules being applied to a FLC, the accuracy of the control action is enhanced at the expense of longer computational time. As a result, FLC implementation requires fast and high performance processors. In this paper, it is shown that the inference rule table of a two-input FLCs used to control a magnetic levitation system can be reduced to a Single Input Fuzzy Logic Controller (SIFLC), which can be easily implemented using a lookup table. Simulated results are presented to demonstrate the equivalency of SIFLC and CFLC.

Control of torque in switched reluctance motor

Switched reluctance motor is gaining large interest of industry due to it mechanical simplicity, ruggedness behavior and low cost. On the other hand its advantages are over shadowed by need of intelligent control for its inherent issues like torque ripple, acoustic noise and high non linear characteristics. This paper focuses on torque ripple issue and its reduction through phase current control. Two quadrant and four quadrant chopper operation is discussed mathematically and simulated in Matlab, results aided with graphs are discussed to conclude which drive provides better control over phase currents.

A Novel technique for Optimization of Generic SRM Drive

The switched reluctance motor is an aged member of the electric machine family. Its simple structure, rugged behavior, and economical manufacture ability makes them attractive for industrial applications. However, these merits are over shadowed by its inherently nonlinear characteristics, acoustic noise, and complexity of control. This paper discusses the practical approach of finding optimum drive parameters to control switched reluctance motor. The technique mentioned in this paper requires the test run of motor at given speed and torque for formation of lookup tables referred as training mode and then motor can be switched to normal run referred as operational mode. Eventually this technique does lead to low cost control of switched reluctance machines.

Multimedia based student-teacher smart interaction framework using multi-agents in eLearning

Multimedia content comprises the graphics, audio & video clips, animation and text to present learning materials in a style, which improves learner expectation in eLearning paradigm. Electronic learning gained the popularity due to its immense coverage of students and subjects all over the world. The aim of this study is enhancements using agent-based framework through multimedia data in eLearning paradigm. Analysis of multimedia contents and eLearning data are helpful for the course designers, teachers, and administrators of eLearning environments to hunt for undetected patterns and underlying data in learning processes. This research improves the learning curves for the students. It also needs to improve the overall processes in eLearning paradigm. Information and Communication Technologies supported education, and virtual classrooms environments are mandatory. In eLearning data is evolving day by day that includes the semi-structured data, unstructured data, and structured data which is also collectively marked as multimedia big data. Multimedia data has the potential to mining for the analytics and learning. The learning outcomes for the students are very important to find the facts that what impacts the input data on the student. There are 1108 students posted questions in online Learning Management System (LMS) and instructors reply these queries. Sensor data is also gathered by the mobile GPS to find the student location. The system has analyzed the relevance of the replied answers. The student satisfaction is achieved by providing the multimedia-based student-teacher interaction. This can lead to synchronous communication and multimedia content conversation in eLearning paradigm. Machine learning techniques are applied to that data to discover the patterns and behavioral trends. It can also be used in the eLearning environments for the teacher to assist and enhance the pedagogical skills and for student’s learning curve enhancements.

Multimedia based IoT-centric smart framework for eLearning paradigm

Multimedia content boosts the learning trends. This paper is aimed to presents an electronic learning system based on Internet of Things (IoT) for the synchronous and asynchronous communications. The infrastructure of IoT provides the adaptable, scalable and open access for the eLearning paradigm. The multimedia-based IoT-centric environment is suitable to enhance the effectiveness of the delivery of learning contents. Students can take full advantage of 7As of IoT, which provides the opportunity to the students that they can access everything on the internet at any time and place. It creates a flexible eLearning paradigm for the teachers and students. The proposed eLearning modeluses sensors to detect the student location, temperature, and mobile camera to identify the student activeness in thelearning environment. Virtual campuses are controlled from a centralized location that may be called the head office. The MAQAS framework provides the solutions to the problems and analyzes the results for the efficient and connected eLearning paradigm. The MAQAS system is used to answer student’s queries, which are responded to automatically by agent-based question answering system. The results show that the students’ participation towards learning and teacher’s pedagogy are more efficient in synchronous and asynchronous modes. Performance evaluated by comparison to the existing question answering Live QA Trak, Quora Yoda QA Live and AskMSR-QA with MAQAS.

Modified Mobile Transaction Authentication Number System for 2-layer security

Mobile phones are commonly used by web servers to validate users identification and authentication. It enhances users trust in online transactions and empowers him to use his mobile phone network as an additional layer of security. This mechanism is known as Mobile Transaction Authentication Number System (mTAN) which is used by e-banks and social media sites. This system has some weakness and users are still vulnerable to serious security risks. Unauthorized individuals can find their ways to get unauthorized access in traditional mTAN system. In this paper, security risks associated with current mTAN system are discussed and some modifications in existing system are proposed for using mTAN in a more secure way.

A simplified yet effective fuzzy logic controller for chemical ship tanker

This paper proposes a simplified yet effective control scheme to design a fuzzy logic controller (FLC) for the ship tanker. The proposed method exploits the feature of signed distance method for reducing the conventional two-input FLC (CFLC) into a piecewise linear single input FLC (PWL-FLC). It has been shown that the proposed FLC has a similar structure to the CFLC, exhibiting analogous control performance. However, the main features of the proposed method are the absence of fuzzification, rule inference and defuzzification processes that are essential for CFLC implementation. The proposed PWL-FLC could be easily programmed into a low cost microcontroller using just a look-up table. To authenticate its effectiveness, the control algorithm has been implemented using the marine system simulator in Matlab/Simulink ® platform. The result signifies that both the PWL-FLC and CFLC results in identical functioning performance; however, the former requires least possible tuning effort and its execution time is in the orders of three magnitudes less than its conventional counterpart.