Research Of EFPI Optical Gas Sensing System Based On FPGA

In recent years, China’s coal mine safety monitoring technology due to lacking of coal production resulting accidents occur frequently, which occupy a large proportion of gas accidents. We always choose the gas sensors made by traditional black and white catalytic and thermal conductivity components for coal mine safety monitoring Because black and white catalytic component frequent calibration, thermal conductivity component errors and two large gas mixing elements on the outstanding response was not quick enough so inadequate, so that the detection technology can not accurately measure the gas concentration. In view of the existing disadvantages of coal mine gas monitoring technology, we design a FPGA-based EFPI optical gas sensing system. The system uses a new type of fiber optic sensors to quickly and accurately measure the gas concentration signal, and the signal through the FPGA to complete a quick calculation and processing, to the maximum extent possible to meet the demand for coal mine safety monitoring.This article first introduced the optical fiber, optical fiber sensors and the basic principle of optical fiber sensor; Then part of the overall structure of the system and has made the detailed introduction; Then respectively describes the system hardware and software design method of the hardware part of the system shall be the responsibility of the FPGA signal acquisition and A/D conversion, using the fast Fourier transform (FFT) algorithm optimize the collecting signal processing and storage, by CAN bus to PC system data to ground. System software part respectively by Quartus Ⅱ and Nios Ⅱ two development platform set up and configure the system hardware and software engineering, to create a Nios soft II nuclear, phase-locked loop PLL, the FPGA realization by programming and debugging of the online hardware emulation.Finally, by setting the PC software parameters, displaying and processing the datas CAN bus upload online, through the analysis of the specific changes of gas concentration curve to realize the on-line monitoring of gas concentration and alarm processing.