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Sugarat

Cut off & lost confidence

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Is this something that could be improved by the manufactures? If so it really should be a focus area since rider safety is so important, I keep reading people getting cut-offs and a lot of tips how to prevent them, having to rely on 3rd party apps with alarms just to get better insight when it could possibly happen, but can't the software in the EUC be made smarter to prevent it from happening in the first place? I mean before it draws all that power it doesn't have can't the software be proactive and not let you do that? Like you lean but it doesn't let you because it already knows it can't deliver? I'm not an electrical engineer so maybe it's just wishful thinking but I also think there is so much responsibility put on the rider and it's not always easy to predict these things due to all the parameters involved.

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5 minutes ago, Zopper said:

If you lean forward, the EUC can do just one thing: it tries to balance you. If it doesn’t, you fall. A common safety measure is a tiltback, which makes it uncomfortable for you to lean forward and so you lean back and the EUC can slow down. And it’s used (maybe not by GW) when the EUC gets at its limit but still have some power reserve.

But the tiltback needs time for the rider to do something and a tiny bit more power than normal balance, because in practice it means “put a bit more power than needed into the motor, so the EUC body overshoots the balance by a tiny bit.” If the EUC is already at its max power, because it hit a curb and now you are in an overlean (which people frequently mistake as a cutoff), the EUC can’t squeeze even a bit more - if it could, it would balance you. And the more you are falling forward, the more power it would need, so even when it gets over the thing that caused it all, your body is too far in front of the EUC for it to do anything. And you faceplant.

The manufacturer can’t do much else than the tiltback and beeping - they could make a much bigger power reserve, but then people wouldn’t buy a twice as pricey wheel as a competitor has, so they make some minimal margin (GW lets you set it closer to physical limits, IM will keep it a bit lower) and let the user to set the max speed. Which is effectively the same thing as if the wheel was made with a larger power headroom.

So if you want a safer wheel, don’t ride and it’s full speed. Limit it in the app to 2/3 or so to give it a larger headroom. But this is only that - a bigger headroom - and even that can be overwhelmed if you have a bad luck.

IM is the most conservative in this regards and if it thinks you are riding their wheel too hard (measured by current flowing into the motor), they will start a continuous tiltback that will force you to stop entirely and dismount (or fall down if you try to ride it anyway). Ask @DjPanJan. :D Think of it like: “Geez, I almost dropped you, bro! You can’t ride me like that!” But then you get complains from heavier people that it is doing this to them all the time, so they buy a KS or GW which lets them ride faster, even if it can be with lesser headroom (depends on the wheels we would be comparing).

Thanks for the explanation.

But you are also describing things the wheel can not predict like curbs and such but there is also stories of the wheel cutting off because people accelerated too fast when the battery was too low and drew too much power and there wasn't time for the wheel to give a  tiltback or warning, couldn't things like that prevented by some smart prediction algorithms that would give you tiltback not based on a set speed limit but rather on how much power you have left in the battery vs how much power it predicts you need at the rate you are trying to accelerate? i.e. some form of predictive tiltback. I'm just thinking freely here and could not be possible for what I know. 😅

I think rider safety issues is and will be the biggest hurdle for EUC's going forward in terms of legislation, same for all personal electric vehicles scooters etc.

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3 minutes ago, Rawnei said:

give you tiltback not based on a set speed limit but rather on how much power you have left in the battery

Most wheels do this already by lowering the speed limit as the battery depletes.  There does still need to be a degree of mechanical sympathy by the rider, if the rider hasn't felt the tiltback start to occur and pushes through it (by subconsciouslly placing more weight on the toes to compensate for the tilting wheel) the wheel will try to accelerate to compensate.

Unfortunately there are limits as to what a given wheel can achieve.  In an ideal world the wheel would always have enough power in reserve to accelerate underneath a rider leaning forward and force the rider to tilt back.  Leaving enough motor and battery power in reserve to do this would result in wheels with much lower top-speed limits and in a culture where riders are buying wheels purely based upon the listed top speed an arms race of maximum advertised speed occurs.

The three big names seem to take different approaches here:

  • Inmotion says "Screw you, we're setting the speed limit low enough that we think the wheel can cope with most things.  We don't trust riders to know what they're doing and we'll set the tiltback very aggressively."
  • Gotway says "Speed!  We'll give you more speed.  Ride at the limit but don't overlean/overpower the wheel.  We trust that you know what you're doing."
  • Kingsong says "Speed?  Yeah, we can lie about that and report that you're going faster than you actually are to leave some headroom.  We will tiltback but it's up to you to know when you're overleaning or overpowering the wheel."

Although I have ridden a Sherman I have never got anywhere near its top speed to know how it behaves...

