Research On Distributed Sensing System For Single Fiber Grating

For the study of distributed sensing, a scanning interferometric demodulation system has been designed on the study on single FBG; improved the skill of fiber embedment by using coupling agent and viscose agent; developed the program of data acquisition and feedback control on Visual Basic. The exploration work of developing smart manipulator based on FBG sensor network was initially finished. The research work will be illustrated from the following four aspects:Firstly, developed a single FBG scanning interferometric demodulation system, it can observed the energy of reflect light of the different point in FBG, and confirmed the optical path of the FBG precisely; identified the position and quantity of pressure on FBG; measured the axial stress on FBG.Secondly, developed the program of data acquisition and feedback control on the basis of serial communication by using Visual Basic, the system can read data automatically and record the data by calling EXCEL. By real-time analyzing the data, the program can send command to the control circuit of the manipulator so that the fingers can adjust their action. It can reach the result of intelligent feedback control.Thirdly, studied the technology of fiber embedment, choosed the viscose agent and polymer materials which were used in bonding FBG and skin of manipulator by camparing several kinds of viscose agent and polymer materials in experiment; improved normal skill of embedment, enhanced the binding power between fiber and coating materials.Fourthly, one arm of the all-fiber Mach-Zehnder interferometer was covered with silicon fiber to increase the sensitivity of pressure sensing. Illumining with a broadband and a narrowband light source, respectively, wavelength- shift can be obtained by observing the variation of the peak position of the interferometric spectrum with an optical spectral analyzer (OSA). The change of its peak power is measured by using a power-meter. Successfully measured the mini-pressure and increased the accuracy of measurement. When the pressure is changed 1.03×10^-4MPa, the wavelength shifts 0.02nm, the sensitivity of sensing is 1.96×10^-4nm/Pa.