Bosch's brake-by-wire system may be the next big leap in automotive tech
newatlas.com
newatlas.com
Is it really as simple as "cheaper to produce"? Is it cheaper to replace?
The article mentions "saves weight and installation space" - it seems this savings come at the expense of massive complexity; how big can the savings be?
As an aside, IMHO every time a component changes to "by wire" the driving experience tends to suffer due to latency.
Separately, hydraulic systems are an inspection item with a serviceable fluid. Electronic systems work without servicing until they don't, at which point a lamp on your dashboard lights up. More convenient for the manufacturer/dealer, less convenient for you, but that's typical for modern anti-consumer (pro-producer/corporation) design.
Then servicing a hydraulic system is more manual labor intensive (replacing hoses, bleeding the system, replacing the fluid), while electronic systems come with components that are replaced wholesale, where the consumer pays the price for the new component. I guess it's obvious which ones the manufacturer prefers.
Driving experience suffers, but not in a way that measurably affects consumer behavior. Most people tend to care about other characteristics more than the particular issue of latency. As another example, see the issue of rev hang - a type of latency on its own.
This is kinda where we need to shift more towards EVs because that would take out a lot of the complexity you get with modern automobile design.
What do you think how well documented car internals are? What would you do if you open a control device and you see an unmarked ASIC?
Personally I really like how Tesla did their online service manual. It's a good balance of technical but not to technical.
https://service.tesla.com/docs/Model3/ServiceManual/en-us/in...
With regard to your edit. That's where there's a practical limit of what do you (a manufacturer) publish that the tech needs to know. So you need to cross it between technical know how, and how detailed you need to get. Me personally would pull out the oscilloscope and make some probes to get an idea of what to do. You set a carburetor on my desk and that would probably take me a bit longer over electronics. It's a skillset issue, basically, and we're transitioning off strictly mechanics to mechanics and electronics working together. Which naturally raises labor costs because people aren't use to that.
Based on your comment, I expect newer cars to have lower maintenance and repair costs, fewer part failures, and less guessing about exactly which part is broken.
> while electronic systems come with components that are replaced wholesale, where the consumer pays the price for the new component
Repair costs are skyrocketing with newer cars.
Or a oil pipework that cannot be removed from the engine because there is a bracket in the way, which can only be removed by taking out the the master brake cylinder, which requires the brake pedal to be loosened. The brake pedal braket is mounted by 4 screws, one is only accessible by removing the cladding behind the steering wheel, the steering wheel blocks that, so you have to take that off, too.
.. fixing cars is a special kind of hell.
Unlike older cars, the way newer cars work is shielded within software and hardware black boxes and aren't particularly modular. You can't just pull a carburetor out of one car and put it in another. And you're fully dependent on the manufacturer to publish meaningful diagnostic information.
What happens when the car has a failure that kills all the electrics?
That's a much more common failure scenario than people think. Batteries go flat. Wiring gets chewed and shorts with vibration. CAN buses need only a brief short to go out entirely and not reset. Even in a modest crash the car can lose its battery and alternator, or get a system short.
Tesla owners have learned this lesson repeatedly with getting locked out, locked in, stuck in park, unable to shift to neutral for a tow, etc. Other car owners have learned this with electric parking brakes getting stuck on.
If the electrics fail and the car is moving, I need steering, brakes, and the gear lever to all work to stop safely. If they're by-wire, I'm just a passenger.
But I'll take my mechanical overrides.
Yeah, but what about economy of safety?
_window-by-wire_ & _mirror-by-wire_ seems fine.
The discussion was not about failure.
Also, my pinko commie ass would be remiss if I weren't to speculate about how if you fall behind on your car payments, these features among other drive-by-wire features would also allow a dealer to remotely lock out the vehicle until you pay up, and given the other shady things they already do to folks, I can't imagine this won't be an application for this tech too. Gotta fuck those poor folks till the line goes up, of course.
