Frowny faced Segway pitched me off my ride today

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Originally Posted by [email protected]

I'm also surprised that nobody has mentioned the "prevent overcharging" feature that's operative because Segway charges its batteries while going downhill. Not sure whether that might be applicable here - because the OP didn't say whether the Segway was fully charged at/near the top of the hill.

Thanks for posting the confirmation from Steve Wozniak.

And it's not a "design flaw" - the potential energy (combined weight of you and the Segway, coupled with the vertical distance) has to go somewhere. Into stored chemical energy in the battery, and/or into heat. At some point, there just is no big "heater" that can be turned on to dissipate the energy.

The "design alternative" would be to just gently stop, and not let you continue down the hill. That's essentially what happened - with prior warning. You got into an argument with the Segway, and insisted that the Segway go down the hill (thus harming itself). The designer had a difficult choice at that point:

A. Accept being forced to continue down the hill, thus probably "breaking" the Segway.

B. Refuse to continue down the hill.

Note that at that point, the Segway would be quite happy to just balance in place (expending energy), or glide back uphill (expending energy).

[dangerlampost]

Thanks for the reply - I understand the physics here. The design flaw is not the fact that Segway needs to stop or discharge it's batteries before going down hill - that is totally fine.

I think the design flaw is that the Segway key/display does not tell you *why* it's slowing down. Normally, when going down hill, Segway will tilt you back and slow you down to prevent you from going too fast. Totally understandable and desirable.

At some point, Segway decides that it can't take any more charge - this information should be communicated to the rider. There is no clue to the rider that Segway needs to stop and can't go down hill any more until you burn up some charge. This "reasonable person" here assumed that the reason for the slow down was the same as the speed limit slow down - no way to know that now I actually had to stop altogether. (Except for the, now obvious in hind site, fact that Segway stopped and started going backwards while going downhill. OK, that was a very good clue that I ignored! But unless you knew why, you wouldn't know to burn off more charge, which is my point I guess.)

Probably there is other useful information that could be communicated too, like "you're going too fast", or "low battery", or "battery too full", or "you're not level", or whatever the reason for no smiley face.

Now that I know what the problem is, I can avoid it. But I suspect other riders will keep having this problem, as it's really not obvious what's going on.

EDIT: This is a geeky side-track, but: What would be the most efficient (and safe) way to discharge the battery - I am thinking of a modification to the Segway design rather than just running it around for a while. I believe there is a maximum discharge rate the battery can sustain (it's not a capacitor in other words). What's the cheapest, safest, fastest way to discharge the battery? A big light? A heater? Can the energy be dissipated as a form of radiation other than light or heat?

What if Segway came with a built in (and very bright) light? When Segway detects that it's full and going down hill, it can automatically turn on the light. Might this give you a little more downhill before you need to stop and burn off more charge? If you can burn up enough extra power, you might even be able to sustain your downhill to the bottom.

[[email protected]]

Originally Posted by dangerlampost

I think the design flaw is that the Segway key/display does not tell you *why* it's slowing down.

I can agree with that. Of course, the 2nd Gen Segway was released in August 2006. There were a few limitations in display technology, and a few limitations in controller capability, then. But (when possible) saying why would certainly be good.

Originally Posted by dangerlampost

EDIT: This is a geeky side-track, but: What would be the most efficient (and safe) way to discharge the battery - I am thinking of a modification to the Segway design rather than just running it around for a while. I believe there is a maximum discharge rate the battery can sustain (it's not a capacitor in other words). What's the cheapest, safest, fastest way to discharge the battery? A big light? A heater? Can the energy be dissipated as a form of radiation other than light or heat?

What if Segway came with a built in (and very bright) light? When Segway detects that it's full and going down hill, it can automatically turn on the light. Might this give you a little more downhill before you need to stop and burn off more charge? If you can burn up enough extra power, you might even be able to sustain your downhill to the bottom.

"Can the energy be dissipated as a form of radiation other than light or heat?"

Well, yes - RF, Xrays, etc. But nothing that we would like.

And a bright light is just a heater. A 100-watt bulb dissipates 100 watts. Yes, a heater could certainly be added, for those cases where the battery is already "full".

My back-of-the-envelope calculation says that a 250-watt lightbulb (specially made for 75-volt service) would do the trick for the limited case.

