Students from Perkins School for the Blind walk on Boston Common on International White Cane Safety Day, October 15.
Students from Perkins School for the Blind walk on Boston Common on International White Cane Safety Day, October 15.
David L. Ryan/Globe Staff/FILE

For years, engineer Rich Madison has been developing a system that could help soldiers or unmanned vehicles navigate in environments where GPS signals falter.

Imagine a group of soldiers searching for a cache of weapons within a dense forest or a rover on another planet trying to pick its way toward a destination, well beyond the reach of turn-by-turn, satellite-sent directions. The Draper Laboratory engineer’s technology instead uses two cameras—a system like our eyes—to assess how much distance has been covered and when the vehicle has turned.

Madison is interested in technologies that could be used to assist people with disabilities, but says the tough part is finding the technology that people want to use. He’s brainstormed a device that would allow color-blind people to “hear” color, by playing a tone that corresponded to a particular color. But that was impractical, color-blind people told him. It might override other important aural information, such as traffic noise. Another idea, for an electronic patch that could be placed on the back of someone’s hand and provide pricks that signaled visual information by touch, was deemed too distracting.

Advertisement - Continue Reading Below

Then, last summer he was giving a presentation at a conference focused on soldier navigation and a professor at Auburn University who worked on transportation technologies asked if he’d like to collaborate. Perhaps their joint expertise could be used to build a prototype of a device that could help blind people navigate—not just at the street level, but within buildings and through parking lots.

Through a contract with the Federal Highway Administration, researchers at both institutions are now working to develop a device that could help blind people navigate, or simply know where they are at a given moment. The Draper technology is based on two cameras that each see a slightly different view. That information can be used to generate feedback on the direction and distance covered. Madison said that placing the cameras as far away from each other as possible—such as on epaulettes—would give the greatest accuracy, though attaching them to a hat or glasses seems more likely.

The technology, which will be designed with the input of the National Federation of the Blind, could help blind people facing everyday navigational problems. In a statement, they laid out a scenario in which a blind person could take the subway to a show, weave her way through the station, and then enter a concert arena and be guided directly to her seat by a sophisticated navigation system that can “see” the local environment.

The trick will be designing the technology so that it helps the people who need it. Assistive technologies can often be less adept than the people they are designed to help.