About eighteen months ago, I told you about a tricycle with square wheels which needed a specially designed road. But now, Distributed Robotics, a company from Troy, N.Y., is developing robots with square wheels which don't need specific roads. These new 'cars' propel themselves on flat surfaces by taking advantage of gravity. This might sound crazy, but the inventors think it could lead to new robots and toys, and more generally to new micro-machines or MEMS applications.
A new method of locomotion has recently been invented that may prove useful in many scales of operation. While the title suggests a very narrow topic, there are in fact many interesting variations that arose during the development of this patent pending device. The application of which include robots, micro machines, novelty toys, and others.
So how does the prototype work?
The first prototype consisted of a car with 4 square wheels, in the general configuration of a typical car, with all 4 wheels mechanically connected together so they must all turn in unison. Furthermore, the rotational orientation of the wheels are sequentially off-set from one wheel to the next by 22.5° (¼ of 90°), moving around the vehicle in a CW or CCW direction as viewed from above.
"The weight shifting that propels the car is facilitated by a weight offset laterally from the center of the car that is moved in a rotational manner around the center of the car," says inventor Jason Winckler of Global Composites. "The rotation is provided by a driven shaft extending vertically from the center of the car, with a lateral arm and off-set weight. As the shaft rotates, the weigh shifts in a circular manner around the car."
Below is a picture of this square wheel robot in action (Credit: Global Composites, Inc.).
This picture, as the other one below, has been extracted from this short video (Credit: Global Composites, Inc.).
Here are more details about the prototype.
The main driving force for the table top prototype is produced by gravity pulling downward. Other forces that could hold the car against a surface, and provide the moving force necessary to increment the car along, include aerodynamic, hydrodynamic, magnetic, electromagnetic, and electrostatic. Such forces could be independent of the car mass, and could thus propel the vehicle with much greater force and velocity. In some instances, these forces could provide their own means to move from wheel to wheel, eliminating the central motor used in the prototype.
Here is a link to a slightly different version of the press release mentioned above, Reinventing the Wheel (PDF format, 2 pages).
Now what do you think? Is a square wheel robot viable? And can it really be useful? And is the company really serious?
Sources: Global Composites, Inc. news release, December 2, 2005; and various web sites
You'll find related stories by following the links below.