Legendary Bose Magic Carpet Suspension Is Finally Going Global(thedrive.com)
thedrive.com
Legendary Bose Magic Carpet Suspension Is Finally Going Global
https://www.thedrive.com/news/legendary-bose-magic-carpet-suspension-is-finally-going-global
184 comments
Didn't GM have a camera/software combo that would relax the MR dampener before bumps at one time? It didn't have active movement - just a regular shock but with fine control over fluid movement.
I think you're saying you have a pump that moves hydraulic fluid in anticipation of a road defect/speedbump, and does it per-wheel and proportional to the correction needed. Which is fascinating.
With regards to pre-crash posture, I'm not sure if this is to move the occupants into a more advantageous position for airbag deployment or to get more crash structure involved for a dissimilar vehicle crash (sedan vs. truck). Can you talk more about it? Is there going to be IIHS/Euro NCAP/C-NCAP testing?
I think you're saying you have a pump that moves hydraulic fluid in anticipation of a road defect/speedbump, and does it per-wheel and proportional to the correction needed. Which is fascinating.
With regards to pre-crash posture, I'm not sure if this is to move the occupants into a more advantageous position for airbag deployment or to get more crash structure involved for a dissimilar vehicle crash (sedan vs. truck). Can you talk more about it? Is there going to be IIHS/Euro NCAP/C-NCAP testing?
Yes correct, we use electric motors to directly control an efficient compact pump to bidirectionally pump fluid, or use back electromotive force to dampen motion (and capture energy while doing so). This eliminates the need for controlled valves, but requires advanced controls to mitigate system dynamics (hydraulic losses, etc).
For ride control, machine vision helps a bit, but it’s limited due to the need to determine high fidelity road z-measurements which requires very high resolution and clarity at speed, and no visual occlusion. It helps with simple problems like bump vs hill (which is not trivial to predict just with accelerometers), but we’ve figured out how to get most of the benefit of machine vision with just accelerometers and fast actuators. GM was able to use vision to improve pothole performance, but it’s still a semi-active system that only provides fast adjustable stiffness (damping).
For pre-crash, the system uses cameras to detect a collision-path vehicle and determine an optimized impact zone for that vehicle. For example, the frame or bumper has more structural rigidity which may be desirable in certain crash scenarios.
For ride control, machine vision helps a bit, but it’s limited due to the need to determine high fidelity road z-measurements which requires very high resolution and clarity at speed, and no visual occlusion. It helps with simple problems like bump vs hill (which is not trivial to predict just with accelerometers), but we’ve figured out how to get most of the benefit of machine vision with just accelerometers and fast actuators. GM was able to use vision to improve pothole performance, but it’s still a semi-active system that only provides fast adjustable stiffness (damping).
For pre-crash, the system uses cameras to detect a collision-path vehicle and determine an optimized impact zone for that vehicle. For example, the frame or bumper has more structural rigidity which may be desirable in certain crash scenarios.
If you are looking for future ideas:
While most vehicles used in ag are going to be combustion based for a long while, if you could apply the shock mitigation to a just a chair in spray rig (https://hayandforage.com/images/29-Thome_MR_38-WEB.7650.png) or fertilizer buggy, a lot of spines could be saved.
These vehicles are lighter and generally run faster than tractors, and applicators who run them for decades tend to be forced to retire in pretty bad shape.
While most vehicles used in ag are going to be combustion based for a long while, if you could apply the shock mitigation to a just a chair in spray rig (https://hayandforage.com/images/29-Thome_MR_38-WEB.7650.png) or fertilizer buggy, a lot of spines could be saved.
These vehicles are lighter and generally run faster than tractors, and applicators who run them for decades tend to be forced to retire in pretty bad shape.
What a waste of people's health and workforce. Do they not have pneumatically sprung seats, at least, if the vehicle has no suspension? These have been available for a long time - my dad was a farmer and had one on his mid 80s Fendt tractor.
Yes, those exist and are very much used (and replaced as a maintenance item).
Unfortunately does not eliminate the slow accumulative injury of going over rough and tilted ground for decades.
It seems like more of an issue here in the willamette valley of Oregon than it was in southwest kansas. I think the steep hills limit what is reasonable for suspension to counter with spines held at an off angle for long periods.
Unfortunately does not eliminate the slow accumulative injury of going over rough and tilted ground for decades.
It seems like more of an issue here in the willamette valley of Oregon than it was in southwest kansas. I think the steep hills limit what is reasonable for suspension to counter with spines held at an off angle for long periods.
> "Infinite preview" control using crowdsourced road data with <3cm localization precision
Let me guess, all those demos are with carefully mapped bumps.
Let me guess, all those demos are with carefully mapped bumps.
That was certainly how the original tech demo worked.
Sure, but that invalidates any seemingly/misleadingly direct comparisons like the one linked above. Hell, you could even build bump course in a way to exaggerate bmw/audi wobblines by hand tuning for resonant frequencies those cars are most sensitive to and run it at carefully selected worst case speed.
A other future idea: offer back the crowdsourced data to city and state planners to find the roads in dire need of repairs, and evaluate the quality of road construction to select the best companies
> "Infinite preview" control using crowdsourced road data with <3cm localization precision
Question: Why not use an onboard front-facing camera to detect potholes in real-time? Using crowdsourced data can definitely have outdated-ness issues. Unless, you'll eventually plan to elegantly in-place switch over the data source to near real-time LEO satellite imagery over even better - below-LEO [0] satellite imagery.
[0] https://techcrunch.com/2025/04/29/near-space-labs-nabs-20m-t...
Question: Why not use an onboard front-facing camera to detect potholes in real-time? Using crowdsourced data can definitely have outdated-ness issues. Unless, you'll eventually plan to elegantly in-place switch over the data source to near real-time LEO satellite imagery over even better - below-LEO [0] satellite imagery.
[0] https://techcrunch.com/2025/04/29/near-space-labs-nabs-20m-t...
The article says that Bose gave up and sold the rights because:
"Sadly it was totally impractical for mass production in 2004"
What does that mean? Was it too complex or costly to make it back then? Did that change now with your developments?
Better tech is nice but if it's to expensive or hard to mass produce then it could end up the same way as with Bose.
What does that mean? Was it too complex or costly to make it back then? Did that change now with your developments?
Better tech is nice but if it's to expensive or hard to mass produce then it could end up the same way as with Bose.
To create enough force to lift the car using linear motors requires massive copper coils and rare earth magnets, which is heavy and expensive. It’s also wasteful, because in real world drive cycles peak force is only needed for short periods of time and at relatively low linear velocities. Further, linear motors require significant packaging space which requires the chassis be designed around it. Instead, we use a much smaller motor and a high “gear ratio” using hydraulics to achieve high forces via mechanical gain. This reduces raw material cost by a factor of >10x while achieving similar performance.
If I recall it was heavy. I think speculation had it adding over 20% to the weight of the Lexus.
And those electric motors and control hardware would not have been cheap. But nobody knows how to estimate it - just that it would be prohibitively expensive.
And those electric motors and control hardware would not have been cheap. But nobody knows how to estimate it - just that it would be prohibitively expensive.
