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View Full Version : Two Wheels, Servos, Microprocessors....



Bones
04-29-2006, 08:10 PM
Not sure if this should be in this section or another, BUT, since there has been yet MORE bantering back and forth about electronic control systems (dare I say ABS?) and our two wheeled beasts I just had to share this recent two wheeled experience.

I just got back from Disney World with the family. One morning I signed up for a two hour two wheeled experience on the Segway personal transport "thing" that is right out of the Jetsons. Perhaps you have seen them?

You stand on a platform that is about 12" (I am guessing) high and the whole thing looks kind of like a pogo stick with mini motorcycle handle bars. The wheels are just lateral to each of your feet. This thing has ten microprocessors, five gyroscopes and the wheels are turned by servos. The one I used had a speed limiter of 5 mph. To go forward, you very slightly lean forward. All you have to do is put some pressure on your toes. To stop or go in reverse, you do the opposite. To go left, you twist the left grip counterclockwise. To go right, you twist the left grip clockwise.

I got the hang of it in about 5 minutes. If you are an experienced motorcycle rider, there are some things that are a bit counterintuitive, but you quickly get over that. Once you "get it" these things are absolutely amazing and more fun than you can possibly imagine.

They accelerate very quickly and stop, literally, on a dime. Once you get good at it, you can stop very quickly while turning and turn around and go in reverse, kind of like ice skating.

So, here is something interesting. Torque. You know, the motorcycle magazines list all these figures for new bikes. Most modern motocycles are making between 40 lb ft and 90 lb ft of torque, right? This little ditty makes..........300 lb ft of torque .....PER WHEEL! The most fun you can have between 0 and 5 mph, I tell you. The instructor's machines had a limiter at 12 mph, but they can be programmed to go over 20 and probably higher.

Now, with all the banter back and forth about ABS and servos that I missed while I was away, it occured to me while riding this thing that basically, it is a giant ABS/servo, period. What seperates this from all that has been argued in another thread is that this thing is light years more sophisicated than anything used in motorcycles.

The most interesting thing to me was that once you got the hang of it, it became clear that the machine has a better sense of balance than any of us, even if you are a tight rope walker or trapeze artist. It really felt like an extraordinary extension of your body. You just don't fall over on these things because they sense more than what you sense and adjust for it in a way that YOU can process the info and act accordingly.

For example, the speed limiter can't just stop the wheels from going more than 5 mph, because as you would try to go faster, you would lean forward and fall over the front. So, as it gets to 5 mph, it calculates how much pressure you are putting on your toes vs. your heels and the forward lean of the pole, and it starts to lean the pole back towards you, so you CAN'T lean forward beyond your balancing point. It adjusts all the inputs over 1,000 times per second. Seamless and it feels intuitive. Amazing.

So why can't BMW make a speedometer that doesn't crap out after 2,000 miles? Oh, sorry, that was another thread.............

If you ever get a chance to ride one of these, do it. Fantastic.

Jeff

DarthRider
04-29-2006, 08:21 PM
Cool!
What happens if you try to peel out? Wheelie over on your ass?
Any hop-up potential?
What would they be like to race?
C'mon Bonesie, let's have the good stuff!
300 ft. lbs....hmmmm

Dave

Bones
04-29-2006, 08:33 PM
Darth,
You are always wheeling, because the wheels are side by side. If you try to lean the thing forward as fast as you can, it will just accelerate like a banshee, to keep the thing under you. You can't fall over the front even if you try. But, it also senses the rate of change 1K per second, so it leans the pole back at you as you lean forward, so you can't lean too far forward in the first place. It is amazing. Same thing with stopping. If you are tooling along and want to skid to a stop, it won't because it senses not only your aggressive backward lean attempt, but also the rate at which you are trying to lean it back, so it will stop you faster than you can imagine, but smoothly and seamlessly. Giant ABS, really. The motors are brushless servos. All torque, all the time.

I was trying to test the limits of the thing, kind of without being too conspicuous about it. One of the instructors said "let me guess, you ride motorcycles." I just smiled. He said, "have fun. The gyros and microprocessors will take care of the rest." He just warned me about trying to zip around a tight turn on a wet patch, because the thing can't detect and process sideways uncontrolled movement. He told me he has fallen off one doing that. At 10 mph it might not be as big a deal as going faster, but I have found that hitting concrete at any speed is not good when you are over 40.

I really thought it would be interesting, but maybe not a hell of a lot of fun. I was wrong. It was both. Of course the most fun was weaving around things, going up and down ramped surfaces, stopping and starting. Of course the faces of people when you whiz by was priceless, too.

www.segway.com is the link. There is a video there that does not do these things justice.

Jeff

DarthRider
04-29-2006, 09:44 PM
Yeah, these are cool!
We can race these, I know we can.
We gotta dump those wimpy electric servos though and get some internal combustion going there!
It's just a matter of time...

Dave

BobFV1
04-29-2006, 09:47 PM
One morning I signed up for a two hour two wheeled experience on the Segway personal transport "thing" that is right out of the Jetsons.

Boner - You have to get out more...

Note to self ... try out the Segway...

R4R&R
05-02-2006, 07:45 PM
I've seen a few places that rent them in tourist parts of big cities. They are neat. The agency I work for demo's them to visiting police groups to show how useful they would be for an officer that would have to be on the street.

I know a few years ago when they first came out, the DC council was debating wether to let them on the sidewalks - they are considered a motorized vehicle which are not allowed on the sidewalks (except for electric wheelchairs). I'm not sure what the outcome was but I rarely see them in the Chinatown area. I have seen the signs for the rentals and I would guess they are down closer to the national mall/Smithsonian area.

geechie
05-03-2006, 02:36 PM
Last year at Homestead, one of the IRL teams had one in the paddock. It looked way, way cool. This particular machine clearly had no speed limiter.

George

arkline
05-03-2006, 03:47 PM
And you can get the "dual-sport" model for tearing up the terrain...

http://www.segway.com/segway/model_xt.html

http://www.segway.com/images/v1/main_xt_modelb.jpg

DJ Down Under
05-03-2006, 05:27 PM
Thanks Bones...I can't wait to try one myself.

So that's how Rossi does it...:icon_smile: ...maybe his bike is like a big Segway...btw..has anyone seen that Bombardier or Rotax one wheel concept bike that uses the Segway priciple.. http://www.brp.com/en-CA/Media.Center/Press.Releases/1/2003.07.09.htm...I'm looking forward to that.


"Following the release of the Segway, Bombardier (the makers of such things as Ski-Doo and Lynx snowmobiles) announce their prototype Embrio - a motorcycle-like unicycle that uses gyroscopes to balance itself and runs off hydrogen fuel cells. It also features a landing gear that automatically retracts once you reach 12 m.p.h.

http://www.brp.com/NR/rdonlyres/33780DB7-E2A8-49E7-8643-E7A3B2B0F354/0/embrio20030709.jpg

DJ