Riza Muhida

Efficiency improvement of solar cell using compound parabolic concentrator and sun tracking system

This paper presents how the efficiency of solar cell can be increased with the design of compound parabolic concentrator (CPC) and the implementation of sun tracking system. Sun tracking systems is an application of the machine vision (MV) and collaboration with data acquisition (DAQ) to systems by using a webcamera as a sensor and sound card as an output channel to drive a motor. The motors will react as the mechanism of the camera to make sure it always focuses on the target of sun. By using a MatLab software programming environment, closes loop control is implemented to provide interaction between camera and sound card as a device to control the motor to track the sun. Sun tracking system with webcamera will be an effective tool to increase the efficiency of the solar cells. Camera is the sensor of the system, be an eye of the human to take care and observe the sun. As soon the sun can be tracked with the CPC, the voltage, current and power received will always be at the maximum of the efficiency. This research could provide significant improvement in alternative energy.

Solid Phase Crystallization in Initial Growth Region of Polycrystalline Silicon Layer During Deposition at 180°C by Plasma Chemical Vapor Deposition

Microstructures of low-temperature-grown polycrystalline Si (poly-Si) have been studied by transmission electron microscope measurements. Two poly-Si layers with different thicknesses in the n-i-p structure were prepared by plasma chemical vapor deposition at 180°C. The ~50-nm-thick amorphous-rich layer is observed at the bottom of the 0.5-µm-thick poly-Si layer. Meanwhile, in the first hundreds of nanometers in the 2.4-µm-thick poly-Si layer, an increase in the crystalline fraction due to crystalline columns grown onto the substrate n-layer is found. Solid phase crystallization during the deposition in the initial growth region down to the substrate is discussed.

Control Strategy for Automatic Gantry Crane Systems: A Practical and Intelligent Approach

The use of gantry crane systems for transporting payload is very common in building constructions. However, moving the payload using the crane is not an easy task especially when strict specifications on the swing angle and on the transfer time need to be satisfied. Various attempts in controlling gantry cranes system based on open- loop and closed-loop control systems were proposed. However, most of the proposed controllers were designed based on the model and parameter of the crane system. In general, modeling and parameter identifications are troublesome and time consuming task. To overcome this problem, in this paper, a practical and intelligent control method for automatic gantry crane is introduced and evaluated experimentally. The results show that the proposed method is not only effective for controlling the crane but also robust to parameter variation.

Solar cell efficiency improvement using compound parabolic concentrator and an implementation of sun tracking system

This paper presents how the efficiency of solar cell can be increased with the design of compound parabolic concentrator and the implementation of sun tracking system. Sun tracking systems is an application of the machine vision (MV) and collaboration with data acquisition (DAQ) to systems by using a Web camera as a sensor and sound card as an output channel to drive a motor. The motors react as the mechanism of the camera to make sure it always focuses on the target of sun. By using a MatLab software programming environment, closes loop control is implemented to provide interaction between camera and sound card as a device to control the motor to track the sun.

State of the art review on walking support system for visually impaired people

The technology for terrain detection and walking support system for blind people has rapidly been improved the last couple of decades but to assist visually impaired people may have started long ago. Currently, a variety of portable or wearable navigation system is available in the market to help the blind for navigating their way in his local or remote area. The focused category in this work can be subgroups as electronic travel aids (ETAs), electronic orientation aids (EOAs) and position locator devices (PLDs). However, we will focus mainly on electronic travel aids (ETAs). This paper presents a comparative survey among the various portable or wearable walking support systems as well as informative description (a subcategory of ETAs or early stages of ETAs) with its working principal advantages and disadvantages so that the researchers can easily get the current stage of assisting blind technology along with the requirement for optimising the design of walking support system for its users.