Impressive, but is it as stylish and smooth as the 1978 Royal Deluxe II?
https://www.youtube.com/watch?v=vnOwHu_wchg
https://www.youtube.com/watch?v=vnOwHu_wchg
> This video contains content from NBC Universal, who has blocked it in your country on copyright grounds
any work with US automakers planned? Are there issues working with EU / China due to current political realities?
Hello. How does this suspension handle severely neglected roads with large potholes or even off-road type with say 40-50mph? And I mean regularly, for years?
Why would you drive any vehicle on a road like that at 50mph? At some point a neglected road isn’t a road anymore and shouldn’t be considered as such.
I mean I am asking only because my government has failed to fix these roads and we've had protests that lead to nothing. They are the only connection between the rural parts of the country, as in the only ones.
You have no choice but to go at a speed useful enough to get anywhere. For me, these are real-world conditions.
You have no choice but to go at a speed useful enough to get anywhere. For me, these are real-world conditions.
That's going to destroy your tires regardless. The suspension isn't going to save your tires if you deliberately abuse them.
> The original version replaced traditional dampers with linear electric motors that used sensor data to literally move the wheels up and down and cancel out bumps. ClearMotion adapted the control software and applied to active valve dampers with a magnetic fluid.
So, in other words, ClearMotion is producing a technology that other OEM's have been doing for years. Just off the top of my head, Cadillac has their magnetic suspension (which uses a fluid that changes viscosity in the presence of a magnetic field. I guess this is the same as what TFA claims is brand new.) The Ford Raptor with their live valve by Fox has a solenoid valve that regulates the shim pack. (Funny enough, I've spent all morning doing a FEA analysis of their valve.) The latest Mercedes Gelandewagen also has solenoid valves in their dampers to switch between soft and hard damping. Citroen has been doing it since the 50's with a purely mechanical system.
The basic idea is very simple: you want a computer to regulate the damper between soft and firm, as the road dictates. The implementation of this can become very complicated and there's a number of very different implementations. If I remember right, the Bose implementation required too much electricity to be practical. Most other implementations have some type of solenoid valve to control the pressure drop of the hydraulic fluid across an orifice. Again, the theory is simple, but mass producing a system that is cheap, reliable, yet can respond in milliseconds is difficult.
So, in other words, ClearMotion is producing a technology that other OEM's have been doing for years. Just off the top of my head, Cadillac has their magnetic suspension (which uses a fluid that changes viscosity in the presence of a magnetic field. I guess this is the same as what TFA claims is brand new.) The Ford Raptor with their live valve by Fox has a solenoid valve that regulates the shim pack. (Funny enough, I've spent all morning doing a FEA analysis of their valve.) The latest Mercedes Gelandewagen also has solenoid valves in their dampers to switch between soft and hard damping. Citroen has been doing it since the 50's with a purely mechanical system.
The basic idea is very simple: you want a computer to regulate the damper between soft and firm, as the road dictates. The implementation of this can become very complicated and there's a number of very different implementations. If I remember right, the Bose implementation required too much electricity to be practical. Most other implementations have some type of solenoid valve to control the pressure drop of the hydraulic fluid across an orifice. Again, the theory is simple, but mass producing a system that is cheap, reliable, yet can respond in milliseconds is difficult.
> Citroen has been doing it since the 50's with a purely mechanical system.
I remember watching Citroens demonstrating losing a wheel, and continuing to drive, in the early 1970s.
Citroens are cool. Maybe their build quality wasn't so good, or they were too expensive, as I've not seen them on this side of the pond.
I remember watching Citroens demonstrating losing a wheel, and continuing to drive, in the early 1970s.
Citroens are cool. Maybe their build quality wasn't so good, or they were too expensive, as I've not seen them on this side of the pond.
Citroën pulled out of the North American market in the 1970s, due to US regulations that required headlights maintained a consistent height. Since their suspensions allowed them to raise and lower their height, there was no way they could be compliant without massive changes to their system. Besides, the Citroën network was not big in the US anyway, and since the DS had few facelifts in its 20 years in production, it was falling out of favour with US consumers who didn't want to be seen driving yesteryear's car.
Their build quality is fine, at least contemporarily to the rest of the market; of course today, we would find its steel pitiful. It's not without reason that people who maintain Citroëns of that era tend to replace the panels with fibreglass ones.
Additionally, as Citroën pulled out, the maintenance network in North America began to falter, as the suspension system required significant know-how. There are still a dedicated group of Citroën fans in North America (albeit small), and I met a lot of them when I drove from coast to coast (and back again) back in 2017 in a 1998 Citroën Xantia. A car that may not seem particularly interesting to Europeans (although it was the Activa V6 model), but it was extremely rare in North America.
Their build quality is fine, at least contemporarily to the rest of the market; of course today, we would find its steel pitiful. It's not without reason that people who maintain Citroëns of that era tend to replace the panels with fibreglass ones.
Additionally, as Citroën pulled out, the maintenance network in North America began to falter, as the suspension system required significant know-how. There are still a dedicated group of Citroën fans in North America (albeit small), and I met a lot of them when I drove from coast to coast (and back again) back in 2017 in a 1998 Citroën Xantia. A car that may not seem particularly interesting to Europeans (although it was the Activa V6 model), but it was extremely rare in North America.
https://en.wikipedia.org/wiki/Moose_test
"It is noteworthy that the previous record holder (set in 1999) was the Citroën Xantia 3.0i V6 Activa, an unassuming family car with a unique active roll bar system.[15]"
"It is noteworthy that the previous record holder (set in 1999) was the Citroën Xantia 3.0i V6 Activa, an unassuming family car with a unique active roll bar system.[15]"
> 1970s, due to US regulations that required headlights maintained a consistent height.
Were headlights bouncing up and down a problem back then?
Sounds so ridiculous, especially considering there is no regulation about the headlights’ actual height/color/intensity/angle, which causes many drivers to blind others these days.
Were headlights bouncing up and down a problem back then?
Sounds so ridiculous, especially considering there is no regulation about the headlights’ actual height/color/intensity/angle, which causes many drivers to blind others these days.
Unfortunately, I cannot find an actual source for this ban. So many sites repeat the claim, but with no citation. So now I am not even sure it's true. I tried searching NHTSA's website, but it's kind of a mess. I do know, that Citroën pulled out in 1974 from the US. The CX, released the year after, was never sold in the US, and the last year of the SM, which was popular in the US, only saw sales in Europe.
There absolutely is, at least in the EU.
You can have any colour, as long as it's 6000-ish K.
In France, every two years you gotta have your car legally checked. Misaligned headlights is ground for not passing, or being fined if the police notices it in between.
Ever since high power Xe headlights are a thing, headlight leveling is mandatory to be automatic.
You can have any colour, as long as it's 6000-ish K.
In France, every two years you gotta have your car legally checked. Misaligned headlights is ground for not passing, or being fined if the police notices it in between.
Ever since high power Xe headlights are a thing, headlight leveling is mandatory to be automatic.
The point of the regulation was to kick Citroen off the market
They should have just lobbied the government instead.
Citroën? A French auto-maker lobbying the US government so they can stay on the US market? Besides Citroën was basically always about to go bankrupt before Peugeot bought them in 1976. Buying Maserati and building the SM had not turned into the success they had hoped for.
