The researchers will be presented at CHI2019.
"Despite recent efforts to improve accessibility, airport terminals remain challenging for people with visual impairments to navigate independently," said Chieko Asakawa, one of the researchers.
Airport and airline personnel are available to help them get to departure gates, but they usually can't explore and use the terminal amenities as sighted people can.
"It becomes a hassle when you get a five- or six-hour layover and you need to get something to eat or use the restrooms. It would be lovely to be able to get up and move around and do things that you need to do and maybe want to do," said one legally blind traveller who participated in a focus group as part of the research.
"An increasing number of airports have been installing Bluetooth beacons, which can be used for indoor navigation, but often they are deployed to enhance services for sighted travellers, not to help blind people," said Kris Kitani, an assistant research professor at the Robotics Institute.
He and his colleagues deployed NavCog, a smartphone-based app that employs Bluetooth beacons, at Pittsburgh International Airport.
Previously, the app has been deployed on campuses, including CMU, and in shopping malls. They modified it for use at the airport, where extremely wide corridors make users vulnerable to veering, and for use with moving walkways.
"Part of our commitment to the public includes making sure our airport works for everyone, particularly as we modernise our facility for the future," said Pittsburgh International Airport CEO Christina Cassotis.
The app gives audio directions to users. It relies on a map of the terminal that has been annotated with the locations of restrooms, restaurants, gates, entrances and ticketing counters.
Ten legally blind people tested the app using an iPhone 8 with good results, traversing the terminal's large open spaces, escalators and moving walkways with few errors.
Most users were able to reach the ticketing counter in three minutes, traverse the terminal in about six minutes, go from the gate to a restroom in a minute and go from the gate to a restaurant in about four minutes.
The NavCog app for iPhone is available for free from the App Store and can be used at Pittsburgh International in the ticketing area of the landside terminal and in the concourses and centre core of the airside terminal.
Another team, including researchers from the University of Tokyo and Waseda University in Tokyo, developed the smart suitcase, called BBeep, to help with another problem encountered in airports -- navigating through crowds. The assistive system has a camera for tracking pedestrians in the user's path and can calculate when there is a potential for collision.
"Sighted people will usually clear a path if they are aware of a blind person. This is not always the case, as sighted people may be looking at their smartphone, talking with others or facing another direction. That's when collisions occur," said Asakawa, who has been blind since age 14.
A rolling suitcase itself can help clear the way and can serve as an extended sensing mechanism for identifying changes in floor texture. BBeep, however, can also sound an alarm when collisions are imminent -- both warning the user and alerting people in the area, enabling them to make room.
A series of beeps begin five seconds before a collision. The frequency of the beeps increases at 2.5 seconds. When a collision is imminent, BBeep issues a stop sound, prompting the blind user to halt immediately.
In tests at the airport, six blind participants each wheeled BBeep with one hand and used a white cane in the other as they maneuvered through crowded areas.
They were asked to walk five similar routes in three modes -- one where the suitcase gave no warnings, another in which the warnings could only be heard by the user through a headset and another in which warnings were played through a speaker.
The researchers said the speaker mode proved most effective, both in reducing the number of pedestrians at risk of an imminent collision and in reducing the number of pedestrians in the user's path.
"People were noticing that I was approaching and people were moving away ... giving me a path," one user observed.