Design And Implementation Of Building Deformation Monitoring With Internet Of Things

In recent years,with the improvement of China’s urbanization level,the number of high-rise buildings has also increased day by day.Following this is the safety inspection and firefighting safety of high-rise buildings.How to deal with the collapse of buildings and ensure personal safety at the scene such as fire has become a huge challenge for firefighting practitioners.The current methods of building deformation monitoring require a lot of manpower,material resources and time costs,and it is difficult to achieve reliable all-round real-time building health monitoring and early warning in harsh environments such as fires.Therefore,firefighting practitioners urgently need a reliable online building deformation monitoring system that works in harsh environments to ensure the personal safety of firefighters and reduce maintenance costs.With the rapid development of wireless sensor network,large-scale,all-weather and fully automatic online monitoring can be achieved through sensors and wireless networks.This thesis implements an online building deformation monitoring system with Internet of Things,which can be used in daily environment and fire environment scenarios.This research mainly carried out the following work from three aspects: building deformation sensor network design,wireless network time synchronization and wireless sensor network reliability design:1.Aiming at the problem that the current method of building deformation monitoring is single and the maintenance cost of building deformation monitoring is high,it is impossible to achieve reliable all-round real-time building health monitoring in harsh environments such as fire.This thesis implements the design of the building deformation monitoring system with Internet of Things.MEMS tilt sensor,GNSS RTK displacement sensor and K-type thermocouple temperature sensor are used on the sensor to monitor the deformation and temperature changes of the building structure online.The tilt sensor and temperature sensor are used for indoor building structure monitoring,and the displacement sensor is used for the overall building structure monitoring;the wireless sensor network uses the low-complexity Lo Ra WAN,which has the advantages of low power consumption,long distance and large capacity,which is conducive to the realization of the indoor wireless sensor network coverage of the building and provides reliable data interaction between the enddevices and the servers.2.In response to the need for the time synchronization of various enddevices by the back-end data processing methods of the building deformation monitoring system,this thesis implements the application of the improved flooding time synchronization protocol in Lo Ra WAN.Through the application of hardware time stamp technology in gateways and enddevices,and the iterative weighted least squares fitting method has an excellent effect on the suppression of outliers.Under the premise of maintaining low network load and low power consumption in each enddevice,this solution achieves results of high accuracy and good stability.The stable time synchronization effect can meet the needs of the building deformation monitoring Internet of Things.3.Lo Ra WAN uses the ALOHA algorithm to achieve wireless channel anti-collision.This algorithm will cause problems such as decreased throughput,decreased reliability,and increased power consumption under the situation of high network load.Considering the above problems,this thesis implements the reliability design of the wireless sensor network.Through the application of time division multiple access on Lo Ra WAN,the throughput and reliability of the system are improved while the system input load remains unchanged,and the power consumption of enddevices are reduced;through the selfdefining time slice and time slot scheduling function,it solves the problems of reduced system flexibility caused by the fixed time slot allocation in the past,and improves the data utilization rate of the back-end.