Why is there a seemingly unending shift in the automobile industry toward digital/electric controls and away from anything mechanical/physical? (I'm not asking about entertainment/cabin items, just the ones that start/stop/move the car)
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.
Overall system complexity might be higher (due to more electronics), but this type of complexity tends to have a more favorable profile for economies of scale. One, generally, writes software once, but has to route hydraulics, reservoirs and so on for every car produced.
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.
Don't forget the possibility of adding digital locks so it can only be serviced with authorized parts by authorized dealers "for your security and safety".
Also, these systems are much more difficult to diagnose if they fail to function correctly. This means you are going to pay for 5 different things to be replaced, each after replacing the previous one didn't fix the issue. And you are going to pay big time for every replacement.
Not really. The issue with modern automobiles they don't really report much useful information about themselves beyond general upstream faults. One issue can flag errors in five modules, and it depends on the tech to know about the underlying technology in addition to diagnosing whatever mechanical issue. Techs also tend to be the type of people to throw up their hands and start throwing parts.
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.
> and it depends on the tech to know about the underlying technology in addition to diagnosing whatever mechanical issue. Techs also tend to be the type of people to throw up their hands and start throwing parts.
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?
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.
Not sure if my point came across. This is a knowledge problem. How can you test an ASIC for correct function if you have no knowledge of its intended function?
Right. That's what I added. You have to reverse engineer what's going on. As with anything if you don't know how it works. If your IC is producing crazy readings, or you look under a thermal camera, probably can blame the chip. Good luck getting a replacement.
Some of these sound like upsides to me. I've owned a lot of older cars, and they're always a mystery box of "what will fail next?". So many moving parts, and they're often hard to diagnose.
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.
Newer cars do have lower maintenance and repair costs. This is why vehicles with over 100k miles still fetch a fair amount of money. Computers are very good at doing the same thing over again indefinitely, unlike fully mechanical implementations which tend to drift out of spec slowly over time. A side effect of that is they require more time to actually get in and fix things.
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.
Off the cuff, I'd say at least half of my repair costs are the labor. Any chance you've seen figures on how much more expensive the parts are for newer cars?
It has to do with modularity and commoditization. Modern parts can be highly integrated and digitally customized to specific applications, in such a way that they become increasingly scarce and eventually impossible to find, whereas older cars are mostly made from commodity components where the same part is interchangeably used in tens or hundreds of vehicle models, and many become cheaper and easier to obtain as time goes on and tooling costs are amortized over decades.
Its not just the replacement parts cost. Modern cars are more tightly packed and not designed for individual parts being replaced afterwards. Sometimes its just things like a screw holding something behind the center console being accessible from the engine compartment in a position that forces a full engine/transmission removal. These are tiny things but can turn a 30 minute job into two person days.
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.
My main concern is the same as with electronic gear levers/selectors, electric parking brakes, steer by wire, and throttle by wire:
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.
Same thing that happens if a brake line pops, steering wheel locks up, or the throttle gets jammed open. There are ways of designing redundancies into those systems. Multiple communication channels, reserve sources of power. A lot of new model vehicles already have this stuff, drive by wire for example has pretty much been the standard for twenty years now. Typically, the entire system doesn't go down because they're designed for that not to happen.
My one-off experience. Parked my car once for a long holiday (two months). Mice chew through the main wiring loom behind the dashboard and urinated over electronics (urine is slightly corrosive). 1) no mechanic has time to repair single wires 2) dashboard removal is more than day of labor 3) main can bus failures are hard to find and require pulling modules till canbus high/low get the right voltages
I’d say a hard NO towards flybywire brakes.
> 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?
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.
Funnily enough, A380, A350, B787, and other new aircraft have their brakes connected by Ethernet (specifically AFDX, a modified variant of Ethernet) so braking actuator signals (and sensor data back) goes as UDP messages.
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
Aircraft don't need their brakes to be as responsive as cars do. There is virtually no chance of hitting a person or another plane while landing or maneuvering on the runway.
Aircraft brakes are life or death issues that require instant response times to changing conditions, which is why ABS originated in aircraft.
