NavBelt and GuideCane
This Electronics Engineering Seminar Topic deals with the following:
Recent revolutionary achievements in robotics and bioengineering have given scientists and engineers great opportunities and challenges to serve humanity. This seminar is about “NAVBELT AND GUIDECANE”, which are two computerized devices based on advanced mobile robotic navigation for obstacle avoidance useful for visually impaired people. This is “Bioengineering for people with disabilities”.
NavBelt is worn by the user like a belt and is equipped with an array of ultrasonic sensors. It provides acoustic signals via a set of stereo earphones that guide the user around obstacles or displace a virtual acoustic panoramic image of the traveller’s surroundings. One limitation of the NavBelt is that it is exceedingly difficult for the user to comprehend the guidance signals in time, to allow fast work.
A newer device, called GuideCane, effectively overcomes this problem. The GuideCane uses the same mobile robotics technology as the NavBelt but is a wheeled device pushed ahead of the user via an attached cane. When the Guide Cane detects an obstacle, it steers around it. The user immediately feels this steering action and can follow the Guide Cane’s new path easily without any conscious effort. The mechanical, electrical and software components, user-machine interface and the prototypes of the two devices are described below.
MOBILE ROBOTICS TECHNOLOGIES FOR THE VISUALLY IMPAIRED.
With the development of radar and ultrasonic technologies over the past four decades, a new series of devices, known as Electronic Travel Aids (ETA’s), was developed. This seminar introduces two novel ETA’s that differ from the ETA’s like C5 laser cane, Mowat sensor, in their ability to not only detect obstacles but also to guide the user around detected obstacles.
Obstacle Avoidance Systems (OAS) originally developed for mobile robots, lend themselves well to incorporation in Electronic Travel Aids for the visually impaired. An OAS for mobile robots typically comprises a set of, ultrasonic or other sensors and the computer algorithm that uses the sensor data to compute the safe path around detected obstacle. One such algorithm is the Vector Field Histogram (VFH). The VFH method is based on information perceived by an array of ultrasonic sensors (also called Sonars) and a fast statistical analysis of that information. The VFH method builds and continuously upgrades a local map of its immediate surroundings based on recent Sonar data history. The algorithm then computes a momentary steering direction and travel speed and sends this information to the mobile robot. The ultrasonic sensors are controlled by the Error-Eliminating Rapid Ultrasonic Firing (EERUF) method. This method allows Sonars to fire at rates that are five to ten times faster than conventional methods.