100% Electronic Braking on Escooters

[InfiniteWheelie]

Unlike our wheels, all powerful electric scooters on the market come with disc brakes. As someone who's also very into in escooters, I want to make the case that they should ditch the discs.

If you look at the latest and greatest scooter from Minimotors called the Dualtron Storm Limited, you'll see it has dual 5.75kw motors and an optional 3800 wh battery. These things are more powerful than any wheel, hit higher speeds, and have more traction. With properly designed controllers you could get tremendous braking power out of a scooter like this.

There are many benefits to purely electric braking. It increases range through regen, eliminates brake maintenance, reduces weight, complexity, cost, noise, and would definitely make the scooter look sleeker. You could also have different customizable braking modes and even ABS. 

Now you may think about safety problems. What if you're at 100% and brake down a big hill, overcharging the battery? The simple answer is to limit charging to slightly below 100%. This will improve battery longevity and provide a buffer during that short period of full charge. What if the brakes fail? If you design dual controllers to work independently in the event of a failure you'd still have a backup brake. 

Like ewheels, escooters are uniquely suited to implement this due to their powerful dual motors. For example you could never rely solely on electronic braking with an ebike. I hope scooters manufactures take advantage of this and take their scooters to the next level. I want to hear other people's opinion on this, so what do you think?

 

Edited March 7, 2022 by InfiniteWheelie

[Planemo]

Personally I would always take mechanical brakes over relying on electronics any day simply due to them being a reliable failsafe. Its also why Tesla, electric trains and god knows how many other electric vehicles use mechanical brakes. Not having a mech brake is one good reason why lawmakers in the UK will struggle to legalise any EUC over 15mph.

Excellent hydraulic MTB brakes cost peanuts these days and are largely fit and forget bar changing the pads occasionally which as you know is a 5 minute job with no special tools.

You talk about the complexity of mech brakes but then talk of running dual controllers as a redundant system 'just in case' as an argument for reducing complexity. I find this not the best support for your case, nor having to reduce max charge to 80% 'in case' you need to brake on a hill.

That said, your argument for electronic ABS is a good one, and its something which hasnt filtered down into MTB brakes yet.

[goatman]

google search Plug Braking and see if the controller has that function.

[Chriull]

Major problem with electromagnetic breaking is the inabiity to apply breaking force at low speeds.

[InfiniteWheelie]

On 3/6/2022 at 6:07 AM, Planemo said:

Personally I would always take mechanical brakes over relying on electronics any day simply due to them being a reliable failsafe.

Why is it fine on an ewheel with zero redundancy, but unacceptable on an escooter with two separate motors/controllers?

On 3/6/2022 at 6:07 AM, Planemo said:

Excellent hydraulic MTB brakes cost peanuts these days and are largely fit and forget bar changing the pads occasionally which as you know is a 5 minute job with no special tools.

Maybe if you ride in sunny, dry conditions all the time. In reality the pads will get crap in them, start squeaking, and the fluid will need replacing eventually which isn't exactly user friendly. They discs are also highly susceptible to damage from crashes or even bumping into things while moving the scooter around.

On 3/6/2022 at 6:07 AM, Planemo said:

You talk about the complexity of mech brakes but then talk of running dual controllers as a redundant system 'just in case' as an argument for reducing complexity. I find this not the best support for your case, nor having to reduce max charge to 80% 'in case' you need to brake on a hill.

I believe dual controllers are already the norm, though possibly placed on the same board. You'd need to place them on physically separate boards, and design them to work independently if one fails. I can't see this adding much cost at all, especially since you're entirely eliminating two hydraulic brake systems.

Charging to 80% is already the preferred way to charge for battery longevity (even Tesla recommends this). With top scooter batteries approaching 4 kwh I think the range hit is a non issue. In fact I doubt 80% is necessary, wouldn't something like 95% suffice on a pack that big? Not to mention, couldn't this be entirely avoided by using resistive braking instead when the battery is full?

 

On 3/6/2022 at 2:20 PM, Chriull said:

Major problem with electromagnetic breaking is the inabiity to apply breaking force at low speeds.

Well I know that's technically true for regen braking. The faster you're going the less forward torque you have available but the more braking torque, and the reverse is true at low speed. 

