Navbelt andguidecane

Presented by:

M.Pavan Kumar

(08KR1A0431)

Guided by:

Kiran Sir

indexINTRODUCTIONMOBILE ROBOTICS TECHNOLOGIES NAV BELTOPERATIONAL MODESADVANTAGES DISADVANTAGESIMPROVEMENTSGUIDE CANEHARDWARE IMPLEMENTATIONADVANTAGESDISADVANTAGES IMPROVEMENTS CONCLUSIONBIBLIOGRAPHY

introduction

This seminar is about “NAVBELT AND GUIDECANE”, which are two computerised devices based on advanced mobile robotic navigation for obstacle avoidance useful for visually impaired people.

MOBILE ROBOTICS TECHNOLOGIES

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

Obstacle Avoidance Systems (OAS) originally developed for mobile robots, lend themselves well to incorporation in Electronic Travel Aids for the visually impaired.

NAV BELTThe NavBelt consists of a belt, a portable

computer, and an array of ultrasonic sensors mounted on the front of the belt.

Eight ultrasonic sensors, each covering a sector of 15˚ are mounted on the front pack, providing a total scan range of 120

Following figure shows the prototype of the device

OPERATIONAL MODES

Guidance Mode

Directional-Guidance Mode

Image Mode

ADVANTAGES

NavBelt can detect objects as narrow as

10mm.

NavBelt can reliably detect objects with a

diameter of 10cm or more, regardless of the

travel speed.

The current detection range of the NavBelt is

set for 3mt.

DISADVANTAGESFor object with diameter of 10mm, the

detection is possible if the objects are

stationary or the subject is walking slowly

(less than 0.4 m/s).

It does not allow fast-motion.

The NavBelt uses a 2-D representation of the

environment.

IMPROVEMENTSThe Nav Belt is currently not able to detect

over hanging objects. This problem can be

removed by using a camera and a laser

scanner attached to a special helmet.

Adding more sonars to the front pack of the

Nav Belt can provide additional information.

GUIDE CANEIt can be thought of as a robotic guide dog.

A servomotor, operating under the control of the

built-in computer, can steer the wheels left and

right relative to the cane.

For obstacle detection, the GuideCane is

equipped with ten ultrasonic sensors, and to

specify a desired direction of motion, the user

operates a mini joystick located at the handle.

FUNCTIONAL COMPONENTS OF THE GUIDE CANE

HARDWARE IMPLEMENTATION

Two basic types of hardware used are: -

O Mechanical hardware

O Electronic hardware.

ADVANTAGES

It allows fast walking, up to 1m/s while

completing complex maneuvers through

cluttered environments.

It can be used to travel or detect staircases.

Easy to handle, and no extensive training

needed.

It rolls on wheels that are in contact with the

ground, thus allowing position estimation by

odometry.

DISADVANTAGES

It uses ultrasonic sensor-based obstacle

avoidance system, which is not sufficiently

reliable at detecting all obstacles under all

conditions.

It cannot detect overhanging objects like

tabletops.

IMPROVEMENTS The Guide Cane is currently not able to

detect tabletops but it can detect these

objects with additional upward-looking

sonars. This can improve the Guide Cane’s

performance to a level.

The implementation of an additional type of

sensor will be required to allow the Guide

Cane to detect important features, such as

sidewalk border’s.

CONCLUSION Both the Nav Belt and the Guide Cane are novel

navigation aids designed to help visually impaired

users navigate quickly and safely through densely

cluttered environments.

It is fundamentally different from the existing ETA’s

(Electronic Travel Aids) that, at best, only inform

the user about the existence and location of

obstacles but do not guide the user around them.

BIBLIOGRAPHY

NICHOLAS G.B., SYPROS T., “BIO-ENGINEERING FOR PEOPLE

WITH DISABILITIES”, IEEE JOURNAL, ROBOTICS AND

AUTOMATION – MARCH 2003.

I.ULRICH and J.BORENSTEIN, “VFH: LOCAL OBSTACLE

AVOIDANCE WITH LOOK AHEAD VERIFICATION”, IEEE

JOURNAL, ROBOTICS AND AUTOMATION – AUGUST 2000.

J.BORENSTEIN and Y.KOREN, “THE VECTOR FIELD

HISTOGRAM- FAST OBSTACLE- AVOIDANCE FOR MOBILE

ROBOTS”, IEEE JOURNAL, ROBOTICS AND AUTOMATIONJUNE

2000.

Thank You