Air quality monitoring, using urban public-transportation infrastructure

Abstract

As we move closer to the smart-cities era, it is important that we have services that serve the city and its citizens, spending less energy and with minimal delay. One very important service is the real-time monitoring of the air quality inside the city, and the timely warning towards the citizens, given that the one eighth of deaths annually is caused by air-pollution [5]. Although there are researches and projects for stationary nodes that can sense the quality of the air nearby, the latest trend is to embed these nodes to vehicles and monitor the air quality during their route, as it will be able to gather samples from areas that a stationary node would not reach. This technology for remote nodes is not nourished yet, in contrast to the stationary nodes, and there are a few resources available to study, but we can expect that in the near future more projects will emerge and offer proposals. This study is structured in 6 chapters. The first chapter introduces the reader to the Internet of Things (IoT), sensor-nodes, and wireless sensor networks notions. The key technologies behind hardware, software and telecommunications that led to their development will also be presented and discussed. The second chapter presents the importance of sensing the quality of the air in a city, as well as IoT-based projects for both stationary and moving nodes, and cloud enhancements. The third chapter proposes a node for measuring the quality of the air, which will have the special characteristic of being embedded on a public transportation vehicle. The specifications of the node, the hardware chosen, and some software concepts are also given here. The fourth chapter presents the results taken from various tests, from the proposed node. The areas that were studied are the efficiency of the energy-harvesting module, the reliability of the GPS module, the transmission of long messages, and the effect of the software design on the node. The fifth chapter analyses the previous results and attempts to compare them with the results of other projects. Furthermore, it presents areas that had to be adjusted after the tests and the troubles faced during the design. The final chapter presents the conclusion of this study, and gives a general direction for enhancements on future projects.