Getting Onboard

[hodgepoj]

G'day Mates,

Today's question is a perfect example of why it doesn't pay to think too hard. In anticipation of D day*, I started my gedanken training. My first act was to grab one or both handles and step up onto the Segway platform with either foot. And I was already in trouble. For this first step, is the Segway switched on or off?

If you step onto it with the power off, it doesn't help you to keep your balance so you immediately fall over.

If you step onto it with the power on, it senses the unavoidable small fore and aft leanings of the pedestal and immediately rolls the wheels to maintain balance. So you start to move forward or backward even before you are settled in the driver's seat.

My conclusion is that it is impossible to mount the damn thing and get ready before you take off across the ground.

Those of you who are already riding your Segways have obviously solved this problem. Would you mind sharing (and explaining) the solution?

* delivery day



hodgepoj

[pam]

You have to turn the power on before you step up on your Segway. You'll get so adept at stepping right up on it, upright, that if you move, it will only be a tiny bit. It's rather like stepping up onto a stair, you don't lean your weight forward or back.
Pam

quote:Originally posted by hodgepoj

G'day Mates,

Today's question is a perfect example of why it doesn't pay to think too hard. In anticipation of D day*, I started my gedanken training. My first act was to grab one or both handles and step up onto the Segway platform with either foot. And I was already in trouble. For this first step, is the Segway switched on or off?

If you step onto it with the power off, it doesn't help you to keep your balance so you immediately fall over.

If you step onto it with the power on, it senses the unavoidable small fore and aft leanings of the pedestal and immediately rolls the wheels to maintain balance. So you start to move forward or backward even before you are settled in the driver's seat.

My conclusion is that it is impossible to mount the damn thing and get ready before you take off across the ground.

Those of you who are already riding your Segways have obviously solved this problem. Would you mind sharing (and explaining) the solution?

* delivery day



hodgepoj

[BruceWright]

The Segway is powered on, but is not attempting to balance until it feels a foot on the footpad. It's upright because you're holding the handle.

When it's powered on, and nobody's standing on it, it is pulling forward a bit. So a hand on the handlebar is keeping it from rolling forward about 4 feet and clattering to the ground.

You hold the handle, and step with one foot onto it. Instantly you are balanced. You put the other foot on.

When doing this, there is NO THINKING required. It is natural, even for first-timers. Don't worry about it! I didn't even notice it until you just asked!

I recommend forgetting about this whole conversation. ;)

-Bruce Wright

Segway: Vehicle of Dream

[RedKey]

The bigger question is how/why do you have access to a HT without ANY training?

[pam]

quote:Originally posted by RedKey

The bigger question is how/why do you have access to a HT without ANY training?




He doesn't. He's just trying to anticipate. Those last few days are the hardest, while you're awaiting some action. Your mind goes bonkers thinking up things to do. <G>
Pam

[hodgepoj]

quote:Originally posted by BruceWright

The Segway is powered on, but is not attempting to balance until it feels a foot on the footpad.


This would require some sort of pressure sensor beneath each footpad. I don't doubt you but I've never heard before that the Segway has such a sensor.

quote:
It's upright because you're holding the handle.


But what if I push the handle forward or pull it backward? Isn't that how you tell it to go?

quote:
When it's powered on, and nobody's standing on it, it is pulling forward a bit.


What is the purpose of this design feature?

quote:
So a hand on the handlebar is keeping it from rolling forward about 4 feet and clattering to the ground.


How does pulling back on the handle prevent it from rolling forward? It seems to me that it will roll while the pedestal tilts backward until the horizontal component of your pull causes the motors to stall.

quote:
You hold the handle, and step with one foot onto it. Instantly you are balanced. You put the other foot on.


So somehow it interprets the slight fore and aft pedestal leaning as an unbalance on your part rather than as a command to roll. I wonder how it knows.

quote:
When doing this, there is NO THINKING required. It is natural, even for first-timers. Don't worry about it! I didn't even notice it until you just asked!
I recommend forgetting about this whole conversation.


I'm not going to worry about it, Bruce. I appreciate your and Pam's answers. But I'm curious and I can't forget about the conversation until my questions are answered.


hodgepoj

[Deviant]

hodgepoj, you're right; it doesn't work! ;)

Actually, nearly everyone oscillates their first time. I have had a few testers who didn't, but they are the rare ones. That's why the initial period requires someone standing on the ground, firmly holding the handlebars. After the rider is comfortable with standing on the HT, the subsequent mounting and dismounting gets easier and smoother.

[JaneJetson]

Also hodgepoj, there are four sensors under the footpad, two for each foot. When you put your first foot on the footpad, the Segway beeps to let you know that it knows you're there. According to my instructor, at least two of the sensors have to be activated for the Segway to continue to operate in balance mode.