Just yesterday I was remembering the ride on a Citroen XM in the 90s which has the full blown hydropneumatic suspension (https://en.m.wikipedia.org/wiki/Hydropneumatic_suspension) . Decades later I haven’t been in a car with such a smooth ride
I can confirm. Was driving for a while, impervious to any sign of having a flat tyre before someone on the street signalled me to stop. And that was on a Citroen Saxo, which I don’t think had the suspension of C5 etc. Amazing car, lasted for 15 years with me, with only battery and frankly inconsistent oil changes. The lady who bought it when we immigrated still runs it 15 years later. Build quality is a hit and miss per model I think.
they even had a project for hydraulic-driven wheels - some kind-of water-mill in each wheel, and a huge pump, and that's it :)
p.s. long time ago i bought a 15y old hydraulic Citroen, drove it for 10 years.. the hydraulics was less breaking than the engine :/ . Now i have another (recent) Citroen but that "road-surface-ignorant" feeling of the hydraulics is completely gone.
p.s. long time ago i bought a 15y old hydraulic Citroen, drove it for 10 years.. the hydraulics was less breaking than the engine :/ . Now i have another (recent) Citroen but that "road-surface-ignorant" feeling of the hydraulics is completely gone.
The Citroen system was very ingenious but also physically quite simple.
It got a bad rep through an initial design flaw that was quickly solved, and (US) mechanics that did not know or learned how to do maintainance on these.
https://www.autoevolution.com/news/citroen-hydropneumatic-su...
It got a bad rep through an initial design flaw that was quickly solved, and (US) mechanics that did not know or learned how to do maintainance on these.
https://www.autoevolution.com/news/citroen-hydropneumatic-su...
I've had automatic inertial valve adjustment in my mountain bike for 10+ years as well.
This looks similar to Porsche Active Ride Suspension discussed here https://news.ycombinator.com/item?id=39739404.
My 1991 Mitsubishi 3000gt VR4 had switched dampers stock! These were not reactive it was just high or low with a button and maybe some automatic logic. But even on stiff mode, aftermarket struts were stiffer so I replaced them.
> If I remember right, the Bose implementation required too much electricity to be practical
Battery powered cars might have solved that? Although the extra battery mass would prevent "leaping".
Battery powered cars might have solved that? Although the extra battery mass would prevent "leaping".
It's really smart though: Why spend a lot of energy moving the wheel up and down, when you can just control the damper and rely the spring to store energy.
It's not the same.
For a simple example, let's say you are simply driving in a circle. The car wants to lean toward the outside. The linear motors can provide a countering force, lifting the outside, lowering the inside, so the car stays level. Variable damping can only control the rate that it rolls. It will still roll in sub-second timescales, unless it completely locks down the suspension, which is terrible for both handling and comfort.
For another simple example: going over a speed bump. Linear motors can lift the front wheels over the bump, and then the rear wheels, so the body stays level the whole time. An active damper can go full-soft the moment the wheel hits the bump, but the compressed spring will still start lifting the front of the car. An active damper can do a better job managing the rebound on the far side so it doesn't oscillate, but it can't entirely prevent the bump from pitching the body up and down in the first place.
That's not to say it's worthless. Very fast active dampers can improve both handling and comfort. It's just nowhere near the level which is possible with linear motors.
For a simple example, let's say you are simply driving in a circle. The car wants to lean toward the outside. The linear motors can provide a countering force, lifting the outside, lowering the inside, so the car stays level. Variable damping can only control the rate that it rolls. It will still roll in sub-second timescales, unless it completely locks down the suspension, which is terrible for both handling and comfort.
For another simple example: going over a speed bump. Linear motors can lift the front wheels over the bump, and then the rear wheels, so the body stays level the whole time. An active damper can go full-soft the moment the wheel hits the bump, but the compressed spring will still start lifting the front of the car. An active damper can do a better job managing the rebound on the far side so it doesn't oscillate, but it can't entirely prevent the bump from pitching the body up and down in the first place.
That's not to say it's worthless. Very fast active dampers can improve both handling and comfort. It's just nowhere near the level which is possible with linear motors.
This is my biggest fear of technologies like these.
The whole point of a speed bump, for example, is to ensure that behaviour that puts others at risk will, at the very least make the driver uncomfortable. If we then deploy technologies that make speed bumps “disappear” from the perspective of vehicle occupants, it’s going to enable people to comfortably drive a lot more aggressively at the expense the people on the other side of the windshield.
Conversely, if we were to deploy technologies like speed governors, then we could do away with the speed bumps and the need for fancy suspension.
The whole point of a speed bump, for example, is to ensure that behaviour that puts others at risk will, at the very least make the driver uncomfortable. If we then deploy technologies that make speed bumps “disappear” from the perspective of vehicle occupants, it’s going to enable people to comfortably drive a lot more aggressively at the expense the people on the other side of the windshield.
Conversely, if we were to deploy technologies like speed governors, then we could do away with the speed bumps and the need for fancy suspension.
>technologies that make speed bumps “disappear”
My 2004 Land Cruiser has such technology. It's called "being a Land Cruiser". As a sports car fan, I'm quite familiar with how hard it is to make speed bumps that work for every vehicle. You're not wrong, but also it's a pretty crude technology, speed bumps.
My 2004 Land Cruiser has such technology. It's called "being a Land Cruiser". As a sports car fan, I'm quite familiar with how hard it is to make speed bumps that work for every vehicle. You're not wrong, but also it's a pretty crude technology, speed bumps.
The problem with speed bumps is that the level of annoyance is drastically higher for the already-slow prudent driver in a reasonable vehicle, compared to the lackadaisical latently-fast driver in an oversized monster SUV. So most of the intended targets get punished with "wow that was bouncy lol!" while the collateral damage gets comically slow crawling and/or frame damage. Speed bumps also draw the attention of drivers towards focusing on the obstacle, and away from staying alert for pedestrians.
I just had an experience with a parking lot (at a place generally full of kids), that had added a horrible speed bump at the entrance and then removed it a few months later. As far as I know there was no problem with people speeding in the lot, it was likely just some busybody trying to make things "better". Thankfully someone more in charge saw the light of reason.
I just had an experience with a parking lot (at a place generally full of kids), that had added a horrible speed bump at the entrance and then removed it a few months later. As far as I know there was no problem with people speeding in the lot, it was likely just some busybody trying to make things "better". Thankfully someone more in charge saw the light of reason.
It's easy to underestimate just how slow digital systems are in many real time scenarios compared to analog systems.
Consider it in the context of camera based self-driving cars, it's tangential to this discussion but it's an easy to visualize metaphor:
- A car traveling 60mph is traveling at 88 feet per second
- Assuming a 60hz camera, there would be a 16.67 ms gap between each frame
- The car is traveling 1.5 feet between each frame interval
- A certain amount of exposure time is necessary for the camera to generate even 1 frame or it will be blurry
- High framerate cameras often work around this by staggering/interlacing multiple sensors, but doing this implicitly increases the latency of each frame
- A 120hz camera might deliver double the frames per second, but each frame could be arriving 4 frames late in exchange
- 4 frames would be imperceptible to humans, it would be 3 feet for the car
- You haven't even processed any of these frames yet.
- Your off the shelf library introduces a random 1 second delay for some reason and costs you 88 miles in processing time
- The car can drive as fast as 120mph
All digital sensors implicitly have a sampling frequency, and the fundamental disconnect is always high sampling frequency =/= low latency. People constantly make this mistake over and over, and by the time you notice you are already too deep into development to make a change.
