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The Car Navigation System / 1981

global.honda

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Re: The Car Navigation System / 1981

#3

Post by RicoElectrico »

> For example, on a map of a 1:100,000 scale, a road of 10 meters wide is shown via a line only 0.1 mm thick. However, in an area where many roads run close together, a number of thin lines will necessarily overlap, making the map difficult to read. In such a case the roads are shown by ignoring actual distances to a certain degree. This practice, called "deformation," has long been common in cartography.

Surely it's Engrish. The proper term is generalization, or in this particular case displacement. (ArcGIS calls this "conflict resolution").

Re: The Car Navigation System / 1981

#6

Post by omoikane »

There was a recent Japan's Top Inventions episode on this:

https://www3.nhk.or.jp/nhkworld/en/ondemand/video/2091030/

It's very much the same content, but in video form.

Summary: current location of car is tracked using dead reckoning[1], then plotted against maps that were printed on transparencies. Highlights include using the rocket-inspired gas-rate gyro for finding car heading, and figuring out that the car's location tracking was more accurate than the maps they were testing with.

[1] https://en.wikipedia.org/wiki/Dead_reckoning

Re: The Car Navigation System / 1981

#7

Post by stefan_ »

omoikane wrote: post #6

There was a recent Japan's Top Inventions episode on this: https://www3.nhk.or.jp/nhkworld/en/ondemand/video/2091030/ It's very much the same content, but in video form. Summary: current location of car is tracked using dead reckoning[1], then plotted against maps that were printed on transparencies. Highlights include using the rocket-inspired gas-rate gyro for finding car heading, and figuring out that the car's lo…

Were these "mechanical" gyros somehow vastly superior to the various MEMS contraptions, even the expensive ones? From my experience, the latter ones would dead reckon you to the moon within seconds.

Re: The Car Navigation System / 1981

#9

Post by JohnBooty »

cavisne wrote: post #4

Great podcast that touches on some of these early systems https://www.youtube.com/watch?v=0HCGn9_aVu0 It blows my mind that they used dead reckoning instead of GPS and it (supposedly) worked!

It blows my mind that dead reckoning ever works, at all. The very definition of "compounding error."

I have seen it said that military/aviation-grade inertial navigation gyroscopes are among the most impressive bits of technology ever manufactured.

Re: The Car Navigation System / 1981

#10

Post by jfoutz »

stefan_ wrote: post #7
omoikane wrote: post #6

There was a recent Japan's Top Inventions episode on this: https://www3.nhk.or.jp/nhkworld/en/ondemand/video/2091030/ It's very much the same content, but in video form. Summary: current location of car is tracked using dead reckoning[1], then plotted against maps that were printed on transparencies. Highlights include using the rocket-inspired gas-rate gyro for finding car heading, and figuring out that the car's lo…

Were these "mechanical" gyros somehow vastly superior to the various MEMS contraptions, even the expensive ones? From my experience, the latter ones would dead reckon you to the moon within seconds.

I think so, yeah. The space age made precision manufacturing relatively accessible. The U.S. military had a pretty insatiable appetite for these kinds of things for all sorts of stuff. submarines, torpedos, aircraft, drones, and on and on. https://en.wikipedia.org/wiki/Inertial_navigation_system

a quick search didn't find any hard numbers. but, yeah, I'd bet a few dollars they they were (are?) very good.

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