So why isn't this a problem for ewheels? I guess because the slower we go the less braking force we need? I also remember reading on this forum once, that at very slow speeds ewheels switch braking method at some point. Regardless, since this isn't a problem for ewheels, why would it be for escooters? Especially since they have bigger batteries, more powerful motors, and more traction.

 

Edited March 7, 2022 by InfiniteWheelie

[Planemo]

26 minutes ago, InfiniteWheelie said:

Why is it fine on an ewheel with zero redundancy, but unacceptable on an escooter with two separate motors/controllers?

It's not fine on an ewheel and I never said it was. I would very much like to have a mechanical brake on my EUC but it's not possible at the moment.

26 minutes ago, InfiniteWheelie said:

Maybe if you ride in sunny, dry conditions all the time. In reality the pads will get crap in them, start squeaking, and the fluid will need replacing eventually which isn't exactly user friendly. They discs are also highly susceptible to damage from crashes or even bumping into things while moving the scooter around.

Please. You're trying to tell someone who has used hydraulic MTB brakes for many years that they carry high maintenance. A bleed once a year (if that) and maybe a few sets of pads at 5 minutes a time is not exactly onerous. And I suspect I ride MTB in much nastier conditions than most escooter/EUC riders.

As for damaging discs...maybe be a bit more careful? Don't bash it into things and try to reduce crashing? Either way, discs are not exactly expensive, especially the piddly little ones used on escooters.

26 minutes ago, InfiniteWheelie said:

Charging to 80% is already the preferred way to charge for battery longevity

Oh gawd lets not get started on the '80% charging is best' thing again..  At least not with the usual chargers and BMS' we see with Chinese PEV's. Tesla charging systems are infinitely more complex.

Look, throw away mech brakes if you wish. But I would rather have them given the option, and it also makes things a lot less twitchy for the lawmakers when they are looking to see that a vehicle is 'safe'.

[InfiniteWheelie]

It's clear that disc brakes are cheap and work well. For low and midrange scooters they're fine. However I'm talking about the engineering end-game for high end scooters.

This would require a level of engineering and quality we're unlikely to get from Chinese manufactures, at least initially. However I could see this happening from a company like Rion in the US. If designed properly there's nothing but positives. I think once a company steps up and does it properly I'll be proven right, hopefully in the near future.

Edited March 7, 2022 by InfiniteWheelie

[Eucner]

9 hours ago, InfiniteWheelie said:

If designed properly there's nothing but positives.

Please check first if it is even allowed by the law to have a electric scooter without mechanical brakes. In the most EU countries it is not.

[Richardo]

Coming from an escooter I agree with you completely, but think this vision of the future is a ways off. 

Why? Because escooter controllers are crap. I don't know the technical specifics, and maybe it's different with the $10k+ models, but the "acceleration curves" are awful- like they must just multiply the percent reading of the Hall effect sensor by the voltage applied to the motor.

If you have a powerful scooter, even solemn concentration plus well-developed fine motor skills plus a gentle touch to the throttle will cause your wheels to burn out and break traction on a start. You won't ever be able to go at a speed slower than 5mph because the resolution of your throttle doesn't allow it. And I tried multiple thumb throttles and trigger throttles. At this time, it can only be mitigated by applying a global limit to the power going to your motors. It seems like it'd be relatively easy to fix this with a bit of programming, but I'm not aware of any manufacturers with that on the roadmap. Hell, there is only one manufacturer (titan group) for most scooters, and the 'brands' do everything they can to hide information on what controller you're actually running.

The same applies to electronic braking, but worse. There are generally 5 settings on electronic breaking, but you only can set one in the controller. It's an on-off effect-they're either fully applied or not. There are no scooters (as far as I know) with a hall-effect breaking system. Levels 1-3 add such tiny breaking you can hardly notice it, and 4-5 mean that touching your breaks at all applies enough force to throw you around unless you've crouched low in preparation. 

 

And this really sucks because a powerful scooter devours break pads. It weighs close to 100lbs, moves at 40mph, and it's carrying a rider that can be another 200lbs easy. The pads are basically designed for mountain bikes, and they're around the size of a thumbprint. Thats a lot of messy dust and a lot of maintenance. The overall experience of ownership would be drastically improved by using electronic braking, even if the energy was dumped into a resistor and heat sink rather than trying to recapture it. 

