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Killed my Ninebot P in 25 miles.


Douglas Ingram

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2 hours ago, Chriull said:

I could not imagine any other effective feedback system from the EUC to the driver which would work, because ...

 

2 hours ago, Chriull said:

... this just slowing down the wheel is _not_ possible. It would imply a negative torque, resulting in a faceplant of the driver. Especially if one is already leaning forward to accelerate!

This is also the reason for overleaning, which most peoples confuse with a shut down. And while faceplanting by overleaning, the EUC still tries to accelerate and by this stabilize the driver - if in this situation the wheel slows down to show the driver that the limit is about to be reached, the impact of the face on the street will just get harder... ;(

 

2 hours ago, Chriull said:

+1 for no shutdowns. But with no tilt back - please come with another better feasable solution. Imho there is none ;(

Well, you can accelerate and then decelerate, right? You also can keep ~constant speed, right? Now when you are close to the top speed (or you ride uphill and you're close to the max power you can get) the system tilt you back, which is dangerous for new riders. Of course are calm with tilt back, but the only thing it does here it stops you from accelerating or giving more power to the motor by leaning forward. And I'm not talking about over-leaning.

The solution is easy: each EUC should have a system that instead of beeping and tilting you back when you're riding top speed, should limit the speed. So if the safe speed (no tilt back) for E+ for 80 kg person is 23 km/h, it shouldn't allow you to cross 23 km/h by simply cutting the acceleration sensors, so leaning forward wouldn't do anything more. You'll just be riding full speed and that's all.

We know Ninebot can detect when you're riding at top speed or using maximum power and it can do tilt back, shaking (tilt front and tilt back and so on) and beeping, which is useless and extremely annoying. If it can tilt you back or even tilt you forward (for example when accelerating immediately), it can also not tilt you at all. I just shouldn't send more power to the motor, that's all. But the engineers haven't implemented that, they've implemented blocking YOU from giving more power to the motor which is ridiculous.

Let me put this another way. The construction of Ninebot One is so simple, that there is no mechanism that controls the engine separately from the user behaviour. They've implemented giving power by accelerating and getting energy back by decelerating. But then they figured that the battery can actually shut off (possibly the developers and engineers that took care of the electronics weren't responsible for the batteries). Some of manufacturers didn't figure it (like in previous Gotways you could get shut off without even tilt back) at all.

Instead of implementing a system to keep constant, maximum speed with some power reserve (according to the current battery status), they've used the battery electronics (which is often created by a separate company) to create beeping and tilt back :) Clearly they don't give a shit.

After I first reached the top speed of my E+, I jump off, because the tilt back was so scary and not intuitive.

Bottom line, it's essential to control motor power and RPMs via electronics (motherboard) and keep some power reserve from the battery.

- When a user accelerates too fast (the signal from leaning is strong), the unit should limit the power given to the motor and slow down the acceleration instead of shake the unit forwards and backwards (+beeping),

- When a user decelerates too fast (the signal from leaning back is strong), the unit should slow down fast, but not too fast, simply safe enough to get as much energy back as possible to the battery and to keep the unit from burning.

- When a user reaches the top speed (calculated by the power consumption, which can be different according to user weight, going up/down hill etc.), the unit should keep that speed constant and simply not allow to forward more power to the motor, also block the user from leaning forward.

Also, it should be assumed that none motherboard can burn and none battery can burn. Batteries should be bigger though or the used motors should have less power (which still would allow to go 25 km/h, just with slower acceleration). But the power forwarding should be limited by the board in the first place.

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3 minutes ago, Bat said:

The solution is easy: each EUC should have a system that instead of beeping and tilting you back when you're riding top speed, should limit the speed. So if the safe speed (no tilt back) for E+ for 80 kg person is 23 km/h, it shouldn't allow you to cross 23 km/h by simply cutting the acceleration sensors, so leaning forward wouldn't do anything more. You'll just be riding full speed and that's all.

The thing is, if you lean forward to go faster and the wheel does not go faster (doesn't accelerate) to stay under you, you will fall forward. The only way to keep the wheel from trying to go too fast is to keep the rider from leaning forward.  Hence the tilt back.

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24 minutes ago, Shoe73 said:

The thing is, if you lean forward to go faster and the wheel does not go faster (doesn't accelerate) to stay under you, you will fall forward. The only way to keep the wheel from trying to go too fast is to keep the rider from leaning forward.  Hence the tilt back.

