Phones, Cameras, Cardkeys - What Will Track You Next?

Thanks to a new system developed at EPFL, building owners can detect the number of occupants and track their movement using sensors installed on floor slabs. This novel approach could be particularly useful for enhancing safety in retirement homes or managing buildings' energy use more efficiently...

Scientists at ENAC's Applied Computing and Mechanics Laboratory (IMAC), headed by Professor Ian Smith, have developed an alternative approach.  

"By installing sensors in a building's floor slabs, we can measure the vibrations created by footsteps. That lets us calculate the number of people in the building as well as where they are located and their trajectory," says Slah Drira, the IMAC Ph.D. student who completed his thesis on this topic.

To each his own gait...

"The signals our sensors record can vary considerably depending on the person's anatomy, walking speed, shoe type, health and mood," says Drira.

His method uses advanced algorithms—or more specifically, support vector machines—to classify the signals recorded by the sensors. Some interpretation strategies were inspired by the convolutional neural networks often employed in pixel-based image recognition, and can identify the footstep characteristics of specific occupants. more