Design Of Optical Fiber Strain Data Acquisition And Processing System Based On LabVIEW

Non-electrical signal such as temperature and strain is an important basis for evaluation of the health state of building structure. How to measure and collect non-electricity information in building structure and how to deal with this information is introduced in this paper. Intelligent structure characteristic data analysis and display system is developed by LabVIEW including filtering, spectral analysis, the current data and historical data display. LabVIEW has characteristic of multi-task real-time synchronization operation, guarantee requirements such as real-time, reliability and scalability of the intelligent structural characteristics data processing and display system.In this paper, the health monitoring demodulation system for intelligent structure based on the LabVIEW mainly includes these functions: data sampling and transmission, data process and analysis, data storage and retrieval. The virtual instrument technology is applied in this system design, which has brought convenience to system development and integration, reduced system development cycle and improved the development quality simultaneously. This system adopts the SCM hardware system and the LabVIEW software system to guarantee the measuring accuracy and the stability. Thus the formidable handling ability of computers and the mensuration and control ability of instrument hardware are unified together, which greatly raises the process monitoring software's development efficiency. This system has also realized the data memory and the long-distance demonstration. It has the advantages of easy operation, the high reliability, the formidable function, strong expansibility and so on. It makes the health monitoring to the intelligent structure to be more scientific and reasonably.In this paper, improved demodulation algorithm is proposed based on the general demodulation algorithm through changing certain parameters of the algorithm aimed to improve the quality of the signal after demodulation. The output signals of scene sensor probe is sampling, sampling data through filtering. By using the improved fiber optic sensor signal demodulation algorithm, the system can fully improve the quality of the signal after demodulation under the premise of maintains the minimum sampling rate. The characteristic of this system is multi-channel synchronal real-time data acquisition. Meanwhile, histogram threshold value analysis is used to analyze signals in time-domain; energy spectral density analysis is used to analyze the distribution of frequency energy in frequency domain. This system has the advantages of high measurement accuracy, facility operation, strong functions and easy to extend. It has the broad application prospect in the field of structural health monitoring.