Well, going too fast doesn't bother Ninebot to shake you forwards and backwards, right? Or maybe just my unit does that at top speed? It doesn't make much sense, does it?

That's what I just said. There is no system that prevents the user from leaning forward, instead of there is a system that tilts back the whole unit or shakes the user.

If leaning forward too much would be an issue, the shaking wouldn't be possible.

Also if the unit can tilt back, it also can use the same mechanism to prevent you from leaning forward, just instead of tilt back that much, it'd keep the horizontal position and constant speed. 

It's a win win, the user would know that accelerating more is not possible, but it'd be pleasurable to ride smoothly with constant speed.

We all know that tilt back and sudden shut downs (when the system couldn't handle the unit power consumption fast enough) it's the source of injuries, why are you defending a system that simply does not work?

Imagine a Tesla car that shuts off the car when you accelerate too fast or reach the maximum speed. Or that shakes your car by taking over and driving left and right repeatedly :D Imagine that your Tesla shuts off because you were driving it downhill with 100% charged battery :D Tesla simply cuts the regenerative braking circuit if there is a risk of overcharge. And Ninebot shuts off. You want to tell me that this is the only way it can be done? To shut off the unit when you drive downhill with full battery? Maybe they should advertise it as a "safety feature" - "When riding downhill with fully charged battery, your Ninebot keeps you safe by simply shutting off the unit to avoid riding downhill at all! Leave your Ninebot at home and be safe!" or "When riding downhill it's possible you'll fall and your unit will brake, but hey, that's our definition of safety!" or "We recommend caring additional battery charged 50% in order to swap it when you'd like to ride downhill!".

It's not possible because Tesla power train (engine) and batteries are controlled by advanced electronics. Musk even said once that faster acceleration and higher top speed is just matter of software. They set some variables to keep both range and power, because with faster acceleration the battery would be drained much faster.

Tesla prevents it from happening, why Ninebot can't? Because the electronics in Ninebot is similar to LEGO constructions - very simple. Simple is good, but safe is better. I'm just thinking about my E+ in terms of prototype. The electronics and software has to be improved and most of the things could be done without even changing the hardware.

edit

The following topic confirms that the motor behaviour can be controlled by different software. After updating to 1.3.5 all units behave differently. I still keep my 1.3.0 :) 

 

 

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3 minutes ago, Bat said:

Also if the unit can tilt back, it also can use the same mechanism to prevent you from leaning forward, just instead of tilt back that much, it'd keep the horizontal position and constant speed.

The unit is self-balancing, in other words it is compensating for for the riders leaning, in order to keep the rider from falling over.  If the rider leans forward and the unit keeps a constant speed the rider will fall forward, its that simple.

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29 minutes ago, Bat said:

We all know that tilt back and sudden shut downs (when the system couldn't handle the unit power consumption fast enough) it's the source of injuries, why are you defending a system that simply does not work?

I don't think anyone is defending a system that does not work.  We're defending Physics. ;)

29 minutes ago, Bat said:

Tesla simply cuts the regenerative braking circuit if there is a risk of overcharge. And Ninebot shuts off.

Tesla has Mechanical Brakes.  How would you implement those on a NineBot?  If you simply cut power to regenerative breaking, that means it freewheels.  That's what is currently happening, but you are not happy with that.  What is the solution?  And remember, it only has ONE wheel.

29 minutes ago, Bat said:

Tesla prevents it from happening, why Ninebot can't?

They Try.  It's called Tilt Back.  Anything else is called Magic. :wacko:

29 minutes ago, Bat said:

I'm just thinking about my E+ in terms of prototype. The electronics and software has to be improved and most of the things could be done without even changing the hardware.

This whole hobby IS Prototype.  You are involved in early development, and as such, things need to be improved, as they have been, and will be. Be patient, they aren't sitting on their laurels doing nothing.  It takes time and money, and LOTs of both.  I'm sure they are hoping to make their wheels better so they can continue to sell more.  Would not make any business sense if they didn't.

And again, I'm not JUST speaking about NineBot, but all the Major Players (NON Knock-Offs).

