Design Of Railway Roadbed Subsidence Data Acquisition System Based On LoRa

In recent years,China’s railways have developed rapidly.By the end of 2018,the mileage of Chinese railways has reached 131000 kilometers.The huge railway transportation system,the increasing pressure of passenger and freight transport,not only requires the railway transportation to have a fast speed,In addition to large volume and high accuracy of arrival time,it is necessary to ensure its high level of stability and safety.The existing railway subgrade settlement monitoring method mainly relies on the manual and rail inspection vehicle to carry out periodic detection,and aims to solve the problem that the existing railway subgrade settlement monitoring method is low in efficiency,can not acquire in real time and monitor the settlement displacement of the railway subgrade,and designs a railway subgrade settlement data automatic acquisition system;The railway subgrade settlement data acquisition system is designed on the principles of low power consumption,strong anti-interference performance,long transmission distance,high accuracy,convenient installation and expansibility,etc.The intelligent static leveling system is adopted.Combined with wireless LoRa technology,a wireless sensor network with fault tolerance can be built according to the needs of railway roadbed monitoring,and a visual monitoring interface is designed.The railway staff can grasp the settlement information of each monitoring point of railway roadbed conveniently and quickly.The main contents are as follows:(1)The main contents are as follows: in the aspect of system hardware,by analyzing the relevant regulations and technical requirements of railway subgrade settlement monitoring,the static level instrument of high precision JS-100 model is selected as the data acquisition sensor of the field monitoring unit.The SX1278 represented by the LoRa technology is used as a radio frequency chip,and the MCU of the STM8L151C8T6 D model is used as a main control chip,a wireless transceiver module operating in the 470 MHz band is designed.(2)In the aspect of system software,the Contiki operating system and its own Rime protocol stack are transplanted on MCU to complete the multi-hop transmission of Mesh network.In the Matlab platform,the AODV routing algorithm applied to the Mesh network is analyzed and improved.On this basis,the LEACH clustering mechanism is introduced to form a new algorithm AODV-L,so as to improve the life cycle of the whole wireless sensor network and reduce the energy consumption of the network.Visual Studio 2012(VS2012)environment is used to design the visual monitoring interface.(3)The function of the system is tested,the radio frequency characteristic of the wireless transceiver module is tested,the transmission distance and the packet loss rate are tested,and the overall performance of the system is tested in the railway simulation test site.The feasibility of the system is verified,including the collection of railway subgrade settlement data,wireless transmission of data and visual monitoring interface.