Edit: Or hell, doesn't even need to be if you miss payments. If you go too long for an oil change, your OEM could lock you out. If you aren't up to date on your Chevrolet+ subscription, they can make your steering wheel harder to turn. Or if you gasp try to service your own vehicle, ohhhh there could be all kinds of hell to pay.
Just, rampant opportunities to fuck with consumers just as hard as tech companies do. And isn't that what we all want in the end? Cars just as grating and irritating to use as our computers and cellphones are, in the thousand tiny ways per day they are?
Your fear of being locked out makes no sense. That was feasible the moment you had a cellular modem and computer control of the ignition. Modern cars already have electronic control of the brakes for ABS, it’s just not in between the pedal and the calipers. Brake by wire changes nothing in terms of the ability to remotely disable a car.
I'm not saying there aren't ways to make this equally safe with software, I can think of many ways. Do I necessarily trust the built-to-cost auto industry to do them? Ehhhhh....
And when corners get cut, the software development lifecycle tends to be an easy target.
Now, I certainly wouldn't trust anything written with a typical app development process with my life, but it's not the only way to do things. I'm totally on board with being pessimistic about most software reliability, but it's not realistic to say that no software can be reliable enough to trust with your life.
The software is limited to being able to flutter pressure going to the actuators within the calipers. Basically it de-pressurizes/re-pressurizes the actuator very quickly. ABS cannot engage or disengage the brakes in totality, that is exclusively done via the pedal. (In the systems I've worked on anyway)
> Uncommanded acceleration is another possibility that might have actually killed people (or maybe it was just floor mats).
Rather famously, early Prius models had issues where the drive-by-wire throttle would become stuck on due to a software malfunction.
> Outside of cars, your microwave could burn your house down in the middle of the night with the right sort of software bug.
Um... how? I could see this if something suddenly let go quite violently in the power supply maybe, but that's far likelier to happen when the unit is in use, not when it's sitting idle. And more to the point even if the computer inside had a bug that caused the magnetron to engage at full whack with nothing in the microwave... I mean it probably wouldn't be good for the microwave, but I don't see how that equals a fire.
> So could any device with a lithium-ion battery.
That one's true though. But good electronics are monitoring all the voltages across all the lithium cells involved, along with temperature, and many have perma-kill switches if anything looks too off for this exact reason.
> And of course numerous airliners are fly by wire and they remain the safest form of travel out there.
They're also absolutely drenched in aeronautics gear that is both managing the aircraft and verifying that the redundant systems are ready to take over, reporting the same data, and that all is well. And aircraft regularly get grounded if anything even seems like it might be off with it.
And yes, I know airliners have all sorts of stringent standards. But the fact remains that many of them do rely on software to keep the occupants alive.
Making software reliable enough to bet your life on it is hard, but not so hard that we should consider it to be an unattainable goal.
It's not just software: is software running on redundant systems that can check one another for consistency and performance. You're never going to see that level of engineering in an automobile, cars would be far too expensive if they were as complex, electrically, as an aircraft. Aircraft are only getting away with it because, as you correctly observed, if the computers malfunctioned, they're going to fall out of the sky and kill all your passengers. If your car malfunctions, it just won't move/will stop moving.
In any case, the sentences I was replying to was:
> But as a software engineer, I can tell you that current software development practices do not produce software that is reliable enough to entrust it with your life.
All I’m saying is that this is wrong and we do routinely trust software with our lives. If you want to explain how it’s done and why it’s done that way, go for it, but it sounds like you think you’re arguing against it.
* Automation (emergency auto braking, full adaptive cruise, autonomy) is here and needs electrical signal input. AEB is very nearly standard everywhere now, so there's an electrical input braking component that has already been added to the system.
* If you look at modern brakes, it's hardly simple anymore. Brake boosters, ABS, master/slave systems. It's run on a corrosive fluid that is water sensitive and uses hard pipe plumbing.
I agree that routing hydraulics everywhere is not nice, but this is the last component that I want to have a cliff failure mode profile, which is usually the caee with electronics - they work until they don’t. Hydraulic and pressure systems usually fail somewhat gracefully.