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The first parachutes needed improvement...someone had to fall to prove it.   I think we'll see fairly quick mfg action because it will cost them.  The US is on the brink of banning hoverboards....$$.  What may not be quick enough for us parachuters will be great for next gen post lawsuit generation of riders lol

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Here is an example of the scooter hero Berlin , as is exactly beschieben what is a bad , unsafe wheel that Cat 1 rad Mad in Germany . How in the end at an accelerating wheel simply turns off without vorwahnung and is therefore called not sure must not be in a good wheel , and that's what makes the Ninebot always surprising that is a fact , for whatever reason , Ninebot is remedy this deficiency , I presume . Thus, each feels safe again on his Ninebot . Of course, it depends on the driving style of the individual , with excessive loads , there will always be surprises , but use in nomalem and Stress of the wheel , it should not be the case. Ninebot should be a safe and reliable wheel again that I hope by the engineers from China

 

 

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17 hours ago, Bat said:

Also if the unit can tilt back, it also can use the same mechanism to prevent you from leaning forward, just instead of tilt back that much, it'd keep the horizontal position and constant speed. 

With an electric motor you can have speed or you can have torque. You cannot have both simultaneously. When you are at maximum speed you have minimum torque. Torque is required to keep the pedals flat when you lean forward, it is also required to tilt the pedals back for the warning. The Ninebot cannot wait until you are at maximum speed to give a tilt warning because at that point it lacks the torque to tilt the pedals back. The only choice they have is to tilt back the pedals earlier as you approach max speed. However you can still overlean in many situations, for example if you attempt to maintain a constant speed as you go from flat terrain to climbing a hill. The torque that was sufficient to keep you balanced on flat surfaces may not be enough to also climb a hill.

In short, you can't change the laws of physics.

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There's so many things wrong in how Bat thinks these work and how the physics work, that I haven't even bothered to answer ;)

EDIT: This was a bit of trolling, I most certainly don't know everything about the motor control of these wheels, but I do believe I know enough to tell for example that claims like " they've used the battery electronics (which is often created by a separate company) to create beeping and tilt back" are nonsense.

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Ok, I'll bite, although I probably shouldn't ;)

 

--
Tesla cars have mechanical brakes only because these are required by law and for emergency braking when the engine can't decelerate that fast.
--

The mechanical brakes are there also because you can't use regenerative braking with full batteries, or when decelerating really fast, you can't push all the energy into the batteries. There's a smart brake control system that can apply either regenerative braking, mechanical brakes or both in varying degrees.

--
Besides Teslas don'tshut off, don't tilt back and don't beep when you accelerate faster than Lamborghini 
--

There's no need for tilt-back, it isn't self-balancing. As for shutdown and beeping, they are unnecessary also because the car doesn't need to "go faster than it can", unlike an EUC, where the rider can keep leaning forwards, trying to force the motor accelerate (limited by torque / current) and keep turning faster than it can (limited by voltage / back-EMF).

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So why developers haven't implemented a mechanism to just slow down the wheel even if the user pushes it forward even more? It's not hard at all.
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Not hard to do, but without acceleration (or even worse, deceleration like you suggest), you fall forwards when leaning, so it's not a good idea in general.

-- 
Well, you can accelerate and then decelerate, right? You also can keep ~constant speed, right? Now when you are close to the top speed (or you ride uphill and you're close to the max power you can get) the system tilt you back, which is dangerous for new riders. Of course are calm with tilt back, but the only thing it does here it stops you from accelerating or giving more power to the motor by leaning forward. And I'm not talking about over-leaning.

The solution is easy: each EUC should have a system that instead of beeping and tilting you back when you're riding top speed, should limit the speed. So if the safe speed (no tilt back)
--

Again, "limiting the speed" (ie. preventing acceleration) will cause the rider to fall forwards when (s)he leans. Think of doing a wheelie on a bicycle or motorcycle: you apply more torque (ie. accelerate) to get the front wheel up in the air. You then keep it in the air by applying acceleration (if the wheel starts to fall forwards) or deceleration/braking if you start to lean too far backwards. The principle is the same: you control the "balance" (ie. keep the front wheel up in air) by controlling the deceleration and acceleration. If the wheel starts to drop forwards towards the ground, and you keep your speed steady, it will end up hitting the ground (ie. "falling forwards").