[InfiniteWheelie]

I'm well aware that today's controllers are crap, and I agree that fully electric braking probably won't happen soon...

I'm just looking at the big picture about what's possible and desirable in escooters. Having a huge battery and very powerful dual motors, there's no reason this couldn't be accomplished with the right hardware and software. You could have extremely powerful acceleration/braking, combined with very smooth and precise control. Plus safety could be greatly improved with traction control and ABS. Of course we'll need a Tesla or Apple-like company who cares about making high tech, highly refined products to make this happen.

Edited March 7, 2022 by InfiniteWheelie

[Planemo]

5 hours ago, Richardo said:

And this really sucks because a powerful scooter devours break pads. It weighs close to 100lbs, moves at 40mph, and it's carrying a rider that can be another 200lbs easy.

Totally agree and therein lies the problem with rhe high speed escooters. MTB brakes arent designed to repeatedly haul down a scooter which are now doing what...65mph? I am running 220mm discs front and rear on my MTB but I assume they would be too big for most escooters?

Escooters doing more than 25mph or so need bigger wheels or some other solution as per the OP's post. I'm just not sure the solution of eradicating mech brakes completely is near to fruition yet.

Edit: even if escooters got to the point where they had motor systems to brake effectively without mech brakes, I would still desire mech brakes as a failsafe, just as I would with an euc given the choice. But for a high speed escooter it would mean bigger wheels than they run currently.

Edited March 7, 2022 by Planemo

[InfiniteWheelie]

1 hour ago, Planemo said:

Edit: even if escooters got to the point where they had motor systems to brake effectively without mech brakes, I would still desire mech brakes as a failsafe, just as I would with an euc given the choice. But for a high speed escooter it would mean bigger wheels than they run currently.

To be fair, escooters could also run dual discs per wheel which would probably suffice. That said I don't personally see the need for mechanical brakes as a backup. If the system was truly high quality and redundant (including resistive braking for battery failure), I see that as more than safe enough. To me totally ditching mechanical brakes is very desirable, but everyone has their own view. 

Edited March 7, 2022 by InfiniteWheelie

[Richardo]

Another thing that makes me agree with you is wanting a device to have as parts as possible, and especially as few moving parts as possible. 
 

i dont know if there is a name for that aside from wanting to avoid complexity, but an electric scooter just has too many parts right now. Especially after riding EUCs for a while. 

[Richardo]

My dream for the e-scooter -and this might be the dumbest thing youve ever heard- 

is independent controls for the front and rear wheels, and rather than a throttle, theyre like the pitch bend control on a keyboard, able to make the motor go forwards or in reverse. Easing off the throttle does electronic braking like a tesla, to the speed matching how far you now have it depressed. Letting it go breaks traction and locks the wheels. If you go backwards youre spinning the wheels backwards.  
 

This would capitalize on the complexity of the E scooter requiring dual motors, and turn it into a wild drifting injury machine that I believe would be unmatched on planet earth. 
 

For me, a lot of the fun of the scooter is being thrown around by acceleration, and the way it can rip the pavement.

But all that acceleration/stopping power is not very fun without a lot of control. So let’s lean into that and make something truly crazy.

Anyway, once I realized this was outside my ability to achieve, it contributed to me losing interest in scooters and selling them

Edited March 8, 2022 by Richardo

[InfiniteWheelie]

I'm the opposite. I want really good traction control and ABS so you can just "floor it" and zoom around like crazy without spinning tires or skidding. Of course with the option to turn it off when you feel like it.

Edited March 8, 2022 by InfiniteWheelie

[RagingGrandpa]

On 3/6/2022 at 2:20 PM, Chriull said:

Major problem with electromagnetic breaking is the inabiity to apply breaking force at low speeds.

On 3/6/2022 at 4:15 PM, InfiniteWheelie said:

So why isn't this a problem for [EUCs]?
I also remember reading on this forum once, that at very slow speeds ewheels switch braking method at some point.

Reverse drive modes. EUC's are a 4-quadrant control scheme; scooters usually do not include controls for reversing.
(It means: EUC's aren't regenerating any substantial energy below 3mph; instead, we're using energy to drive current into the motor.)

