"IT" Revealed, and I'd REALLY like to understand how it works..

[Animal -OCXL-]

Time article


Finally the pulled the curtains.
"Only a scooter?" I dont think so. This thing sounds amazing.
And I am very curious oh how it works, how it looks, EVERYTHING.

 

[MadRat]

Sounds fanciful, drive all day on 5 cents of electricity? If it sounds too good to be true then it is. The cost of electricity is obviously the least expensive cost of ownership. It probably has a $1000 3-month fuel cell or some nonsense like that.

 

[c0rv1d43]

Remember when people were so busy speculating about the IT a few months ago? Some of the suggestions were hilarious -- teleportation devices, hovercraft, robotic woman -- especially considering the fact that the source of the first rumors (the guy with the book deal mentioned in the Time article) specified that the personal version would cost about $2,000. BTW, notice that the price has gone up a little?

The device is just about exactly what most of us with a little engineering background would have supposed, given the few facts available at the time. I don't think people should be so quick to disparage the idea. People love to move about on funky transportation devices. The proof will be, as they say, in the pudding. The quality of the design's execution is going to be of paramount importance. But if it works as well as the writer of the article indicates, then it's going to be very interesting to see how the public responds.

Oh, and the articles tells what type of batteries are used in the prototype. Actually those rechargeable batteries would undoubtedly be more expensive to use than some of the fuel cell technology that's coming around the corner.

Those who think the thing is silly should have another think. If, and I do mean if, the design is truly effective, it should be about as safe as walking, and somewhat faster. Think about the ramifications for a large city if, say, 50% of the work force started moving around on these devices. The possibilities for improvement of the environment and reduction of traffic congestion are certainly appealing.

If you think people will stay away in droves consider the fact that the postal service is mentioned in the article. If the device works really well, and if people start seeing postal workers flying about their neighborhoods silently and efficiently on these strangle little beasties -- almost anything could happen.

Of course, there are going to be a lot of people, many of whom stand to lose a lot of money if this thing catches on, who are going to try to stop it.

- Collin

PS: Oh yeah, anyone thing that the name "Segway" could be significant?

 

[Agent004]

<< teleportation devices >>



Damn, I would love one of these

Talk about efficiency and fuel consumptions

 

[OUdejavu]

No kidding, IT is crazy!
Anybody know how it counters the torque since it only has one axel?

 

[CTho9305]

what do you mean, counter the torque? if you lean forward, it accelerates, so you dont fall forward. if you lean back, it decelerates so you don't fall backwards. After discussing IT with a bunch of friends last night, we figured they spent way too much money for something that is not all that complicated (at least based on our understanding of how it works)

 

[c0rv1d43]

Gyroscopes are wonderful toys, and they're going to make this toy a lot of fun to use!

I wonder if he'll try mass marketing first in a really crowded place with a high-tech society. I'd bet the market in Tokyo would be tremendous!

- Collin

 

[OUdejavu]

By torque, I mean the whole equal and opposite reaction thing. Ya know like the charger in gone in sixty seconds.

 

[CTho9305]

as i said, i think the leaning person would be countering the torque... if you lean forward, and it accelerates forward, the torque would tend to push you back upright, and that would be countering it

 

[c0rv1d43]

There are a number of ways this could be implemented, but simply causing acceleration to counter the operator's tendency to fall when leaning wouldn't seem to be workable all by itself. Think about the dynamics of the system. The moment arm through which gravity seeks to cause rotation of the device about the wheels' axis of rotation is greatest at the greatest lean angles for the operator. That's where the electric motor has the least ability to apply sudden acceleration in the same direction. So when the operator decides to hang ten (so to speak) and the machine is already running near its maximum speed, there's no ability to accelerate hard enough to drive him back into an upright position again. On the other hand the greatest torque produced by an electric motor for this sort of application occurs at zero rpm. So the device's greatest rate of change of acceleration would occur when we least want it, when we're trying to have the system sit stable and upright at zero speed over the ground. Why? Because there's where the minimum moment arm for gravity to cause the device to fall will be exerted, and at the same time it's the place in the operational envelope where the motor develops maximum torque. That's why I don't think that there's any way that a simple device which reacts by driving the two wheels when it senses the operator leaning could work. It would seem to be a dynamically unstable design, if that's all there is to it.