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 for E+ for 80 kg person is 23 km/h, it shouldn't allow you to cross 23 km/h by simply cutting the acceleration sensors, so leaning forward wouldn't do anything more. You'll just be riding full speed and that's all.
--

"Cutting the acceleration sensors" (I believe you mean the gyroscope+acceleration MEMS?) would mean that the wheel totally gives up all control over the motor torque (I think you mean keep running at constant speed current?), because it needs to know the rotational position and change in that (acceleration around the sideways X-axis (pitch), not motor acceleration in this case). Again the problem is the same: The wheel will keep moving at a steady speed of X, whereas rider starting to lean forwards would need a burst of acceleration to be moved back upright. If the wheel does not accelerate, the rider will faceplant.

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We know Ninebot can detect when you're riding at top speed or using maximum power and it can do tilt back, shaking (tilt front and tilt back and so on) and beeping, which is useless and extremely annoying.
--

I don't think the "shaking" is actually intentional (at least I don't recall anyone else saying that their Ninebot does this). I've experienced a similar "rocking" back and forth with Vee's MCM2s at high speeds, but I don't think that was intentional either, maybe the acceleration / deceleration "overshoots" a bit in high speeds.

--
If it can tilt you back or even tilt you forward (for example when accelerating immediately), it can also not tilt you at all. I just shouldn't send more power to the motor, that's all. But the engineers haven't implemented that, they've implemented blocking YOU from giving more power to the motor which is ridiculous.
--

Tilting forward during "accelerating immediately" probably just means that the wheel cannot produce (immediately) enough torque to pull you back upright, so it's nearing an "outlean"-situation.

The tilt-back is there to warn you that you're either nearing too high speed (the back-EMF of the motor is so high that no high torque can be produced anymore with the battery voltage) or nearing an "unsafe" level of power used by the motor (limited by the maximum "safe" current that can be pulled from the batteries and/or that the motor/drive half-bridges can take without burning).

--
Let me put this another way. The construction of Ninebot One is so simple, that there is no mechanism that controls the engine separately from the user behaviour. They've implemented giving power by accelerating and getting energy back by decelerating. But then they figured that the battery can actually shut off (possibly the developers and engineers that took care of the electronics weren't responsible for the batteries). Some of manufacturers didn't figure it (like in previous Gotways you could get shut off without even tilt back) at all.
--

Actually, I believe the mechanism isn't even up to the user. What the wheel electronics try to do, is to keep the leaning angle of the wheel at or near 0 degrees (where 0 degrees is "upright"). The wheel will stay upright with or without you on top. What happens is that when you lean forwards, the gyroscope- and acceleration-sensor data is used to detect the error between the upright and current position, and this data is then used in some form of a PID-loop to control the amount of motor acceleration / deceleration. Of course on top of that, there are certain other parameters used, like when tilting back, I'd believe they offset the "0-degree" position when calculating the error, to make the wheel seek a balanced position where the device is partially tilted back. Another case is slow speed turning, where many wheels tilt the pedals forwards (probably based on speed and sideways lean, ie. rotation around z-axis (roll)).

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Instead of implementing a system to keep constant, maximum speed with some power reserve (according to the current battery status), they've used the battery electronics (which is often created by a separate company) to create beeping and tilt back :) Clearly they don't give a shit.
--

How about instead of keeping the speed constant and letting the rider fall forwards, you'd, I don't know, tilt the pedals back before the full speed/full power and let the rider know that there's some power reserve but (s)he's nearing the limit?

As for "they've used the battery electronics to create beeping and tiltback", I call bullshit. There are no gyro/accelerometer-sensors in the battery BMS (or the cells themselves for that matter), no way to send the data to the mainboard (unless you'd do that over the discharge wires, which would be hard and just stupid) and no speaker. So how do the "battery electronics" cause the tiltback and beeping? Simple: they don't. Pretty much all the BMS does is control charging (protections and balancing) and discharging (protections). All the speaker/tiltback/motor-drive etc. logics are in the mainboard firmware.

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Bottom line, it's essential to control motor power and RPMs via electronics (motherboard) and keep some power reserve from the battery.
--

At least on this I agree, and that would seem to pretty much be how it's done currently. The "power reserve" is there, if you don't on purpose try to lean more when the wheel starts to tilt-back (or give you the final beeping warnings).

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- When a user accelerates too fast (the signal from leaning is strong), the unit should limit the power given to the motor and slow down the acceleration instead of shake the unit forwards and backwards (+beeping),
--

Again, faceplant. The only thing keeping you up is acceleration during leaning. The more you lean, the more acceleration is needed.

