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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!"
Once again back on topic, I've heard about simmiler projects, the first one that comes to mind is the guy who made a copy machine out of legos here. (He now works for them.) Has anyone else seen any other insanly cool projects?
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
You lost that bet. It hit just under 1600 before it caved.
Check it out here...he just went over his data transfer on Yahoo =P.
Mike
The plural of 'lego' is in fact, 'lego'. Thank you.
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
A third leg, however minor, makes it a different device. Try again :)
:)
You don't need the kickstand to make it work. You can either:
a) Go in one direction, then reverse.
or
b) Design the device such that the wheels don't have clearance when it is horizontal. Looking at the pictures of the lego device, it appears to already be made this way.
Nice reply. Try again
?!?!???!?!
They're actually $200 each.
Any sufficiently simple magic can be passed off as mere advanced technology.
While you probably meant that as a joke, youe might want to take a look at the Slashdot article about TCP/IP for LegOS. The TCP/IP stack used already includes a simple scriptable web server...
20mb you say.. ok theres over half a million slashdot users. Now say just 1% of users visit the slashdot cache - 5000 users. Now say they download just 5% of that site - 1mb. That's 5gb of traffic from just 1% of /. users - 1% of registered users. Now say that happens on one site a day - 30x5gb=150gb/month.. That's one whole lot of bandwidth.. at a lot of $$. Now imagine of 5% of registered users looked at these sites.. 750gb.. 10% and you're up to 1.5tb
http://perso.freelug.org/legway/LegWay.html
Actually, the problem is it's only good at one thing:
Balancing while navigating flat terrain.
Anything less than flat, and the distance sensor is going to be confused. It may overcorrect and send the thing tumbling. Really broken terrain, or areas with grass and plants, OR DENSE TRAFFIC would send this simple sensor crying home to momma.
Ginger, on the other hand, uses a complex internal gyro system to determine which way is up, which means that no external interference is possible ( short of rigging gravity, and even then GINGER will always be right! ). The only way to make it tip over is to give it an external impulse that it's motors cannot respond to fast enough.
Man is the animal that laughs.
And occasionally whores for Karma.
Umm, most of us have 6 sensory devices in our heads that allow us to process light, sound, taste, and smell. We also have innumerable pressure sensors in our skin. Ever try walking with numb legs? Hard, eh?