Pedestrian dead reckoning

A localization technique that estimates a person's position by counting their steps (to determine distance) and detecting turns (to determine heading changes) from a known starting point, using inertial sensors in a smartphone or wearable device. For blind indoor navigation, pedestrian dead reckoning supplements or replaces Bluetooth beacon positioning, but algorithms developed for sighted walkers produce significantly higher error rates for blind cane and guide dog users due to different gait patterns.