Minipro intermittently LIFE-THREATENING unsafe, veering right

[Rider222]

When the problem happened to me, my gut feeling was that either it was an "edge case" algorithmic problem, or, more likely an actual physically bad component/connection/trace.  When the unit has acted up, there was always a vibration/bump involved, but always your normal fairly common minimal bump.  I typically ride (hundreds of hours of experience) over extremely bumpy off roading/dirt/gravel roads with no sign of any problem.  So having this errant Minipro randomly veer right, while riding full speed on an otherwise common smooth sidewalk with the vibrations only being somewhat normal expansion joints is what makes it this issue so randomly odd, and scary.  And, I could never repeat the problem in a controlled manner.  I spent hours trying to repeat the problem and never could.  The problem would only repeat under normal riding,  when I would least expect it.

[trevmar]

4 hours ago, Rider222 said:

When the unit has acted up, there was always a vibration/bump involved, but always your normal fairly common minimal bump.

Exactly! Even though I have a ledge at the end of my driveway which always causes problems it is just 2cm high. But there is a slight down-slope from the bitumen  getting to it, and a slight up-slope on the other side. In my case the problem is repeatable. We can take bigger bumps (pine cones and tree roots are common around here, for example) but it is this innocuous one which causes trouble... Interestingly, the entrance to our local park is shaped exactly the same, and it also throws me in exactly the same way... But other driveway ramps are not a problem...

Edited March 11, 2019 by trevmar

[Zephyrzone]

16 hours ago, Rider222 said:

When the problem happened to me, my gut feeling was that either it was an "edge case" algorithmic problem, or, more likely an actual physically bad component/connection/trace.  When the unit has acted up, there was always a vibration/bump involved, but always your normal fairly common minimal bump.  I typically ride (hundreds of hours of experience) over extremely bumpy off roading/dirt/gravel roads with no sign of any problem.  So having this errant Minipro randomly veer right, while riding full speed on an otherwise common smooth sidewalk with the vibrations only being somewhat normal expansion joints is what makes it this issue so randomly odd, and scary.  And, I could never repeat the problem in a controlled manner.  I spent hours trying to repeat the problem and never could.  The problem would only repeat under normal riding,  when I would least expect it.

The first time I encountered this bug it was exactly as you described: a minimal undulation in the sidewalk that’s commonplace and should never cause an issue. The second time I had the bug was just a few meters later on a more gradual ‘bump’ (in quotes because it barely qualified as a bump). If those bumps I rode over are likely to cause issues then the MP simply can’t be ridden outdoors...but I know that’s not the case.

The subsequent times I encountered the bug were on  perfectly flat tiles AND immediately after powering up. Now, about 50% of the time the thing just spins clockwise upon boot-up

I’ll upload a video once I export.

 

—edited for spelling

Edited March 12, 2019 by Zephyrzone

[mrelwood]

Please, everyone who has experienced the bug where the MiniPro shoots right at a tiny bump, if you haven’t already, contact Ninebot/Segway support. They really need to know about this issue, and that it’s not an isolated incident.

[Smoother]

To me a mini-pro is just a glorified hover board (no offence) When you have two computers controlling two different wheels independently and something unexplained happens (like this ) or even something explained like running one wheel over an unobserved rock You're going down hard. I feel your frustration.  Maybe you should have sent that wheel back to Amazon.  Is it too late for that?

Appologies if this has already been covered, I didn't read the whole thread.

[mrelwood]

1 hour ago, Smoother said:

When you have two computers controlling two different wheels independently 

Don’t know about hoverboards, but the MiniPro has a single mainboard with a single processor chip running a single software. Just like my seated Airwheel A3.

On the A3 the motors do have their own power distributing boards with their own  MosFets, and IIRC MiniPro has them separated as well. Either way the single firmware controls the whole vehicle.

During the winter I noticed several times when one wheel got stuck or started skidding, that rather than trying to stay upright with the remaining wheel (your scenario), the MiniPro tries to stay facing forward even if it means falling down. Which is of course the only sane way to make a vehicle like this to behave.

Edited March 12, 2019 by mrelwood

[Smoother]

3 hours ago, mrelwood said:

Don’t know about hoverboards, but the MiniPro has a single mainboard with a single processor chip running a single software. Just like my seated Airwheel A3.

Ah, ok.  What I meant was two wheels driven and one encounters a problem.  I remember in my (original) segway days, if one wheel hit a patch of mud it would spin up to speed wildly, even though the computer knew the other wheel was still only crawling forward.  If the wild wheel suddenly found grip, the inertia of the wheel would jerk the whole machine, often followed by a fall.  Why the wheels didn't share their relative speed info, I have no idea.  But regardless of that firmware fail, a lot of the segway/hoverboard fails show one wheel suddenly having a different idea of speed (usually rider induced (not the OPs issue) or by riding over something, or clipping something, with one wheel. It's basically a flawed design concept IMHO.

