- they are faster and can carry higher payloads than bipeds,
- they are more agile (for getting around tight spaces) than robots that require more than two wheels, and
- are usually quite simple/fast to build using a LEGO NXT MINDSTORMS kit.
But they are not without disadvantages: They need to use at least one sensor port and need a motion control algorithm for balancing.
The following are a few examples as inspiration for building your own self-balancing robot.
Hitachi’s EMIEW robot:
Toyota’s MOBIRO robot:
The Segway (of course):
These all balance in one axis. If you are looking for more of a challenge, you can refer to Carnegie Mellon's Ballbot, which balances in two axes:
In Part II, I will post a tutorial to show you how easy it is to make your own self-balancing robot.
If you want a head start, here are some MINDSTORMS' examples of self-balancing robots:
Steve Hassenplug’s Legway
http://thenxtstep.blogspot.com/2006/05/we-all-knew-it-was-just-matter-of-time.html
http://thenxtstep.blogspot.com/2007/03/gyro-working.html
http://thenxtstep.blogspot.com/2007/04/gyro-sensor.html
http://thenxtstep.blogspot.com/2007/08/self-balancing-robot.html
http://thenxtstep.blogspot.com/2008/02/nxt-standalone-another-self-balancing.html