May/June 2011

'Sighted' wheelchair gets test drive

Research on an electric wheelchair that can sense its environment and transmit information to a visually impaired person has been tested at Luleå University of Technology. Daniel Innala Ahlmark, a prospective graduate student in the research project, and himself visually impaired, made the first public test, according to ScienceDaily.

The wheelchair has a joystick for steering and a haptic robot that acts as a virtual white cane. With the help of a laser scanner, a simplified 3D map is created of the wheelchair surroundings. The laser scanner uses Time-of-flight technique. The 3D map is transferred to the haptic robot so a visually impaired wheelchair driver can "feel or see" obstacles, such as open doors or oncoming people, and navigate past them.

The "sighted" wheelchair has been developed by Kalevi Hyyppä, a professor at Luleå University of Technology and his research team at the LTU division EISLAB.

"This may be important aids for the visually impaired who are wheelchair users. Many have already been in touch with me and asked if they can come for a test drive," said Hyyppä.

The first test of the "sighted" wheelchair for an audience was carried out in one of the corridors of the Department of Computer Science, Electrical, and Space Engineering at Luleå University of Technology.

Ahlmark tested the wheelchair while explaining how he experienced it-and he did so before the entire local and even national media in Sweden. "I feel safe when I run it; it is like using a white cane," he said as he avoided various obstacles along the corridor.

There is much research left when it comes to improving the 3D sensor and the haptic robot. The laser beam that sweeps in front of the wheelchair hits only objects of a certain height. It does not have the capacity to see things that are higher or lower than that height. Now the research team plans to develop a 3D camera that can do a full 3D measurement. Then the sighted wheelchair can be manufactured and used for real.