Hara Ra wrote:
>  Lego Toy Problem
> Yes. A very good way to attempt this is to use Lego blocks. (Seriously!)
> Lego is developing a series of toys which can interface with the PC (about
> $200, available this fall). For the moment these devices will be physically
> too feeble to pick up the Lego blocks and push them together, and the
> sensor technology is also very crude. If you did have adequate actuators
> and sensors (I can see it now, hydraulically driven Lego-Bots!), consider
> the design of a Lego-Assembler, which given a suitable PC, and a suitable
> supply of Lego blocks, is capable of assembling a copy of itself.
> The point of such a 'toy problem' (groan) is to reveal the higher level
> conceptual difficulties of doing such a thing and to reveal the detailed
> problems of actually doing it. (like, how do you sense the difference from
> a Lego block and a sugar cube?)
> The next Lego problem is to eliminate the major non-Lego components,
> especially the PC. Most solutions to this problem (in principle!) involve
> combining a standard set of components, a general purpose assembler, and a
> data tape whose structure as a media is simple. The data tape is read and
> the assembler executes the instructions. It builds the duplicate assembler,
> and then duplicates the tape.
Sounds pretty ambitious for a first attempt. It seems to me a macro scale assembler would be very useful, even if it used some complex components like computer chips. So long as it could assemble copies of itself, and useful large articles like chairs, tables or houses from durable components it could be useful. And it would be really useful if it could dissasemble the components and build new products from them. For those of us who live in variable climates, a house that was small and snug in the winter, and large and airy in the summer would be worth having.
Perhaps you don't need to worry too much about sugar cubes if you don't actually use Lego blocks. Make your building components distinct enough from casual matter to be easy to identify. Bar codes spring to mind. So long as you work in a contained space, you only need to check at the entrance and exit to the workspace.
I've been thinking about this problem for a while, but it seems too complex for one person to tackle.