4d . . I can see how you might be able to track objects over time . . but I’m trying to figure out how you’ll change your robots 4th dimensional velocity from 1 second per second to any thing else . . well with using COTS parts.
Yes!!! 
I suggested this a couple of days to our team. Now, there’s visual proof it can be done!!!
But I was wondering, what’s the range of the NXT ultrasound sensor?
I think they might win an innovation award if they manage to essentially time travel . a devise that runs off a 12 volt battery, and weights less that 100 pounds, and is controller by 2 small processors, impressive to say the least. Also, since its 4-D it will fly. (Note: yes i know that acceleration disrupts the flow of space-time, but the original post inferred true navigation of 4 dimensions not minute undetectable changes)
Theoretically, anywhere from 0 to 100 inches. Practically, it’s “accurate” (depending on your definition of accuracy) from between about 2 to 40ish inches.
I dont think he meant 4D as you guys are thinking it. The clue was Part of our 4d navigation system. As in the system has many parts, specifically 4 parts. This is one dimension of a four dimension sensor system. (gyroscope, accelorometer, sonar, gear tooth)