Team 871 - Homebrew Segway

We call it the “Craigway” named after the student in charge of getting this project rolling.

After the Nationals a few of Team 871’s students were getting restless. After seeing a couple homebrew segways at the Nationals, they decided they wanted to build one, but they wanted to have it actually run on two wheels like the real machine. Honestly, I thought it was never going to materialize, boy was I wrong.

The prototype does not yet support the rider. The rider must try to remain balanced, but when the rider leans in one direction, the “Craigway” moves in the desired direction.

Hopefully we will soon have a web site up following the project. Our goal is to have a self balancing (which it does) machine to move a human rider around like the real segway (i.e. only 2 wheels and no training wheels)

Enjoy the videos at the site below. Be kind and post a mirror if you can, this is being hosted from a cablemodem.

.30 MB Divx and 60 MB MPEG 1 clips are available.

E-mail me if you are interested in the 120 MB MPEG 2 video.

We would like to here everyone’s comments. I’ve seen the other treads, but didn’t want this getting LOST in the tread :slight_smile:

I should also point out that thet built the prototype in about 2 hours (power wheels wheels, 3/8" plywood, fisherprice motors and gear box, 1 gyro)

They spent about 2 weeks programming until they got the autobalance to work. Once balanced, a slight lean in that direction moves the “Craigway” in that direction.

We plan on testing the final design (see video or pics in the above link) with the CIM or Van door motors…

Final project ETA is in Fall 2003…

My Team is also working on a homebrew Segway. Maybe we could get together and work on it with each other? I have some Inventor drawings of the base and controls I could share, I’d like to see the programming involved in that. You can reach me here or on AIM (ace32456 or CodeMonkey263).

I’m hoping to have a web page up within a few days, as soon as it is up we will post all specs, designs, future ideas and current code.

Then we can collaberate a bit :slight_smile:

I don’t know if Segway, LLC would appreciate giving out info on a homebrew ripoff… but meh

well, we aren’t trying to mass produce a competiting project.

Here is a temperary site with some pics and info…

I’d like to talk to your programmer about the autobalance code, any contact info available?

the URL in my last post is for his web site… his e-mail is on there.

I guess I am not the only other person that has been working on a Segway summer project. I to would like to get in contact with your programmer. I couldent find his e-mail on the website, maybe I am just not looking in the right place.

I looked over your website, but I don’t believe you mentioned exactly what you were using as a control computer. We’re looking into using the edubot RC as our controller. Also, in some pics I noticed a radio modem, why not just connect the OI directly via tether, since with the radio you can’t legally use it at competitions. Plus, with a remote control base it limits your range to that of the radio. All info appreciated. TTYL

Hey all this is the programmer/web site guy. If you have q’s about the programming i’d love to help you develop your own code.

[email protected]

you can see some code hidden in the pics of my notebook on my site. However since the bulk of this project is programming I will hesitate on giving all that info away so quickly. It takes the fun out of it. :smiley:


I know the Robot controller holds all the programming to run the thing but I’m not quite sure how the radio and possibly OI come into play. It is controlled by the rider right? Could you explain this a bit. Also, how do you turn? I know how it would work mechanically but how does the user input his preference?

Well generally the OI and RC function as a couple, I don’t believe the RC will let anything happen without an OI giving it the ok. Correct me if I’m wrong

*Originally posted by Matt Krass *
**Well generally the OI and RC function as a couple, I don’t believe the RC will let anything happen without an OI giving it the ok. Correct me if I’m wrong **

That is correct. If the radio (or tether) link is not established, the RC won’t do anything. Even autonomous.

Quote: Gadget470 …

"I don’t know if Segway, LLC would appreciate giving out info on a homebrew ripoff… "

This is true I believe, I have been trying to get ANY response from Segway, pro or con, on the design sharing matter since the
Championship! I have been asked to share the design of our TWO wheeled “segway” by a lot of teams and I have been trying to do it fair and with the blessing of Segway.

No answer at all… What does that tell you?

I would not be suprised to hear a FIRST ruling for next year… “No homebuilt “Segways” at the events!” That would be very typical.

Good job MrB! Looks like your summer team is on the right track to get a self-balancing rideable “Craigway”!

Thanks, but I didn’t do much :slight_smile:

As for the RC and OI, you guys are right, I would guess, in the final drivable version (this was just a crude prototype) we would tether the RC and OI, and run them off the battery. It is either that or go to a completely different micro controller, and that doesn’t seem like it is worth the effort until this machine is almost 100% operational.

I’m still worried that the Innovation FIRST equipment will not be able to react quickly enough to support a rider. It was never designed to work in real time. But then again, i’ve seen teams build robots as sophisticated as what were are trying to do…

To respond to the turning question, it doesn’t not yet :slight_smile:

The prototype only gies forwards and backwards and is controlled by the input from 1 gyro. Will’s plan is to add a potentiometer for CW/CCW rotation. That will probably be put into effect as soon as we build a new platform, in Sept.

Bingo. The code has what i call a correction factor that adjusts how fast the motors throttle to react to the sway of the rider. By intergrating potentiometers we will be able to manually adjust the correction factor to add more or less acceleration and decceleration.

Hence turning by adding more acceleration to one side while removing from the other side.

However you can’t spin in place like this. From what i see in the segway videos the 3 angular rate sensors help detect lean into the turns so one doesn’t fall off the side of the seqway.


*Originally posted by D.Fahringer *
I would not be suprised to hear a FIRST ruling for next year… “No homebuilt “Segways” at the events!” That would be very typical. **

Actually, I recall hearing an announcment in the pits at Houston asking teams not to ride around on ‘personal transport devices’ in the pits. I’m guessing that was geared towards the teams who had thier own segways (or gokarts).

How’d you guys interface with the gyro, did you do just connect it directly to the analogs and do some programming miracles or did you use some kind of special circuit? I was looking in to using a resistor/capacitor circuit to emulate the behavior of a “real” gyro, any info appreciated.

just attached the gyro to the analog inputs…

nothing fancy on the device yet :slight_smile: