Team 871 - Homebrew Segway

[D.Fahringer]

Was The "J-Way" a 190 WPI project or Team 871's?
It went everywhere at the Nationals I remember!

[Matt Krass]

Originally posted by Willum
I'm begining to think that i'm the only graduated high school senior crazy enough to try and build a mostly functional self balancing robotic scooter.

Is there any knowledge of any other teams trying to do this, or is everyone just building segway look-alike's???

I'm also trying to make mine two-wheeled and self balancing. But I just passed ninth so I'm crazier than you.

And thanks for the encouragement guys, these forums rock!

[MrB]

The "J-way" is a team 190 project....

Team 871 has no affilation with Team 190....


ppppppttttt on the J-way :-P


(WernerNYK is a former Team 871 student team leader)

WPI yada yada yada :-)

[Adam Y.]

Meet the ev warrior!!

http://www.enigmaindustries.com/Bosch_EV_Warrior.htm
These powerhouses are designed to move a human on a bycycle. An alternative to the motors that you see in the kit. It may not be as powerful at 12volts but you can definately overvolt these to 24 volts. You really can not do that with the drill motors.

Is there any knowledge of any other teams trying to do this, or is everyone just building segway look-alike's???

Im not sure where my post went but I have decided two wheels are too easy. One wheel. That is where the challenge lies.

[gc02]

Here's a technical paper on a "mobile inverted pendulum" that could be of some use.

JOE

And some videos of it in action.

http://leiwww.epfl.ch/joe/

[seanwitte]

I remember seeing a two-wheeled balancing robot made with Mindstorms that used IR proximity sensors to balance instead of a gyro. We used some of the Sharp IR sensors this year, I don't have the part number handy but they're the ones with 6" - 6' range. Using one on the front and back, pointed at the floor, you can figure out your angle of tilt. They're pretty fast, you might be able to make a balancing platform without a computer, just a closed-loop with the sensors as feedback.

[Willum]

I've considered a single point balancing device. You couldn't use only one wheel, you'd need a sphere to balance on. You'd need to come up with a fancy turning mechanism or program because leaning like on the segway will only provide motion in that direction, not spin the rider around.

otherwise it's a good idea. just a little out of the range of the parts we're supplied with.

Will

[Adam Y.]

I've considered a single point balancing device. You couldn't use only one wheel, you'd need a sphere to balance on. You'd need to come up with a fancy turning mechanism or program because leaning like on the segway will only provide motion in that direction, not spin the rider around.

Actually there are quite a few designs to building a monowheel robot. One design involves contructing a giant wheel and then balancing the person inside the wheel. To move the wheel all you would need to do is shift the devices weight like a mouse in its little wheel.

[MrB]

Originally posted by seanwitte
I remember seeing a two-wheeled balancing robot made with Mindstorms that used IR proximity sensors to balance instead of a gyro. We used some of the Sharp IR sensors this year, I don't have the part number handy but they're the ones with 6" - 6' range. Using one on the front and back, pointed at the floor, you can figure out your angle of tilt. They're pretty fast, you might be able to make a balancing platform without a computer, just a closed-loop with the sensors as feedback.

My concern is that the IR sensors would be prone to errors depending on what type of surface you are running on.

I would guess and ultrasonic signal would be better, like what they use in wall "stud finders".

I like the gyro idea the best though, The Craigway's goal is to mimic the Segway, with the standard KOP.

This way other teams can duplicate the results (after we are finished that is :-)

[Rickertsen2]

I have used SHARP GP2D12 IR proximity sensors and surprisingly, they are almost entirely impervious to to differences in color, texture and angle. Their man drawback is that they are not linear and this must be corrected for. The problem is especially bad at large distances. Other than that, though these things are great. Sonar could be another interesting option.

[Willum]

Ok i finally revealed some stuff for the holiday weekend. This includes some of the physics and two key lines of code.

Enjoy! (it's on the incomplete, but available MASSIVE PHYSICS page)


Will

http://frohawk.no-ip.org/physics.htm

[Rickertsen2]

Ahh a fellow case modder as well!

[Matt Krass]

Alright, working on the design guys. Does anybody know of a drill motor model for Inventor besides the FIRST one? The FIRST one has a tendency to bring my system to its knees in crashes. Anyhow, using a 3:1 reduction on the drill to sync it with FP at 100 rpm, expecting about 65 rpm under normal load. I'm looking in to using 14" bicycle tires and wheels. Anybody have an opinion on how well the FP can handle the tweaks back and forth to balance? Can it at all? The drills wont kick in until you start moving, that darn slop.....Thanks

[MrB]

we used the FPs on the Craigway, they respond well, just not powerful enough for dynamic balancing. And I would take the stop pins out of the drill motors, otherwise you are going to wind up throwing someone off the device when it comes to a screeching stop.

[D.Fahringer]

That is a good point MrB, you have to be able to coast and use "engine braking", and that reminded that the picture I put in of the 2001 Drill motor and it's source of slop does not mention that we build our own shafts and the original shaft and it's related parts ALSO may contribute to play...I think it is the "Hammer" feature.


By the way I got a big kick out of the Joe series of balancing robot videos...high tech and what a riot! And it would do no harm to take a 30 LB weight and add it to the stalk to see what happens!