[Sailor]

quote:Originally posted by RedKey

The bigger question is how/why do you have access to a HT without ANY training?

He's doing "thought" training (visualizing using the segway).

"gedanken" is "thought" in german.

[BruceWright]

WOW, Hodgepoj, TOO MUCH THINKING! Now you're SURE to ocillate on your first glide! ;)


quote:
This would require some sort of pressure sensor beneath each footpad. I don't doubt you but I've never heard before that the Segway has such a sensor.



Actually, it has 4 such sensors on the footpad. Pressing any two triggers the balance mode. (If you want to get really geeky, each pressure sensor has 2 separate circuits, just for backup sake. So really it has 8 sensors that work as 4!). I was shown these personally by a Segway trainer during the Ride it Event, so I believe him!

quote:
But what if I push the handle forward or pull it backward? Isn't that how you tell it to go?



Not until it's balancing. After that, it isn't the pushing or pulling of the handle, it's the center of gravity of your body. You can go forward and backward without touching the handle. I did it myself, just by tilting my body forward at the hips.




quote:
How does pulling back on the handle prevent it from rolling forward? It seems to me that it will roll while the pedestal tilts backward until the horizontal component of your pull causes the motors to stall.


It KNOWS you want to step on it. This is a mode programmed to let people climb on it. It is NOT the same behavior that it exhibits when it is being ridden. It is pulling forward against your hand just a little, waiting for you to climb aboard.



quote:
So somehow it interprets the slight fore and aft pedestal leaning as an unbalance on your part rather than as a command to roll. I wonder how it knows.


Not sure what you mean by this. Once you have one foot on, it is balancing. It does move forward and back, almost imperceptably. But its very small and very slow. It seems alive.

The Segway is designed to be easy to get on. It has been programmed with different behavior before you step on it. It is pulling slightly against your hand until you stand on it. I mean SLIGHTLY. Just a little tug forward, using the weight of the arm.

A balanced, empty Segway wants to go forward natually, because the handle is forward of the axel. So there's a little weight and a tug from the Segway. If you have a handle in one hand, it won't go anywhere.

Next step, one of your feet is off of the ground, but hasn't planted yet on the footpad. You are balancing on one foot. Segway is not yet in balance mode.

Next step, your foot almost contacts the pad, but your weight isn't on it yet. Segway is not yet in balance mode.

Next step, your foot contacts the pad, and you shift your weight onto the Segway. You lift the other foot from the floor. Segway is in balance mode. This is performed as a smooth step up, just like a staircase.

(Because you do that in one move, just like a stairstep, it doesn't matter if the device shifts forward or back slightly, your weight is securely on the platform. Stop in the middle, and try and equally distribute your weight between two feet, and you will have problems. One smooth step up.)

Next step, both feet are on the Segway and you're gliding!


You ARE thinking about this too much now ;)

If I may draw an analogy, it's like stepping onto an escalator, or a moving sidewalk. There's nothing to it, but if you freak yourself out, you'll ocillate.

Think of it like a stationary step, and you'll do fine. One smooth step up.

Getting off is the same. Stand upright and take one smooth step down.

-Bruce Wright

Segway: Vehicle of Dream

[ftropea]

Well, this is going to be tricky...

To me, this question is like asking me to describe how to tie your shoelaces. It's easier for me to show you and have you try it rather than explain it...

But, since you asked..

1) When a Segway HT is powered off, it isn't stable in the fore/aft plane and the handle bar/column will fall either forward or back.

2) In order to power a Segway HT on, you need to level the platform by holding the handle bar in such a way where the platform is basically horizontal and parallel to the ground. If you don't "right" the machine in this manner, the Segway HT won't allow you to power it on.

3) Once powered on, and it's leveled, the Segway HT determines whether or not you're standing on it. There are (4) rider detect sensors/buttons beneath the rubber platform cover.

4) If you're not on the machine, the Segway HT would continue to roll forward (handles upright) for about 6 feets and then automatically power off. But since you're holding the handle bars, it isn't going anywhere... Also, since it doesn't detect a rider.. it responds to you either pushing or pulling the handle bar.. rolling the Segway HT towards or away from you. But you're remembering to keep it steady.. because you're about to mount it.


5) While holding on with both hands, you place one foot on the platform - pressing down one or two of the four detect sensors. The Segway HT senses a rider is about to step aboard and its performance characteristics automatically change.. It feel much more stable.

6) Now.. here is where I think your question is answered. When you step on, you don't push the machine away.. and you don't pull it towards you. You step down on the platform, placing your weight down - directing it perpendicular to the ground. Just like when you climb stairs, you don't push yourself away from a step.. or pull yourself towards it. You STEP UP on top of it.. Force vector facing down, towards to ground.

