Research And Implementation Of Low Power Wireless Sensor Network For Rail Traffic

It is an important measure to ensure safe operation of trains by using wireless sensor networks to monitor the health of trains.However,most carriages are difficult to provide a stable power supply so that some sensor nodes completely depend on battery,resulting in high cost of battery replacement,limited power problems and all that.It is an effective solution to design sensor nodes by using energy harvesting technology.However,due to the slow rate of energy collection,nodes still need to reduce power consumption during networking and transmission.In addition,sensor nodes in carriages need to transmit data through multihop routing,which may cause the problem of overloading some nodes,then it may lead the paralysis of whole network and seriously affect the transmission efficiency and stability of the network.Aim at the above problems,the design and implementation of low power wireless sensor networks are carried out combining with the rail traffic application scenario in this paper,which includes the following three aspects:Firstly,a low power wireless sensor network is designed.The requirements of the application scenario for the low power wireless sensor network are analyzed and the corresponding solutions are proposed.For the low power wireless sensor node,the vibration energy collector,voltage regulator circuit,dual power supply scheme and automatic switching circuit are designed.The selection are carried out for the microprocessor,accelerometer and RF module.For the low power wireless sensor networking scheme,the networking scene is analyzed.The corresponding network topology,network packet,relay node selection scheme and node networking operation process are designed.The superframe time slots are allocated according to node tasks.Secondly,a low power wireless sensor network is implemented.For the characteristics of the low power wireless sensor node,pins of the microprocessor are allocated to realize the communication between the microprocessor and external modules.The main functions of the software execution process,task scheduling system,hardware driver and low power consumption function are introduced.For the low power wireless sensor networking scheme,a time-division multiple access communication technology with higher controllability and better real-time performance is adopted,and network packets are defined.The superframe time slot tasks,superframe time slot synchronization,network message resolution process,single slot wireless transceiver process,node networking operation process and relay node selection scheme are realized.Finally,the low power wireless sensor network is tested,including testing of the node and networking scheme.The energy collection rate of the node,the power consumption rate under different working conditions and the functional procedures involved in the networking scheme are given.For the testing of the node,the results show that the vibration energy collector has a faster energy collection rate while ensuring the operation of nodes.For the testing of the networking scheme,the functions of the node time service,relay node selection,relay node replacement and data transmission are verified.The problem of node energy limitation is effectively solved.The low power wireless sensor networking scheme ensures the energy balance among nodes under the premise of reliable data transmission.The low power wireless sensor network has not been deployed in the actual train environment,but it can be deployed and can collect mass vibration data in the future.The machine learning algorithm model can be used for analysis to realize real-time diagnosis of train faults.