If the gyroscopes actually do provide a high enough rotational momentum to cause a physical resistance to rotation about the wheels' axis that would be helpful in that it would induce a sort of damping effect to give the machine a little time to react and make adjustments. But I suspect that what we have happening is much more of an actual balancing act than a driving act. I suspect that the operator's platform is made to slide fore and aft with respect to the axis of rotation to help the machine maintain its fore-aft balance. That type of balance doesn't depend upon the ability of the machine to provide acceleration at odd moments in time, like when the machine is already at its operational limits speedwise. And a well-designed rack-and-pinion sort of arrangement should be capable of providing the very precise positioning of the platform necessary for this type of attitude control. Proper design would ensure that the platform position could almost always have more effect on the gravitational moment arm than any reasonable amount of leaning by the operator. (He'd really have to hang off the front of the vehicle before he could overcome even a modest shift to the rear by the platform.)

In the end, I'm not surprised by how much they spent to develop this thing. I'm surprised by how little they spent. My guess is that the materials science and controls development that went into this baby are pretty sophisticated.

- Collin

 

[TDSLB]

does anyone know where I could find some information on hydrogen engines. I have always wondered how exactly they work. Do they burn H2 or do thay run on a more complicated system?

 

[pm]

If the 'engine' used to run it were based on a horizontally spinning flywheel (axis is perpendicular to the ground), and this flywheel were spinning sufficiently fast and was mounted on actuators, you could use it to keep the thing balanced. So the 'engine' is a gyroscope itself and adjustments to it maintains the balance. If the rotational friction on the flywheel is low enough, then using a flywheel to would be a fairly efficient way to allow fast acceleration/deceleration of the unit while not stressing the batteries with high current demands, and it would be power efficient too since breaking could act to spin up the flywheel further.

Going out on a limb with a weird thought: another thought that I just had was that using a flywheel could figure into the rumors that this device would eventually use a new Stirling engine (AKA "heat engine", AKA "external combustion"). I know that DEKA has worked on Stirling designs for a while. I've tinkered with Stirlings for a while, and there are a couple of designs where the engine displacer (the equivalent of a piston in a heat engine) is made from a large flywheel (the displacer occupies half of the flywheel).

 

[MadRat]

The unit is unstable until it moves, lending me to believe its a vertically mounted electric motor, not flywheel. I watched it for a little bit on the TODAY show and noticed how easy it can be caddied when not ridden. Also note how each wheel moves independent of the other for turning; there is no single axle. I noticed that turning was always on the axis of one wheel, never having an axis between the wheels, lending to the idea that the wheels never stop but rather can ONLY change speeds to make the turns.

It probably uses a constant velocity motor and some type of variable-angle belt drive to motivate the wheels. The constant velocity would give it the same gyroscopic stability at all speeds. Its readily apparent that they recharge on stops; the inventor said the motor would spin until it comes to a complete stop. The variable belt drive would allow instant torque control to the wheels at different wheel velocities without a sudden impulse applied to the gyro when the wheels engage/disengage.

It most likely has a pair of motors or pullies to work the wheels. If it had a single flywheel (or motor) then it would be gyro-stabilized while turned off and the flywheel spins down... plus on spin down it would probably twist out from under the rider! Counter-rotating motors/pullies would counteract each other, negating any twist.

 

[DRGrim]

It has one brushless electric motor and one transmission for each wheel. There dosn't seem to be any specific balance mechanism.
You can see exactly how it works at Segway.com


<< Not only does it have no brakes, it also has no engine, no throttle, no gearshift and no steering wheel. And it can carry the average rider for a full day, nonstop, on only five cents' worth of electricity. >>


There is no specific chunk of harware called the steering wheel, throttle, etc. but you can plainly see they exist in one form or another.
As for riding all day, it can go 17 miles in perfect conditions. At 12.5 mph, this is a bit over an hour, or quite a bit less then a day.
The cost is how much electricity it takes to charge the batterys; possibly five cents, I'm betting more. I don't know what the author was smoking when he wrote this article, but it must be strong.

 

[c0rv1d43]

Funny, I didn't even think of looking for a segway.com. Duh! Thank you for pointing out what should have been an obvious link!

It's an hilarious design. If it works as well as it seems to, it's an astonishing accomplishment. So, no massive gyros or flywheels -- which it didn't seem large enough to house anyway. It's all done by using what appear to be tiny gyroscopic sensors and very sophisticated controllers for a pair of motors. Now that is what I call a class act.

