An RFID Based Indoor Navigation System for Visually Impaired and Blind People

The main goal of the project “Ways4all” was to develop an overall navigation system (for indoor and outdoor use) to aid blind and handicapped people in finding their way.

The navigation system “Ways4all” uses passive RFID tags for routing in the indoor area and GPS in the outdoor area. Additionally, communication between the navigational device and the means of public transportation is developed for information exchange, like route number, entry or exit request. Furthermore real time information, like timetables, platform changes is aimed for increasing the feeling of safe travel.

The visually impaired and blind people can plan their trips on the internet platform at home. The necessary information to be entered is the day and time of departure, place of departure, place of arrival and the preferred means of transport. This information will be saved temporarily in the database. After leaving the house the outdoor GPS can guide him/her towards the first means of transport. While travelling, the application will use the mobile internet to gain access to the necessary information. If the route is changed or the planned route is no longer available (e.g. detour, failure of transport), the user is given new routing information during the trip. As soon as he/she enters the indoor area, the smartphone will receive the routing information by the RFID tags.

The basis for the routing is the tactile guidance system. At all of the strategic spots inside the building (entrance, platforms, intersections) passive RFID tags are placed into the tactile guidance system. The tags unique identification number is stored in a central database. When travelling through the building the RFID reader reads the number of the RFID tag and sends it to the smartphone by Bluetooth. The smartphone checks the number and uses the Dijkstra-algorithm and the person’s profile to calculate the route. The information given to the user (by a screen reader like talks, talk back or voices over) is either navigation instructions or by location descriptions, depending on the settings in the user profile. In the software, different user profiles are pre-programmed, like blind person, wheelchair user or physically handicapped can be adjusted to their preferences.

One of the main advantages of the navigation system is that it needs no absolute position (coordinates) of the tags but uses the tag relations (distance and angel) to find a way through the network, which makes the system easy to install.