Decreasing latency is expensive, and requires specialized knowledge. Often you get expert software engineers who end up bottlenecked by the hardware limitations they can't even comprehend or the reverse, hardware guys bottlenecked by the software they can't introspect. The latency is only truly understood when you get to integration testing.
Nearly every step of the way you discover you need specialized hardware, software, operating systems, sensors. Every part of the chain each costing you more latency. It's like it's own ecosystem where almost everyone writes everything from scratch and doesn't share anything. It's gotten better in recent years though.
Full disclosure: I work in medtech and don't actually deal with cars, but it's a very similar problem space. We often use the same hardware/software cars use for this reason.
Consider it in the context of camera based self-driving cars, it's tangential to this discussion but it's an easy to visualize metaphor:
- A car traveling 60mph is traveling at 88 feet per second
- Assuming a 60hz camera, there would be a 16.67 ms gap between each frame
- The car is traveling 1.5 feet between each frame interval
- A certain amount of exposure time is necessary for the camera to generate even 1 frame or it will be blurry
- High framerate cameras often work around this by staggering/interlacing multiple sensors, but doing this implicitly increases the latency of each frame
- A 120hz camera might deliver double the frames per second, but each frame could be arriving 4 frames late in exchange
- 4 frames would be imperceptible to humans, it would be 3 feet for the car
- You haven't even processed any of these frames yet.
- Your off the shelf library introduces a random 1 second delay for some reason and costs you 88 miles in processing time
- The car can drive as fast as 120mph
All digital sensors implicitly have a sampling frequency, and the fundamental disconnect is always high sampling frequency =/= low latency. People constantly make this mistake over and over, and by the time you notice you are already too deep into development to make a change.
Decreasing latency is expensive, and requires specialized knowledge. Often you get expert software engineers who end up bottlenecked by the hardware limitations they can't even comprehend or the reverse, hardware guys bottlenecked by the software they can't introspect. The latency is only truly understood when you get to integration testing.
Nearly every step of the way you discover you need specialized hardware, software, operating systems, sensors. Every part of the chain each costing you more latency. It's like it's own ecosystem where almost everyone writes everything from scratch and doesn't share anything. It's gotten better in recent years though.
Full disclosure: I work in medtech and don't actually deal with cars, but it's a very similar problem space. We often use the same hardware/software cars use for this reason.
88ft not 88 miles. I don't understand your 120hz camera line, I also have a degree in imaging tech and that part I do not understand, would you be so kind as to expand upon it??
Wew I'm getting a lot of pedantic replies here. Yeah I got the units wrong there my bad, you get the point I was making though right?
In regards to the 120hz camera line, I would be happy to expand on that for you. To be clear, I'm specifically talking about how when you try to increase sampling rate by interlacing multiple concurrent digital sensors you need to deal with the following potential problems (this is a property of all digital sensors):
- Real time synchronization between concurrent sensors requires additional processing time to ensure proper ordering. The samples need to be processed together in small batches. This adds latency and the more things you are trying to synchronize the more latency is introduced.
- Inter-sensor calibration to account for variations between individual sensors can be used to reduce the latency introduced by synchronization but lacking this, you are bottlenecked by the slowest sensor. There are a lot of different ways to handle this though so I'm speaking very generally.
- Broadly speaking most signals need to go through some kind of filter to remove noise, most digital filters have a certain amount of algorithmic latency built-in that is physically unavoidable. When you are interlacing multiple different sensors, you are getting more noise, so the likelihood of a filter being required starts to increase.
I want to stress here that these are not impossible challenges. In fact they are largely solved problems. But they are not universally solved in the same way, you need to balance between precision manufacturing, signal quality and signal latency. In practice most people are not prioritizing latency, so a 120hz camera might be optimizing for video recordings and not live processing scenerios. So long as you know what you are looking for you can avoid this when choosing which camera to use.
Computers can be fast, but fast can mean different things when dealing with real-time situations in high speeds. Bottlenecks need to be considered from all levels. The clock speed of the computers CPU often gives product managers weird ideas about what is possible. This was the main point I was trying to make here.
In regards to the 120hz camera line, I would be happy to expand on that for you. To be clear, I'm specifically talking about how when you try to increase sampling rate by interlacing multiple concurrent digital sensors you need to deal with the following potential problems (this is a property of all digital sensors):
- Real time synchronization between concurrent sensors requires additional processing time to ensure proper ordering. The samples need to be processed together in small batches. This adds latency and the more things you are trying to synchronize the more latency is introduced.
- Inter-sensor calibration to account for variations between individual sensors can be used to reduce the latency introduced by synchronization but lacking this, you are bottlenecked by the slowest sensor. There are a lot of different ways to handle this though so I'm speaking very generally.
- Broadly speaking most signals need to go through some kind of filter to remove noise, most digital filters have a certain amount of algorithmic latency built-in that is physically unavoidable. When you are interlacing multiple different sensors, you are getting more noise, so the likelihood of a filter being required starts to increase.
I want to stress here that these are not impossible challenges. In fact they are largely solved problems. But they are not universally solved in the same way, you need to balance between precision manufacturing, signal quality and signal latency. In practice most people are not prioritizing latency, so a 120hz camera might be optimizing for video recordings and not live processing scenerios. So long as you know what you are looking for you can avoid this when choosing which camera to use.
Computers can be fast, but fast can mean different things when dealing with real-time situations in high speeds. Bottlenecks need to be considered from all levels. The clock speed of the computers CPU often gives product managers weird ideas about what is possible. This was the main point I was trying to make here.
> I'm getting a lot of pedantic replies here. Yeah I got the units wrong there my bad, you get the point I was making though right?
You get the most pedantic replies when you're right and people don't like it.
I work on a latency sensitive product. You're pretty correct about most of it.
You get the most pedantic replies when you're right and people don't like it.
I work on a latency sensitive product. You're pretty correct about most of it.
Anything with latency is amusing. You can send data a few thousand km in the time you can make it show up on your screen.
Honestly I'm just a dumb web dev and even though many of our performance problems can be solved by horizontal scaling, there are a minority of cases where latency is important and that's when things get really fun :-) No more downloading random halfbaked libraries off the web, architecture starts to matter, vm settings start to matter, gateways/load balancers in the middle start to matter, even code optimization starts to matter again just like in good old days.
I can’t quite understand your comment.
> Assuming a 60hz camera, there would be a 16.67 ms gap between each frame. The car is traveling 1.5 feet between each frame interval.
Ok? So? You are just stating this as if we should understand the implications. I do in fact work with self-driving cars. What you say is true, but it is not a big deal. Why do you feel this maters? Or what is your point?
> A certain amount of exposure time is necessary for the camera to generate even 1 frame or it will be blurry
This is a confused statement. A certain amount of exposure is necessary for the camera to collect light. If you don’t have long enough exposure the picture will be dark, not blurry. Your statement makes it sound as if avoiding blur is why we need exposure time, which is a complete nonsense.
In reality none of this is a problem. There are automotive grade cameras which can collect enough light fast enough that the images are not blurry in practice. Yes, these cameras have a non-zero exposure time. Yes, this adds latency. No, this is not a problem.