[Zephyrzone]

In my case the MP is now spinning to the right without provocation; it’s happening half the time I boot it up without even standing on it. It wasn’t doing that prior to the sudden veering. Could be coincidence, but I doubt it.

Ninebot didn’t see anything unusual in the black box data, which is disconcerting. I’m suspecting a hardware malfunction of the steering mechanism.

[Rider222]

3 hours ago, Zephyrzone said:

In my case the MP is now spinning to the right without provocation; it’s happening half the time I boot it up without even standing on it. It wasn’t doing that prior to the sudden veering. Could be coincidence, but I doubt it.

Ninebot didn’t see anything unusual in the black box data, which is disconcerting. I’m suspecting a hardware malfunction of the steering mechanism.

So in your case, did your Minipro always have noticeably odd issues, or, does it seem to be getting worse over time?  Did your issues only become noticeable after a firmware upgrade?  What I'm asking is if a "logical" change (programming) could be causing your issue, or, is some component is gradually (or instantly) failing.

I feel MY Minipro probably always had this issue, firmware upgrades over time, didn't change anything.  Again; MY "veering right" issue happened extremely rarely,  and, possibly (see my original post) very early on.  And, MY veering issue was ALWAYS extreme; instant 90deg veer right, during my riding high speed straight ahead on smooth/fairly smooth surface, hitting slight bump.  After I was certain a problem existed, I tested for hours riding slow in an empty asphalt parking lot paying full attention to oddities, and twice I might have felt it "twitch" right".  That's when I called it quits on that unit.  That unit is now stripped down to it's bare parts in which I did full visual inspection of all parts/traces/solder joints using magnifying glass and could find nothing odd.

I have never felt any oddities on my other two Minipros [yet].  But we haven't had the opportunity to ride them anywhere near as much lately.

 I'll post if I feel anything odd.

 

[Zephyrzone]

My MP has seemed a little odd since first run, but nothing obvious- much more in line with your ‘did it happen or didn’t it?’ twitchiness. Nothing noticeable by someone who isn’t hyper sensitive. 

The overall performance and stability never changed, regardless of firmware. The sudden veering- and now constant spinning- came on suddenly unrelated to a software update. I get the distinct impression that whatever sensors are used for steering have been ‘gracefully’ degrading until a final failure point. 

[68bugboy]

I still think some thing is going on with the hall sensor.

Mine did the same spinning while idle.

Bouncing the unit around would sometimes stop it.

I believe the bouncing would make the cold solder joint re connect

for a short time until the next bump or jarring.

Reflowing the solder on the hall sensor board fixed it.

There are solder connections on both sides of the board.

[Zephyrzone]

10 hours ago, 68bugboy said:

I still think some thing is going on with the hall sensor.

Mine did the same spinning while idle.

Bouncing the unit around would sometimes stop it.

I believe the bouncing would make the cold solder joint re connect

for a short time until the next bump or jarring.

Reflowing the solder on the hall sensor board fixed it.

There are solder connections on both sides of the board.

Oh, really? That’s interesting. I’m going to test bouncing it, this very well could be the root cause on mine. Would you happen to have pics or be able to describe the location of the Hall effect sensor so I know what I’m looking for?

[68bugboy]

Here is what it looks like.

It is under the shark fin on top of the platform.

 

Edited March 25, 2022 by RagingGrandpa
(removed broken link)

[Zephyrzone]

Awesome, thanks!

[SegwayMiniPro]

On 3/9/2019 at 11:58 PM, Zephyrzone said:

About 40.

I let the unit sit for a few days and tried it again. Worked for a few meters then shot off to the right. Tire pressure is good, knee bar is tight and centered. I did the upside down calibration 4 times and as well as the software, sensor calibration. Now the unit spins to the right immediately after I turn it on, about half the time.

It’s thrown me off twice, I was lucky not to get hurt.

Ninebot customer service asked me to get a video and upload the black box data, which I did a couple of days ago. Supposedly the data is being reviewed by the engineering team now and I should hear back by the end of the week.

-edited to specify “right”

I use it alittle more, the lean back feature at first throws you off. 

[Bugboy]

My Ninebot just pulled this move today. I was going full speed and it felt like the left wheel just locked up. And it veered hard left and threw me to the pavement. After that I turned it off and back on and it just spins in circles left continually. Any ideas what needs fixing? 

[Rider222]

Sounds like you have the opposite "left" veering variation, which is probably somehow highly related to my "right" veering problem.  Or, is your left wheel actually locked up?  Anyhow, I have no answers, my errant machine is still in pieces, retired.  My new unit hasn't yet malfunctioned, but we aren't riding them as much lately either.  Problem only happens when you least expect it.  Wear HELMET and be safer.

[Mitch Wells]

This same problem to the right is happening to me as well.

