Blind and visually impaired people can have problems monitoring an electric wheelchair. A project initiated by Luleå University of Technology is trying to change that and drastically improve the lives of numerous older and disabled people. They are working on a wheelchair with ability to scan its surroundings and communicate information to its user.
The project is new and is only just getting started, but project manager Kalevi Hyyppä is very optimistic. There is advanced technology behind the work on the seeing wheelchair, Hyyppä’s team focuses on optical navigation sensors and algorithms suitable for this specific purpose. The goal is to develop and evaluate a new technique in using sensors, enabling the wheelchair to scan its surroundings and thus navigate on its own. Furthermore, it is supposed to be able to transmit the measured 3-Dimensional information to its blind users. There are commercial laser scanners available today, but they are too impractical and expensive to use on wheelchairs.
Hyyppä says the idea is for the wheelchair to be equipped with two levers, one on each armrest. The right lever, assuming the user is right handed, would just like on standard electrical wheelchairs control speed and direction. The left lever would function as an antenna or virtual rod.
“Using the optical sensors and something called the Time-of-Flight technique the wheelchair creates a 3D- map of its immediate surroundings” Hyyppä explains, “Time-of-Flight means a short pulse of light is sent from the chair and when meeting resistance, causing the light to reflect, the distance is measured by the time it takes for the reflected light to return to the chair.
”The user would rotate the lever in the direction he or she wants to “look” and perceive the distance based on how far the lever can be moved before it meets resistance.
For those incapable of monitoring the levers, it can drive on its own as long as the user lets it know where to go. The method is a result of ongoing research concerning autonomous robots and means the scanner examines the surroundings to find the best way towards the given destination. In practice, this would mean the user could, either by voice or other means of communication, command the chair where to go and the rest would be automatic since the scanner recognizes thresholds, stairs and other obstacles.
However, Hyyppä stresses the importance of adjusting each system after each individual user.
“The different techniques are only supposed to help the person with whatever he or she cannot do on their own” he says. “It’s really important not to help too much and let the wheelchair take over and do things the users could do themselves.”
So far, the systems have not been tested on blind or visually impaired people. But a group of older, physically disabled people have gotten to try the different systems for wheelchairs and the response has been very positive. However, the testing made Hyyppä realize the importance of not becoming close minded.
“It’s easy to forget what’s everyday matter for us is very complicated to others” he says, “some of the people in our tests had never used a computer mouse before, which is important to consider when developing and adjusting the systems.”
Kalevi Hyyppä says he is expecting to have a prototype ready for the market within two years. He has recently established contact with an American company, working with similar systems but for computer games, and hopes to cooperate with them in purchasing certain products.
“It would save us a lot of money” says Hyyppä, “and also, it is sort of comical that their technology can be used in our field.” And it is a field with extensive interest and need for the new technology. The market is following the project with great anticipation.
CMTF, c/o Tillämpad fysik och elektronik
Umeå universitet, 901 87 Umeå
Tel: +46 (0)90-786 96 38.
E-post: Britt Andersson.
