Robotic vision may phase out walking stick to help blind navigate

London -  Researchers are adapting technologies - originally made for robot navigation - to help visually impaired people navigate indoor and outdoor spaces independently.

One such system, being designed by Edwige Pissaloux and colleagues at the Institute of Intelligent Systems and Robotics at the Pierre and Marie Curie University in Paris, France,  comprises a pair of glasses equipped with cameras and sensors similar to those used in robot exploration.

The system, launched at a talk at the Massachusetts Institute of Technology this month, produces a 3D map of the wearer's environment and their position within it that is constantly updated

and displayed in a simplified form on a handheld electronic Braille device, New Scientist reported.

According to Pissaloux, it could ultimately let blind people to make their way, unaided, wherever they want to go.

“Navigation for me means not only being able to move around by avoiding nearby obstacles, but also to understand how the space is socially organised - for example, where you are in relation to the pharmacy, library or intersection,” she said.

Two cameras on either side of the glasses produce a 3D image of the scene. A processor analyses the image, picking out the edges of walls or objects, which it utilizes to craft a 3D map.

The system’s collection of accelerometers and gyroscopes - resembling those used in robots to monitor their position - keeps track of the user's location and speed.

This data is combined with the image to find out the user’s position in relation to other objects.

The system generates nearly 10 maps per second that are transmitted to the handheld Braille tool to be displayed as a dynamic tactile map.

The Braille pad includes an 8-centimetre-square grid of 64 taxels - pins with a shape memory alloy spring in the middle.

When heat is applied to the springs, they expand, lifting the pins to symbolize boundaries. The Braille version of the map is updated fast enough for a visually-impaired wearer to pass

through an area at walking speed, said Pissaloux.

However, this is not the only robotics project to be re-purposed. Software that envisages how far a robot has travelled based on information from its on-board sensors is being modified to

track a person’s movements on the basis of their stride length.

David Ross at the Atlanta Vision Loss Center in Decatur, Georgia, asserted that the sensing problems faced by robots and blind people are alike but there are huge differences.

“Sensing systems developed for mobile robots may have some application, but must be adapted considerably to suit a wide variety of human needs and situations,” he added.