--
- When a user decelerates too fast (the signal from leaning back is strong), the unit should slow down fast, but not too fast, simply safe enough to get as much energy back as possible to the battery and to keep the unit from burning.
--

Same in reverse. If the deceleration isn't strong enough in comparison to your backwards lean, you fall backwards.

--
- When a user reaches the top speed (calculated by the power consumption, which can be different according to user weight, going up/down hill etc.), the unit should keep that speed constant and simply not allow to forward more power to the motor, also block the user from leaning forward.
--

Here's the dilemma: the only way to prevent the user from leaning forwards more is to accelerate faster, and/or tilt-back (which doesn't actually totally prevent the leaning, but at least makes it harder and gives the user a warning).

--
Also, it should be assumed that none motherboard can burn and none battery can burn.
 Batteries should be bigger though or the used motors should have less power (which still would allow to go 25 km/h, just with slower acceleration). But the power forwarding should be limited by the board in the first place.

--

The power (acceleration) of the motor IS limited and precisely controlled by the mainboard. If the acceleration were too FAST during forwards leaning, it would make you fall backwards (the wheel would "shoot out" from under you). Less power would just make it more likely for you to outlean it, the maximum speed can be and is limited by software (and tilt-back/shutdown) and of course the component limits (but crossing those will end up burning something).

All in all, it sounds like you've somehow misunderstood that acceleration and tilt are two separate things. The acceleration and deceleration is what controls the tilting (counteracting the lean of the rider), nothing else.

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By the way @Bat, I don't believe we are trying to gang up on you, although the "Bull Shit" responses would be deserving of it, but we are trying to explain why Physics limits what an Electric Unicycle (Or Manual Unicycle for that matter) is able to do.

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A critical issue lost in translation like the democratic economy. Unexpected vs Expected shutdown. Unexpected shutdown is shutdown under expected normal operations. Expected shutdown is shutdown at operations near critical conditions. Let us all discuss only the unexpected shutdown. The tilt back, shaking. ALARM, and voice activations does not get activate under unexpected shutdown.  What are the possible solutions to the unexpected shutdowns? Why are the manufacturers not implementing them? What can we (the consumers and dealers) do to obsolete these manufacturers?

...Once the unexpected shutdown is eliminate, then would be more timely to discuss elimination of expected shutdown.

If the manufacturers can not control the more easier unexpected shutdown, dont bother discussing solutions for expected shutdowns.

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53 minutes ago, OneWheel said:

A critical issue lost in translation like the democratic economy. Unexpected vs Expected shutdown.

That is a good point @OneWheel.  Expected vs Unexpected.  There have obviously been hardware failures posted that should not have happened when a motherboard, battery, or motor have had weak points.  Those definitely need to be addressed.

But again, there are still limits to what is Physically possible, so there will still be failures that cannot be designed out completely, even when Quality Control has been addressed properly, which it has not been up to this point.

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I have a few things to contribute here - lets start with rapid acceleration and falling over

- It takes a TON of torque to keep someone standing on a wheel, with the center of gravity so low upright.  it takes even more torque to do that while moving.  The faster you are moving, the less torque available to keep you straight up.  Depending on your size, height, weight, etc... if you are going full speed and give a good push forward, there is a good change the motor does not have enough torque left to pull you back.  When designing these things it's a trade off between performance and stability.  All you can do is optimize for most situations.  if you decide to go all out past the manufactures intended operating limits - That is on you.  That is how physics works.

 

As for blowing the board slowing down quickly 

-A motor in reverse is a generator.  That is how regenerative breaking works.  The higher the load, the more power it takes to move the motor, and when the motor isn't being powered, the more electricity it will make.  Typically in a good motor controller design you put a large capacitor on the motor to help control the incoming current. (pololu motor controller image attaced.)  When the motor is not dissipating, it is generating, and the last thing you want is for a generator to feed directly back into the control electronics without a filter (capacitor).  As far as I can tell the electronics for the P are the same as the E+, yet the P has a higher performance motor which will generate more electricity while not under power.  I would imagine this is the culprit for the blown electronics when stopping extremely quickly.  A larger capacitor is usually the answer.  If there is a board revision after the first few P's come out, I would bet that is what it is.

