Nxt2saurus Can Avoid Obstacles, Rotate in Place, Balance Self - With Only Two Motors

Name of Model: Nxt2saurus

Created by: Menno Gorter

Found at: http://technicbricks.blogspot.com/2011/01/week-techvideo-2011-01-biped-saurus.html

Details: Try wrapping your head around the mechanism behind this model. Using only two motors and a simple program, this robot can turn in place, avoid obstacles, and balance itself by shifting its center of gravity. The builder is intentionally not making it too obvious how it works, but I think it's possible to reverse engineer some of it. The "feet" actually spin, so the axles going down to them must be geared to power that feature. The shifting of the center of gravity could be worked in by providing extra friction somewhere in the gear train - conveniently, this design combines that with the task of lifting each foot to take steps. Some of the clever parts of this design don't actually involve gearing at all. Putting the weight of the motors low in the legs makes the walking motion much easier on the gear train. The combination of a touch sensor and an ultrasonic sensor handles obstacle avoidance in a way that should be easy to program - and since the ultrasonic sensor is mounted loosely, it sways from side to side to allow for more thorough detection of obstacles. This is a masterpiece of showing how to get a variety of features out of very few sensors and motors.

A brief note about this "of the day" blog: It just hasn't been possible to post daily lately. Among other things, last minute plans to be at all four days of BrickFair have eaten up time that would normally be spent posting. We'll get back on schedule after we come back with a full report from the event.