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9 minutes ago, Rawnei said:

But you are also describing things the wheel can not predict like curbs and such but there is also stories of the wheel cutting off because people accelerated too fast when the battery was too low and drew too much power and there wasn't time for the wheel to give a  tiltback or warning, couldn't things like that prevented by some smart prediction algorithms that would give you tiltback not based on a set speed limit but rather on how much power you have left in the battery vs how much power it predicts you need at the rate you are trying to accelerate? i.e. some form of predictive tiltback. I'm just thinking freely here and could not be possible for what I know. 😅

They could, as i tried to summarize theoreticly in https://forum.electricunicycle.org/topic/7855-anatomy-of-an-overlean/

KS already has an 88% alarm, which is burden dependend. It is shown in Euc World as safety margin. But they do not trigger a tiltback by this (by now).

 

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On 9/2/2020 at 12:42 AM, Rawnei said:

Is this something that could be improved by the manufactures? If so it really should be a focus area since rider safety is so important, I keep reading people getting cut-offs and a lot of tips how to prevent them, having to rely on 3rd party apps with alarms just to get better insight when it could possibly happen, but can't the software in the EUC be made smarter to prevent it from happening in the first place? I mean before it draws all that power it doesn't have can't the software be proactive and not let you do that? Like you lean but it doesn't let you because it already knows it can't deliver? I'm not an electrical engineer so maybe it's just wishful thinking but I also think there is so much responsibility put on the rider and it's not always easy to predict these things due to all the parameters involved.

Its all about battery size, bigger battery means more expensive. So yes they can, no they can not without drastically increasing price. A unicycle with 2000$ worth of battery inside would have a HUGE overhead of power to draw from.  It would also have to retail at over 4k$

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So I guess, to sum up this thread.... 

 

Respect the tilt-back and warning beeps?

Ignore at the risk of performing the patented Gotway™ "ground brake maneuver©" which involves using your face/hands/arm/body as a braking medium. :lol:

Edited by onizukagto

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20 minutes ago, onizukagto said:

So I guess, to sum up this thread.... 

 

Respect the tilt-back and warning beeps?

Ignore at the risk of performing the patented Gotway™ "ground brake maneuver©" which involves using your face/hands/arm/body as a braking medium. :lol:

Riders getting hurt is not a joke. 

 

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4 hours ago, gon2fast said:

Riders getting hurt is not a joke. 

 

As someone who has experienced a cutoff and suffered injuries directly from it, i agree.

Riders getting injured is not a joke and in no way im i making fun of anyone getting hurt. 

However, if you are wearing protective clothing and padding and respect the tilt-back and warning beeps, 99% of the time, you will not find yourself on the ground, slowing yourself down with your body.

Luckily i was wearing the right protective equipment and safely used those protective measures to slow my body down without serious injuries, except a only a few road rashes and a severely bruised ego.

My comment is to tell everyone that they should avoid doing the patented Gotway™ "ground brake maneuver©" at all cost, learn from the information in this thread to understand why cutout happens and how to avoid it.

And if something unavoidable does happen and you experience a cutout with no fault of your own, be prepared. 

That is the only message i am trying to express in my comment. :thumbup:

Edited by onizukagto

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Hi Everybody,

I bought a Inmotion V8 3 years ago. I have the V10f also.  I rode about 1,500 miles during this time, without any problems. 
Last Saturday with V8, at an acceleration starting from zero, my wheel stopped. It happened about  18-19 miles. Three loops followed. All my limbs are injured and my back and shoulders. Fortunately  only one finger broke,  but it needs to be operated on because it has moved. There was not signal or any alarm. I am about 80kg.It was almost fully charged.  What was my mistake? 

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On 9/8/2020 at 11:41 AM, onizukagto said:

However, if you are wearing protective clothing and padding and respect the tilt-back and warning beeps, 99% of the time, you will not find yourself on the ground, slowing yourself down with your body.

And whats about the 1% rest?

Thats when the wheel breaks for whatever reason. This happenend to me last week. Since than, no more EUC riding. It's a Nikola 84 V whoch stopped balancing and will not work at all now. No power on/off or whatever.

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50 minutes ago, Dr. Zee said:

Hi Everybody,

I bought a Inmotion V8 3 years ago. I have the V10f also.  I rode about 1,500 miles during this time, without any problems. 
Last Saturday with V8, at an acceleration starting from zero, my wheel stopped. It happened about  18-19 miles. Three loops followed. All my limbs are injured and my back and shoulders. Fortunately  only one finger broke,  but it needs to be operated on because it has moved. There was not signal or any alarm. I am about 80kg.It was almost fully charged.  What was my mistake? 

Ouch, what protection did you have?

15 minutes ago, MBIKER_SURFER said:

And whats about the 1% rest?

Thats when the wheel breaks for whatever reason. This happenend to me last week. Since than, no more EUC riding. It's a Nikola 84 V whoch stopped balancing and will not work at all now. No power on/off or whatever.

That sucks, what protection did you have and are you ok?

