When one speaks of a navigation system nowadays, it almost always refers to something which depends almost exclusively on GPS. Sure, there're enhancements and even location detecting alternatives to GPS, but all nav systems depend on outside data to know where they are.

I propose a system which is capable of functioning even if it's only knowledge of where it is is provided manually. In other words, it can function "blind" with respect to GPS.

It would have a built in set of maps, plus accellerometers, gyroscopes, and compasses; also, it would have voice sysnthesis and voice recognition.

If it can't get a GPS signal when it's turned on, it will ask it's user, aloud, where it is, using a sequence of questions similar to those used by computerized versions of the "Twenty questions" game.

Once it's figured out approximately where it is, it would use dead reckoning in order to continue to know where it is.

Naturally, if the device does detect a GPS signal, it would use it, but if at any time it loses that signal (e.g., you drive into a tunnel), it could switch to dead reckoning.

In all other respects, it would be just like a regular (GPS based) nav system. (It might feature an option to use the 20Q style of questioning, together with voice recognition, to program in a destination... but that's a seperate idea).
-- goldbb, Apr 22 2009

It would ask you what contry, state, county, or city you're in, what street you're on, what the crossstreet is, etc.. It might also ask if you see certain landmarks (e.g., "do you see a Starbucks?")

Naturally, the device would contain a map with this sort of information on it... curiously, none of the three links you posted mention anything about maps, only "location", which could merely mean longitude, latitude, and altitude.

The other plus of including a map is that it can be used to help correct for accumulated error in the dead reckoning measurements -- it could ask the user, "Are you still on street [whatever]?", if location estimates indicate the user is travelling on a non-road area parallel to a real road, or has seemingly jumped from one road to another without using a crossroad.
-- goldbb, Apr 27 2009



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