Performance characterisation of a new photo-microsensor based sensing head for displacement measurement

This paper presents a robust displacement sensor with nanometre-scale resolution over a micrometre range. It is composed of low cost commercially available slotted photo-microsensors (SPMs). The displacement sensor is designed with a particular arrangement of a compact array of SPMs with specially designed shutter assembly and signal processing to significantly reduce sensitivity to ambient light, input voltage variation, circuit electronics drift, etc. The sensor principle and the characterisation results are described in this paper. The proposed prototype sensor has a linear measurement range of 20 μm and resolution of 21 nm. This kind of sensor has several potential applications, including mechanical structural deformation monitoring system

Simulation and modeling of the behavior in the four-stroke spark ignition engine by using CFD simulation

Computational fluid dynamics (CFD) is a branch of fluid mechanics that use numerical analysis and data structures to analyze and solves problems that involve fluid flows. CFD have been applied to a wide range of research and engineering problems in many fields of study and industries, including engine and combustion analysis. The objective of this review paper is to analyze the behavior in the four-stroke Spark Ignition (SI) engine by using CFD simulation. To get the require result a few methods have been used to analyze the behavior in the engine such as using CAD geometric model where the solid works software have been prepared. Then, in the CAD geometric model also have ANSYS software to perform analysis in engine module. To predict the behavior of the engine during its working two type of analysis can be performed namely port flow simulation and combustion simulation. So, in first part of this report, the CFD analysis is carried out to analyze the performance parameter, including intake stroke, compression stroke, power stroke and exhaust stroke with hexane fuel combustion. For the results, some details of the engine model and some predicted results including temperature, flow time and pressure profiles. With the existence of CFD simulation it can help many fields of study and industries by predict and analyze the possibility that can be happened in the future. At the same time, serves as a quick and economical way of future engine designs and concepts

Advanced deep space communication systems study Final report

Deep space communication system requirements for period 1970 to 198

OPTICAL TRANSCEIVER INTERFACE FOR DATA TRANSMISSION OVER OPTICAL LINK

This final year Project Part 2 is designed for all fmal year students and it is compulsory to be taken. It is designed such so that all the final year students will be trained to produce practical solutions besides having a hands on feel before leaving to the industry. This report presents the intention of creating an optical transceiver interface for data transmission over an optical link. The project is targeted to be completed by the end of the course that is by developing the modulator I demodulator which converts the electrical data from PC to optical data as well as retrieve the optical data back to electrical data before it can be read by the other client PC at the receiving end. These days, the utilization of data via the optical transceiver is very limited and in the recent years, news about communication networks technology always seems to involve some pronouncement on the urgent need for more bandwidth. Thus this is part of creating a device to overcome all these problems. This project covers two parts that is research and design. Fourteen weeks have been allocated to complete the design of this project. The project has been researched about and certain components have been purchased to complete it. Besides that, this project also allows us to design on our own and implement as we want it to be

Enhanced Optical Wireless Channel For Indoor And Intravehicle Communications: Power Distribution And Signal To Noise Ratio Analysis

Visible light communication—(VLC) provides wide bandwidth and high security capabilities for free space optical communication. This thesis presents the key concepts, underlying principles and practical applications of visible light communications. In particular, this thesis focuses on the received power distribution pattern and signal to noise ratio for line-of-sight indoor and vehicular applications. Several methods are used to modify the SNR and power distribution levels. It is shown that in the absence of obstruction, the optical footprint is nearly circular and offers a platform for large- scale deployment in commercial environments, which is similar to micro and Pico cells. By studying various kinds of commonly used VLC channel analysis: diffuse and line of sight channels, a simple improved indoor and intra-vehicular VLC transmission model for power distribution and SNR is presented. Employing optical wireless communications within the vehicle not only enhances user mobility, but also alleviates radio frequency interference, and lowers system cost through the utilization of license free spectrum. Moreover, a solution to increase the received power by changing the semi angle at half power is presented. The simulation results show the improved received power distribution and SNR. A VLC system, based on color-shift-keying (CSK) modulation and code-division multiple-access (CDMA) is presented. CSK–CDMA VLC system is used to enhance the VLC system capacity and mitigate single color light interference, which allows multiple users to access the network

Optical fiber transmission systems for in-door next generation broadband access network.

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London.This thesis investigates the generation and radio-over-fibre (RoF) transport of unlicensed 60 GHz millimetre-wave (mm-wave) frequency band. The investigated benefits of transmission schemes applicable for the mm-wave generation include optical carrier suppression (OCS), optical frequency multiplication (OFM) and remote heterodyne detection (RHD). For the in-door cabling of the mm-wave transmission, a low-cost polymer optical fibre (POF) along with bend-insensitive single mode fibre (BI-SMF) has been investigated for short-range networks. Transporting mm-wave generated signals over POF and BI-SMF cables based on OCS scheme showed results with the highest spectral efficiency and least inter-symbol interference over a 2.5 Gbit/s data delivery. Based on this thesis analysis, OCS simulation of POF showed the most reliable power penalty performance and receiver sensitivity at 30-m whilst the BI-SMF fiber produced equal observations at 150-m and more. In observing the free space links of delivering the RoF signal, the attenuation on the received signal power for both POF and BI-SMF was insignificant but expected, as the simulation assumed complete and total collimation of the light beams onto the aperture of the photodetector. OCS scheme for mm-wave generation and transport was explored based on the cost effectiveness of using one external modulator compared to other generation schemes that utilised more than one external modulator. OFM scheme was simulated to transport LTE and Wi-Fi signals along with 60 GHz RF band through both SMF and MMF-POF/BI-SMF cables. OFM transport scheme produced the highest attenuation on LTE, Wi-Fi and mm-wave signals carrying 100 Mbit/s data as simulated POF lengths increased. The best performance POF length was observed at 10-m. The application of offset launch technique at the coupling of SMF and POF showed insignificant improvement on signal bandwidth. The free space OFM transmission also demonstrated negligible change to the received signal power. This reinforces the attributes of deploying OWC system in an in-door environment. In other investigation, the simulated successful delivery of mm-wave signal using RHD scheme modulated and transported 10 Gbit/s data signal over POF and BI-SMF cables. Additional observed unrecorded result also showed BI-SMF cable maintained a 2% reduction of received power for 450-m fiber cable from 150-m. The attributes to RHD includes its low operating power system application and delivery of localised 60 GHz signal for uplink RoF transmission. The conceptualised design of Gigabit data delivery for indoor customer applications either through POF or BI-SMF cable, transporting various wireless channels has been presented in this thesis for the design of a robust next generation Broadband access network to reinforce the fiber-inside-the-home (FiTH) deployment