> Your off the shelf library introduces a random 1 second delay for some reason and costs you 88 miles in processing time
You mean 88 feet. If my off the shelf library introduces a random 1 second delay i will chuck it in the bin post haste. Use stuff whose performance characteristics are well understood by you and is not terrible.
> Nearly every step of the way you discover you need specialized hardware, software, operating systems, sensors.
I do not recognise the world you describe.
> Assuming a 60hz camera, there would be a 16.67 ms gap between each frame. The car is traveling 1.5 feet between each frame interval.
Ok? So? You are just stating this as if we should understand the implications. I do in fact work with self-driving cars. What you say is true, but it is not a big deal. Why do you feel this maters? Or what is your point?
> A certain amount of exposure time is necessary for the camera to generate even 1 frame or it will be blurry
This is a confused statement. A certain amount of exposure is necessary for the camera to collect light. If you don’t have long enough exposure the picture will be dark, not blurry. Your statement makes it sound as if avoiding blur is why we need exposure time, which is a complete nonsense.
In reality none of this is a problem. There are automotive grade cameras which can collect enough light fast enough that the images are not blurry in practice. Yes, these cameras have a non-zero exposure time. Yes, this adds latency. No, this is not a problem.
> Your off the shelf library introduces a random 1 second delay for some reason and costs you 88 miles in processing time
You mean 88 feet. If my off the shelf library introduces a random 1 second delay i will chuck it in the bin post haste. Use stuff whose performance characteristics are well understood by you and is not terrible.
> Nearly every step of the way you discover you need specialized hardware, software, operating systems, sensors.
I do not recognise the world you describe.
> I do in fact work with self-driving cars. What you say is true, but it is not a big deal. Why do you feel this maters? Or what is your point?
Sorry not trying to dunk on you here, but this reads like something a junior engineer would complain to me about. These are not trivial problems, and I'm sure your co-workers who resolved them already so you didn't need to worry about them would agree with me.
> In reality none of this is a problem. There are automotive grade cameras which can collect enough light fast enough that the images are not blurry in practice. Yes, these cameras have a non-zero exposure time. Yes, this adds latency. No, this is not a problem.
You are contradicting yourself here, yes there are automotive grade cameras, but if this wasn't a problem, why would automotive grade cameras need to exist? My post wasn't saying these were impossible problems but hard ones.
> You mean 88 feet. If my off the shelf library introduces a random 1 second delay i will chuck it in the bin post haste. Use stuff whose performance characteristics are well understood by you and is not terrible.
Look I might have typed the wrong unit but it's a bit ironic you gave me this word salad right after complaining about this... Yeah you obviously don't use the library that adds a 1 second delay, but often you don't have the luxury of knowing that until after you learn about it through integration testing.
Libraries don't usually come with latency stats calibrated to your desired hardware right on the tin, would be pretty sweet if they did though.
> I do not recognise the world you describe.
I don't find this surprising :)
Sorry not trying to dunk on you here, but this reads like something a junior engineer would complain to me about. These are not trivial problems, and I'm sure your co-workers who resolved them already so you didn't need to worry about them would agree with me.
> In reality none of this is a problem. There are automotive grade cameras which can collect enough light fast enough that the images are not blurry in practice. Yes, these cameras have a non-zero exposure time. Yes, this adds latency. No, this is not a problem.
You are contradicting yourself here, yes there are automotive grade cameras, but if this wasn't a problem, why would automotive grade cameras need to exist? My post wasn't saying these were impossible problems but hard ones.
> You mean 88 feet. If my off the shelf library introduces a random 1 second delay i will chuck it in the bin post haste. Use stuff whose performance characteristics are well understood by you and is not terrible.
Look I might have typed the wrong unit but it's a bit ironic you gave me this word salad right after complaining about this... Yeah you obviously don't use the library that adds a 1 second delay, but often you don't have the luxury of knowing that until after you learn about it through integration testing.
Libraries don't usually come with latency stats calibrated to your desired hardware right on the tin, would be pretty sweet if they did though.
> I do not recognise the world you describe.
I don't find this surprising :)
> These are not trivial problems
My complaint is that it is not clear why you think what you describe is a problem. You describe that by the time the next image arrives the car traveled a certain distance. And that is correct. But you imply that it is a problem without spelling out why it is a problem in your opinion.
You seem to assume it is so trivial to understand that you don’t even need to spell out the problem. But it is not. Because i don’t know what is in your head I can’t argue with the details of it. I know that whatever you feel is a problem is not a problem in practice.
Definietly not a problem you would solve by having higher frame rate cameras. So what I’m seeing is that you are unclear on the problem and jumping at a non-solution. One which adds other complexities without actually solving anything for you. And that is a certified junior engineer behaviour.
> if this wasn't a problem, why would automotive grade cameras need to exist?
Automotive grade cameras are special in their supported temperature range (they won’t die if you leave them baking in the sun) and their physical and electrical intefaces being resilient to vibration and electrical interference. You can point your smartphone out the window of your car and see that it can record clear images.
My complaint is that it is not clear why you think what you describe is a problem. You describe that by the time the next image arrives the car traveled a certain distance. And that is correct. But you imply that it is a problem without spelling out why it is a problem in your opinion.
You seem to assume it is so trivial to understand that you don’t even need to spell out the problem. But it is not. Because i don’t know what is in your head I can’t argue with the details of it. I know that whatever you feel is a problem is not a problem in practice.
Definietly not a problem you would solve by having higher frame rate cameras. So what I’m seeing is that you are unclear on the problem and jumping at a non-solution. One which adds other complexities without actually solving anything for you. And that is a certified junior engineer behaviour.
> if this wasn't a problem, why would automotive grade cameras need to exist?
Automotive grade cameras are special in their supported temperature range (they won’t die if you leave them baking in the sun) and their physical and electrical intefaces being resilient to vibration and electrical interference. You can point your smartphone out the window of your car and see that it can record clear images.
"My complaint is that it is not clear why you think what you describe is a problem."
Well, while you read, do the math in your head and think about what OP was trying to say. The point - latency is a cold and often uncalculated bitch that will screw with reliability and integrity of the system - got across to me quite easily. I was already on that page by the 4th sentence.
Well, while you read, do the math in your head and think about what OP was trying to say. The point - latency is a cold and often uncalculated bitch that will screw with reliability and integrity of the system - got across to me quite easily. I was already on that page by the 4th sentence.
> while you read, do the math in your head and think about what OP was trying to say.
I did the math in my head. Before i read their comment in fact. Did calculations both on paper and spreadsheets too. Run simulations, and field tests too. Based on what i know i do not believe that the latency imposed by the frame rate of the cameras is a limiting factor on self-driving car performance or safety. I was asking to see if they have some particular scenairo in their mind to check if maybe i’m missing something. If anything I’m much more concerned about the latency of brake actuators.
> The point - latency is a cold and often uncalculated bitch that will screw with reliability and integrity of the system - got across to me quite easily.
Ah, ok. If we are just catching the vibes, then sure. The vibes are great.
I did the math in my head. Before i read their comment in fact. Did calculations both on paper and spreadsheets too. Run simulations, and field tests too. Based on what i know i do not believe that the latency imposed by the frame rate of the cameras is a limiting factor on self-driving car performance or safety. I was asking to see if they have some particular scenairo in their mind to check if maybe i’m missing something. If anything I’m much more concerned about the latency of brake actuators.
