 | | Re: GPS (was: mindstorms NXT and memory)
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(...) Cool! Might be complicated to calculate with the NXT, but I'm sure there's a way (PIC PIC PIC :). But how do you accurately find the coordinates of the base station? Google earth :P? (18 years ago, 11-Jan-06, to lugnet.robotics)
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| | Re: GPS (was: mindstorms NXT and memory)
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(...) Well, Google earth isn't going to get you very far - the best precision it has is something like a half meter - but the photographs are likely to be aligned with real-world lat/lon coordinates using non-differential GPS. But what does your (...) (18 years ago, 11-Jan-06, to lugnet.robotics)
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| | localization (was re: GPS)
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On another list, we've spent some time researching differential GPS. Turns out it's not as simple as having two GPS units compare notes. You have to know which satellites you are talking to, and that's complicated. They tend to switch on and off (...) (18 years ago, 11-Jan-06, to lugnet.robotics)
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| | Re: localization (was re: GPS)
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"dan miller" <lego-robotics@crynwr.com> wrote in message news:20060111050603....hoo.com... <SNIP> (...) </SNIP> Blasphemy!!!! :P -Rob www.brickmodder.net (18 years ago, 11-Jan-06, to lugnet.robotics)
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| | Re: localization (was re: GPS)
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(...) No, you do in general have to have them looking at the same satellites in the constellation at the same time, and even then there was a good bit of number manipulation to do. But the group I cave with did this with two laptops (to record the (...) (18 years ago, 11-Jan-06, to lugnet.robotics)
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| | Re: localization (was re: GPS)
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I've always been partial to ultrasonic rangefinding. It's not too difficult indoors under controlled circumstances. The old Nintendo PowerGlove used this technique. For robot localization, you'd probably want a minimum of three non-moving marker (...) (18 years ago, 11-Jan-06, to lugnet.robotics)
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| | Re: localization (was re: GPS)
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(...) I have tried all sorts of tricks with ultrasonic stuff, you're right :) There are a couple of different schemes for the ultrasonic beacon type things. You can have ones which are triggered from the 'bot via radio or IR. I've tried the IR one. (...) (18 years ago, 11-Jan-06, to lugnet.robotics)
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| | Re: localization (was re: GPS)
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Hi John, A localization scheme I have used with the RCX is uses the angles between light beacons in known locations, measured with a rotating light sensor. Two angles (3 beacons) are enough to calculate, with a bit of trig, the robot coordinates and (...) (18 years ago, 12-Jan-06, to lugnet.robotics)
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| | Re: localization (was re: GPS)
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(...) There are lots of interesting varients on that theme: 1) A lateral thinking way to do that is to reverse the situation. Put a rotating laser pointer on top of the robot and hook up light sensors in the corners of the room to another (...) (18 years ago, 12-Jan-06, to lugnet.robotics)
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| | Re: localization (was re: GPS)
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(...) Have you checked out the ARTag software? (Agumented Reality Tagging) I downloaded the Rev1 demo (2 is out now) and it was really amazing, even using a super-cheap web-cam: (URL) sdk provides the means to identify their graphical tags, as well (...) (18 years ago, 12-Jan-06, to lugnet.robotics)
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| | Re: localization (was re: GPS)
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(...) I also played with a light beacon system, but with a twist. Well actually two twists. I used small pieces of "rear view mirror repair kit" mirror to make some 45 degree rotatable mirrors. These mirrors were used to make beacons with (...) (18 years ago, 12-Jan-06, to lugnet.robotics)
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| | Re: localization (was re: GPS)
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(...) ;) (...) Right. I'm assuming something that basically assumes Line of Sight between bot and 3 or more beacons, just like GPS. GPS doesn't deal well with multipath either. ;) > The other thing you have to do is be able to address (...) Right. (...) (18 years ago, 12-Jan-06, to lugnet.robotics)
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