The Early Warning Device Of Railway Task Based On Optical Fiber Sensor

Railway construction is for the normal operation and security of rail transport. To ensure the construction safety, it’s currently commonly used:job scheduling and artificial observation of the way. As to the the tedious maintenance work, skylight time is difficult to meet the requirements, so it need to work in train interval. Then the safety requirements of construction is higher, and we usually use the way of observation. With the speeding up of the railway, especially the large number of high-speed train routes, it’s unable to promptly notify the construction workers on the scene, which easily leads to the occurrence of the dangerous situation in the accident.Compared with other sensors, optical fiber sensor has high sensitivity, better reliability, and better anti-jamming ability etc. This paper introduces a railway operational early warning device based on optical fiber sensing, which achieves early warning by the use of 433MHz wireless transmission mode. The warning device is divided into the detection module and the receiving module. In each side assigning a detection module beside the up and down of construction of the railway, when a train passes, detecting module detect train arrival, producing a wireless alarm signal and sending it to the receiving module in the construction. The receiving module detects train downward direction and triggers an audible and visual alarm.Firstly, the optical fiber sensing technology is introduced briefly, then I design the optical fiber sensor based on M-Z interferometer to introduce and analyze it. Then the paper introduces the 3×3 coupler demodulator based on M-Z interference and uses Matlab to simulate it. Then an analysis is made on the design of demodulator.Secondly, the paper designs a photoelectric detector circuit.The circuit can make the modulated optical signal convert into electrical signal and to be amplified.Then I design the noise reduction circuit and use multisim to simulate the amplifier circuit. The results accord with the design theoryAgain, this paper analyzes the various types of microcontroller and wireless transmission mode.For the equipment of high and low energy consumption demand consideration, the paper introduces the minimum system development board E06-STM8-V2 based on microcontroller STM8L and the wireless module, OLED module, which are easily connected with the development board. And then the pin interface and basic use of each modulec and circuit design is introduced.Finally, I make software design and hardware experiment to detecting module and receiving module. Wireless receiving and transmitting device can send data between each other to perform self-checking to ensure the normaly device communication. By the self-checking and simulation sensing signal experiment, it’s verified the feasibility of the transceiver device for signal detection and transmission and the device can be used in the early warning system.