[FastForward]

Hi

As an absolute beginner I'm reading all the security-related threads (thank you for sharing tips) and, maybe, I've found a clue about the sudden veering issue:

@Boogieman wrote:

Though falling from pot holes is no issue, the nb is so solid with the old fw and does NOT cut off when you shortly step of pedals (can happen at jumps) like fw 1.7 does...so it feels safe and i just run ahead if it throws me off from ie a pothole and it just stands there stuck, waiting for"daddy" to jump back on.

The most dangerous thing i experienced was a single wheel cutoff = it was still balancing. I admittedly forced it to cut out just to see if it was possible and it was. Left went NB, me right. 

Is there a chance that the SV is due to a temporary cut off when you shortly step of pedal?

[Boogieman]

5 hours ago, FastForward said:

Hi

As an absolute beginner I'm reading all the security-related threads (thank you for sharing tips) and, maybe, I've found a clue about the sudden veering issue:

@Boogieman wrote:

Though falling from pot holes is no issue, the nb is so solid with the old fw and does NOT cut off when you shortly step of pedals (can happen at jumps) like fw 1.7 does...so it feels safe and i just run ahead if it throws me off from ie a pothole and it just stands there stuck, waiting for"daddy" to jump back on.

The most dangerous thing i experienced was a single wheel cutoff = it was still balancing. I admittedly forced it to cut out just to see if it was possible and it was. Left went NB, me right. 

Is there a chance that the SV is due to a temporary cut off when you shortly step of pedal?

No, i tried to skid in gravel and as one wheel started to skid, i just think it stopped that wheel instead as the turn became super sharp instead of sliding/skidding. Though normally you don't try to force the wheel to cut out like that.

No problem with lifting feet on my old FW. I tried it by lifting it off ground with hand on pedal and releasing hand when tyres turn, but they did not cut out.

[Boogieman]

On 3/13/2019 at 7:49 AM, Zephyrzone said:

In my case the MP is now spinning to the right without provocation; it’s happening half the time I boot it up without even standing on it. It wasn’t doing that prior to the sudden veering. Could be coincidence, but I doubt it.

Ninebot didn’t see anything unusual in the black box data, which is disconcerting. I’m suspecting a hardware malfunction of the steering mechanism.

Its not that you have the control bar stuck in a slight"turn position" for example by dirt accumulating causing it to"constantly turn" until you bump it and it compresses the dirt enough to stop?

[Bowhackem]

I've had my MP for 1.5 yrs and this issue has happened a few times. At first I thought it was an operator error and something I was running over or doing wrongly. Eventually I had a chaotic situation happen which lead me to put the unit on the shelf for awhile. I purchased an aftermarket steering handle for the MP and took it back out for a spin. Around half battery life the MP did it again but this time I was able to hold the steering column from turning right. The MP continued to try to veer right, Shortly afterwords i was having to turn the handle to the far left in order to stay straight. I stepped off the unit and let go of the handle bars to see what it would do. The unit immediately turned right and at around 270 degrees it was no longer veering right and now going forward. Once i regained control of the unit it balanced back to normal like nothing had ever happened.

Im not sure whats the cause of this issue but it seems to be software related to me. I would strongly recommend getting your units a steering handle in order to gain control of knowing you wont be thrown off the unit randomly. Hopefully this can be fixed with a future firmware patch.

 

[trevmar]

I am still recovering from the dislocated shoulder I received a month ago when a miniPRO running 1.1.7 stopped working while going down a steep hill when I was testing the 243Wh batteries. Probably battery related, as I had been down the same hill several times with a 320Wh battery without failure. I weigh 90Kg. The miniPRO ended up beside me in the right hand gutter beeping continuously and with its motors depowered. I can't remember exactly what happened. I can't remember what happened when it broke my right ankle several months ago, either. There is no way the miniPRO could have ended up beside me in that way unless it had slewed around about 270 degrees.

I have therefore bought an Airwheel S5 with the 16" wheels, bigger motor (1500W), and bigger battery (680Wh). A totally different experience (it is not a speedster). Let's see if that turns out more reliable in the long run. I have had too many failures from my MiniPROs

Edited July 26, 2019 by trevmar

[cleanoldman]

Accomplished rider here. Many happy miles until March 2017. Same sudden turning behavior described here left me with a severely torn shoulder. Surgery was required. Recovery was over a year. Only after Segway read the 'black box' data, did they ship me a new one. This thread is the first I've found to acknowledge the problem in depth. I'm afraid someone is going to get killed. I truly love this machine but now my trust is gone.

[FastForward]

@trevmar

Quote

 It happens on all four of my family's miniPROs,  better than one out of 4 times when we run over the ledge at the end of our driveway. I consider that 'replication', and certainly not 'uncommon'. The miniPRO takes larger obstacles OK, and smaller ones, but this particular size (and/or shape)  it doesn't like... There is an identical road-edge at the inlet to our local park. It threw me there, too

So you can replicate the issue and see what's happening. 

Could you please make a video of it?