> The point - latency is a cold and often uncalculated bitch that will screw with reliability and integrity of the system - got across to me quite easily.
Ah, ok. If we are just catching the vibes, then sure. The vibes are great.
> Based on what i know i do not believe that the latency imposed by the frame rate of the cameras is a limiting factor on self-driving car performance or safety.
This is would be pretty tangential to the discussion so not sure why you are bringing it up? Did you think my post was illustrating that camera based self driving cars were infeasible? Also it appears you are mistaking framerate for latency, something I specifically warned about in my post... I don't really know what to say here.
This is would be pretty tangential to the discussion so not sure why you are bringing it up? Did you think my post was illustrating that camera based self driving cars were infeasible? Also it appears you are mistaking framerate for latency, something I specifically warned about in my post... I don't really know what to say here.
> Did you think my post was illustrating that camera based self driving cars were infeasible?
You said this line: “The car is traveling 1.5 feet between each frame interval” As I said before, this is a true statement. What I’m asking is what do you think is the significance of this value. You wrote it. It does indeed sound like you were saying this is an impediment, or at least a complication for implementing a camera based system. But I don’t know because you didn’t spelled it out, and I can’t read your mind. Hence I asked why do you feel that number is a problem. (If you don’t think it is a problem, just an interesting fact you wanted to share of course you can say that too.)
> it appears you are mistaking framerate for latency
I’m not. If you are measuring latency from “something is happening in the world” to “robot is reacting to it” then a component of that end-to-end latency is the time delay before your sensor captures a new measurement. That delay is a function of your framerate. This delay is only part of the full end-to-end latency. It appeared to me you were concerned about this delay and that is why you calculated how much the vehicle travels during this time.
> I don't really know what to say here.
I asked specific questions. If you would care to answer them we would be ahead. When i wrote “I can’t quite understand your comment.” that is not a retorical snipe. It literally means what i wrote: I do not understand your comment and I’m asking for clarification. I even quoted the bits which I don’t understand and asked my specific questions about them.
> This is would be pretty tangential to the discussion so not sure why you are bringing it up?
Because it seemed to me you were bringing it up in your comment. Or at least that is how i could interpret those few lines in your comment I was talking about.
You said this line: “The car is traveling 1.5 feet between each frame interval” As I said before, this is a true statement. What I’m asking is what do you think is the significance of this value. You wrote it. It does indeed sound like you were saying this is an impediment, or at least a complication for implementing a camera based system. But I don’t know because you didn’t spelled it out, and I can’t read your mind. Hence I asked why do you feel that number is a problem. (If you don’t think it is a problem, just an interesting fact you wanted to share of course you can say that too.)
> it appears you are mistaking framerate for latency
I’m not. If you are measuring latency from “something is happening in the world” to “robot is reacting to it” then a component of that end-to-end latency is the time delay before your sensor captures a new measurement. That delay is a function of your framerate. This delay is only part of the full end-to-end latency. It appeared to me you were concerned about this delay and that is why you calculated how much the vehicle travels during this time.
> I don't really know what to say here.
I asked specific questions. If you would care to answer them we would be ahead. When i wrote “I can’t quite understand your comment.” that is not a retorical snipe. It literally means what i wrote: I do not understand your comment and I’m asking for clarification. I even quoted the bits which I don’t understand and asked my specific questions about them.
> This is would be pretty tangential to the discussion so not sure why you are bringing it up?
Because it seemed to me you were bringing it up in your comment. Or at least that is how i could interpret those few lines in your comment I was talking about.
Ingenuity's wobble from a color vs bw frame is a great example of solvable but surprising latency problems along the way.
Awesome post, illuminating metaphor, +1.
Tangent: why do so many people (even smart articulate ones like you) in our field (which involves precision with syntax and grammar) get apostrophes wrong?
"It's [IT IS] like its [ITS/HIS/HER/MY/YOUR/THEIR] own ecosystem..."
I anticipate downvotes for picking nits (let alone mentioning karma points), but FTR my intent is to help non-native English speakers (and mostly-literate English language-natives). Getting this "it's : its" distinction wrong is increasingly common and sometimes leads to signal loss.
Yesco, rereading your comment makes me slightly ashamed of this apostrophe rant, I hope others comment on the substance here. / end tangent
As someone who spent years doing web performance optimization for a living, your observations resonate. Beyond obvious low-hanging fruit, latency gains are rarely simple to achieve in practice; tradeoffs abound.
Tangent: why do so many people (even smart articulate ones like you) in our field (which involves precision with syntax and grammar) get apostrophes wrong?
"It's [IT IS] like its [ITS/HIS/HER/MY/YOUR/THEIR] own ecosystem..."
I anticipate downvotes for picking nits (let alone mentioning karma points), but FTR my intent is to help non-native English speakers (and mostly-literate English language-natives). Getting this "it's : its" distinction wrong is increasingly common and sometimes leads to signal loss.
Yesco, rereading your comment makes me slightly ashamed of this apostrophe rant, I hope others comment on the substance here. / end tangent
As someone who spent years doing web performance optimization for a living, your observations resonate. Beyond obvious low-hanging fruit, latency gains are rarely simple to achieve in practice; tradeoffs abound.
To your tangent. When I was taught its vs it's, I was never given the association to his/hers/etc. It was just arbitrary and something you just had to memorize. Reading your post I am shocked I never made the connection earlier but it was just never knowledge I was provided with to work from.
Ha yeah it reads a bit silly, to be honest I lazily typed my original post on my phone while sitting on a hammock outside, I didn't really review it much before posting. Autocorrect can make it challenging for me to do apostrophes correctly since it often overassumes my intent.
IME autocorrect costs me more time and keystrokes than doing without, so I always disable it (shrug)
different strokes...
different strokes...
[deleted]
Precision, repeatability, responsiveness.
> I've spent all morning doing a FEA analysis of their valve.
You did a finite element analysis analysis?
You did a finite element analysis analysis?
RAS syndrome is not actually a problem, it's never actually misunderstood, in fact it usually adds clarity as redundancy in language usually does.
>You did a finite element analysis analysis?
That'd what it's called when you put the FEA in the circular file because the part is an inconsequential revision of something that's been in production forever and works fine.
That'd what it's called when you put the FEA in the circular file because the part is an inconsequential revision of something that's been in production forever and works fine.
Exactly what I came here to post. Mag fluid suspension has been mainstream for a while. Cadillacs aren't exotic.
I would guess this feels quite a bit different, the clearmotion tech puts electrohydraulic actuators in every corner of the vehicle and is proactively pushing and pulling wheels. MagneRide isn't even active (maybe semi-active, not sure) - never mind predictive and proactive.
So...more like Mercedes' system?
except that this demo isn't ClearMotion, and instead of actuators they are using magnetic fluid and valvework...
much like every luxury brand has tried at least once or twice in the past 30 years.
much like every luxury brand has tried at least once or twice in the past 30 years.
The demo in the page of the "NIO ET9 SkyRide Fully Active Suspension system test"? - I presume they included that to show the legacy systems? If you do a technical dive through the CM technology it's clearly not just a magnetic fluid/hydraulic, this site gives a good breakdown: https://mf-topper.jp/articles/10003931
Adjusting damping rates is very different from proactively lifting a wheel just as it reaches a bump.