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Unfortunately I had no protection. This is obviously my fault. But ,what do you think of the wheel ?

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2 hours ago, Dr. Zee said:

Hi Everybody,

I bought a Inmotion V8 3 years ago. I have the V10f also.  I rode about 1,500 miles during this time, without any problems. 
Last Saturday with V8, at an acceleration starting from zero, my wheel stopped. It happened about  18-19 miles. Three loops followed. All my limbs are injured and my back and shoulders. Fortunately  only one finger broke,  but it needs to be operated on because it has moved. There was not signal or any alarm. I am about 80kg.It was almost fully charged.  What was my mistake? 

19 mph is the absolute top speed of the v8 , there likely was warnings you just didnt notice them.  When traveling at max speed, even a small bump can cause you to lose contact with the ground and the wheel can free spin and cut out. 

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There are plenty of people jumping with wheels without the free spin causing cutouts. 
IMO its more likely the lack of available torque at upper speed which can make a bump overpower it.

The V8 isn't a very powerfull wheel, you might have gotten too used to the v10f.

Edited by null

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1 minute ago, null said:

There are plenty of people jumping with wheels without the free spin causing cutouts. 
IMO its more likely the lack of available torque at upper speed which can make a bump overpower it.

Are they jumping the wheels at maximum speed? The free spin is not instant, it can only happen if the wheel is already near max speed. Inmotion will tilt back and ask you to get off the wheel if it runs out of torque to hold you.

Edited by GoGeorgeGo

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There is something like +10-20kmh free spin compared to top speed, which takes time to reach, while a normal road bump won't have you airborne more than a fraction of a second. The energy to make you airborne in the first place would IMO have overpowered a wheel already at its edge.

You might be onto something but I never heard of a cutout due to free spin, especially if the rider doesn't even report having made some particularly huge jump. The rider is 80Kg going to the top speed of a V8, it wouldn't take much to overpower.

Edited by null

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At least I ' ve  worn wrist guards. So I scratched on them on the street. Bloody elbows and so on - but nothing broken. But my confidence in Gotway has actually gone.....

And in chinese service as well. Although warranty (1 year) - nobody helps me. 

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1 hour ago, GoGeorgeGo said:

Are they jumping the wheels at maximum speed? The free spin is not instant, it can only happen if the wheel is already near max speed. Inmotion will tilt back and ask you to get off the wheel if it runs out of torque to hold you.

If it runs out of torque, it won't tiltback because of lack of torque :) This is called overlean. To tilt you back, wheel needs to speed up. Behaviour you're writing about is an overpower or overload. This happens when you overload your wheel above safe limit. Usually it will still have a safety margin to tilt back and ask you to get off ;)  But it's also possible to overpower the wheel so violently that it will cutout instantly. This mostly applies to wheels with weaker motors and/or batteries.

Free spin condition doesn't cause immediate motor shutdown. There is some delay, usually about 2-3 seconds. It's unlikely that you'll stay airborne for such a long time :D

Edited by Seba

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17 minutes ago, Seba said:

Free spin condition doesn't cause immediate motor shutdown. There is some delay, usually about 2-3 seconds. It's unlikely that you'll stay airborne for such a long time :D

I dunno, I bet Fantomas is getting near that... :shock2:

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On 4/18/2020 at 5:51 PM, Sugarat said:

Hi All, 

  I've been a huge EUC fan ever since I got my InMotion V5F+ about 2.5 years ago.  I've done almost a thousand miles on it and love it to bits.  

BUT..  A few months ago I was on my way home from work on the wheel. I was just overtaking a pedestrian on the pavement when out of nowhere, it cut off on me. No warning sounds, no time to react, it just died, for the first time ever. I did a faceplant straight into the pavement and almost broke my arm. I ended up in hospital the next day but thankfully after about a week, the pain died away and I could use my arm again.  It was a close call. 

To this day I am unsure what caused the problem. There was a light rain which I thought may have tricked it into shutting down, but after some tests it doesn't seem to turn off when the wheel is in motion, so it can't have been a bit of water on top of the wheel.  I suspect maybe the battery was cold, as it had been outside for a while. 

I have run 'Diagnostics' in the app, and everything passes.  But now, I have lost confidence to use the Unicycle.  What if it does it on me again and I break my arm this time? That is something I cannot afford..  Was it a one off, or is something faulty, and will it do it again? 

For me, this now seems like a big risk. But I do miss using the unicycle terribly.  What does one do in such a situation??  Is there a wheel out there that has additional circuitry to protect against cut offs? I'm not sure what to do now. 

Cheers

I have the same problem using Segway Ninebot One S2.
I wrote an article in my blog http://blog.holzl.it/index.php/free-software-in-free-world/454-monoruota-il-mezzo-del-futuro-il-pericolo-del-presente

You need to translate from italian, but Cut Off using Monoweel is very very dangerous.

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