 

It doesn't matter how big of a cap you put on there, you will ALWAYS be able to overpower it's filtering if you try hard enough, but the bigger the cap the harder that is to do.  The bigger the motor, the easier it is to do.

IMG_20160123_135834868.jpg

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"Tesla has Mechanical Brakes.  How would you implement those on a NineBot?  If you simply cut power to regenerative breaking, that means it freewheels.  That's what is currently happening, but you are not happy with that.  What is the solution?  And remember, it only has ONE wheel."

I didn't say to cut power to the motor, I said to cut or limit the power from the motor to the battery if it's too big and causes shut off by BMS. In that situation the motor can power itself to brake and stabilise you, right?

Bottom line, it should brake slower, even if we push it too hard.

Tesla's mechanical brakes don't have anything to do with it. Tesla uses the engines to brake in most cases, not the mechanical brakes. And the battery never cuts off the power!!!


"Not hard to do, but without acceleration (or even worse, deceleration like you suggest), you fall forwards when leaning, so it's not a good idea in general."

So you think that cut off and a faceplant is a better idea, like it's done right now?
It's easier to change your weight center than to rescue yourself when cut-off happens.


"Again, "limiting the speed" (ie. preventing acceleration) will cause the rider to fall forwards when (s)he leans. Think of doing a wheelie on a bicycle or motorcycle: you apply more torque (ie. accelerate) to get the front wheel up in the air. You then keep it in the air by applying acceleration (if the wheel starts to fall forwards) or deceleration/braking if you start to lean too far backwards. The principle is the same: you control the "balance" (ie. keep the front wheel up in air) by controlling the deceleration and acceleration. If the wheel starts to drop forwards towards the ground, and you keep your speed steady, it will end up hitting the ground (ie. "falling forwards")."

It's a bad example. You can stay in place with one wheel up, it's even used in "trials". It's just harder to do and involves your balance.
It can be done with pendulum, but you don't need it actually.

You don't get it the most important thing. Ninebot actually not only tilt you back, but sometimes it leans you forward and backwards alternately. 
If it can tilt you forward on full speed and you're still riding, and it can tilt you back, that means it has ENOUGH torque to do it and it can prevent you from pushing the pedals more.
It's already done in the newest software, well almost done, because pushing pedals is harder, it's easier to maintain constant speed, but constant speed still should be maintained by NB completely. But it's a good start.

Of course you can always overlean by taking something havier than you in front of you, but we're not talking about extreme senarios that won't ever happen or about infinite leaning limit. I'm talking about a design that can prevent a normal user from overleaning and simply keep a constant speed when a user stays with body straight and pushing on the pedals a bit when at maximum speed. Just to ride it more comfortably at maximum speeds.


"I don't think the "shaking" is actually intentional (at least I don't recall anyone else saying that their Ninebot does this). I've experienced a similar "rocking" back and forth with Vee's MCM2s at high speeds, but I don't think that was intentional either, maybe the acceleration / deceleration "overshoots" a bit in high speeds."

What? Let's try to accelerate as fast as possible on your E+. I don't know how is it solved in 1.3.5, but <= 1.3.0 it will "swing" you forwards and backwards few times, with beeping, when you're still accelerating!
It's not possible it's only my unit. I'd need to make a video.
How can it "swing" forwards and still running when it warns you about too much power? I can see the power output in the app, it reaches the maximum when accelerating that fast.


"Tilting forward during "accelerating immediately" probably just means that the wheel cannot produce (immediately) enough torque to pull you back upright, so it's nearing an "outlean"-situation.

The tilt-back is there to warn you that you're either nearing too high speed (the back-EMF of the motor is so high that no high torque can be produced anymore with the battery voltage) or nearing an "unsafe" level of power used by the motor (limited by the maximum "safe" current that can be pulled from the batteries and/or that the motor/drive half-bridges can take without burning)."
It's not "probably", it's intended feature that came up with 1.2.2 version release I guess, something about it.
It's not one time "tilt forward", it swings/shake forwards and backwards few times.
My distributor told me that's normal "warning" behaviour.


"How about instead of keeping the speed constant and letting the rider fall forwards, you'd, I don't know, tilt the pedals back before the full speed/full power and let the rider know that there's some power reserve but (s)he's nearing the limit?"

