Comment by AlotOfReading | Hacker News Reader

Comment by AlotOfReading | Hacker News Reader

The author has some points that could be improved. Things like the "accelerator braking" (regenerative braking) exist because they're some of the most important efficiency gains EVs can implement. Yes, it's different behavior than gas vehicles, but it's not a bad thing if the regeneration curve is good.

Having been involved with auto production, I have a bit more insight into how the sausage is made. People do test these things before they're on the road, quite a lot of people in fact. Many of these issues do come up in testing, but for various reasons aren't addressed or the relevant teams that could change them are never even informed. With something like the handle design, the direction is likely coming from product design, who you don't want to fight with as an engineer unless they're asking for something especially stupid.

One of my projects involved a camera and product had unnecessarily chosen to mount it facing upwards towards the sun. This was pointed out when engineers saw the first prototypes and kept being pointed out as an issue throughout implementation. The design got to mass production without changing the angle.

Guess who got the panicked call from product when field testing discovered the camera was unusable at certain times of day? They were informed of root cause, the software knobs we built to mitigate the issue when it arose and I even offered to help them with field testing the fixes. No response.

> Yes, it's different behavior than gas vehicles

It's different than *some* gas vehicles.

Have a manual transmission? a automatic Mercedes? what about use paddle shifters or manual mode? what about turning off overdrive? of, use the S, 1-3 gears?

In the US, yes, the automatic transmission is most common, but worldwide, less so. Even then, we've failed to educate how to use the settings of the automatic transmission to not overheat brakes on steep grades, varying terrain, or actually control a vehicle.

One thing I hate about driving an automatic transmission car is that it doesn't have a predictable engine braking mechanism.

I got an European plugin hybrid after manual car and there is one thing I very much like about it. When I take off my foot from the gas pedal then it automatically kind of behaves like a manual car depending on the situation. If there is nobody in front of me then it continues to move forward with the same "gear", if there is a slower car in front of me then it will use regenerative breaking to slowly go down in speed and when I turn on turning light and there is an intersection upcoming then it will use more aggressive regenerative braking to slow down the vehicle. It is very similar to how I would have used engine braking in such situations. I'm quite confident that the full electric version of the car would behave similarly.

> Things like the "accelerator braking" (regenerative braking) exist because they're some of the most important efficiency gains EVs can implement.

No please no. You are resurfacing my nightmares from working in the autoindustry programming BEVs. Good damn I had to fight against regen braking when releasing the gas.

You want to be able to coast.

Regen braking should be on the brake pedal or a separate lever.

Yeah regen breaking on the accelerator is so bad and unnecessary.

It makes sort of sense from a non-human what’s the motor doing now perspective if this was similar to a gas pedal and removing all gas/juice input. but has no meaningful technical reason to mimic that functionality of the gas pedal rather than the coasting functionality.

In fact, some EVs actually do instead mimic the coasting part rather than the remove all juice part. They mimic the function result rather than not the actual detailed process which doesn’t actually translate well.

The plug in Subaru crosstrek for example configured the thing super well. Let up on the gas pedal, the car coasts with similar slight slowing to a gas car. The brake pedal when starts in regen mode, the tachometer indicates regen. Press harder it transitions to both regen and actual brakes. It’s sensical and just seems so obvious that it should be that way.

There is no “reason” for the car to coast either. I love single pedal driving, it is one of the best parts of electric and hybrid vehicles.

My only problem with it is a few manufacturers have done a bad job with the amount of jerk from the transition.

He is also wrong that the brake lights don’t come on, the ones I have driven definitely do.

You want to coast because it's the most efficient. Regen is better than burning brake pads, but you'll go further by coasting than you will by Regen and then pushing it back out later.

Also, the gas pedal doesn't have enough resolution to handle forwards, coasting, and decent braking all one one pedal travel. You have to be super careful to go straight to coast on a 1 pedal driving modem. It's much better to just be able to lift of the go pedal.

> There is no “reason” for the car to coast either.

The user wants it to! That's a really great reason for the machine to obey.

The driver generally has superior information/ estimates about upcoming conditions and decision-trees which the gearbox does not.

For example, "That intersection's red light will probably become green soon, allowing me to efficiently coast for a bit before accelerating again, and I don't (yet) need to brake if instead it stays red."

A similar scenario exists for highways, where the driver is managing their following-distance to buffer-away repeated cycles of braking and acceleration.

Then there's also the problem of cars where the precise increment on the gas pedal isn't accessible or ergonomically viable, and then coasting serves as a way to moderate the output.

> The user wants it to! That's a really great reason for the machine to obey.

No, the user wants to maintain a speed or slow slightly, that does not demand rolling in neutral.

Maybe it is because I have grown up with cars with manual transmissions or maybe it is because I live somewhere with hills and regen is extremely useful, but I don’t find it particularly hard to modulate a vehicle with regen, nor do I think there is an inherent reason for a car to coast other than “it is what I am used to.”

