Research On Self-healing For Optical Fiber Sensor Networks

As developing toward high-capacity, multi-parameter application, Optical FiberSN with self-healing and high-reliability has attracted more and more attention.However, the research of this kind of Optical Fiber SN is still on qualitative stage,which is lack in appropriate analyzing method. To solve this problem, a usfulquantitative method, K-terminal reliability, is presented to evaluate the theself-healing and reliability of Optical Fiber SN. Based on this method, the formulas ofK-terminal reliability on different topologies Optical Fiber SN which include linear,ring, bus and star structure are derived and compared. We also theoretically andexperimentally analyze an active Star-Ring Optical Fiber SN. To solve the high costand real-time problem of the active self-healing Optical Fiber SN, we have designed apassive self-healing FBG sensor network. The principles and problems in theapplications have been discussed in detail. On the other hand, we have experimentallystudied the output signals of FBG in the self-healing passive Fiber Optic SNcombined with Fiber Optic Rotary Joint (FORJ). The work of this paper can be usefulfor designing self-healing, Optical Fiber SN with high reliability.Main work of this paper:1. We describe the current development of the self-healing Optical Fiber SN, andpoint out that the self-healing Optical Fiber SN is still on the stage of design of noveltopologies and its evaluation standard is still blank. We got the conclusion that thedesign of Optical Fiber SN with the self-healing function is to improve the reliabilityof the network.2. We present K-terminal reliability as the evaluation criterion of self-healingOptical Fiber SN, and the K-terminal reliability is employed to quantitativelyanalyzing four basic topologies-linear, ring, bus and star.3. The star-ring Optical Fiber SN including the structure and the Link Node (LN)design is studiedand the classification of active and passive Optical Fiber SN isdefined. With K-end reliability as the evaluation criteria, we theoretically andexperimentally analyze self-healing of the active star-ring Optical Fiber SN. 4. A self-healing passive fiber Bragg grating (FBG) SN is designed. And itsself-healing ability of this SN is theoretically and experimentally evaluated in detail.We also discuss its application with fiber optic rotary joint. We improve the passivestar-ring structure and get a double star ring structure which increases its self-healingfunction. Further, we have studied the influence of the Fiber Optic Rotary Joint(FORJ) on the optical signal of FBG sensors during rotating.