7) Once footing is established, you're brain/machine takes care of the rest. You balance yourself upon the platform much in the same way you balance yourself upon a step. If you aren't balanced, and are leaning or falling forward - the Segway HT will take you forward.. back is vice versa. If you're balanced on the platform - EVEN ON ONE FOOT - you're good.. not going anywhere.

So that's about it I hope. Let me know if this makes sense..

Regards,

Frank A. Tropea
[/sc] Admin - "Keep your wheels on the ground!" - Contact Me (segwaychat@segwaychat.com)

[hodgepoj]

quote:Originally posted by BruceWright


(ME) But what if I push the handle forward or pull it backward? Isn't that how you tell it to go?

(YOU) Not until it's balancing. After that, it isn't the pushing or pulling of the handle, it's the center of gravity of your body. You can go forward and backward without touching the handle. I did it myself, just by tilting my body forward at the hips.


I understand what you're saying, Bruce, but I have a problem with it. Based on what I've read about how the Balance Sensor Assembly works and also based on the videos I've seen of folks riding a Segway, the pedestal must tilt forward for the machine to move forward. You may not intentionally push the pedestal forward when you lean forward at the waist but I'll bet you're actually tilting it forward a fraction of a degree.

Being unbalanced, by definition, means that the footpad is not horizontal. The Tilt Sensors in the BSA provide the horizontal reference. The only way the BSA could detect a shift in your center of gravity without the footpad (or the pedestal) being tilted is if the pressure sensors in the footpad compare the pressure under your toes to that under your heels. I don't think it does that. It makes more engineering sense for it to detect a slight fore and aft tilt away from the balance position.

Aside from that single nitpick, I think your answer is complete and informative, and I appreciate your thoroughness.

hodgepoj

[greenbean]

I still don't get it. How does it work again?

Just kidding - MY BAD.




-=torin

[BruceWright]

Hodgepoj,

You're correct, the footpad isn't sensing differences in toe-heel pressure, it's the tilting of the platform that does the trick -- kind of.

Here's what's going on. It's about your center of mass. Moving it tilts the platform. Move your center of mass any way you want, push your body away from the handles, shift your hips forward, rock forward on your toes, have someone shove you, whatever. Center of gravity is what determines the tilt of the platform. (Thanks, Isaac Newton!) That tilt is what determines velocity.



-Bruce Wright

Segway: Vehicle of Dream

[Deviant]

Correct, Bruce.

Also, the part about the HT going forward on its own without a rider is specific to the i-series because its center of gravity is forward of the platform. The e-series has extra weight (racks, bags, luggage) above the platform to counteract the forward leaning of the control shaft. When I installed the optional front bag onto my i-series, the forward weight is even more pronounced. Earlier, I "e-parked" my i with a potted plant on the platform. After the front bag attachment, I don't think that same plant did the trick anymore (might have been a different one, though).

Regardless, the center of gravity is worse on an unmanned HT if there is more weight off the front handlebars.

[hodgepoj]

This response is what I had hoped for. I commend all of you who answered, especially Bruce and Frank. But convert the gedanken experiment into an actual experiment:

Place a pushbroom (or a rake) on the floor so that its handle can move fore and aft but not sideways. Place a small stool between the broom and you. Now step up onto the stool while holding the broom handle and try to hold it perfectly steady (vertical). I can't do it. The handle will tilt -- perhaps only a fraction of a degree -- as you step up.

The Segway's Balance Sensor Assembly can detect such tiny tilts. And since your weight is on the footpad, it knows you are on board. Normally, a tilt of the pedestal even as small as this when you are standing on the pad (like Bruce bending at the waist) makes the machine roll. But it doesn't -- it just balances while standing still. There must be a built-in delay of a second or two after mounting before the BSA interprets a tilt as a command to roll.

N'es pas?



hodgepoj

[SegwayLongIsland]

OK. This is really funny! I haven't laughed this long and hard since I saw "Catch Me If You Can"! You guys are all kidding aren't you?

I can only imagine hodgepoj the first time he was faced with an escalator!! He must have stood there for two hours with a calculator and a tape measure figuring out the angle of the steps and the speed of the moving handrails!

Either he just gave up and jumped on the damn thing, or it sliced him into thin wedges like a tomato in a veg-a-matic!

Just watch PTs video "E-stand". A picture IS worth a thousand words.

[MrTechno]

I'm facing my Segway and trying to get up the nerve to ride it....but all the preceding postings have totally confused me. Lets see...keep my head still, keep my left arm straight, keep my....oh no---that's "how to swing a golf club!!!!" Now I'm really confused!!!

[GadgetmanKen]

Hodgepoj, I think the trick is to step up quickly, one foot then immediately the next, from all that I'm reading. I don't know exactly because I don't have one, but, this got me to thinking. As almost anything does anymore.

