1. Development of Vision-Based Navigation for a Robotic Wheelchair Matt Bailey, Andrew Chanler, Mark Micire, Katherine Tsui, and Holly Yanco University of Massachusetts, Lowell Bruce Maxwell Swarthmore College

2. Outline Goal Redesign of Wheeley SLAM using stereo vision Human cue detection Manipulation Future work

3. Goal: How do I get to…? Photo from http://lib.store.yahoo.net/lib/umallvt/umall-directory-2006-05-26.gif

4. Wheeley: Hardware Wheelesley v2 Vector Mobility prototype chassis Differential drive RobotEQ AX2850 motor controller Custom PC Sensor platform Vision system

5. 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

6. 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

7. 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

8. SLAM using Stereo Vision Why use vision instead of traditional ranging devices? –Accuracy –Cost –Detail

9. 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

10. SLAM Data Flow

12. Results

13. Human Cue Detection Swarthmore Vision Module (SVM) –Basic text detector and optical character recognition

14. Manipulation: Motivation Direct inputs from 4x4 keypad, joystick, or single switch May not correlate well with user’s physical capabilities Layered menus Micromanage task and progress Image by Exact Dynamics

15. Manipulation: Visual Control

17. 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

18. Future Work Additional Wheeley modifications: –PC for mapping –Mount touch screen LCD –New Videre Stereo Head –Mount robotic arm Integrate Wheelesley navigation

19. 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

20. Questions? http://www.cs.uml.edu/robots