Page 258 - The Ultimate Palm Robot

Color profile: Generic CMYK printer profile
Composite Default screen
Bots /The Ultimate Palm Robot/ Mukhar & Johnson / 222880-6 / Chapter 9

Chapter 9 Sensors and Enhancements 241

Walking robots have been around for years, but most of them have more
than two legs. It’s just much simpler to maintain balance when your robot has
four or more legs. It’s only recently, with Honda’s Asimo as one of the best
examples, that robots have been created with autonomous two-legged motion.

Robots with wheels don’t have to worry about balance and walking, but
like walking robots, they have the same challenge of needing to sense their
environment and maneuver through that environment. To solve this problem,
various approaches have been attempted by researchers. One approach is to
limit the boundaries of the problem. By limiting the scope of the problem, the
solution becomes simpler.
What is that limited scope? From the title of this section, you might guess
that it involves following a line. And you would be correct. By limiting the
challenge from free maneuver through the entire environment to movement
along a predefined track or line, our robot becomes much simpler to design.
Creating a robot that successfully navigates a line is much easier to build than
a robot that has the ability to meet all the challenges of its environment.

To be sure, making that limitation is not always possible. The Mars Sojourner
robot, a robot that needed to operate semiautonomously in its environment—
the surface of Mars—would not have been viable if all it could do was follow a
line. But since our robot is not going to Mars, we can use this solution.
We tried out two different sensors with our robot. The first is a reflective
infrared (IR) sensor made by Lynxmotion, Inc. (www.lynxmotion.com). The
second is a solid-state photoreflector from Hamamatsu Photonics
(www.hamamatsu.com). Both sensors are available from Acroname.

P:\010Comp\Bots\880-6\ch09.vp
Monday, May 12, 2003 4:33:40 PM