Here's the Porsche way and it's actually available, today, if you go to a Porsche dealership and buy a Panamera with the active ride system:
(active ride begins at half the vid, at 1:17):
https://youtu.be/LU9s4q0FUS8
Or look the slalom at about one minute in the vid. That's not 3D.
https://www.youtube.com/watch?v=ELmY_HLtxTo
(active ride begins at half the vid, at 1:17):
https://youtu.be/LU9s4q0FUS8
Or look the slalom at about one minute in the vid. That's not 3D.
https://www.youtube.com/watch?v=ELmY_HLtxTo
> Over 20 years ago,
Why would we be interested in the technology from 1980s… oh.
Also, this is Bose of active noise cancellation - very fitting, since this looks like anc for wheels. They did anc for car seats too and sold it to the same buyer:
> As part of the deal, ClearMotion also acquired the technology for Bose Ride, a special "active" car seat for truckers that improves ride quality and reduces occupant fatigue. Bose used what it had learned from developing the active car suspension system to create Bose Ride, but it remains a niche product.
https://www.cnet.com/roadshow/news/bose-sells-its-futuristic...
Why would we be interested in the technology from 1980s… oh.
Also, this is Bose of active noise cancellation - very fitting, since this looks like anc for wheels. They did anc for car seats too and sold it to the same buyer:
> As part of the deal, ClearMotion also acquired the technology for Bose Ride, a special "active" car seat for truckers that improves ride quality and reduces occupant fatigue. Bose used what it had learned from developing the active car suspension system to create Bose Ride, but it remains a niche product.
https://www.cnet.com/roadshow/news/bose-sells-its-futuristic...
> since this looks like anc for wheels
I was wondering why the heck Bose got into this. Thanks, that was the missing link -- I never thought of suspensions as noise cancellation but of course they are!
I was wondering why the heck Bose got into this. Thanks, that was the missing link -- I never thought of suspensions as noise cancellation but of course they are!
I got a tour of Prof. Bose's factory as a student while taking his course on acoustics. Active suspension is basically a speaker voice coil but scaled up and pushing a car wheel instead of a cone. A lot of the physics and perhaps more critically, the manufacturing processes, were shared between speakers and suspension as they implemented it. I actually got to sit in the car as it drove over bumps, it was pretty magical. iirc you could flip a switch and set a suspension profile that made it emulate other cars road feel as well. Years later I built a toy model of it using an actual speaker to make a pushbutton switch that could emulate the feel of a broad range of other switches.
At one point, Bose was a few scientists who happened to have a consumer tech company.
BYD has had active suspension in their Yangwang U9 supercar for two years now. It's over the top.[1] It can sense and jump potholes. Drive with one wheel missing. Dance to music. Do tank turns. There's even a LIDAR watching the road surface for bumps.
That's not just adjustable damping; that's a fully powered suspension.
[1] https://www.youtube.com/watch?v=zIKAn8yDkpA
That's not just adjustable damping; that's a fully powered suspension.
[1] https://www.youtube.com/watch?v=zIKAn8yDkpA
While cool as a shower thought, in reality, having a 1200HP car jump and go airborne while you're swerving to avoid a pothole is just about the last thing you want it to be doing. Traction control is pretty good these days, but not that good that you want to lose all traction at 120km/h (75mph, the speed shown in the video).
Which is exactly why you want that suspension.
Both this and the Bose linear actuator one lift just the wheel that needs lifting, just enough to clear the obstacle, keeping everything perfectly steady, it's incredible.
The fact that it can also do silly jumps for marketing reasons is a different topic.
Both this and the Bose linear actuator one lift just the wheel that needs lifting, just enough to clear the obstacle, keeping everything perfectly steady, it's incredible.
The fact that it can also do silly jumps for marketing reasons is a different topic.
Right. This is a demo.
A more impressive demo is that it can do precise turns in place without skidding.[1] That's the U8, BYD's answer to Rivian. The U9 can do that too.
Rivian did demo a turn in place, but they were spewing dirt all over.[2] Rivian took the feature out.
Now, those are BYD's high end supercars, to show off the technology. The high-end volume vehicle, the U7, just came out.[3] That is under US$90K (depending on what tariffs are on this week) and competes with Tesla's higher end products. All the fancy torque and suspension control of the supercar, but at a lower price point.
BYD isn't offering it in the US. Just the rest of the world.
[1] https://www.youtube.com/watch?v=fhvjPwshME0
[2] https://www.youtube.com/watch?v=7BkxjHkOvYY
[3] https://electrek.co/2025/03/27/byd-launched-first-ultra-luxu...
A more impressive demo is that it can do precise turns in place without skidding.[1] That's the U8, BYD's answer to Rivian. The U9 can do that too.
Rivian did demo a turn in place, but they were spewing dirt all over.[2] Rivian took the feature out.
Now, those are BYD's high end supercars, to show off the technology. The high-end volume vehicle, the U7, just came out.[3] That is under US$90K (depending on what tariffs are on this week) and competes with Tesla's higher end products. All the fancy torque and suspension control of the supercar, but at a lower price point.
BYD isn't offering it in the US. Just the rest of the world.
[1] https://www.youtube.com/watch?v=fhvjPwshME0
[2] https://www.youtube.com/watch?v=7BkxjHkOvYY
[3] https://electrek.co/2025/03/27/byd-launched-first-ultra-luxu...
Rivian is spewing dirt around because someone is flooring it in the mud, undoubtedly part of someone's marketing vision. There is similar video of U8 slinging sand around while doing 360 in the desert.
G-wagon also ships with tank turn https://www.youtube.com/watch?v=Es01er7RnGs
Seems BYD really put some engineering behind this gimmick to make it as graceful and controllable as possible, while Rivian just winged some pointless demos and G-Wagon one is rough and very situational (sand/snow/wet).
G-wagon also ships with tank turn https://www.youtube.com/watch?v=Es01er7RnGs
Seems BYD really put some engineering behind this gimmick to make it as graceful and controllable as possible, while Rivian just winged some pointless demos and G-Wagon one is rough and very situational (sand/snow/wet).
> Seems BYD really put some engineering behind this gimmick to make it as graceful and controllable as possible.
Yes. That makes it useful. The automatic parking feature can use a precise skidding turn when necessary.[1]
[1] https://www.msn.com/en-us/autos/other/byd-s-new-feature-make...
Yes. That makes it useful. The automatic parking feature can use a precise skidding turn when necessary.[1]
[1] https://www.msn.com/en-us/autos/other/byd-s-new-feature-make...
> While cool as a shower thought, in reality, having a 1200HP car jump and go airborne while you're swerving to avoid a pothole is just about the last thing you want it to be doing.
Surely the system takes cornering into account. Having a suspension that can use predictive motions to compensate for a pothole would ideally produce better handling by minimizing the disruption of a pothole imparting a massive disturbance to the vehicle.
Surely the system takes cornering into account. Having a suspension that can use predictive motions to compensate for a pothole would ideally produce better handling by minimizing the disruption of a pothole imparting a massive disturbance to the vehicle.
