Using Bluetooth RSSI for Visually Impaired Navigation

There’s new research from the University of Bristol on Outdoor Localization Using BLE RSSI and Accessible Pedestrian Signals for the Visually Impaired at Intersections.

The idea is to use Bluetooth received signal strength (RSSI) to enable the blind and visually impaired (BVI) to safely to cross intersections on foot. Audible systems already exist but users find them confusing when crossing complex road intersections. The researchers developed a system called CAS (Crossing Assistance System) that provides pedestrian positioning.

The system uses k-nearest neighbors (kNN) method Support Vector Machine (SVM) with various RSSI features for classification, including a moving average filter, that was able to localise people with 97.7% accuracy.