I think they may have a hard time getting people in places like most parts of America to understand just how useful these things could be. I think they're very wise to try to sell them to the postal service and package delivery companies. If people start seeing postal workers sporting huge grins whilst going about their appointed rounds... No one who has sat through a London, Tokyo, L.A. or New York traffic jam will fail to get the point.

I'm gonna get one whether or not it looks like they'll work out. I've never met a funny gizmo that I didn't like, and this one is the funniest I've seen.

Only thing is, they're really going to have to watch out for the way this thing mixes with pedestrian and motorized traffic. I predict mayhem. I think it's funny that they talk about testing the chassis with the approximate weight of three SUVs. I'm not sure it's wise of them to remind would-be purchasers of the possibility that they might some day be staring up at the axles of Grand Cherokee!



- Collin

 

[Shalmanese]

I think this is a classis case of the "inverted pendulum" problem in control theory. Basically, get a big stick and try to balance it on the palm of your hand. Same principle.

One of the main challenges of this implementation though would have to be very heavy damping because large oscillations would be unacceptable. Also, not knowing the weight distribution of the rider could lead to problems if the machine isnt designed to auto-calbrate.

BTW: segway.com is down

 

[MustPost]

yeh, there were lots of rumors that he was working on a sterling engine.
But it was pretty obvious from his comments beforehand and copyrights that the guy took out that if their was a sterling engine, it was going on a scooter.

 

[Mday]

well first, its not one axel, they are independently moving wheels.

and there are like 5 gyroscopes in that thing.

its design is based on the inventor's previous invention of a wheel chair that could go up stairs, that design could also stand on 2 wheels allowing the handicapped to "stand" at a normalish height.

what the machine can do is know what position itself is in, and correct its position (there is a lag there if you have seen demos) immediately. its dem computers...

since the mobile market has manuevered the design of batteries to be as MUCH MORE ADVANCED as they were 10, even more so 20, years ago, we can see a lighter version very soon.

 

[c0rv1d43]

Actually, in vehicular terms, this device is effectively a single-axle design because its wheels have a single axis of rotation. The rear axles of cars aren't joined by single pieces of metal either. In many cases there are several independent links. It's still referred to as a rear axle.

I would have thought that they'd have to hedge their bets, so to speak, by at least allowing the platform to slide fore and aft above the "axle" to aid the motors in preventing the machine from falling, but the response time must be nearly instantaneous. I'll look forward to getting my hands on one of these puppies to see how it behaves at the extremes of its operational envelope.

- Collin

 

[RazeOrc]

If you guys have ever seen the wheel chair he invented (they showed it on a discovery program) they you would know that this must have been pretty easy for him to build. After all the wheelchair that has 2 independent sets of wheels mounted on a seperate platform from the chair can climb stairs, and if the person wants to be taller while sitting in the chair (by about 2-3 feet), it can stand up on 2 wheels and balance, even move. He showed just how stable it was when he got it up on 2 wheels and drop kicked it while on it, it didn't move, but he did, he fell off. IT, is simply a stripped down version of his wheelchair (which runs in the 10s of thousands of dollars due to development costs).

I think IT is significant because if it catches on, in big cities it could lead to REALLY RAPID personal transportation devices which would be awsome. Instead of driving a car through downtown rush hour traffic (you don't know big city traffic till you visit downtown central NYC) you could go to the PTD rental shop, grab ur scooter or hoverboard, or whatever and zoom along, or just own your own.

 

[CTho9305]

a hoverboard would be much cooler

 

[Ladies Man]

they better get a better battery cus 1-2 hours isn't gonna cut it for post office workers or anyone else for that matter

 

[Soccerman]

muahaha.. Ballard will rule all!

anywho, the reason I thought of such 'impossible devices,' like the transporter when I first heard of this, is simple, I don't believe that anything else would meet the claims that they were boasting.

second, Teleportation, though not practical now, may be around in some form or another anyway in the future (quantum teleportation).

this to me is SIMPLY another transportation device, that happens to be powered by electricity. big deal

I mean, it might have sophisticated technology or something to make it unique in the way it works, but it's not interesting to me..

 

[c0rv1d43]

Sometimes an invention that looks pretty humble can have far-reaching influence over a society. I think this one has the potential. But I'd be willing to bet that it will face enemies. It's going to be interesting to see how this pans out. People are fascinated by anything that can move them from one place to another. And a significant percentage of us just love anything weird!

- Collin

 

[SammyBoy]

man, it would be great if they had demo days to get the consumer market there. I'd be pumped. Theres a video on their website....sweet!