Research On Optical Fiber Curvature Sensor For Underwater Measurement

With the rapid development of optical fiber sensing technology and the improvement of industrial intelligence,optical fiber sensors have been widely applied to the health monitoring of smart structures.Especially in the field of wearable devices,medical rehabilitation and other health monitoring,fiber optic sensors regularly appear.However,the research foundation of the application of optical fiber sensing technology to the monitoring of underwater deformation is still relatively weak.Therefore,in this paper,the optical fiber curvature sensor is discussed and studied,so that it can be well applied to underwater deformation monitoring and other underwater engineering.In order to make the optical fiber curvature sensor well applied to underwater,the following research work has been completed:Firstly,the optical power loss of the sensor is studied and the model for the optical power loss and the bending radius is set up,which explains the polarity and sensitivity of the sensor effectively,and reveals the sensing mechanism.Secondly,the sensor micro signal conditioning circuit with magnification,filtering and voltage conversion is designed,and the reasonableness of the circuit performance parameters of each part is verified by the simulation software.The key performance indicators such as noise and dynamic range of the circuit system are tested on the PCB board.These test results show that the circuit meets the design requirements and requirements.Thirdly,the output voltage of the sensor is collected by STM32 microcontroller,and the visual upper computer system can be written to communicate with the lower computer;The upper computer monitors curvature measurement of underwater deformation,and verifies that it can realize underwater deformation monitoring.Finally,the characteristics of the optical fiber curvature sensor are analyzed,and the important characteristics,such as the measurement range and accuracy on water,are compared with the previous research results and the characteristics applied to underwater measurement.The results show that the sensor can be applied to underwater deformation measurement.