No, keeping the maximum speed constant and not allow the user to push forward even more sounds much better.
Everyone knows what is the maximum speed. I'm talking about normal users, that want to ride with maximum, constant speed - not ride uncomfortable with tilt back, slow down, then straight, then tilt back again, then slow down again etc. It's just stupid.
I want to ride for example 25 km/h with my body straight and not accelerate anymore. Currently when pushing the pedals more it tilts back, when leaning backwards it slows down too much to 22 km/h, then I accelerate again and it's hard to keep constant, comfortable speed. But it shouldn't be.


"As for "they've used the battery electronics to create beeping and tiltback", I call bullshit. There are no gyro/accelerometer-sensors in the battery BMS (or the cells themselves for that matter), no way to send the data to the mainboard (unless you'd do that over the discharge wires, which would be hard and just stupid) and no speaker. So how do the "battery electronics" cause the tiltback and beeping? Simple: they don't. Pretty much all the BMS does is control charging (protections and balancing) and discharging (protections). "

So you call bullshit that BMS is responsible for cutting of the power and faceplants?
And you seemed like a clever guy :)


"All the speaker/tiltback/motor-drive etc. logics are in the mainboard firmware."

No shit!!! That changes everything... 
I'm just kidding. Is my English that bad or you can't read with understanding? I bet the second option.

What I meant, is BMS cuts the power due to battery, not user protection. The motherboard should be connected to a custom BMS made by Ninebot (because they haven't made their own BMS as far as I know), that sends "live" battery status to the mainboard.

Then, motheboard knows where is the limit and can protect the battery cut off by simply even leaning forward a bit, to keep the user from braking too fast, but it should tilt forward a little bit, just to slow down the braking. 
If it can tilt back when accelerating, it should be able to tilt forward when braking, right? Why then Ninebot allows to burn the motherboard like in this topic when decelerating too fast? 

The tilt back/forward mechanism wouldn't be a bad idea to solve the problems, if the BMS status would be known by the motherboard AND the tilt back/forward were only a little (angle).

Problem solved! 
You have some issues with understanding and thinking, right?

 

"At least on this I agree, and that would seem to pretty much be how it's done currently. The "power reserve" is there, if you don't on purpose try to lean more when the wheel starts to tilt-back (or give you the final beeping warnings)."

Well, then it's not enough. You can still cut-off the power when accelerating or decellerating too fast, not because of overcharging the battery, but because of not enough power.

"Here's the dilemma: the only way to prevent the user from leaning forwards more is to accelerate faster, and/or tilt-back (which doesn't actually totally prevent the leaning, but at least makes it harder and gives the user a warning)."

That's not the only way, you just don't know any other way.
Your deductive thinking and conclusions are wrong.
Because cars can't fly it doesn't mean flying is not possible for humans. A proper car/drone could fly. It's just another design, another way to make things.

Besides the tiltback mechanism wouldn't be too bad if done properly (like I said earlier).


"- It takes a TON of torque to keep someone standing on a wheel, with the center of gravity so low upright.  it takes even more torque to do that while moving.  The faster you are moving, the less torque available to keep you straight up.  Depending on your size, height, weight, etc... if you are going full speed and give a good push forward, there is a good change the motor does not have enough torque left to pull you back.  When designing these things it's a trade off between performance and stability.  All you can do is optimize for most situations.  if you decide to go all out past the manufactures intended operating limits - That is on you.  That is how physics works."

"That is how physics works" sounds like "The speed of sound is the limit".

The MIDDLE AGES.

You are all ingorants defending poor designs.
Loosers simply say "this cannot be done", winners don't listen to loosers and just find a way.

We could even fly with "EUCs" in the future, who knows?

It reminds me like fans of Apple were amazed by a phone that couldn't send a MMS, record a video. It can't send files via bluetooth to this day :-)
But that was all OK, because "it can't be done" :-)
 

"All you can do is optimize for most situations.  if you decide to go all out past the manufactures intended operating limits - That is on you.  That is how physics works."

This is just hilarious :-)
If I drive Tesla and it'd let me constantly accelerate by pushing the gas pedal, and the car would "shut down", it's my fault I pushed the gas pedal? Tesla simply won't allow you to harm the motor or the battery, the acceleration and speed is limited.

Ninebot released a new software that won't allow you to overlean too easily and you need to give much more weight to the front, which doesn't happen when you ride with your body straight. Someone before said it's not possible, but now it is?

