Research And Design Of Manhole Cover Condition Monitoring System Based On LoRa

As the entrance and exit of urban underground pipeline network and ground,the manhole cover of urban pavement plays an important role in the management of municipal public facilities.With the continuous expansion of urban scale and the increasing level of urbanization,the number of manhole covers of various functional pavement is also growing rapidly.At the same time,it also brings about the problem of the management of the manhole cover on the road.The damage of the manhole cover on the road is more and more caused by floods,illegal theft and traffic rolling.If the damaged well cover can not be repaired in time,it will bring serious security risks to pedestrians,vehicles and the normal operation of equipment.The traditional management method of pavement manhole cover is a combination of manual regular patrol inspection and masses reporting.This method not only need high labor cost and large working face,but also is not timely,inefficient and easily missed.The emergence of LPWAN(Low Power Wide Area Network)technology has solved the problem that the communication distance and power consumption of wireless technology in the Internet of Things can not be taken into account.Its characteristics of long communication distance,low power consumption of equipment and large network capacity are very suitable for the application of outdoor,large node capacity and battery-powered Internet of Things terminal equipment.Combining with LoRa's technical advantages,this paper applies it to the monitoring of manhole cover on urban pavement.A monitoring system of manhole cover condition based on LoRa is studied and designed,including manhole cover detection equipment,concentrator gateway equipment and remote management platform.The 24-hour real-time on-line monitoring of the manhole cover on the urban road surface is realized.Once the abnormal inclination or movement of the manhole cover occurs,the alarm information and location information will be sent to the remote management center and the staffs mobile phone immediately,so that the maintenance personnel can be notified in time for maintenance.Firstly,starting with theoretical research,this paper studies the technology of manholel cover displacement detection and the optimization of LoRa wireless transmission network structure.A method based on acceleration sensor for detecting the state of the manhole cover using angle tilt detection and displacement detection is proposed.Aiming at the problem of uneven power distribution of nodes in traditional LoRa star network in the practical application of manholel cover condition monitoring,a multi-hop LoRa network structure with optimal energy consumption is proposed.On the basis of theoretical research,three core equipments are designed and developed,namely,manhole cover monitoring trigger device,concentrator gateway device and handheld configurator device.Finally,by setting up a specific application scenario to calculate and verify the superiority of the optimized multi-hop LoRa network structure over other structures,and through a lot of laboratory tests and field deployment tests,the test results show that the system works well,realizes various design functions and achieves various design targets.It provides theoretical and technical support for future digital and intelligent monitoring of urban pavement manholel cover.