Less parts, less things to break, less things to install, less things to maintain. Etc. All good things when it comes to cost. You'd be surprised how that stuff adds up quickly.
Take a step back and look at how complex brake systems have evolved at the present date:
On one hand, sure, it's just a foot-operated hydraulic pump and four hydraulic actuators.
On the other hand, the ABS module has valves to both cut off each brake caliper and to drain hydraulic pressure from each brake to prevent lockup. In an emergency braking scenario, the foot pump will quickly go the floor as pressure is drained, so the ABS module also has an electrical pump to put fluid back into the system.
All US-legal cars have some form of electronic stability control (and often have lane keep assist), which can use the same components to pressurize one or several brakes to make the car follow the driver's intent (as measured by a steering wheel angle sensor and a body yaw rate sensor. Europe-legal cars also usually some form of emergency brake assist which again uses the ABS module components to apply the brakes automatically.
To keep this all safe, you need pressure sensors to monitor valve and pump functions, sensors to monitor driver input, and sensors to monitor vehicle dynamics.
When you look at the system holistically, as it exists today, it is bandaids on top of bandaids and you realize that you no longer have just a simple hydraulic system.
I would make an analogy to the 737 Max vs. Airbus FbW here: We started with something very simple, and then incrementally increased complexity in (seemingly) appropriate ways. Then, many years later, we realized that our "simple" mechanical system is actually more complex and prone to more complex failure modes than a system which started out complex and rigorously managed that complexity.
But it makes the system less complex and easier to handle, as there's one kind of cabling, and complex functions like ABS equivalent are handled from avionics bay
The aircraft braking systems are very complex, including active thermal management and automated braking systems that take multiple data sources to manipulate breaking force, including understand how long the brakes survive when taken beyond melting point (RTO setting on autobrake)
There is approximately zero chance of an aircraft pilot needing to stomp on the brakes because of a random pedestrian or animal, whereas that happens constantly for cars. Cars stop and go all the time and have to avoid each other. Aircraft hardly do that at all when they are on the runway. They use their brakes to not accidentally roll or be blown about, and in the process of landing. Those applications don't need epic response time.
Now consider that the same network used to control the brakes also is sufficient to control every other sensor and servo on the aircraft s well.
I would like to add, brake by wire may be more reliable on planes than cars because planes are maintained very well by experts. Automobile design should strive for simpler and more failsafe options because owners are usually clueless people with limited budgets, who want to do as little maintenance as possible. The fact that hydraulic brakes work so well even in very old cars says a lot about how good they are. When they do get blamed for poor performance, it's usually due to something stupid like the owner not replacing worn out hoses after 20+ years of heavy use. I only found out about that one recently. Old hoses start breaking down and they gradually get congested.
Because it is cheaper.
Electronic systems are much simpler by part count, lighter, and smaller.
When communication fails, you know it's failed, and you know where it's failed.
Adding sensors for real time feedback is extremely cost-efficient. If your current/torque/temperature are not within an expected profile, a braking system failure may be inferred. This is extremely cheap, reliable and fast on low-end hardware.
In this case, they do not need left and right forms, they can just produce one part. Right away that's a huge saving in mold cutting time, mold storage, part production, distribution, etc.
In a mechanical system, if something fails, you have to disassemble the subsystem, identify the failure, search the supply chain for the part in question (possibly not labeled), obtain or manufacture the part, re-install it, and then hope for the best.
In a digital system, it can probably tell you what fails. It's probably cheap. It probably has the part number printed on it. And it certainly knows how many hours it has been used, and how heavily.
About latency, the key point is that humans suck. There's no way 1ms latency is going to alter driving outcomes. If you care about latency, you're autonomous driving. And that's something that electronics excel at versus humans. Let's say signals begin to come in suggestive of brake failure on one of four brakes while rounding a corner at high speed. ABS systems can compensate for the failure in real time and intervene to guarantee safety, even across subsystems such as by reducing speed. Mechanical systems are subsystem-bound and will leave the driver to 'discover' the 'new handling characteristics' at the point when it's already too late.
