By monitoring mobile phones searching for Wi-Fi signals, students from the Technical University of Denmark (DTU) are testing a tracking system to show how many people are present, how they move, and where they go.
As a pilot project the TrackSafe system consisting of eight sensors was deployed in the food court of the university.
The eight sensors in the food court contain a tiny Raspberry Pi computer and a Wi-Fi module. The sensors track mobile phones that are automatically searching for a Wi-Fi connection—even when the phone is in standby mode.
It aims to provide information to help the stalls optimize staffing and prepare the right amount of food required so as to limit food waste.
A system such as TrackSafe can also be used to improve safety by highlighting situations where there are too many people gathered together in a small area.
“For example, we noted that more than 7,500 people streamed past our sensors in just 10 minutes when the gates to the festival area were opened on Wednesday,” says Peter Juhl Savnik, an electrical engineering student.
Large-scale test
The project is part of a major DTU project that involves installing sensors in the lamp posts on DTU Lyngby Campus.
The intention behind testing the set-up at Roskilde Festival is to help develop the system and provide new knowledge.
The concentration of festival-goers can be displayed on what is known as a ‘heat map’, which turns red when there are a great many people in one place.
“Throughout the day, the longest queue consistently formed at the beer stall, but then suddenly at 1 a.m. the food stalls were most popular,” said Savnik.
Story by Tom Nervil, Technical University of Denmark
