BlindSquare Indoor Navigation

BlindSquare BPS

What is BlindSquare BPS?

BlindSquare BPS stands for BlindSquare Beacon Positioning System. It is an indoor navigation system that can be used with BlindSquare, the popular GPS app for iOS devices developed for people who are blind or have low vision. It is used in more than 130 countries by more than 10.000 people. Relying on Foursquare and Open Street Map data, it announces public and private POI as well as street intersections, if the user is within a defined radius of these points. The information is read aloud automatically, so that the user does not have to touch their phone while traveling. However, as soon as the user enters a building, accuracy declines and the information provided is no longer reliable. Furthermore, relevant information about the inside of the building is not at all available. This is where BlindSquare BPS takes over.

The BPS consists of iBeacons installed in the building. These are small, low energy Bluetooth devices. Each of them broadcasts a unique ID that can be received by smartphones. The smartphone can detect the distance to an iBeacon by the strength of the signal being received. It will be strong if the smartphone is close to the iBeacon and weak when it is further away. In BlindSquare BPS several messages can be associated with an iBeacon. When the user launches BlindSquare, it will check for information about iBeacons near the user’s location and, if available, download it to the user’s device. When the iPhone receives the signal of an iBeacon, BlindSquare will read out to the user one of the messages associated with that iBeacon. If several messages are linked with an iBeacon, it will depend on various factors which of them is read out. These may be the user’s walking direction, the direction they are pointing their device in, or the iBeacons that have been detected earlier. This helps BlindSquare BPS to be context aware. If the user leaves an underground station, an iBeacon can inform them that there is a shopping mall nearby. If the user leaves the shopping mall, the same iBeacon can direct them to the underground station.

BlindSquare BPS can be installed in any building to make it more accessible to people who are blind or have low vision. In a shopping center, it can assist visually impaired people to find businesses or restaurants. Installed in a museum, it can not only help them to navigate the building, but also make the exhibits more accessible by providing audio information that is usually only available in print. If busses are equipped with iBeacons, they can announce their arrival to blind and low vision passengers, helping them to make sure they get onto the right bus.

iBeacons are battery powered. This ensures that BlindSquare BPS will also be available in the event of a power outage. Depending on the settings of the individual iBeacon, a battery may last two to four years.

Installing BlindSquare BPS

Each installation of BlindSquare BPS must be carefully tailored to the individual premises.
What is the information that should be conveyed? Which details are important for blind and low vision users? When do they need to hear each piece of information? Where should iBeacons be placed to cover as large floor space as possible with as few iBeacons as possible? Since listening to audio information takes time, the messages must be phrased as succinctly as possible.

Because the information conveyed through BlindSquare BPS is not stored in the individual iBeacons but online, it is easy to edit the information once the iBeacons have been installed.

Managing BlindSquare BPS information

BlindSquare uses a proprietary technology, CLIS (Customized Location Information Service) for managing a fleet of iBeacons in a BPS. CLIS data uses Google Docs, and specifically gSheet, a fully functioning spreadsheet, to record and distribute data to devices with the BlindSquare application. Data is created and maintained in gSheet and then published to the cloud via the link supplied. Once the data has been published, it is immediately available. Each time BlindSquare is launched, it accesses the cloud repository and downloads new data as required. Once the information has been downloaded, BlindSquare BPS can be used even when the iPhone is not connected to the internet.

Activate to open sample data in accessible format on new page
Sample of BPS data in Excel format

We decided to use gSheet to record and manage data, because it is easily available, many people are familiar with spreadsheets, and because it is accessible and can be edited by screen reader users.

Some of the columns in the sheet are:

  • the unique ID broadcast by the iBeacon.
  • Active: Tells BlindSquare whether to act when seeing this iBeacon.
  • Description: This field is used to provide an informative description for the Google Sheet user. This data is NOT used by BlindSquare.
  • Type: This field will define the response behavior of BlindSquare when detecting the iBeacon. A sound indicating the type may be played. Some possible types are stairs, bus, business, corridor, entrance, escalator etc.
  • Heading: Values in this field determine the response of the iBeacon depending on the direction the user approaches the iBeacon from. If it is left blank, the message defined in this row will always be read out, regardless of the user’s walking direction. If you want a message to be read only if the user approaches the iBeacon from north, you would enter 270-90, as north corresponds to 0, east to 90, south to 180, and west to 270 degrees. If an iBeacon should trigger messages depending on direction, a new row needs to be created for each message. While data such as UUID must match all of the entries associated with this iBeacon, fields such as type or heading must be edited individually.
  • MESSAGE EN and MESSAGE EN2 define English messages associated with the iBeacon. While message 1 will always be read, message 2 will only be read when the user is stationary. Message one will always be read out by BlindSquare, but message 2 will only be announced if the user pauses near the iBeacon. For example, message one can alert the user of a bank of elevators. When the user stops, they will hear more information, for example how many elevators there are and which floors can be reached.

Once a BPS has been installed in a building, the information associated with the individual iBeacons can be edited and updated any time using the gSheet. We plan to make available an Android app that can see all iBeacons in the environment and edit associated data directly.

This overview is only an introduction to BlindSquare BPS to help you understand how it works. You may read to learn more about the background of the project.

Please use the following form if you would like more detailed documentation, a demonstration of BlindSquare BPS in either Helsinki or Toronto, are interested in having BlindSquare BPs installed on your premises, or would like training to become authorized to install BPS on our clients’ premises.

See also: Solving way-finding challenges of a visually impaired person in a shopping mall by strengthening landmarks recognisability with iBeacons

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