So the summary is: cheaper to produce, cheaper to assemble, cheaper to debug, cheaper to maintain, cheaper to replace, less unique parts, more freely positioned within a vehicle design, more readily reusable across vehicle designs, safer in some conditions, more suited to forward-looking applications such as autonomous driving.
(Disclaimer: I am not a mechanic, however I do have a fairly solid understanding of multi-disciplinary mechatronic design problems.)
As an aside, although we have no ongoing connection, I would note from experience some years back that Bosch VC have been one of the most stand out professional venture firms I have spoken to. If you have an industrial project, particularly one that connects with their existing business lines, they will not waste your time in providing a well considered and efficient response. Definitely a class act.
Maybe I'm just biased, but I believe in using the simplest tech that will do the job. You don't need an Arduino to blink an LED.
Everything goes to hell if you need to connect to the internet or use high-level software.
The objective measure of what qualifies as "well designed embedded systems" is inherently gray; and where industries have seen some semblance of consensus as a matter of unconditional need, it has always been accompanied with the tears of executives complaining of non-trivial expense.
Isolated embedded systems can be like mechanical systems in that they're simple enough to be tractable and even deterministic.
A system running Linux and calling AWS lamda functions through the cell network isn't tractable.
That being said, there's a time and a place for software. Software is a solution to a problem, and I'm not clear on what problem this system is solving. Sure, Bosch's product makes the brake system smaller and lighter. Cool. To what extent does that make the car smaller and lighter? Amdahl's law applies to more than computers. Are we really optimizing the right thing here?
To be sure, when measured against prevailing market trends, this is objectively not a good thing. For safety-critical systems like a vehicle's brakes, I fully expect much more than the superficial considerations I would normally give to appliances.
A mechanical linkage of cables or rods or a hydraulic system all have their failure points also, but the differences are
the infrastructure required to manufacture a stick or a tube vs a chip and solenoids, motors, sensors,
the fact that a cable or linkage or hydraulic piston usually fails gradually over a long time while still functioning, while a chip dies without warning and completely,
and is not repairable in the field except by replacement, while you can repair a mechanical device essentially indefinitely with essentially any tools and materials that are available.
Same as a throttle. That used to be a wire (perhaps it commonly still is?) but the throttle input shifted from being solely the driver into being other systems like cruise control. As soon as you have an electromechanical system it does seem easiest to keep it electric->mechanical rather than mechanical<->electric. That simplification does ignore the driver feedback, however.
Throttle-by-wire is a different beast entirely. If you step on the gas and don't go, that's usually very annoying, and depending on circumstances could be dangerous. But if you step on the brakes and don't stop, that's pretty much a guaranteed wreck right there.
Every action scene starts with, "MacGyver pulls a laptop from his backpack and..."
Throttle cables have been replaced with wires for at least 20 years. Rack and pinion is slowly going away but odds are still pretty good that an arbitrarily chosen new car won’t use steer by wire; that’s still pretty niche. Shift / clutch has been electric for a while now on most cars but there’s still some “pure mechanical” shifting cars out there.
An all digital break system is probably going to take a _while_ to become standard.
Infinite had it with a backup, but it was bad.
On the good old BMWs with hydraulic steering, you could get Active Steering, i.e. variable steering. They basically introduced a planetary gear set: https://www.youtube.com/watch?v=unL8HpMeVTA
If today you buy a BMW with Active Steering it means you get rear-wheel steering (on top of the standard front-wheel steering, but don't tell the execs, you don't want to need a subscription for front-wheel steering).
On BMWs since the F* (with the electric assist steering) variability was achieved by a variable-ratio steering rack.
I dislike what the future brings (normalizes)
My next truck will not be newer than 2008 and will likely have spent time in a mod shop to modernize it minus the digital cruft. It will not have any drive-by-anything, remote-anything, governors, ammonia, etc... but it will have good set of mufflers to make it quiet, dual alternators and a set of comfy seats.
