Esther Ososanya

Design and implementation of a home automation system for smart grid applications

A home automation system for smart grid is designed and implemented. The system monitors temperature and humidity and controls air conditioning, lights and appliances. The Message Queuing Telemetry Transport protocol and Djanjo web framework are used. A graphical user interface is developed to enable the user to control the devices remotely via a website.

VHDL implementation of the hybrid fuzzy logic controllers with FPGA

In this paper, the VHDL implementation of an intelligent navigation system using hybrid fuzzy controllers has been proposed. Two parallel fuzzy logic controllers are utilized to conquer the major mobile robot navigation challenges in narrow concave U-shaped obstacles, and deep narrow passage, and to track a target in an environment with varying obstacles. The results demonstrate the suitability of the FPGAs in control tasks for multiple fuzzy logic controllers. The implementation of the control units for the robot with FPGA is an important approach in the way for building a real prototype. The proposed algorithm involves fuzzy model of robot navigation system and the hybrid controllers are designed and evaluated based on this models. Such a method will further advance the development of a real-world intelligent control system for performance evaluation of various control strategies in a prototype robotic vehicle.

Numerical modeling and simulation of stable nanowire CdS-CdTe solar cells

Nanowire CdS-CdTe solar cells have been fabricated and their reliability was measured in annealing furnace at 120 °C ambient air for 120 hours. The Numerical simulation models were established to simulate measured J-V characteristics of the nanowire solar cells after fabrication and after the 120 hour thermal annealing. Simulation models demonstrate that donor trap concentration in the CdTe layer is increased from 7.2∗1014/cm3 to 7.6∗1014/cm3 after 120 hour annealing. However, acceptor traps in the CdS nanowires maintain identical concentration after 120 hour annealing. Simulation models indicate that donor traps in the CdTe layer mainly contribute to efficiency loss of the nanowire solar cells. Low defect feature of the CdS nanowires plays a role in device reliability.

Design of Robust Mechatronics Embedded Systems by Integration of Virtual Simulation and Mechatronics Platform

Increasing demands on the productivity of complex systems, such as machine tools and their steadily growing technological importance will require the application of new methods in the product development process. This paper shows that the analysis of the simulation results from the simulation based mechatronic model of a complex system followed by a procedure that allows a better understanding of the dynamic behavior and interactions of the components. Mechatronics is a design philosophy, which is an integrating approach to engineering design. Through a mechanism of simulating interdisciplinary ideas and techniques, mechatronics provides ideal conditions to raise the synergy, thereby providing a catalytic effect for the new solutions to technically complex situations. This paper shows how the mechatronic products can exhibit performance characteristics that were previously difficult to achieve without the synergistic combination.The paper further examines an approach used in modeling, simulation and optimization of dynamic machine tools and adopts it for general optimized design of mechatronics instrumentation and portable products. By considering the machine tool as a complete mechatronic system, which can be broken down into subsystems, forms the fundamental basis for the procedure. Starting from this point of view it is necessary to establish appropriate simulation models, which are capable of representing the relevant properties of the subsystems and the dynamic interactions between the machine components. Many real-world systems can be modeled by the mass-spring-damper system and hence considering one such system, namely Mechatronics Technology Demonstrator (MTD) is discussed here. MTD is a portable low cost, technology demonstrator, developed and refined by the authors. It is suitable for studying the key elements of mechatronic systems including; mechanical system dynamics, sensors, actuators, computer interfacing, and application development. An important characteristic of mechatronic devices and systems is their built-in intelligence that results through a combination of precision, mechanical and electrical engineering, and real time programming integrated to the design process. The synergy can be generated by the right combination of parameters, that is, the final product can be better than just the sum of its parts. The paper highlights design optimization of several mechatronic products using the procedures derived by the use of mass spring damper based mechatronic system. The paper shows step by step development of a mechatronic product and the use of embedded software for portability of hand held equipment.A LabVIEW based platform was used as a control tool to control the MTD, perform data acquisition, post-processing, and optimization. In addition to the use of LabVIEW software, the use of embedded control system has been proposed for real-time control and optimization of the mass-spring-damper system. Integrating embedded control system with the mass-spring-damper system makes the MTD a multi-concepts Mechatronics platform. This allows interface with external sensors and actuators with closed-loop control and real-time monitoring of the physical system. This teaches students the skill set required for embedded control: design control algorithms (model-based embedded control software development, signal processing, communications), Computer Software (real-time computation, multitasking, interrupts), Computer hardware (interfacing, peripherals, memory constraints), and System Performance Optimization. This approach of deriving a mathematical model of system to be controlled, developing simulation model of the system, and using embedded control for rapid prototyping and optimization, will practically speed product development and improve productivity of complex systems.Copyright