Research On Fiber Bragg Grating Sensing System Technology Based On Wireless Transmission

Fiber Bragg Grating sensors are widely used in the field of bridge construction,aviation industry,petroleum exploration and other fields.The main body of the fiber grating sensor is an optical fiber,and the optical fiber is not only anti-corrosion and antiinterference,but also low in cost compared with the conventional sensor.Therefore,FBG sensors have a very good market prospect,and they have a very good economic and social significance for the development of demodulation systems.This paper starts with fiber Bragg grating sensing,combines embedded and IoT technologies,and completes the process of capturing center reflection wavelength data from the fiber grating,processing and storing data,and then sharing the data to the cloud and displaying it to the Android mobile client.This paper shows the whole design of a fiber grating demodulation system from the sensing front end to the display back end.The sensing front end of the entire demodulation system uses a tunable FFP filter demodulation method,and then the front-end demodulated data is captured,processed,stored and shared by an embedded hardware system system based on STM32 and uCOSIII.The main chip of the embedded development board adopts STM32F407ZGT6,which is a 32-bit ARM architecture processor.In addition,data sharing needs to use the Wi-Fi module ESP8266.ESP8266 is installed on the development board of STM32.First,it needs to be hardware-driven.It can be set by using AT command to connect Wi-Fi and access the OneNET cloud platform.The transmitted data is packaged by the EDP protocol and sent to the corresponding virtual communication device data stream on the OneNET cloud platform.This part of the code for the ESP8266 debug setup needs to be encapsulated in the task of the uCOS-Ⅲ embedded system.Finally,developing a mobile client based on Android,the client can obtain data from the corresponding data stream of the OneNET cloud platform,and the client provides an interface to directly display the acquired data,and the client also has an interface to process the data and display it with a line chart.On the Android mobile client,the physical quantity change of the front-end fiber Bragg grating sensing can be visually viewed to realize remote monitoring of the sensor.The fiber grating demodulation system can realize the collection,storage,processing and display of the data of the fiber grating sensor without relying on the computer.After many debugging and testing of the software system,it is verified that the functions of the demodulation system are running correctly and stably.Moreover,the demodulation system adopts modular design and can be divided into front-end sensing module,data processing module in the back end and data display module on the mobile end.The overall structure is clear,the operation is convenient,and the cost is low,and the applicable scene is also quite rich.