Guaranteed robust state feedback controller via constrained optimization using Differential Evolution

Computational intelligence has been successfully applied into many engineering applications including control engineering problems. In this paper, a robust state feedback control design via constrained optimization based on Differential Evolution (DE) is proposed. The feedback controller is designed based on state space model of the plant with structured uncertainty such that the closed-loop system would have maximum stability radius. A wedge region is assigned as a constraint to locate desired closed loop poles. The proposed method is applied into design of anti-swing control of an automatic gantry crane. The experimental result is shown and comparison with that of LQ (linear quadratic) optimal controller is made. The proposed method effectively locates the closed loop poles within the prescribed wedge region and its robust performance is guaranteed.

Virtual Simulation and Remote Desktop Interface for CNC Milling Operation

Advanced development of computer network through Internet brings the technology to Manufacturing. Increasing the demand for effectively use of the production facility requires the tools for sharing the manufacturing facility by remote operation of the machining process. This paper introduces the methodology of machining technology for direct remote operation of networked milling machine. The tools including virtual simulation using CAD model, remote desktop protocol and Setup Free Attachment for remote operation of milling process are proposed. Accessing and monitoring of machining operation is performed by remote desktop interface and 3D virtual simulations. Capability of remote operation is supported by an auto setup attachment with a reconfigurable pin type setup free technology installed on the table of CNC milling machine to perform unattended machining process. The system is designed using a computer server and connected to a PC based controlled CNC machine for real time monitoring. A client will access the server through internet communication and virtually simulate the machine activity. The result has been presented that combination between real time virtual simulation and remote desktop tool is enabling to operate all machine tool functions and as well as workpiece setup.

Relationship between average slope of textured substrate and poly-Si thin film solar cells performance

Abstract This paper presents a nanoscopic characterisation of a series of textured substrates with a structure of Ag-grid/ZnO/p-i-n/ZnO/Ag/SnO2/glass for poly-Si thin film solar cells performed by atomic force microscopy, in order to find the optimum texture substrate and realise the light trapping. The relationship between average slopes (tanθ) and photovoltaic performance are studied based on the experimental results. The experimental results show that the textured ZnO/Ag/SnO2/glass with tanθ of 0·13 yields the maximum conversion efficiency for J sc and V oc. Although the poly-Si deposited on highly textured substrate (σ>37 nm) shows excellent light trapping properties, however, in its microstructure shows a crystal deterioration and exhibits n-type characteristic, yielding poor photovoltaic performances.

Influence of Surface Morphology of Textured Substrate against Poly-Si Thin Film Solar Cells Performance

Since poly-Si is an indirect band gap material and has low optical absorption coefficient in the visible-infrared region, the light trapping in thin film poly-Si layer by using textured substrate is one of the important technical issue for achievement of high short current. Surface texture of a transparent conductive oxide (TCO) layer on a glass substrate as well as SnO2 with a large grain are usually utilized for the light-trapping technique, i.e., path lengths of the incident light in the poly-Si layer are effectively enhanced by the light-scattering at the textured surface. In this paper, a systematic investigation has been carried out concerning the relationship between poly-Si thin film solar cells performance and surface morphology of substrate texture as a function of root mean square roughness of substrate surface, in order to find the optimum textured substrate and realize the light trapping in the poly-Si solar cells. Furthermore, the influence of textured substrate on optical reflectance, poly-Si microstructure and photovoltaic performance are also discussed.

Microstructure and Electrical Properties of AZO Films Prepared by RF Magnetron Sputtering

AZO is an ideal replacement transparent conducting oxide (TCO) for ITO to all corresponding applications. The typical applications include: transparent electrodes for solar cells, flat panel displays, LCD electrodes, electro-magnetic compatibility (RF-EMI shielding) coatings, touch panel transparent contacts, static discharge dissipation. The production of useful and commercially attractive thin films using different deposition processes is very important parameter to investigate. A systematic study of the sputtering condition and their influenced on electrical and structural were studied. In this work, AZO films were deposited by RF magnetron sputtering at 200 °C. The result shows that the deposited time has influenced the characteristic of deposited AZO films. For a longer deposition time, thin film shows a uniform grain growth. The resistivity found minimum at the deposition time of 45 minutes. It can be considered that by reducing of the grain boundaries which enable the electron carries to conduct smoothly.