iCity 2: Sensoren4iCity project

For the investigation of environmental data and air pollution experimental data are required with high spatial resolution in urban areas. Actual measurement systems provide data only at few sampling points due to their size and complexity or the requirement for the connection to electric power installations. For this project the development of compact sensor systems is therefore investigated with a very low power consumption. This allows a very flexible setup and distribution of a network of such sensors without the need for additional installations and supporting means.

The main questions and challenges for this project are the development of sensors with a very low power consumption where at the same time the necessary measurement accuracy must be guaranteed.

To address the two main challenges, low power consumption and high measurement accuracy, suitable sensors are analysed in respect to power consumption and accuracy. The accuracy will be especially tested under the different operation conditions which are to be expected. A right balance between power consumption and measurement accuracy has to be found for the total system. Additional, possibilities for additional energy harvesting will be studied to extend the duration of the self-powered operation of the system.

As part of the project, a microcontroller-based platform has been developed that records the most important environmental data (temperature, humidity, particulate matter PM1, PM2.5, PM5, PM10, CO2, VOC and others) via sensors. This data can be transmitted to a central server via wireless networks (WLAN, Lora). The system is compact (12cmx7cmx5cm) and self-sufficient and can be operated independently for several weeks on battery power. This enables very flexible use of the sensors and the system can be installed in many places with very little installation effort.

 The project has shown that this sensor system can be used to

• Continuous monitoring of an area is possible with the help of a network of 10-15 sensors
• Mobile 2D/3D measurements can be carried out with sensors attached to vehicles (bicycles, pedestrians, drones, etc.) with high spatial resolution.

The sensors therefore provide a very flexible platform for further detailed investigation of the spatial distribution of air pollutants within the other iCity projects as well as for further external research.