Students at Virginia Tech University have succeeded in breaking down another barrier for the disabled: Building a vehicle that allows the blind to drive.

Virginia Tech’s Robotics and Mechanisms Laboratory developed a driver-assist system that uses laser range finders, an instant voice-command interface and a host of other cutting-edge technologies to guide blind drivers as they steer, brake and accelerate. The new system was put to good use last year at a summer camp where 20 blind and low-vision teens were able to take the wheel of a retrofitted dune buggy and navigate a course completely on their own.

“Although we are in the early stages of testing, the National Federation of the Blind — which spurred the project — considers the vehicle a major breakthrough for independent living of the visually impaired,” said Dr. Dennis Hong, faculty adviser on the project.

As expected, the buggy is packed with a host of equipment including a laser range finder, a Hall effect sensor, and a string potentiometer. “The laser range finder acts as the vehicle’s eyes,” said Hong. “It sends out a laser beam many times a second and measures the reflected signal to locate obstacles and lane markers such as curbs. The Hall effect sensor determines the vehicle speed and the string potentiometer measures the steering angle.”

The system communicates with the driver via a series of non-visual interfaces. A tactile vest attached to the inside of the driver’s seatbelt provides information to regulate speed and warn of obstacle proximity. An audio feedback system uses headphones to instruct where to turn and audible clicks tell the driver how sharply he is turning the wheel.

The system’s performance can be measured by the smiles after campers took a turn behind the wheel. Kim Wenger was one of the student team leaders who participated in the event. “The Blind Driver Track was an interactive experience with hands-on activities that took the kids through the entire engineering design process,” she said. “They learned how to change a tire, were able to get their hands on engine parts to observe how pistons operate, and how to be a responsible driver by learning road signs, giving directions, and taking a portion of an actual driving test.”