Development Of GPRS-based Wireless Transmission Fiber Bragg Gating Wavelength Demodulation System

After decades of development, the fiber Bragg grating sensing technology hasbeen gradually mature, because of its unique advantages: sensing one,electromagnetic isolation, easy to set up a sensor-network, so in more and more fields,especially oil, mines and other applications demanding extensive environment. In thefiber bragg grating demodulation system, sensor network and monitoring room tendto have a certain distance, the wired transmission mode is simple and practical whenthe distance is short, but due to the laying of transmission lines in large quantity, notrealizing remote monitoring, to a large extent limits the scope of application of fibergrating sensing system. With the measuring scale is continually expanding, frontsensor network and background detection system may be very broad, far apart in thegeographical distribution. In some special cases, such as in electric power, railway,mining and oil and other special sensing detection field; natural geographicalenvironment in some remote mountain areas and other complex and poor areas, tocarry out detection of these circumstances, would involve the problem of datatransmission and demodulation process, if the transmission cable, in technology andthe economy are not feasible. So the remote wireless data transmission requirementshave become increasingly prominent, has great significance.This paper is on the fiber grating wavelength demodulation system based onGPRS wireless transmission in detail, the whole system including hardware andsoftware, the system hardware is presented focusing on the circuit principle, softwaresystem of the presentation focuses on algorithm level. The main research contents andwork includes the following four aspects: firstly, research on the status quo ofrelevant technology and development, to determine the design scheme of the system;including research on fiber grating demodulation technology, determine the systemscheme; and do research on wireless data transmission technology and the GPRStechnology, data transfer scheme. Secondly, according to the design scheme, thehardware circuit design of the system; this includes the data acquisition moduledesign to the analog-to-digital conversion chip as the core; design a digital to analogconverter chip as the core of the F-P drive signal generation module; module tocontrol the data processing and the system design based on FPGA as the core; wireless data transmission interface design based on GPRS communication module asthe core. Then, using the Verilog and NIOS Ⅱ as tools for developing a softwaresystem based on the hardware circuit; software includes data acquisition, buffering,interface control data acquisition part of Verilog programming; input and outputbuffer, digital to analog conversion, interface control of F-P driving signal generatingpart of Verilog programming; GPRS transmission interface control, data sending andreceiving Verilog control programming; analog to digital conversion signalprocessing, peak searching algorithm, curve fitting, GPRS signal transmission,system operation control such as part of the NIOS II soft core program. Finally,through the system performance test of the whole system to verify the feasibility andeffectiveness of the system design; analysis of testing results, find out the cause ofdata errors and system performance; and the chip upgrade, algorithm optimizationscheme is proposed from two aspects of hardware and software system, pointed outthe direction for the follow-up study.