Technical Information

Specifications:

• Pentium III 800Mhz CPU
• Linux operating system, kernel v2.2
• Wireless ethernet
• Sony DFW-VL500 digital 1394 camera
• Approximately 4' 6" tall, 2' diameter, 300 lbs with batteries
• 4 12V deep cycle lead-acid batteries provide nearly 6 hours of continuous use between charges.

Processor - Lewis is a B21r mobile research robot from iRobot Corporation. It's powered by a single 800Mhz Pentium III processor. This CPU must handle all of the motor drive and low-level robot tasks such processing the data from the large array of sensors. On top of this CPU load is the task of finding faces, navigating crowds, and taking and processing the photos. The two additional processors to be installed in the future will allow Lewis much more power for its photographer duties.

Camera - Lewis currently uses a Sony DFW-VL500 [technical manual] digital 1394 (Firewire) camera. This has a 1/3" CCD that produces 640x480 color images at up to 30 frames per second. Image output is YUV 422 format and is not compressed. The built-in 12X zoom lens is sensitive to 14 lx (F1.8). Higher-resolution 1394 cameras are available, but these do not have built-in lenses; this is bad because focus, aperture, and zoom must be fixed.

Safety - The entire enclosure is lined with bump-sensitive panels, so that if the robot runs into anything, the currently executing program is terminated, the motors are halted, and the brake is applied.

Operating System - The operating system on Lewis is a standard Linux distribution using kernel version 2.2. Various libraries for control of the motors, sensors, pan/tilt unit, and camera are used.

Pictures of Lewis

Download high resolution shots of Lewis:
- full frontal [1600x1200 jpg 760K]
- head shot, close up [1600x1200 jpg 525K]
- full 3/4 view, white background [530x1300 jpg 90K]
- cartoon Lewis [PDF 460K]

Request additional shots or poses from Kevin [kevin@biggreenball.com].