Sensors for urban security in Freiburg

In the »Freiburg Resist« project, the city of Freiburg wants to use digital technology at large events in the future to determine where and how large crowds move in the city—also to prevent uncontrolled movements of these large crowds, for example. The Fraunhofer Institute for High-Speed Dynamics EMI is also involved in the project.  

Several thousand people often gather in Freiburg's city center for carnival parades, the Christmas market, or concerts. But what happens if panic or an accident occurs at such moments? Are the narrow streets suitable for escape movements, and can rescue services reach their destinations quickly enough? Until now, the police and event organizers have been monitoring the situation. In the Freiburg RESIST research project, the city of Freiburg is testing a new approach with the Fraunhofer Institute for High-Speed Dynamics EMI and other partners.

The goal is to develop an integrated, digital resilience management system that helps authorities, emergency services, and event organizers to identify dangerous situations earlier, plan safe large-scale events, and better manage crises.

The system supports the entire resilience cycle – from planning and deployment to follow-up – and links existing data and tools with newly developed functions such as simulations, analyses, and sensor-based real-time information.

Visibility and audibility simulation of warning devices

In this project, Fraunhofer EMI is developing modern tools for evaluating the visibility and audibility of warning devices in urban areas. Based on a digital 3D city model, algorithms are used to calculate

• how well warning signs and information screens can be seen from different angles,
• how loudspeaker announcements spread in complex city centers,
• and which placements of warning devices offer the best coverage.

These tools support cities, event organizers, and security authorities in planning realistic security concepts and identifying critical areas at an early stage.
 

Sensors for detecting crowd density
 

In addition, Fraunhofer EMI is developing key components for privacy-friendly crowd density monitoring.
These include:

• specialized sensors that evaluate anonymized data from Bluetooth signals,
• statistical models that derive reliable estimates of current crowd density from these measurements,
• forecasting methods for predicting people flows and impending bottlenecks,
• calibration methods based on an additional laser scanner to increase accuracy.

This information is incorporated into the emergency services' situation assessment and helps to identify and defuse potential hazardous situations at an early stage.

The Federal Ministry of Research, Technology, and Space (BMFTR) is funding the project as part of the SifoLIFE program with over 6.8 million euros until 2027. The funding period runs from October 2023 to September 2027.