 

On 3/6/2022 at 4:15 PM, InfiniteWheelie said:

Why is [no mechanical brakes] fine on an [EUC] with zero redundancy, but unacceptable on an escooter with two separate motors/controllers?

Consider the result of a throttle switch stuck at 100% (mechanically stuck; or electrically damaged). 

One way passenger cars deal with this struck-throttle failure mode is by sizing the brakes to be more powerful than the engine (therefore you could still slow the vehicle when stuck at full throttle). And, often they include software logic to reduce the throttle command (even if the pedal is stuck) when the brake pedal is pressed. Both of these methods could be helpful to address the stuck-throttle fault in scooters.

[InfiniteWheelie]

8 hours ago, RagingGrandpa said:

Reverse drive modes. EUC's are a 4-quadrant control scheme; scooters usually do not include controls for reversing.
(It means: EUC's aren't regenerating any substantial energy below 3mph; instead, we're using energy to drive current into the motor.)

That makes sense. It goes from regen braking, to actually applying power in reverse at low speeds.

8 hours ago, RagingGrandpa said:

Consider the result of a throttle switch stuck at 100% (mechanically stuck; or electrically damaged). 

One way passenger cars deal with this struck-throttle failure mode is by sizing the brakes to be more powerful than the engine (therefore you could still slow the vehicle when stuck at full throttle). And, often they include software logic to reduce the throttle command (even if the pedal is stuck) when the brake pedal is pressed. Both of these methods could be helpful to address the stuck-throttle fault in scooters.

Sure I agree, there's many potential mechanical and electrical failures that could result in disaster. That said there's nothing that can't be avoided with proper redundancy and fail-safes.  It's only a matter of proper engineering.

It reminds me of when Apple made the first iphone. Other smartphones already existed, as did the individual technologies to make an iphone. What Apple did was bring these technologies together and highly refine them to create a new form factor. Likewise escooters already exist, as do the technologies for (safe) electronic-only braking. Someone just needs to bring it all together in a highly refined product.

Edited March 9, 2022 by InfiniteWheelie

[Chriull]

Btw - @InfiniteWheelie e scooters with one electric brake already exist, like Mi Electric Scooter Pro 2. Even with ABS. They just have as second brake a mechanical disc brake.

As @Eucner mentioned the law - here one needs two independent brake systems.

So for two electric brakes one would need a motor at each wheel with an own controller and an own seperate battery.

[InfiniteWheelie]

You wouldn't need two batteries. The brakes could be entirely independent by having resistive braking as a backup. Secondly, here's why I think PEV laws ultimately don't matter...

Let's start with where these type of regulations originated, gasoline vehicles. Gasoline vehicles are inherently limited to only a few predictable forms due to their physical nature. What ends up being possible is basically cars, motorcycles, and mopeds. Even among the two wheeled variety, mopeds are always low power and clearly distinguishable from motorcycles. If you tried to make a powerful moped, it would just look like a motorcycle. The limiting nature of the internal combustion engine means these simple categories could be easily regulated.

PEVs on the other hand can take countless forms, with the possibility of highly varied power levels within each. Electric motors can be mounted in wheel or attached to the frame. Unlike gasoline engines, very powerful motors can be made very small. PEVs operate in virtual silence, often with the electric parts being almost invisible.

What does this all mean? Due to the chaos that is PEVs, they'll never be able to regulate the various types as they could with gasoline vehicles. The result is one of two things. Either all PEVs are tolerated with virtually no problems from police because it's an overwhelming chaotic situation, or they ban all (or nearly all) PEVs with heavy police enforcement.

This imaginary all encompassing PEV regulation I've seen discussed before will never happen. If you don't believe me look around the world and you'll find it's one of the two scenarios I described. So in other words who cares about the so called legality, just build the best PEVs you can. 

Edited March 10, 2022 by InfiniteWheelie

[xorbe]

On 3/6/2022 at 11:20 AM, Chriull said:

Major problem with electromagnetic breaking is the inabiity to apply breaking force at low speeds.

??? Not only can e-brake stop the scooter, it could make it go backwards too.  The crappy braking at low speeds is just lousy programming.  I keep e-brake on low setting on my DT Thunder, it helps reduce disc brake wear.  On the high setting it's too janky imho.

Edited March 28, 2022 by xorbe