[KSagal]

Most of the things you said it should display it does. It has a speedometer, so it tells you when you are going too fast. It has a battery indicator, so it tells you when the battery is full or empty. While in motion, a balance indicator for tilt is not significant, but while not on the machine, there is a tilt indicator, as well as an indicator that the machine it being told to turn.

I live in a relatively flat area, and have not glode in the high hills that much. I am not as familiar with "mountain" gliding, and I am sure that 700 foot hill does not qualify as a mountain, I am not even really sure what you mean by a 700 foot hill. (I presume it is 700 feet higher in elevation at the peak than at the base, but that could be over 1000 feet (too steep to walk, almost hand over hand) or over 10000 feet of road. Down hill steadily for 2 miles is something I have little experience with.

I do camp in the white mountains, and did take my i2 from the camp up a very steep mountain road for 2 miles or so, and did a touristy visit. I then glode down the 2 miles, but I was pretty low on battery at that point. I returned to camp after the 4 miles on the mountain with almost as much power as when I left. I would guess the peak at over 1000 feet above my camp.

However, none of my longer glides included long hills.

The point of the machine not telling you what was going on is a rather subjective point. It was telling you what it wanted to do, which was go slow. You did not want to listen to it, and thought you could make it do something else. You said in your post, that you did not want to do what it was telling you to do, and kept trying to force it. That did not work.

It did not tell you why, but it did tell you what. You chose to try to ignore the what, and it backfired.

Segways, cars, and many other tools are just that. Very predictable. It is the driver that has most of the variables.

I am glad the issue is explained. Good luck, good gliding.

[dangerlampost]

As a newbie, I guess I just wasn't prepared for the idea that Segway would want to come to a complete stop going down hill, when everything seemed fine (to me) up until then. So I then had the task of trying to figure out why Segway wouldn't budge, and I was kind of in the middle of nowhere. No error lights, full battery charge, smiley face when I was still.

So I turned around to see if I could go up hill, and went up hill for a short distance. Seeing smiley face on again, I figured I had fixed whatever the problem was. Of course, there was no way for me to know what the real problem was (without prior experience/reading/etc.).

So I turned around and went back down hill again. That's when it went very quickly from smiley to serious to frowny (all within a few seconds), and then it pitched me forward. I think the full stop to prevent over charge, followed by the quick turn and short run up hill, followed by going back down hill was the magic sequence that caused it to pitch me forward.

To me, that does not seem predictable. (Of course now with experience, I can predict that.)

By contrast: I can glide long and hard up hill with serious face on consistently without any problems. I can even accelerate in this situation. This may have lulled me into a false sense of security with respect to serious face.

Anyway, if Segway ever updates their firmware/design, it seems like a no brainer feature to add an explanation as to why you're slowing down. A simple indicator near the battery when in danger of overcharging would at least give the rider a clue as to how to resolve the situation.

[jgbackes]

You should probably read the manual (available online if you don't still have the paperback). On page 47 It does a very good job of explaining the stick shake you felt and also about safety shutdown.

WARNING
Read and follow all the instructions in the Getting Started Manual, this Reference Manual and watch the Safety Video for important safety information about the Speed Limiter, Stick Shake, and Safety Shutdown safety alerts.

Also there is this

Battery Pack charge
If Battery Packs are fully charged: When you go downhill the output shaft of the motor spins, generating energy, which is then stored in the Battery Packs and reused next time you require energy. This feature is called regenerative braking. If the Battery Packs are at full charge, and you go downhill, the energy being generated has no place to go. The speed limiter engages to slow the Segway PT down so less electricity will be generated.

I think they've done a pretty good job of explaining the problem. Perhaps you should have been better trained.

I remember the first time I did a very long distance bike ride up and down Mt. Lemon in Tucson AZ. One the way down my brakes overheated and totally failed. Again there was no place to put the heat and the "pads" just stopped creating friction.

If you drive a car, you have probably heard of or experienced "Brake Fade" This is the same problem, no where to put the energy.

Good luck with your future adventures.

jeff

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Folks, isn't that just a bit harsh?

The guy said he is a newbie, asked "why did it do this", and then also took the initiative to check with a local dealer. And came back with a very useful response from a respected source.

I'm betting that most of us just learned (from his experience) what the Segway will do if you try to push it down a hill that it doesn't want to go down.

