Development of a low cost real time strain monitoring system using DSP technique

This paper illustrates the development of a low cost strain monitoring system, using a FBG and a LPG. A tensile strain is applied on a dual supported beam structure. The FBG used here works as a sensing head and the LPG as an edge filter. The use of edge filter is to modulate the Broadband source. The proposed scheme is based on the intensity measurement; a linear relationship between the intensity and strain is obtained. A photo detector is used for optical to electrical conversion. The converted electrical signal is applied as input to the DSP kit TMS320F2812 for continuous signal monitoring and data logging. The obtained data is processed in MATLAB to extract the information of the applied strain in terms of intensity level, which is then located on the fitted linear curve used as a reference. Results are obtained for different values of strain applied on a dual supported beam structure. Thus we obtain a low cost real time monitoring system to give output directly in terms of applied strain on the structure.