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)
I don't think ABS originated in aircraft because of the required braking response time. It originated in aircraft because aircraft must regularly operate in wet and icy conditions, and the performance of aircraft brakes is correlated to the length of runway required to land, which relates closely to the cost of everything in aviation. It was thus economical to use cutting-edge tech on planes long before it was economical to do the same for cars, which are mass-produced and must be affordable to individuals.
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.
Being slightly off in adjustment of brakes when landing an airliner results in dead passengers. It's not as visible for manual braking, but that's because the brakes have been "brake by wire" for some time. The scope of inputs in brake control loop is also much wider in aircraft than in typical car, at times including calculated mass, calculated ground speed, brake temperatures, tire temperatures, pressure on gear, etc.
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.
That is all pretty interesting but I think we've gotten far away from my original comment, which was that planes don't need brakes to be as responsive as cars do. The typical application you're describing is in landing, not in puttering around in the airport. Landing involves executing some braking program continuously until the plane is on the ground. What I'm really getting at here is that the pilot is not going to be taken by surprise and have to apply the brakes in the same way as a driver would. It stands to reason that despite the lower speeds that cars go, they need to brake spontaneously in all kinds of conditions (on worse surfaces than the typical runway, in many cases). I don't know why this point matters anymore but that's what I was trying to say.
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.
* 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.
Imagine you wanted to install a system so you could pull a lever in your kitchen and have it open your front door. Would you string a wire to an electric motor controlled by your lever, or run hydraulic lines and install a pump?
Maybe it's just my bias talking as a senior software dev, but having spent a career watching software fail in inexplicable ways, and in the specific case of "if this door doesn't close, I will likely die" hand me the hydraulics please.
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?
The question was cost, complexity, weight, etc. Reliability is an different issue. But nothing says an electronic system can’t be extremely reliable too.
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.
When it comes to brakes, the first three priorities are reliability, reliability, and reliability. If indeed the brake-by-wire is as reliable as it's cousin, fine and dandy. But I've worked on brake systems and I, to be blunt, like the idea that if you slam on the brake pedal, oil travels through lines and closes calipers upon brake discs. You can do this with a car turned off, with it's engine disabled, with it's electrics completely dead, because the linkage between your brake pedal and the brakes is a mechanical one.
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....
Agreed. In a perfect world, wire-based systems should be cheaper and more reliable. 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.
And when corners get cut, the software development lifecycle tends to be an easy target.
There are plenty of places where we entrust software with our lives. We don't yet have brake by wire, but we certainly have software-controlled brake actuation on any car with ABS, and that could easily kill you if it activates at the wrong time in the wrong way. Uncommanded acceleration is another possibility that might have actually killed people (or maybe it was just floor mats). Outside of cars, your microwave could burn your house down in the middle of the night with the right sort of software bug. So could any device with a lithium-ion battery. And of course numerous airliners are fly by wire and they remain the safest form of travel out there.
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.
> We don't yet have brake by wire, but we certainly have software-controlled brake actuation on any car with ABS
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.
What is checking "if anything looks too off"? Pretty sure there's software involved there.
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.
> What is checking "if anything looks too off"? Pretty sure there's software involved there.
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.
That “it anything looks too off” was battery management systems. I don’t think they have redundant systems.
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.
Space and weight. It saves on both while also being more flexible and presumably much simpler to install. Install times will save money at the factory and the space savings can be used elsewhere. In theory it can also be more reliable. It may also be able to provide smarter brake pressure to come to a stop quicker and more safely. The only real downside will probably be brake feel. You aren’t going to get a lot of feedback, but for day to day driving that isn’t much of a concern.
You can imagine the robot bolts the integrated motor breaking assembly to the body. And then a tech snaps the high voltage and control connectors together. That's it.
I was replying to a comment saying that, replacing mechanical actuation by electrical actuation, in a car, is always a downgrade of the user experience.
My electric drivers window is dead and my driving experience is definitely worse. Electrical stuff is so hard to DIY and work on as well and parts are ridiculously expensive.
> Is it really as simple as "cheaper to produce"? Is it cheaper to replace?
> it seems this savings come at the expense of massive complexity
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.
