Development of Vision-Based Navigation for a Robotic

WheelchairMatt Bailey, Andrew Chanler, Mark Micire,

Katherine Tsui, and Holly Yanco

University of Massachusetts, Lowell

Bruce Maxwell

Swarthmore College

Outline

• Goal

• Redesign of Wheeley

• SLAM using stereo vision

• Human cue detection

• Manipulation

• Future work

Goal: How do I get to…?

Photo from http://lib.store.yahoo.net/lib/umallvt/umall-directory-2006-05-26.gif

Wheeley: Hardware• Wheelesley v2• Vector Mobility

prototype chassis• Differential drive• RobotEQ AX2850

motor controller• Custom PC• Sensor platform• Vision system

Wheeley: Robot Arm

• Exact Dynamic’s Manus Assistive Robotic Manipulator (ARM)– 6+2 DoF– Joint encoders, slip

couplings– 14.3 kg– 80 cm reach– 20 N clamping force– 1.5 kg payload capacity– Keypad, joystick, single

switch input devices– Programmable

Image by Exact Dynamics

Wheeley: Vision System• Manipulation

– Shoulder camera• Canon VC-C50i• Pan-Tilt-Zoom

– Gripper camera• PC229XP Snake

Camera• 0.25 in x 0.25 in x

0.75 in

Wheeley: Vision System• Navigation

– Videre Design’s STH-V1

– 19 cm x 3.2 cm– 69 mm baseline– 6.5 mm focal length– 60 degrees FoV

SLAM using Stereo Vision • Why use vision

instead of traditional ranging devices?– Accuracy– Cost– Detail

Vision and Mapping Libraries • Phission

– http://phission.org

• Videre Design’s Small Vision System (SVS)

• Simple Mapping Utility (pmap)– Laser stabilized

odometry– Particle-based

mapping– Relaxation over local

constraints– Occupancy grid

mapping

SLAM Data Flow

Results

Human Cue Detection• Swarthmore Vision

Module (SVM)– Basic text detector

and optical character recognition

Manipulation: Visual Control

Manipulation: Experiments• Able bodied, August 2006

– Confirmed: With greater levels of autonomy, less user input is necessary for control

– Confirmed: Faster to move to the target in computer

– Unconfirmed: Preference of visual interface

• Target audience, Summer 2007– Access methods– Cognitive ability– Recreation of previous experiment

Future Work• Additional Wheeley

modifications:– PC for mapping– Mount touch screen

LCD– New Videre Stereo

Head– Mount robotic arm

• Integrate Wheelesley navigation

Acknowledgements• Research supported by NSF grants IIS-0546309,

IIS-0534364, and IIS-0415224• Collaborators:

– David Kontak at Crotched Mountain Rehabilitation Center– GertWillem Romer at Exact Dynamics– Aman Behal at the University of Central Florida

Questions?

http://www.cs.uml.edu/robots