The combination of wireless sensor network and structural health monitoring technology is currently a trend of research and practice in the field of structural health monitoring. Recently, the project of "Research on the Construction and Key Technology of Large Bridge Monitoring System Based on Wireless Sensor Network" led by Yang Huazhong team of professor of Department of Electronic Engineering of Tsinghua University won the first prize of 2016 China Highway Society. Domestic bridge bridge installed wireless sensor, data diagram It is understood that, based on existing low-power chips and node technology of Tsinghua University, Yang Hua-Zhong team in order to develop a structural health monitoring system for the bridge, Dr. Wang Pengjun team members to further overcome time synchronization, sensors and a series of problems. Project research results The problem of time synchronization has always been the limitation of the existing international wireless bridge monitoring methods. The project took the lead in the successful application of the accuracy adaptive time synchronization algorithm with a synchronization accuracy of 10 μs, which is much better than the conventional bridge monitoring requirements of 1 to 100 ms. The convergence speed is excellent More than 100% in the traditional, adjustable accuracy can be adaptive. The life-span of the sensor is a key issue that affects the long-term stability of the bridge monitoring system. The project integrates the development and successful application of an average of 100μA (3V time) low-power sensor, the working life is superior to existing sensors up to 2 to 3 times, more suitable for solar power supply and other unstable power supply conditions. It is understood that this project developed and successfully applied based on the power spectrum peak preemptive stress extraction algorithm, the fundamental frequency of cable solution accuracy of 0.1% -1.0% FS, can replace the traditional cable force sensor. At the same time, the project took the lead in the successful application of the dynamic sampling method of vibrating wire sensors with the sampling rate of 5-100Hz and the frequency signal accuracy of 0.1-0.4Hz. It broke through the vibration-type sensors only for static sampling for decades (the sampling rate is usually lower than 0.02Hz) The application of limitations. Based on the above technologies, the construction of a large-scale bridge structure monitoring system integrated with the wireless intelligent sensor and cloud platform successfully developed by this project can reduce the construction and operation costs by more than 50% and save over 70% of the construction time compared with the traditional monitoring methods. Technical practical application In 2012, Yang Huazhong's team deployed the largest monitoring system based on wireless sensor networks in the world on the Ronghu Bridge, an important transport hub in Wuxi, Jiangsu Province, and caused great public concern. Without any cables, the monitoring data of the key structural parts of Ronghu Bridge can be transmitted back to the owner's computer in real time through wireless smart sensors of each size. The owner said that the entire project construction process is short, does not affect traffic, post maintenance low cost and very convenient, accurate monitoring data, the software is also very easy to use. Congo (cloth) Brazzaville Avenue along the cable-stayed bridge, information map Over the past five years, Yang Huazhong and his team have implemented wireless sensor networks based on wireless sensor networks (WSNs), including bridges over dozens of bridges including Liujiang River Bridge in Zhengzhou, Henan Province, the Yangtze River Bridge in Sichuan Province, the Yangtze River Bridge in Tai'an, the Kaiyuan Bridge in Wuxi, Qiaolingqian Bridge in Shandong Zibo, Of the bridge structure monitoring system, has done a lot of special bridge inspection and monitoring projects, and was the first to be used in the Belt and Road project - Congo Brazzaville Avenue along the cable-stayed bridge monitoring. Owner unit feedback that through the use of wireless intelligent cable sensor, access to more accurate than ever before, full and reliable data collection samples, which greatly improves the work efficiency and reduce the labor intensity of the bridge work. In addition, in recent years, Yang Huazhong's team of related wireless smart sensors, sensing cloud services and other technologies have been industrialized, and the application fields have long been broadened from bridges to rail transit, tunnels, slopes, reservoir dams and ancient buildings Facilities area.