How many of us read and totally comprehend all of the instructions in the book for all of the appliances that we use?

[dangerlampost]

Thanks for pointing out the manual paragraphs, that I must admit I do not recall reading (although I did know about the regenerative braking feature). I looked up that paragraph, and that's all it says about this situation, and I don't think that's sufficient (at least for me). I did view the DVD, and I don't recall any mention of this in the DVD. My local dealer also mentioned nothing about this even though I asked specifically asked if there would be any issues about living at the top of a big hill.

Here's what the manual should say instead:

"Segway charges its batteries when it goes downhill. If you're going down a big hill, to prevent the batteries from over charging, you will see serious face and Segway will slow you way down, and may even come to a complete stop. If this happens, you must discharge the battery a little before you can continue going down hill, which you can do by going uphill again for a little while or balancing in place for a while.

If you are about to descend a large hill with a full battery charge, burn off some of the battery first before you start your descent."

That would be so much more useful to me (if I'd read it!).

Also, the Segway design could be improved so that the reason the Segway is slowing you down could somehow be indicated to the rider. If I had seen some sort of "battery overcharge" indicator, I would have stopped, taken out the manual, looked up the code, and figured out what to do. And this would have saved me even without having read that paragraph in the manual.

[airdale]

Originally Posted by dangerlampost

Thanks for pointing out the manual paragraphs, that I must admit I do not recall reading (although I did know about the regenerative braking feature). I looked up that paragraph, and that's all it says about this situation, and I don't think that's sufficient (at least for me). I did view the DVD, and I don't recall any mention of this in the DVD. My local dealer also mentioned nothing about this even though I asked specifically asked if there would be any issues about living at the top of a big hill.

Here's what the manual should say instead:

"Segway charges its batteries when it goes downhill. If you're going down a big hill, to prevent the batteries from over charging, you will see serious face and Segway will slow you way down, and may even come to a complete stop. If this happens, you must discharge the battery a little before you can continue going down hill, which you can do by going uphill again for a little while or balancing in place for a while.

If you are about to descend a large hill with a full battery charge, burn off some of the battery first before you start your descent."

That would be so much more useful to me (if I'd read it!).

Also, the Segway design could be improved so that the reason the Segway is slowing you down could somehow be indicated to the rider. If I had seen some sort of "battery overcharge" indicator, I would have stopped, taken out the manual, looked up the code, and figured out what to do. And this would have saved me even without having read that paragraph in the manual.

I totally agree..... Its never to late to add a better description....

[KSagal]

I think this is a good topic, and had no problem with the OP bringing it up, nor asking for input. His path to the dealer and a quote from the Woz is fine, and informational.

I also do not have any issue with his statement that he thinks the manual wording should be more clear, or more explicit about this particular issue.

The only issue I had, and expressed, were the statements where he said he had no way to know what was going on, and that the segway does not display things that it does display.

Most things in our lives are cryptic. When I am going along in my life, there are no signs that pop up and say, "Karl, you should do this, or that."

Instead, there are signs like the exit number is #40. It is up to me to know that is the exit that I need to take to go home. There are speed limit signs on the road, but nothing in my car that says "Police may stop me if I go this speed on this road". (Actually, my GPS does display my speed and the road speed in red in the lower corner if I exceed the posted speed, but that does not make my argument)

In composing this posting, I felt my original view was completely valid, and still do. We have a responsibility as an operator of any tool to know how to use that tool. That was my point.

But in thinking of examples, I used the speed limit example, and upon considering it, I realized that my GPS gives me an input similar to the kind of input that the OP is asking for.

I understand his point better now. I do not really care one way or another about that particular display on my GPS, as that is not why I have that after market item on my dashboard. But, it is there, and somewhere, someone had decided it should be added to the display. Clearly, the OP would find a notice like that of value, and suggests the segway should have some warnings in addition to what it has, an added value display, if you will.

I better understand his point, but still feel there is a dual need here. He feels there is a need to give him more information, I feel there is a need that will never be adequately met. He did not read the data that was available to him, and stated that he did not believe the data was offered.

I know that he did not know about it. But it makes me think of all the times I was sure I was doing things right, when I was doing them wrong. I know of many times the correct data was available to me, yet I did not find it, or did not recall it, and I was responsible for being wrong. Extra data is nice, but does not change the responsible parties.