Exactly how much weight/space is being saved here?
In an EV with a heavy battery, my guess is not a very significant amount. This looks like an example of ignoring the forest to focus on a tree.
It costs $700 to change a dead battery on some Mercedes cars because the onboard computer has to be reset using special electronic tools.
This "screw the customer" approach is the road to self destruction. Just ask Volkswagen.
I can't find a citation, but I recall seeing an estimate that the German automaker cartel increased prices on the order of $10k per vehicle. I had also read that there is a similar cartel among the automotive suppliers, none of whom seem capable of making a windshield wiper set that isn't hundreds of dollars, or a vehicle lighting below multiple thousands of dollars.
“People of the same trade seldom meet together, even for merriment and diversion, but the conversation ends in a conspiracy against the public, or in some contrivance to raise prices.” -- Adam Smith
https://www.spiegel.de/international/germany/the-cartel-coll...
Talking to the onboard computer is free beyond the initial equipment and it isn't even locked or anything, tools that can do this can be had for cheap, connect to your phone via bluetooth etc.
You can buy dongles and do it yourself, but not everyone is willing to mess with coding their own vehicle.
Which only goes to prove that it didn't need to be and should never have been "a thing".
Not my world, but I don't get it - with throttle by wire you can do fun dynamic/nonlinear response, cut throttle when you don't have traction etc. With this thing, all the clever things are already done by the ABS/ESC unit, so removing the physical connection really only frees up like like 50 cm of a hydraulic piping.
Would love to hear an automotive engineer's take on this to be honest.
Mercedes-Benz USA has also had to give the brake system components an extended warranty to not lose goodwill with its customers. I believe every single Mercedes-Benz with SBC in the USA is still under warranty with no mileage limits?
Definitely not worth the headache despite having a backup system if (or rather, when, as the control unit had a fixed lifespan) the system fails and a separate auxiliary battery just for the brake system. I believe back in the day it was several thousand euro to have the SBC pump replaced when it gave out?
That said, I was able to control my car with a steel cable e-brake handle when it happened, and whatever fancy bs automakers decide to use on the brake pedal, I'm not buying a car without a handbrake for the foreseeable future.
Good luck. Most every car now has a switch connected to the computer that commands a motor to pull a chord that bonks the gerbil cage which starts running in its wheel that turns a fan by belt which blows the toy sailboat which bumps the hinged board that falls over releasing the bowling ball that runs down the ramp into a basket that pulls a rope which turns the burner on the stove boiling a kettle of water which blows the little turbine that pulls the brake pads tight. Cables and levers were too hard for them to install.
This community is going to have natural and reasonable skepticism of this. But consider that many airliners are fly by wire and their safety record is superb. There’s no guarantee an automotive system would be that good, my point is just that it doesn’t have to be worse.
Large airplanes are obviously different to cars and so are the engineering choices. It actually makes a lot of sense to use fly by wire in an plane because the level of existing complexity (and expense) justifies it.
A Boeing with triply redundant mechanical control of control surfaces is still inferior to Airbus fly by wire when the latter can implement a more reliable system, but only because the inherent complexity and expense of planes allows it. The Airbus will have 5 or 7 redundant electrical paths to the control surfaces and numerous redundant power supplies and actuators and beats the mechanical system hands down.
On a car you sharply increase complexity, and therefor reduce reliability. You need redundant power supplies and power connections, for instance. Planes have to be serviced by certified professionals on a strict basis, where as cars do not. So you have to implement a system that still operates under conditions of neglect, all while having severe cost limitations.
Then compare that to an average car. If you change your own oil (like I do), it's possible to go multiple years in between trips to a repair shop for bigger items like tires or a weird noise that popped up.
And let's be honest, a large number of people will hear a weird noise and drive with the check-engine light on for way longer than any manufacturer would recommend (even if they didn't have a profit motive in the form of expensive dealership repair shops). If the machine gets to point B, then whatever that noise is can wait a few more days/weeks.