From reading these posts it got me thinking about several things...

First...
With the two sets of sensors on the base, when stepping up on it with the first foot, does the machine actually do anything, or does it wait until the second foot is positioned?

Second...
With that in mind..Wouldn't wearing shoes with high heels make a difference in the characteristics of how it operates? I remember Pam mentioning riding in high heels. Wouldn't all the pressure be on the toes? What about wearing platform shoes?

Third...
With the SHT being classified under being a "epamd" (as in handicaped) device... has the SHT been tested or is it capable of being riden by a person with one leg? Would two feet be needed to ride the SHT because of the two sets of pressure sensors? Do the sensors run horizontally (widthwise) across the platform? Or are they located at two locations at each side? Where would they put crutches, if they used them? Could a fold up wheel chair be added to it to take along after the ride? If all this is possible then it deserves the "epamd" right of way status. Don't ya think?

"Wouldn't it be cool, if?...is like Folgers in my cup"

[Deviant]

You can ride the HT with only one foot on the platform. Neither my wife nor I wear high heels.

Segway LLC advises that you press the red button to engage balanced mode before stepping onto the platform. Otherwise, if the platform is not flat, and you step on it without engaging balance mode (which won't engage w/o a flat platform), you will fall.

Again, don't try to jump on or do anything special. Just step up, relax, and have fun.

[MrTechno]

The questions you are asking will be answered within your first 120 seconds on the machine. Don't sweat it. Have fun. It's so simple...that's why it's so special.

Yes, there are four foot sensors. That's why you don't put your bowling ball bag on a Segway platform when it's in balance mode....they'll both ride away! No kidding.

[JaneJetson]

GadgetmanKen --

From what my instructor said, the foot sensors detect the presence of a person on the platform, but don't have anything to do with the balance. On the whole, it's probably more important to step on the Segway like you're stepping onto a stepladder than to step on quickly. Balance, rather than speed.

On the high heels front, having ridden my Segway in moderately high heels, I can tell you that they don't change the performance profile any more than they do for walking. :)

JaneJetson

[mzokc]

I really appreciate the detail in this topic. One of my frustrations last year was viewing all the Segway videos where no one ever steps on or off during those videos. When I visited Innoventions at Disneyland last May, the host demonstrated the process and answered many questions. I look forward to my first step during training!

Mark

[GadgetmanKen]

Thanks Jane...
So, I have been all along, believing that the sensors sense differences in pressure from front to back, but just, pressure or presence of being there on it, period.

The gyro stabilizers when out of balance are gotten out of balance by differences in the tilt of the handlebars and not the pressure on the base from front to back. Correct? Then what about users that ride it, hands free. Then it actually has noting to do with the handlebars, either. Just something to hold onto so you dont lose your balance. Correct? Then, the gyro stabilizers detect balance by the difference of pressure from the feet, making the base itself not horizontal. Correct?

Do you think that there is, or could be a weight factor built into it?

Say, maybe an infant or pet climbed aboard while it was in balance mode. Would it take off?

That would be a cool commercial, with the pet riding it, wouldn't it? Seen the dogs ride skateboards and snowboards, but a Segway? That would be funny...don't think it could turn it, tho...

Or say, maybe have weight sensors that will not let a child under your weight be able to ride it? Or someone heavier than yourself?

"Wouldn't it be cool, if?...is like Folgers in my cup"

[MrTechno]

quote:Originally posted by GadgetmanKen

Then what about users that ride it, hands free. Then it actually has noting to do with the handlebars, either. Just something to hold onto so you dont lose your balance. Correct? "


It's the tilt of the base you stand on that counts.

[JaneJetson]

Hi Ken --

To further clarify:

The four pressure sensors in the foot plate pick up the presence of the glider, and use that information to determine whether or not someone is standing on the platform.

The five gyros and the two liquid tilt sensors detect the tilt of the platform, and use that information to control the forward and backwards motion.

The handlebars are there for balance, yaw control (i.e. left and right turning inputs), cargo carrying, and so that the lock, user interface, and mode switch button are conveniently located.

JaneJetson

Whadda ya want to bet that Scooby-Doo will be riding a Segway in the in the next movie? ;>

[GadgetmanKen]

No bets, but it would be neat. And, a tough trick indeed, considering Dooby is animated. Scooby-dooby-dooo...

I think it would be cool if it was used in a new "Time Machine", "Back to the Future, "Terminator" or "Blade Runner" movie.

Or even a new Futuristic "Ben Hur" type movie.

Didn't someone somewhere mention that it was indeed being used in a new movie to come out. Any idea what one?


"Wouldn't it be cool, if?...is like Folgers in my cup"