Slashdot Mirror
Lego Segway
Jeff Lalo writes "This Guy has built a Lego version of Dean Kamens Segway Human Transporter. This thing was constructed using only Legos, two cheap (~$40) custom sensors and some smart programing using the open source BrickOS for the Lego RCX. The LegWay, as the creator calls it, can balance itself on two wheels and follow a line. Pretty cool for few lego blocks!"
Now, if they could only make a Lego Lobbyist for Open Source down in Washington. Seems like the Lego AI would be a whole lot smarter than any politician we have in there at present...
Blog Prophyts - Right On, Man
Looks like someone gave the guy pre-warning, his page only has links to some mirrors, e.g. Here or here or even here .
Steve's Leg-Way
This LEGO robot was built to stand on two wheels and balance, follow a black line, and/or spin in place.
LegWay Program
The program for LegWay was written in BrickOS (LegOS) and uses EOPDs to maintain a constant distance to the ground. As the distance decreases, LegWay moves forward. As the distance increases, LegWay moves backward.
Every 50 ms, LegWay attempts to re-calculate the balance point by measuring the current distance and motor speed.
To move forward (for line following) LegWay actually sets the motors to run backward, causing a tilt, which it automaticly corrects, by moving forward. When one sensor is over the line, it stops that motor, and LegWay balances using only the other motor, causing it to turn.
To spin in place, both motors are shifted "off center" in opposite directions, the same amount, but they still correct for tilting.
In the pictures, you may notice the second sensor is disconnected. The main LegWay program will follow a line if two sensors are attached (always moving forward) or attempt to stand still, if only one sensor is attached.
If the motors are set at full power (either direction) for more than 1 second, LegWay assumes it has fallen over and the program ends.
LegWay EOPD SENSORS
LegWay uses two EOPDs (Electro-Optical Proximity Detector) from HiTechnic Sensors to balance and detect lines.
The EOPDs are based on the IRPD (Infrared Proximity Detector) circuit, but use visible light to determine distance by checking the detector, sending a pulse of light, and checking the detector again to calculate the amount of light reflected. The value returned will change based on the distance to an object AND the color of the object. IRPDs can be used in place of the EOPDs, but they will not work as well for detecting/following lines ** I'm told these sensors will cost the same as the IRPD sensors, and will be available in a couple weeks (November 1)
For this application, a small change in the value will usually indicate a change in the distance to the surface, while a large change will represent a change in the surface color (white to black) The EOPDs usually do not return a usable distance to a black surface, because the light is absorbed.
LegWay VIDEOS
Here are a couple videos, and some more pictures. The videos were taken with my LEGO Vision Command camera, so they're not really the best quality. I don't know my bandwidth limit, so if the videos don't work, try back later.
Brickshelf Pictures
LegWay Following a Line
LegWay Spinning This video really doesn't show how fast it's going. The motors are at full speed (almost) and in this video, it doesn't change direction.
Legway Building instructions
LegWay Past
I attempted to build LegWay using an accelerometer to detect tilt, but soon realized the acceleration due to gravity would not change as the robot tilts, because the robot is accelerating at 9.8 ft/sec?(physics was a long time ago). So the reading will be zero, until it smashes into the floor.
Several people have said they tried (without success) to build something like this with standard LEGO light sensors, but I don't believe they have the resolution required. (not even close)
LegWay Future
My next project will be to make LegWay work with a remote control. I have a couple ideas, which include using a SpyBot remote to drive LegWay around, or use a regular LEGO remote to run some pre-programmed moves.
Another idea is to make LegWay stand up (from a lying position) on it's own. It can't do that right now, because the center of mass is below the axle when it on it's side.
Thanks for checking it out. Feel free to tell me what you think.
Steve
e-mail:hassenplug@mail.com
Get Firefox!
I don't know how he got the impression that he's going to get some major slashdotting... but the list of mirrors is a good idea.
Anyway... IF the Geocities mirror list get's slashdotted, here are the list of mirrors:
http://perso.freelug.org/legway/LegWay.html
http://legway.armorica.biz
http://home1.gte.net/res1g289/StevesLegWay.htm
Welley Corporation - SLM Scammers
"Another idea is to make LegWay stand up (from a lying position) on it's own. It can't do that right now, because the center of mass is below the axle when it on it's side."
Until or unless it's articulated, this will always be true. Segway can't right itself from this position either...?
I give him about 2 days before being slapped with a lawsuit for patent infringement. And then Lego towns all across the Midwest will pass laws preventing them from riding on sidewalks (at the behest of Ford, GM, and Daimler-Chrysler).
I don't know if you were thinking of this one, but this guy made an MP5 and a Beretta out of Legos. Awesome stuff.
...I'll procrastinate tomorrow...
Lego Segway accidents on the freeways, Lego gridlock (sounds like a product?:P), Lego getaway cars...
And I thought I was proud of my lego castle greyskull all those years ago!
"It's not stealing if you don't get caught!"
Check it out here...he just went over his data transfer on Yahoo =P.
Mike
Was I the only one expecting to see a life-sized segway? I thought this guy was riding around in one!