This will not be less parts. It will be integrated modules
Instead of tubing, with each module being about as many parts as the original entire abs system. Cheap to manufacture because cars can be engineered more easily, but each module will be 1000 dollars and unobtainable in 20 years, because it will be very specialized digitally for that specific vehicle models, sub year, etc. non-maintainability is a feature, not a bug.
Cost and the potential for vendor lock-in drive this. How long does anyone seriously think electric brakes will last on cars that bang around in mud and potholes full of water? What is the failure mode? Can you even tell when the brakes are failing? There are hydraulic brake systems many decades old, still in service. There's nothing new about this electric brake stuff that has only become feasible or cheaper today... It was deliberately avoided by engineers of the past because they did not trust the technology. They didn't trust hydraulics either. That's why emergency brakes are cable-driven. Of course, the cable can also work when there is no hydraulic pressure, such as when the car is parked and turned off. It's a smart design that serves multiple purposes.
Hydraulic systems are themselves complex and require many components all of which may fail. Detecting failure in a hydraulic system requires additional systems and is generally only indicative of overall system state rather than specific failure in a specific sub-assembly, on account of the shared nature of the medium. Assembly and testing are expensive.
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.
Electric brakes were avoided up to now for safety reasons, despite potential savings. You don't save money by destroying your reputation with such absurd compromises.
It's not the use of electric control that scares me, it's the inherently complicated control system. A primarminarily mechanical and hydraulic system just plain has less things that can go wrong.
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.
Brake systems have already gone from mostly mechanical/hydraulic to more and more electronic with ABS, radar-autobraking, individual wheel braking with ESP and so on. The drivers brake pedal is just one of many inputs to the eventually hydraulic system, while the other inputs are already electronic. It seems to me you can simplify it but keeping all the brake inputs electronic and fusing them closer to the wheel, instead of having a mixed mechanical/electronic system?
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.
The key difference here, though, is that all of those electronics are integrated into, and do not break the path of, the absolutely-must-work hydraulic path.
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.
Electronics can certainly be made to have appliance-like reliability and consistency. I'm a firmware dev, I'd know. My design philosophy is this: if I'm doing my job right, the customer should never know I exist.
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?
> Electronics can certainly be made to have appliance-like reliability and consistency.
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.
It doesn't matter how bulletproof the software is. It's already a huge downgrade that it must run on a chip.
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.
> A well designed embedded systems based on microcontrollers can be very reliable.
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.
I learned how to program from a series of adventure books in which the protagonist (a reader insert) pulled out his computer and solved the problem with a few dozen lines of BASIC! Angry natives in the jungle? No problem. Those books were from the 80s I'm pretty sure.
No thanks. The first thing I check in any vehicle is if there is any drive-by-wire anything followed by remote telemetry. If it has or had any of that I will not buy it or ride in it. Modern vehicles have a significantly long way to go to prove their local and remote security.
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.
Throttle-by-wire, yes: any modern car has this. Steer-by-wire or brake-by-wire, no. If the power dies, you can still steer to the side of the road and apply the brakes.
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.
Yes hydraulic assist is fine. A skiddie can't hack in and take control. A move fast and break things can't bug my steering. I have lost hydraulic assist whilst driving and there's usually enough pressure left to exit the road before I have to muscle it off the road. And to SR2Z's point yup as long as there is physical linkage I am good.
25 year old truck. I suppose it's a classic now despite it smelling like dead mice.
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.
Whenever I see somebody riding on a onewheel, I like to think they're at the end of a long calamitous journey that started out in a much larger vehicle.
That's the joke: Admitting is different than doing. ;) You really can't take a joke, can you? Get outside, touch grass, get some therapy, and see a lumberjack about that stick up your butt, dude.
I love the One wheel, but it's a trip that the design is inherently dangerous in edge states (over max power output or regen braking with a full battery)
Bosch is famous for being anti-right to repair. To work on their E-Bikes you need a certification and a special tool set. Probably the primary feature of these brake systems for Bosch is locking end users into Bosch certified maintainers and parts.
The German automakers avoid competing with each other in multiple areas, including colluding to limit the size and dispense rate of DEF tanks and collectively claiming to lawmakers that certain emissions regulations would be impractical.
