As a technical feat, the huge South-North water diversion project of China is a success. Three artificial canals, each over 1000 kilometers long, are in various stages of completion and designed to redirect rainy southern water from the country to its parched north.
The massive Internet-of-things (IoT) network that quietly monitors the middle road is impressive in itself. More than 100,000 individual sensors are located on the 1,400-kilometer waterway linking the Danjiangkou Reservoir to Beijing and Tianjin. During the past year, he has swept the canal to detect structural damage, monitor water quality and flows, and monitor intruders, whether they are humans or animals.
“This system benefits more than 50 million people every day, not to mention the people involved in the project,” said Yang Yang, technical director of the Wireless Sensor Network . Communication at the Institute of Microsystems and Information Technology of Shanghai (SIMIT), part of the Chinese Academy of Sciences. He says that what they learn from the network will likely be applied to other massive infrastructure projects, including the East and West Roads of the water transfer system, as well as efforts. more modest, such as the surveillance of glazed facades of skyscrapers.
IoT network planning dates back to 2012. Yang and his team, including Dr. Wuxiong Zhang, associate professor at SIMIT, Chinese Academy of Sciences spent two weeks traveling through the canal, assessing his needs.
They saw a lot of challenges. The water has crossed earthquake prone regions, making the infrastructure vulnerable to damage. The flow of water should be controlled so that nothing is wasted. Its quality should also be checked periodically to ensure that no pollutants or toxins have entered the city’s drinking water supply. In some places, local villagers climbed the fence to fish or swim in the water. This has created security risks.
Yang and his team grouped together the challenges they found in three broad categories – infrastructure, water and security – and, after some discussion, settled on more than 130 types of sensors connected to Internet to install along the channel. . Infrastructure sensors measuring stress, deformation, vibration, displacement, earth pressure and water infiltration have been incorporated into the soil adjacent to the canal and into the shorelines and concrete bridges and 50 dams.
Probes that measure water quality and flow rate were attached to steel support columns that support bridges. Video cameras were spaced every 500 meters along the entire structure.
With all these sensors placed, the question is asked: how to send the data once they have been collected? Although some sections of the canal have access to an optical fiber internet connection, other areas do not have access and traverse remote areas with an irregular or non-existent cellular network service. As a solution, Yang and his team have developed the “smart gateway” to receive streaming data from local sensors and then transmit them to a cloud server using the signal available at the moment. This could include fiber, Ethernet, 2G, 3G, 4G, Wi-Fi, or Zigbee.
“The intelligent gateway can learn the availability of the connection to the cloud, and after a successful transmission it will follow that network the next time, otherwise it will try another,” Zhang says.
The intelligent gateway periodically transmits data to the nearest server, which can be one of 47 regional branch servers in the counties along the channel. Under normal circumstances, transmissions occur at intervals of five minutes, thirty minutes or once a day, depending on the location and water resources in the area. If a special event occurs, such as an earthquake or a chemical spill, the data will be sent immediately and continuously to the cloud. From there, the data is stored or transmitted to one of the five administrative servers in the provincial cities between Danjiangkou Reservoir and Beijing, eventually reaching the main host in Beijing.
Yang and his team have designed a platform and a web interface that allow people working on the server stations to read data and respond to alerts via a website, thus enabling Central Beijing team to learn developments on remote sites and make the right decisions in real time. Because the network is isolated from the World Wide Web, says Zhang, the date is less likely to be hacked by strangers.
“For me, this is a good example of IoT applied to critical infrastructure,” says Adam Drobot, president of IEEE IoT Activities Board and President of Open Tech Works, an Internet security company. and computer consulting firm. “You build it so that it is protected to start and not afterwards.”
Yang says the biggest challenge facing the South-North Water Diversion Project is a large 4-kilometer-wide, 7-meter tunnel that passes under the Yellow River. He would like to see underwater robots eventually developed to monitor and monitor the tunnel more efficiently.
Yang is also working to transform more laboratory-developed IoT technologies into new products and services. For example, his team is developing a network to monitor the integrity of glass facades on skyscrapers. If a window becomes weak or cracked, the IoT network will detect it, alerting a maintenance operator not only of vulnerable persons, but also of the exact size and shape of the glass to be replaced, before the panel cracks and s’ crushes the street below.
“We now have more and more sensors and more and more methods to make our environment smarter,” says Yang.