4 ms·

The Car Navigation System / 1981

14 points by T-A 3y ago

starbase 3y ago
.honda is a TLD now? Whoa.
- pxeboot 3y ago
  If you have enough money, or your own country, I think anybody can buy .tld these day. Last time I looked into it, the application was well over $100k, with similar annual maintenance fees.
  - nxobject 3y ago
    Not a bad moneymaker. It's such a pity that the list of internationalized domain names seems to be empty – Han characters must be an absolute goldmine.
  - the_real_sparky 3y ago
    Maybe Elon can have x.x.x
- bdcravens 3y ago
  The list of brand-name TLDs is large. https://en.wikipedia.org/wiki/List_of_Internet_top-level_domains#Brand_top-level_domains https://en.wikipedia.org/wiki/List_of_Internet_top-level_dom...
RicoElectrico 3y ago
> 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").
cavisne 3y ago
Great podcast that touches on some of these early systems https://www.youtube.com/watch?v=0HCGn9_aVu0 https://www.youtube.com/watch?v=0HCGn9_aVu0 It blows my mind that they used dead reckoning instead of GPS and it (supposedly) worked!
- JohnBooty 3y ago
  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.
  - jfoutz 3y ago
    when MacBooks got the inertial sensor for parking the hard disk, I hacked up a script to estimate velocity and precision. It was bad. It was fun to have friends drive around, and see how well it did. It was great for screwing around. But yeah, getting real precision would be a massive undertaking. __edit__ now that I think about it, they could get massive improvements by counting how many times the wheel rotated. The tire would change size as it wore down, but that would have been a really helpful datapoint.
    - JohnBooty 3y ago
      I hacked up a script to estimate velocity and precision Hahahaha that rules! they could get massive improvements by counting how many times the wheel rotated. The tire would change size as it wore down I think the change in size due to rubber wear would be quite dwarfed by the change in size due to tire pressure changes and tire temperature changes (or somebody just replacing the tires with a slightly different model with different dimensions) Also what happens when you're doing sick drifting and the rotation of your wheels becomes entirely decoupled from your car's motion vector???? still, that totally makes sense. tire rotation is another datapoint (or, four datapoints) and a smart enough system could integrate that. you could also recalibrate the tire data following a complete stop, when the car starts moving again, kind of a zero velocity update thing if I am understanding the wikipedia article on INS in a halfway competent way
omoikane 3y ago
There was a recent Japan's Top Inventions episode on this: https://www3.nhk.or.jp/nhkworld/en/ondemand/video/2091030/ 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 https://en.wikipedia.org/wiki/Dead_reckoning
- stefan_ 3y ago
  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.
  - jfoutz 3y ago
    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 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.

14 points by T-A 3y ago

starbase 3y ago

.honda is a TLD now? Whoa.

pxeboot 3y ago
If you have enough money, or your own country, I think anybody can buy .tld these day. Last time I looked into it, the application was well over $100k, with similar annual maintenance fees.
- nxobject 3y ago
  Not a bad moneymaker. It's such a pity that the list of internationalized domain names seems to be empty – Han characters must be an absolute goldmine.
- the_real_sparky 3y ago
  Maybe Elon can have x.x.x
bdcravens 3y ago
The list of brand-name TLDs is large. https://en.wikipedia.org/wiki/List_of_Internet_top-level_domains#Brand_top-level_domains https://en.wikipedia.org/wiki/List_of_Internet_top-level_dom...

RicoElectrico 3y ago

> 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").

cavisne 3y ago

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

JohnBooty 3y ago
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.
- jfoutz 3y ago
  when MacBooks got the inertial sensor for parking the hard disk, I hacked up a script to estimate velocity and precision. It was bad. It was fun to have friends drive around, and see how well it did. It was great for screwing around. But yeah, getting real precision would be a massive undertaking. __edit__ now that I think about it, they could get massive improvements by counting how many times the wheel rotated. The tire would change size as it wore down, but that would have been a really helpful datapoint.
  - JohnBooty 3y ago
    I hacked up a script to estimate velocity and precision Hahahaha that rules! they could get massive improvements by counting how many times the wheel rotated. The tire would change size as it wore down I think the change in size due to rubber wear would be quite dwarfed by the change in size due to tire pressure changes and tire temperature changes (or somebody just replacing the tires with a slightly different model with different dimensions) Also what happens when you're doing sick drifting and the rotation of your wheels becomes entirely decoupled from your car's motion vector???? still, that totally makes sense. tire rotation is another datapoint (or, four datapoints) and a smart enough system could integrate that. you could also recalibrate the tire data following a complete stop, when the car starts moving again, kind of a zero velocity update thing if I am understanding the wikipedia article on INS in a halfway competent way

omoikane 3y ago

There was a recent Japan's Top Inventions episode on this: https://www3.nhk.or.jp/nhkworld/en/ondemand/video/2091030/ 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 https://en.wikipedia.org/wiki/Dead_reckoning

stefan_ 3y ago
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.
- jfoutz 3y ago
  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 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.