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
I have a couple cars, some german. It absolutely does not cost $700 to change a dead battery any more that it costs $100 for a bottle of water. The cost of goods is cheap. You do need to tell the computer it is a new battery, since it adjusts charging voltages based on battery age, and if you don't do this it may overcharge the battery.
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.
Resetting the BMS via a diagnostic tool is not really a thing on newer Mercedes, but I could definitely see a dealer additionally charging as much as the battery costs to reset it on an older model that does need it.
You can buy dongles and do it yourself, but not everyone is willing to mess with coding their own vehicle.
You save the plumbing to near the pedal box and maybe the plunger to the master cylinder... and that's it?
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.
Not too different from, say, any of Toyota's hybrids (and the TLC100 / GS430 / others using "electronic brakeforce distribution")? Same with almost every EV out there, same with MB's SBC, etc. I really don't see why this counts as a big leap - all I see is the removal of the backup direct hydraulic lines, which doesn't exactly sit well with me.
I mean it's not like hydraulic lines can't fail catastrophically as well though. History has given us somewhat unrealistic ideas about what is and isn't safe - it all comes down to the design, not the underlying technology.
The major "sudden" failure mode of pretty much all those systems has so far been the (brushed!!!) electric motor eating through its commutator (with the brushes still relatively intact) and stopping relatively suddenly - at that point, you'd better not ignore the lights on the dash, as it means there's only what's left in the hydraulic pressure accumulator in terms of assistance - afterwards there's almost nothing. The backup hydraulic lines have never really been an issue with this setup - the backup lines are two and directly go to resp. the front left and right calipers, and the only time they see pressure and fluid movement is during the brake bleeding procedure. The rest of the hydraulic circuits are somewhat safer as cars with such systems can absolutely detect and isolate a "misbehaving" circuit - i.e. if a flex hose is punctured, the rest of the system will work.
I am reminded of the Mercedes-Benz Sensotronic Brake Control (SBC) system that was developed by Daimler and Bosch. It was in two mass-market models, the E-Class and the CLS-Class, and it was so unreliable and expensive that it was replaced with a traditional brake system during mid-generation refreshes for both models.
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?
I rarely do. Working in the automotive industry (not Bosch, though) made me dislike cars even more than I did before, all the safety stuff (AUTOSAR, MISRA, ...) is theater.
Translated from corporate: we're going to a proprietary system that you'll need to have serviced only by us at insane markups in order to gain recurring revenue.
I've had hydraulic brakes fail on me before when a line broke in the winter, this doesn't sound significantly worse.
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.
> 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 is one system in the car that must have mechanical fallback. Yes there are a lot of systems already interacting with the hydraulics (servo assist, ABS, pumps, etc). But fundamentally you can stop the car if you push hard enough on the pedal. Removing that seems like looking for cost savings in a silly place.
It must be reliable. Having a mechanical fallback is a way to achieve that. If an electronic system can be made equally or more reliable, then it’s fine.
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.
One consideration for aviation is that they have inspections, replacements, repairs, etc regulated like crazy. And I suspect it's regulated so tightly because it would be skipped otherwise, because that does NOT sound cheap.
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.
In the abstract that might be true, but you're missing issues of unnecessary complexity which feed into systemic risk.
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.
First of all there is no comparison between car and aviation safety systems. And in aviation, many systems have both an electric and a hydraulically system so that they don’t share dependencies.
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.
On an airplane all systems are triple redundant. That makes it easier because the power and control systems are redundant and there is no need to add that. If only the brakes need to be redundant then they need to have multiple self contained systems including power and that is really complicated
The technology isn't new. There has been some change in supply chain availability with the ability to produce super cheap electronics and servos. Honestly, this could be pretty great for safety overall with improvements to emergency braking performance alone.
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.
the best upgrade for brakes would be to keep them totaly mechanical, but move to indoard brakes, there would be no flex lines, or much shorter and robust flex lines, sprung mass will be reduced, improving handling , and reducing wieght, airodynamics and heat rejection can be refined further, center of mass is now better, and overall efficiency will see a significant improvement, with a statistical improvement in saftey due to better braking and manouverability.
vs a gadjet that is not needed
I wonder how strong the driveshafts would have to be to handle all the braking torque transmitted through them. Dissipating the heat would also be an interesting problem. Also reduced clearance and/or increased drivetrain complexity and a million other things.
