Research And Design Of Pavement Monitoring Sensor Node Based On Temperature Difference Power Generation

In recent years,China's pavement construction has developed rapidly.With the increase of pavement service life and the impact of the environment,different degrees of damage will occur.This is directly related to pavement performance safety issues,so it is very important for pavement performance detection.In order to improve the level of pavement construction and maintenance management,the traditional pavement surface detection methods are timeconsuming,labor-intensive,and inefficient,and it is difficult to achieve the periodicity and realtime defects of detection.It is simple and practical,low in cost,and large in data volume.Research work has been carried out on reproducible pavement inspection technology.Research and implementation of a pavement monitoring sensor node system based on temperature difference power generation,which can be used for real-time monitoring of asphalt mixed pavement of new construction,expansion or resurfacing.The design and testing of the prototype system was completed by solving the key technical problems of the low-power wireless self-powered sensor node.The main research contents include pavement temperature difference power generation technology,embedded low power wireless sensor network and pavement stress detection technology.The main innovations and achievements of the thesis are as follows:(1)The thermoelectric power generation module is designed to supply electrical energy to the road detection system.Through the finite element analysis and actual measurement,the distribution of temperature field inside the road is obtained,and the temperature difference between different depths of the road is determined.The cylindrical metal heat sink is used to ensure the temperature difference between the cold and the hot ends of the temperature difference power generation piece.The temperature difference power generation module is embedded in the asphalt concrete slab,and the output characteristics of the temperature difference power generation module under different temperature difference conditions are obtained through experiments.The rutting experiment under different vehicle stresses in the simulated real roads shows the output characteristics of the thermoelectric modules under different stresses and rolling speeds.(2)The pavement monitoring sensor node is designed to collect pavement temperature and humidity data.The software and hardware design of the sensor node is realized,and the sensor node is packaged and protected to improve the service life of the sensor node in the pavement.The transmission distance and signal strength of the wireless signal are analyzed and tested to meet the pavement monitoring requirements.(3)A piezoelectric transducer is used to detect the internal pressure of the pavement.The piezoelectric transducers are embedded in different depths of the rut board,and are crushed on the rutting instrument to simulate the vehicle load driving test on the pavement.The piezoelectric transducer outputs different sizes under different depths and different rutting pressures.The voltage,the piezoelectric transducer is calibrated to measure the stress on the pavement.(4)The four ruts of the embedded sensor nodes were placed in different temperature and humidity environments.After four months of experimentation,four ruts were damaged to varying degrees.After collecting the temperature and humidity related data of the rutting board,the influence degree of temperature and humidity on the internal structure health of the road is obtained through analysis.