Amazon.com
customerservice@amazon.com
Dear Sir/Madam:
I regret to inform you that I must cancel my current reservation for the Segway, currently listed at $7999.95 (US).
I would like to place another order for the following items now:
- Three MindStorms Lego Robot Kits, version 2.0, at $24.95 each
- One copy of How To Build a Segway Human Transporter for only Fifty Dollars (O'Reilly Press) at $69.95
- One Flux Capacitor at $499.95
I trust that a credit to my account will be arranged.Thank you in advance for your prompt action in this matter.
Sincerely,
Saint Aardvark the Carpeted
Carousel is a lie!
I'm impressed. I've worked on control of legged running, and a friend built a self-balancing unicycle in the 1980s. This new thing is the simplest self-balancer I've ever seen, and it does a good job. The video shows that it's quite stable.
That's ludicrous. A bump or a slope is just a distortion of the 2D surface that the wheels are riding along. It doesn't CLAIM to navigate 3D space anyway. (And the video of it following a line is pretty impressive).
7 November 2006: The day Americans realized corruption and incompetence weren't addressing 11 September 2001
I always have a mirror with me. People used to say I was vain, so I explained I just carry it in case I get slashdotted... now they say I'm insane.
RMN
~~~
obviously, both the lego and the original versions do pretty much the same thing. however, legway cannot guarantee that you do not fall. the segway, OTOH, pretty much does. it has to work with much higher precision sensors and much shorter update intervals. balancing on two wheels was never really difficult, it is basic robotics. making it practical and safe, however, is quite another story
BSD is for people who love UNIX. Linux is for those who hate Microsoft.
> Two sensors? For an object to maneuver itself in 3D space it would need 3 sensors
Counter-proof: You only have 2 eyes, yet you can.
"Robert Metcalfe, the co-inventor of the Ethernet office networking standard, who is a friend of Mr. Kamen, told me via e- mail: 'Some months ago when speculation was running high, I said that Kamen's It was more important than the Internet, but not as important as cold fusion, had cold fusion worked out. The It I was talking about, which I did not disclose, was NOT Segway. That's all I can say.'"
There are 0x40000000 types of people: those who understand 32-bit IEEE 754 floating point, and those who don't.
Could one of you lil' PERL monkies do us all a favor?
In the article submissions form, put a little check box titled "Slashdot can mirror locally" or some other phraseology.
Then provide the original link like you normally would, but on the last line where it says "Read More | XX of YY comments" add another link that says "Slashdot Article Mirror"
Judging by the indirect slashdotting, I'm also deducing that he built his web server out of legos. Apache for LegOS, anyone?
pi = 3.141592653589793helpimtrappedinauniversefactory7
"Lego was meant for the rumpus room, not the sidewalk!", complained an unidentified senior.
Another protested, "Hey! The sidewalks are already dangerous enough what with those dang newfangled bicycles! If you add Lego Segways, I could get killed!"
Among the signs noted at the protest was one proclaiming, "Lego Segways at 11 MPH will injure me!"
mmm... yeah... You see, we're putting the cover sheets on all TPS reports now before they go out...
Lower the water...don't raise the bridge.
Wherever there is an intersection, replace the cross with a circle (diameter same or less than path-mark width), and program in a delay that allows the device to continue straight whenever it sees a circle, still looking for an unbroken path that will override the temporary step.
Another method is to mount the sensors front to rear, scanning for the path itself (inside edge)...not left to right, looking for the outside edge of the path as the legway does.
Here's an artist who made a full-size playable Lego harpsichord (complete with an mp3 file).
Given the ease at which GeoCities bandwidth limits are exceeded, maybe Slashdot could host a mirror to link to from here. This would be in case the person in question needs his site for the rest of the month.
I really think this is starting to become a problem for people doing really cool stuff who don't have the money for a really good webserver. If slashdot thinks that a 20MB site is cool enough to post, surely Slashdot has that 20 MB of space on the its webserver to donate for a limited time. This would ensure that people like me can get to the site and people who do the cool shit aren't punished for doing cool shit.
SetupWeasel
You actually think you can navigate with just your two eyes?
Yes, and I can prove it.
I sail with a friend who's inner ears were damaged by an ear infection in childhood, leaving him with no inate sense of balance. So his entire balance is now done visually.
Does it slow him up? Well he's my dads age, is an ex British Olympic Fin Class sailor, and is now blue water cruising and is an Ocean Yachmaster / Instructor.
I guess if you can cope with the heaving deck of a yacht, you can cope with anything.
The advantage of course is that motion sickness is generally caused by a conflict of 'ear' balance and 'visual' balance (for want of better terms) so he doesn't get seasick. Thats the only way I actually found out, when I mentioned in conversation that he never got sick in rough seas, you'd never ever be able to tell otherwise.
Actually the reason you get motion sickness, and those panaromic cinemas fool you into thinking you are on a roller coaster is because your eyes are very important to navigation and balance.
Of course having the two systems (ear/visual) is a very good idea evolutionary, because one compensates for the weakness in the other.
But knowing that a blind colleuge of mine doesn't fall over in a heap, and my sailing companion doesn't either, I think I can justify in saying humans can operate with only one system perfectly well