When blind people are trying to navigate the city streets, they can get assistance from a speaking GPS-enabled smartphone, just like everyone else. Once they move indoors and lose access to the required satellite signals, however, it’s a different story. While there are some indoor navigation systems that require things like radio-frequency tags to be strategically placed around the building, it’s currently unrealistic to expect to find such systems installed in many places. The University of Nevada, Reno’s experimental new Navatar system, on the other hand, just requires a smartphone loaded up with a digital two-dimensional map of the building in question.
Running as an app on the user’s phone, Navatar starts by establishing their location within the building, and on the map. It then determines the best route to get them to their destination, and guides them along it via verbal cues. In order to keep track of where they’re going, it uses the phone’s compass to keep tabs on their heading, and its accelerometer to estimate how fast they’re moving.
That process alone is inexact, however, so Navatar will periodically get the user to confirm the presence of landmarks such as doors or stairways through touch. This establishes that the user is where the system thinks they are, and allows corrections to be made if they’re not.
Because visually impaired people would have difficulty using the smartphone’s display to confirm that they have located the landmarks, they are instead able to do so verbally, or by pressing a button on the phone or a linked Bluetooth headset – if the headset is used, the phone can stay in a purse or pocket, leaving both of their hands free to use a cane and feel for the landmarks.
Navatar is the creation of computer science engineering team Kostas Bekris and Eelke Folmer. They are now adapting the system for use in conjunction with GPS, in outdoor environments. While it was designed for use by the blind, the duo believe that it could also be useful to sighted people.
Fraunhofer Research is developing a somewhat similar indoor navigational technology, known as Smartsense. It uses a smartphone’s accelerometer to gauge the walking speed of the user, although it additionally incorporates an add-on magnetic field sensor, to track their movement through the Earth’s natural magnetic field. Although both Navatar and Smartsense do require floor plans of the buildings being navigated, these are becoming increasingly available on Google Maps 6.0 for Android.
A demonstration of the Navatar system can be seen in the video below.
Source: University of Nevada, Reno