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.
My guess is torque isn't as big of an issue since on acceleration you break traction before anything snaps. The big issue in my mind is technically cooling and practically packaging since you already have the space inside the wheels.
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.
Brake torque is far higher than engine torque and can be applied at speeds where tire traction is far greater - at least at the front. The rear makes far more sense for this application - assuming a performance RWD or AWD vehicle, the rear driveshafts already handle most of the acceleration load, and max rear braking load is practically severely limited by the load transfer to the front.
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.
Interesting take! Is this suggestion for performance cars only or were you omagining this would be an imporvement for every car?
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
For it to be unsprung, you either need a solid axle or you're relying on a CV joint. Putting a CV joint in the mechanical path for braking at highway speeds will definitely kill people.
The article says
"[being implemented in motorcycles] would also create a host of reliability issues, considering motorcycles endure far more than cars do.
On motorcycles, brake-by-wire would require a lot of redundancy and failsafes to make sure that the smallest malfunction wouldn't endanger the rider."
I don't see why that isn't the case for cars.
Why don't cars require redundancy and failsafes?
I just replaced all four rotors and pad sets on my Land Cruiser. It took me ~75 minutes to do it in my driveway. And that included rotating the tires.
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.
I worry about the security aspect of modern cars, now that they're connected things, many times the thing with the internet connection has access to the CAN bus too.
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.
Your car will come to a stop on it's own when there's no electrical power left. ICE cars can run with a dead battery only as long as the alternator is working and producing electrical power.
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.
> Your car will come to a stop on it's own when there's no electrical power left.
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.
To be a real emergency, it would have to also happen when you were planning on braking very soon. At least with my driving patterns most of the time I'm driving I'd be able to safely coast to the shoulder. The failure would have to coincide with a stoplight turning red or something. Hmmm, even the horn wouldn't be working without electrical power...
How old are we talking about here? If you have power brakes then when the engine shuts off the brakes don't work at 100%. At that point you're needing to push the hydraulic fluid without assistance and you'll find it's really not easy to stop. Also no power steering. A windy mountain road is not a good place to be...
I'm pretty sure my old car's owner's manual specifically said that engine braking effect can be increased by downshifting the automatic gearbox to a lower gear in the manual mode. Current car's owner's manual says to release the accelerator when approaching red lights to "take advantage of engine braking" and since it's a hybrid, it also does regen.
There's also quite a few different ways to make an automatic gearbox, such as double-clutch gearboxes.
That's what my car's manual said, too. But the "lower gear" in Drive mode was electronic. It didn't have a dedicated "low" or "2" or whatever position. On my dad's Toyota it's even worse, the "gearshift" is fully electronic.
You should never pump your brakes, even if you have no ABS. What you should instead be doing is "threshold braking", so you should have as much brake pressure as you can without locking up the tires, and if you lock up, you release as much as you need until you're not locked up anymore. If you just pump the brakes in rhythm, you'll have longer a stopping distance as you're just alternating between no braking and too much braking.
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.
> 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
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.
If the battery is dead, it's not driving, so not need for much breaking power (dunno how they handle the parking situation).
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?
Younger me thought drive-by-wire was awesome. But now I'm aghast at all these systems. Because of feedback. Because yiu no longer have the tactile data to form a understanding & relationship with your 1.5 tons of rolling metal. Digitization strips of affordances that mechanical naturally provides, leaves us adrift in at best simulation of response.
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.
It feels like you are pressing on a tennis ball, zero real feedback whatsoever. Acura MDX has had the brake-by-wire system fo a while now in the latest generation.
Possibly because that’s not the job of that parts being talked about. The brake pedal implementation will have to be separate and each brake pedal manufacturer can implement a different style.
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.
That is not the point at all; We're not talking about a spring rate that increases as you push on the pedal. In a proper braking system, the driver can feel through his foot what the tires are doing, because there is direct mechanical feedback through the brake lines. This is an important safety consideration, and manufacturers are throwing it out for... what?
Yes, and those can all be mechanically emulated at the pedal based on sensors on the brakes, with only an electrical connection between them. You can experience that even on modern arcade racing-simulator games.
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.