1. Development of Vision-Based Navigation and Manipulation for a Robotic Wheelchair Katherine Tsui University of Massachusetts, Lowell

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

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

4. 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

5. 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

6. 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

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

8. 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

9. SLAM Data Flow

11. Results

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

13. 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

14. Manipulation: Visual Control

16. 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: Users will prefer a visual interface. Target audience, Summer 2007 –Access methods –Cognitive ability –Recreation of previous experiment

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

18. References and Acknowledgements Bailey, M., A. Chanler, B. Maxwell, M. Micire, K. Tsui, and H. Yanco. “Development of Stereo Vision-Based Navigation for a Robotic Wheelchair.” in Proceedings of the International Conference on Rehabilitation Robotics (ICORR), June 2007. K. M. Tsui and H. A. Yanco. “Simplifying Wheelchair Mounted Robotic Arm Control with a Visual Interface” in Proceedings of the AAAI Spring Symposium on Multidisciplinary Collaboration for Socially Assistive Robotics, March 2007. Research supported by NSF grants IIS-0546309, IIS-0534364, and IIS-0415224. In collaboration with Crotched Mountain Rehabilitation Center, Exact Dynamics, Swarthmore College, and the University of Central Florida.

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