Research And Realization Of Optical Fiber Microbend Pressure Sensor Based On DSP

With the rapid development of Very Large Scale Integration (VLSI) and computer, the technology of Digital Signal Process(DSP) is applied in various domains such as communication, condition-monitoring. In the doman of project-monitoring, it is advocated and spreaded and developing at a high rate because of its notable advantages, especially after the emergence of the technology of distributed fiber sensing. This paper studies and realizes a kind of sample sensor which meets the needs of special project-monitoring.Firstly, this paper discusses the geometrical condition which is necessary for the light propogation in the fiber and analyses the condition for the coexistence of light-wave of different pattern in the transmission from the view of light waveguide and the condition needed for mutual conversion among different patterns and presents the formula of the relationship between attenuation and distance, which provides the theory for the drawing of OTDR curve. Then this paper discuss the loss aroused by Rayleigh-dispersion, studies the character of backward dispersion optical , acquires the optimal method on processing signal-BOXCAR .This paper discusses BOXCAR on its theory, character of real-time process, the contrast of S/N pre and after the process in detail. At last, this paper discusses the sensing theory of strain senseing setting, all of which provide reliable theory support for the realization of distributed fiber microbend strain sensor.In addition, this paper constructs the hardware platform of the whole system based on DSP(TMS320VC5402) and offers detailed discuss on every part of the system which embodies the system' s advantage.It is important that this paper achives the realization of the system through software includingdata' s collection and process and drawing OTDR curve. In further, this paper brings up amendatory scheme after analyseing the system' s capacity and deficiency.The content of this paper keeps up with the development and renovation of contemporary technology. Especially in the domain of distributed fiber sensing,it is valuable and possesses a certain practicability.