The Wireless Intelligent Monitoring System Of Bridge Structure Health

In recent decades,China's infrastructure construction is developing rapidly.The railway network and the highway network are connected in all directions,we dig out the mountain when we come across it,we build bridges when we come across the river,and tens of thousands of bridges have been built across mountains and rivers.However,the bridge will be eroded by harmful substances in the process of construction and use.The vehicles,natural disasters and human factors may lead to different degrees of damage and deterioration of the bridge structure.These structural health problems can lead to safety accidents.Therefore,in order to ensure the safety,applicability and durability of the bridge structure,it is necessary to strengthen the monitoring and evaluation of the health status of the bridge structure and implement reasonable,long-term and effective maintenance management.However,at the present stage,the traditional manual inspection for bridge monitoring has many disadvantages,such as heavy workload,bad environment and human error.In addition,due to the development of Internet of things technology,semi-automatic and fully automated monitoring methods have emerged,but most of these technologies are relatively expensive and energy consumption is also large,most of them can only implement active uploading of data.Therefore,this paper compares and analyzes the existing methods of bridge structural health and safety monitoring based on the current situation.Then,it realizes the automatic and intelligent monitoring of bridge structural health based on the existing advanced wireless sensor network technology and combined with the new wireless communication,hot big data and cloud computing technology.In this paper,the project research and demand analysis are carried out first,then the feasibility evaluation and determination of the scheme are carried out,and finally the design tasks assigned in the project are completed.The design tasks mainly include displacement(crack measurement),temperature and humidity of the environmental,node temperature,inclination angle,acceleration,vibrating string sensor and other wireless sensor node design,wireless debugging terminal design and upper computer debugging software design.The main development steps include: 1)According to the overall scheme of the system,making plans for each sensor node and wireless debugging terminal,device selection,software and hardware design,debugging,testing,precision demonstration and optimization;2)Set up the upper computer software architecture,and completed the design,debugging,testing and optimization of the upper computer debugging software;3)Combine wireless sensor nodes,wireless gateway and cloud platform for joint debugging and test.In addition,not only the whole system will be designed and realized as low power consumption,low cost,sustainable(using clean energy solar energy for charging),but also they are lightning,waterproof,dust and other design.In order to ensure sufficient resources are used and they have better processing computational performance to process multi-channel sensor data,and we also consider the subsequent redundancy expansion and the problem of low power consumption,so we choice of ST company STM32L443RCT6 as MCU by comparing.The chip has rich peripheral,it can achieve a variety of sensor data acquisition.In terms of wireless communica-tion technology,we combine with a new low-power wan transmission technology which is developed in recent years—LoRa communication technology(reserve NB-IOT technology),SX1278 is adopted as wireless communication IC to construct LPWAN network and realize wireless low-power transmission.Finally,the wireless sensor nodes,wireless debugging terminals and upper computer debugging software are tested.The wireless sensor nodes can collection and transmission data commendably,we using a specific method to verifies the measurement accuracy of node,it is concluded that: the accuracy of temperature the is under ±0.5 ?,and the accuracy of relative humidity is under ±3% for the wireless temperature and humidity sensor node,the accuracy of the wireless tilt sensor node is up to 0.003 °,the accuracy of the wireless sensor node is under ±0.1 mm,the stability of the wireless vibration string sensor nodes is up to ±1 Hz,they all reach the design requirements.The wireless debugging terminal can realize the transmission of data information upstream and downstream stably.The debugging software of computer can satisfy the inclination sensor calibration and the sensor node debugging.Finally,we realize the joint debugging of wireless sensor nodes,wireless gateway and cloud platform from the local to the overall,and then the data information is analyzed and displayed on the platform.