I said it can be improved by the software and they're working on it as we can see.

There are still many things to improve, and many of them require better designs.
We should push the manufacturers then, not defend them and stop the progress.

Because they don't give a shit. If the users would be satisfied with their products, why should they improve them?

It happens with cars from near 100 years. A new Audi drives the same like the old shitty models.
You should thank Musk he was smart enough to become rich, and brave enough to invest in a sector that is a threat to oil companies. And the oil corporations would do anything to slow down the progress.

http://waitbutwhy.com/2015/06/how-tesla-will-change-your-life.html

"-A motor in reverse is a generator.  That is how regenerative breaking works.  The higher the load, the more power it takes to move the motor, and when the motor isn't being powered, the more electricity it will make.  Typically in a good motor controller design you put a large capacitor on the motor to help control the incoming current. (pololu motor controller image attaced.)  When the motor is not dissipating, it is generating, and the last thing you want is for a generator to feed directly back into the control electronics without a filter (capacitor).  As far as I can tell the electronics for the P are the same as the E+, yet the P has a higher performance motor which will generate more electricity while not under power.  I would imagine this is the culprit for the blown electronics when stopping extremely quickly.  A larger capacitor is usually the answer.  If there is a board revision after the first few P's come out, I would bet that is what it is."

No shit, Sherlock :-)

My posts are not about how an electric motor works.

It's simple: power shutdowns, burning motherboards, faceplants - that should not happen at all.

It's possible to build an EUC that does not shut down, does not burn itself and takes care of your safety first.

If you don't believe it, you're just an ignorant.
To get something done, you need to set proper assumptions, then get it done. Not the other way around.

"If you fail to plan, you plan to fail" - I guess there is no Chinese translation for it, because EUC manufacturers should read it first.

You don't know how to build an EUC without shut downs, overheating etc.? Find a f**cking way :-)
It took thousands of lightbulb failures before finally a proper design worked.

But we are people, we don't learn from the past, we deny everything except our own ignorance.

I don't have time to argue with you more, I have better things to do. Wish you all the best and enjoyable rides with EUCs ;-)

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34 minutes ago, OneWheel said:

After 5 years / 300 charging cycles, is it safe to charge the battery packs after recommended 3 years useful life? According to this article dont be afraid to use the battery as it will not last more than 3 years even if not used often.

http://electronics.howstuffworks.com/everyday-tech/lithium-ion-battery2.htm

AFAIK, as long as the battery isn't being overcharged or otherwise abused, the only effect of aging is that the it won't store as much energy anymore, ie. it will run out a lot faster. At least that's what happens with cell-phone batteries usually. Could be wrong though. ;)

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KingSong is the only brand that provides decent battery size. The ninebot one e plus only provide 320wh, 10% goes to overcharge, 20% goes to undercharge, of the 70% remaining ... 35% goes to return trip, left over of 35% effective of 320wh equalling 112wh available for travel distance or 11.2 km travel distance with rate of  0.1km/wh. With spare battery of 388wh get another 13.6km, so my bike trail needs to be 24.8km or less.  2 pack$ battery should be just good enough.

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Most bike trails between 10km to 15km or 20km to 30km round trip. Good to go!

I wonder if charge doctor can be use to verify actually juice left on the battery vs percentage shown on ninebot app. . Are the results same or different. Cant assume at 0% battery level, the manufacturer offset enough juice for consumer benefit to damage the battery a little to cover 1 year warranty on each ride.

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1st distance test @ 8km/hr, 10km distance, 8 degree celsius, little drizzy rain, 150lb, 68kg, 6 very small hills

Battery went down from 91% to 50%.

Side face plant two times over side walk curb bump from lack of speed and not bending the knees resulted in slight scratch to the light ring. Should be able to make it disappear with the rub the scratch auto cleanser.

Comfort was found by moving the unit a little to either side or tilting the feet. Easier to turn and control at slow speed compare to airwheel x8. Seems easier to lose control at faster speed compare to x8 if not careful, wobbling effect from lesser touch. Ninebot was more comfort than x8, only when the proper advance technique used.

As expected, decided to ride backwards final few meters, killed it. Was much easier to ride backwards and transition from backward to forward compare to x8. Seems like can balance on the wheel without moving. Response of the wheel was much quicker than x8. Backward turning was more easier from lesser touch compare to x8.

 

 

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