Second, if this is intended for gasoline/diesel vehicles, then you need two power systems as well. If you lose your alternator on the freeway and don’t notice, or are very far from a safe place to stop, and you drive the car on the battery until it dies, it’s going to slam on the brakes. In some scenarios that’s a safe default. In many scenarios, it’s the wrong thing to do.
You can still retain a redundant mechanical emergency brake.
Not really a big leap, you almost wonder why we haven't done it yet. People understand that we currently rely on power braking and steering for existing vehicles, this is taking that next step. I think anyone who has lost steering and braking power while driving should kind of automatically understand why it might be ok.
I do have my doubts for steering by wire in cars however.
If the car breaks by default - imagine stopping in the middle of a highway where trucks go 140km/h.
If the car does not break by default - trivial. q.e.d.
Personally, I wouldnt love having needing to have a lift to swap my brake pads, or to dissasemble my suspension and pull apart the half shaft to replace my rotors
There are good reasons why people haven't moved away from old school rotors, pads & calipers right at the wheel hub, for basically any application.
I know inboards are used on some formula student cars in the rear (on some karts as well?) but I haven't looked up the issues they have with them.
Formula student cars and other open-wheelers have far greater packaging flexibility as well. A quick search doesn't bring up a whole lot of encouraging discussions on FSAE and related places re: inboard brakes, please share if you've seen such.
I don't see why that isn't the case for cars. Why don't cars require redundancy and failsafes?
I wounder how long the same repairs would take on a car with this new braking system. I wonder if I'd even be able to do the repairs myself with investing in a better scan/diagnostic tool.
You're a privilege escalation away from some piece of software wreaking havoc on the thing and car companies have historically been really awful with software.
When your alternator dies, the car runs until the battery is dead, and then the whole car stops.
Much older vehicles could run without electrical power but now with electronically-controlled engines you've gotta have electrical power.
There's also quite a few different ways to make an automatic gearbox, such as double-clutch gearboxes.
Without ABS the ability for a layperson to brake is greatly diminished
People aren’t going to remember to pump the brakes in an emergency, heck most people don’t even know rhythmically pumping the brakes is a thing
Thankfully most cars on the road at this point are going to have ABS, which just allows you to stand on the brake pedal in an emergency.
> People aren’t going to remember to pump the brakes in an emergency, heck most people don’t even know rhythmically pumping the brakes is a thing
I don't think looking at the extremes is the right approach here.
I've brought my car to a stop thousands of times, yet I've never once required the assistance of the ABS, in fact, I have no empirical evidence that it actually works at all.
Needing to brake and stop isn't an emergency situation, it's a very typical situation, and it would only become an emergency if you _can't_ stop.
If you happen to be having an emergency at the same time you lose electrical braking, you're shit out of luck.
Newton's laws would disagree. "An object in motions stays in motion..."
GP is asking "what happens if the alternator dies, and the battery runs flat while you're driving?" This may sound like an outlandish scenario, but my uncle had something similar happen to him not too long ago.
And not all cars can run solely off the alternator when the battery is dead. Several years ago, my mom's Grand Caravan wouldn't start when she was out. She called AAA, and they jumped the car, and it started just fine. But as soon as the AAA guys disconnected their jumper pack, the van died. They tried it several times and weren't able to get it to stay running.
If your brakes require a fully-functional electrical system to apply any force at all, that seems like an unacceptable failure scenario.
What I wonder is: what if the electrical system has a short, close to the battery and alternator? Would the residual hydraulic pressure be enough to stop the car?
One could even see the possibility that different drivers get different response customization, like how many new cars let you save custom seat, mirror, and driving style configurations.
The threads here seem dominated by questions like how reliable will this be (probably quite), how much weight will this save (not a lot, but it enables design flexibility).
Feedback though... That's really the key thing most users are going to experience as different. And it seems so unlikely that the user will have anywhere near as much accurate timely feedback as the mechanical systems it's designed to replace.
Even if initial models may layer in a variety of sensors to simulate feedback, it seems likely to be reduced over time, to be cost-downed.