That's why I like my Chevy Volt. It has a couple different drive modes selectable with the shifter. Under the normal drive mode the regen braking is controlled by a little paddle on the wheel or during regular braking (hitting brake pedal). In the other mode (I believe they call 'low') the regen is applied when you take your foot off the gas, aka single pedal driving. I normally use the regular drive mode and reserve low for when there's some nasty winter conditions which dictate the sort of subconscious slowdown that the forced regen provides.

It would seem more logical to me if the regenerative braking was tied to a physical user input. Like... the brake pedal from 0 to 30% could be regenerative, and beyond that engage the brake discs. Or it could be tied to the shift stick, on a L-D position, acting like a low gear on a manual car.

I've only familiar with the Hyundai Ioniq and the Chevy Bolt, but both those cars can be configured for that - the Chevy Bolt you only have to ensure it is not in one-pedal driving, which is just a button near the shifter, and the Hyundai Ioniq you just have to set the regen to zero. It's a failure of the rental place that these electric vehicles are not set up in such a way to match the mental model of a usual driver

The Chevy Bolt has it's brake lights come on automatically regardless of what is causing the deceleration, and I believe Hyundai is coming out with an OTA fix for that as well.

When you drive the electric car every day, it's nice using the one-pedal mode... Except it has taught me a large flaw in that my instant braking reaction is to depress the regen paddle, which doesn't work (only 10kW of effort) when the car batteries are well below -20 C, causing me to panic and brake too hard using the traditional hydraulic brakes.

I find that one-pedal is okay as a driver and not so pleasant as a passenger: feet are really quite bad at applying constant pressure, so there’s a tendency to alternate between excessive acceleration and deceleration. This can be nauseating, not to mention a bit inefficient. It’s made worse by the generally fast torque response in an EV.

I’d rather see really nice haptic controls, like so:

One-pedal: the pedal has a detent at the neutral point, so a range of forces will hold it at neutral, and a small conscious effort will switch between acceleration and braking. (For good measure, neutral could be zero acceleration instead of zero torque or power.) This would require some kind of variable electrically controlled haptics, and it would need to fail safe.

Two-pedal: a similar detent, but on the brake pedal at the position where mechanical braking starts.

Either one would need serious driver testing, especially to make sure that drivers won’t fail to apply adequate braking in an emergency.

There's a whole bunch of legislation that specifies what happens when you touch the brake pedal and how much deceleration needs to happen at every part of the input range. Any system involved in that needs to meet much stricter requirements. This also applies to regenerative braking on the accelerator pedal if the deceleration is over certain values. From what I understand manufacturers will actually have multiple "regeneration" modes to work around all this, but I don't have first hand knowledge of this particular area.

But in a stick shift, the engine brakes, even in the highest gear ie 5th or 6th - the car slows on it's own about 3x quicker than an automatic in overdrive.

My volvo xc60 does that.

Yeah, that's how my car does it (unless you "shift" into coasting with the paddle shifters. It does feel a bit clunky when you change between regen levels since the throttle is mapped differently

Almost all brands of electric cars (BEV, HEV, PHEV) use regenerative braking when you press the brake pedal when possible (i.e. they switch to the physical brake pads when the speed gets too low for effective regenerative braking, or when the battery is already full, or in case something's wrong with the electrical system).

Big exception is Tesla: Tesla's braking pedal uses only the physical brake pads. In a Tesla the only way to regenerate brake energy is by lifting the accelerator.

Source: https://onefiniteplanet.org/wp/one-pedal-driving-and-regen-b...

> Things like the "accelerator braking" (regenerative braking) exist because they're some of the most important efficiency gains EVs can implement.

I don't get why this needs to be in the accelerator pedal. Wouldn't it make more sense in the first stages of the brake pedal? (I haven't driven one of these.)

Ordinarily, you want to be able to let a car coast, and single-pedal driving seems to get in the way of that?

So, I kind of get it -- you have acceleration, and two braking mechanisms, which adds up to three things, and you need to come up with some natural way to expose that to the driver without giving them a billion controls to think about. So is single-pedal more about controlling a speed setpoint than about controlling acceleration? Maybe you just get used to it?

The lack of brake lights does seem like a legit problem though.

> you don't want to fight with (the product designer) as an engineer unless they're asking for something especially stupid

Why not?

Because they're a product designer and you're "just" an engineer. Places with product designers usually have them trump the engineers, so you don't want to burn what little social capital you have on silly things like the product actually being usable.

I feel like this explains a lot about modern crapitalism. How did we get to a point where designers who have very little technical understanding have more power than actual engineers who actually build the actual products? Is it just that every company, in some grand vision of world domination, transitioned their culture from "we make good stuff" to "we sell a lifestyle"? Did the marketing wonks really infect and metastasize so completely that the idea of a thing is now more important than the actual thing, even inside the literal engineering of a product? Do these people really think, "well we can sell an idea, but you can't really sell a product"? What the fuck? The actual product is the whole point!! These fucking "idea people" have all conglomerated and seized power and it's really beginning to show in modern life. It feels like most everything i own was crafted to be marketed first and actually fucking work second.

Luckily, we still have Japanese car companies, to put a cultural barrier between drivers and bullshit.

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