If you're swerving in that car and clip any portion of that pothole, you're almost certainly going to lose control anyway. And if you've swerved around the pothole successfully, there's nothing for the suspension to have to jump. ;-)
And Porsche has its Active Ride[1] tech, already implemented in Panamera and Taycan.
Yet, for some reason they, supposedly, want to use the so-called Bose tech too.
[1] https://youtu.be/BohF6I3_QZ4
Yet, for some reason they, supposedly, want to use the so-called Bose tech too.
[1] https://youtu.be/BohF6I3_QZ4
The Bose Magic Carpet was the original version of all of these powered suspension cars 20 years ago.
> It can sense and jump potholes.
The Bose system’s most famous demo was sensing and jumping over speed bumps.
> That's not just adjustable damping; that's a fully powered suspension.
Right, but it appears the company who bought the Bose Magic Carpet portfolio isn’t doing what the original demo did 20 years ago, they’re just using the name.
> It can sense and jump potholes.
The Bose system’s most famous demo was sensing and jumping over speed bumps.
> That's not just adjustable damping; that's a fully powered suspension.
Right, but it appears the company who bought the Bose Magic Carpet portfolio isn’t doing what the original demo did 20 years ago, they’re just using the name.
> The Bose Magic Carpet was the original version of all of these powered suspension cars 20 years ago.
No, the Citroen Activa active suspension was in production from 1996.
No, the Citroen Activa active suspension was in production from 1996.
The Activa/Xantia suspension was nice, but it was nowhere near the Bose Magic Carpet.
It was a nice, mass market adaptive damping suspension.
The Bose is a fully active linear actuator, and fast. It can move your wheel around a speed bump independently. It's awesome. It was also north of $100k just for the suspension and iirc was never used in mass production.
It was a nice, mass market adaptive damping suspension.
The Bose is a fully active linear actuator, and fast. It can move your wheel around a speed bump independently. It's awesome. It was also north of $100k just for the suspension and iirc was never used in mass production.
Yes, this seems significantly more about the IP than a technology breakthrough…more TikTok than 60 Minutes.
Obligatory wheelsboy review: https://www.youtube.com/watch?v=ASIUyfK6K4U
Mercedes does this with hydraulic rams, it's called Active Body Control (or Magic Body Control for the version that scans the road in front too).
That system uses hydraulic rams in series with the usual suspension springs and dampers, and can handle up to 5 Hz (i.e. it controls the lower frequency part of the spectrum so softer springs etc can be used, improving both ride and handling)
That system uses hydraulic rams in series with the usual suspension springs and dampers, and can handle up to 5 Hz (i.e. it controls the lower frequency part of the spectrum so softer springs etc can be used, improving both ride and handling)
As I’ve grown older I’ve come to realize that what truly makes high end luxury cars is the suspension and the sound deadening. The other stuff is important but doesn’t really set the cars apart. Sitting in a little mobile room completely divorced from the sensory input of the outside world truly feels luxurious
I'm in the same boat regarding sound deadening, so when I was in the market for a car this was my #1 priority. But outside of the luxury segment, they do not even talk about sound deadening or noise isolation. This idea simply does not exist. It was very disappointing because this is a fairly low tech, inexpensive feature that could easily find its way to mainstream cars. Sure it adds some extra weight, but the improvement in riding comfort easily outweighs the fuel consumption. It's like flying with noise cancellation headphones. You don't know what you're missing unless you try it once, and then you can never go back.
> when I was in the market for a car this was my #1 priority
Did you look at recent model year trucks? The acoustic treatment on these vehicles is almost too much. I feel like I am in a recording booth every time I roll up my windows. I have to keep them open a little bit or my tinnitus starts to bother me.
Did you look at recent model year trucks? The acoustic treatment on these vehicles is almost too much. I feel like I am in a recording booth every time I roll up my windows. I have to keep them open a little bit or my tinnitus starts to bother me.
Trucks are not a thing where I live, but I wish I could drive in a recording booth.
NAD, but opening up your windows like that might actually worsen your tinnitus. Wind noise can be pretty loud at speeds and you're teaching your brain to expect such background noise at all times. Might be better off playing some audio. If you have a quiet cabin, you can get away with very low volumes, just enough to give your ears something to focus on instead of getting bored and starting to wail by themselves.
NAD, but opening up your windows like that might actually worsen your tinnitus. Wind noise can be pretty loud at speeds and you're teaching your brain to expect such background noise at all times. Might be better off playing some audio. If you have a quiet cabin, you can get away with very low volumes, just enough to give your ears something to focus on instead of getting bored and starting to wail by themselves.
Have you considered hearing aids for the tinnitus?
I'm sure it does, but this just made me realize something.
I drive a Smart Fortwo, which goes in the opposite direction - there's not much suspension to speak of, and the short wheelbase means you rock around a lot more on uneven street surfaces, so you're very much connected to the outside world. One of the things I've noticed when switching back and forth between that and a normal sedan is that, if I'm not consciously thinking about it, I'll drive slightly more aggressively in the sedan than in the Smart. And I think it's precisely because of that difference in connection with the outside world.
The same happened when I rented a pickup truck a while back to move some furniture; I don't remember the model, but I think it was a fairly recent/common one. It was very clear that movements that would have felt pretty aggressive to me if I were walking or biking around felt less so from the driver's seat. And I bet the same is true of these luxury cars.
This is of particular interest to me because my day-to-day method of getting around is not driving but rather walking and biking, and it's worrying to me if drivers are subconsciously acting more aggressively just because they feel more disconnected from the world around them.
I drive a Smart Fortwo, which goes in the opposite direction - there's not much suspension to speak of, and the short wheelbase means you rock around a lot more on uneven street surfaces, so you're very much connected to the outside world. One of the things I've noticed when switching back and forth between that and a normal sedan is that, if I'm not consciously thinking about it, I'll drive slightly more aggressively in the sedan than in the Smart. And I think it's precisely because of that difference in connection with the outside world.
The same happened when I rented a pickup truck a while back to move some furniture; I don't remember the model, but I think it was a fairly recent/common one. It was very clear that movements that would have felt pretty aggressive to me if I were walking or biking around felt less so from the driver's seat. And I bet the same is true of these luxury cars.
This is of particular interest to me because my day-to-day method of getting around is not driving but rather walking and biking, and it's worrying to me if drivers are subconsciously acting more aggressively just because they feel more disconnected from the world around them.
Rolls Royce made the Ghost so quiet testers called it nauseating. They had to remove some sound dampening to make it more comfortable.
Which is pretty neat considering it has a 6.7 liter bi-turbo under the hood.
Which is pretty neat considering it has a 6.7 liter bi-turbo under the hood.
Watching the video I wonder how much of it is combining that plus a car that’s higher off the ground. Mercedes cars will be more performance minded so it’s lower to the ground. Maybe SUVs could have the greater suspension range so it can handle larger bumps but I wonder how much any Sedan could.
The most comfortable car I’ve ridden in suspension wise was a Mercedes SUV. So maybe they figured that out already.
The most comfortable car I’ve ridden in suspension wise was a Mercedes SUV. So maybe they figured that out already.
The Mercedes version is hydropneumatic suspension. It was pioneered in the 1940s and 50s by Citroen. Citroen still use on high end vehicles too. Byd has adopted more recently
It has always occurred to me that the car industry doesntprioritisee a smooth ride or this would be much more widely used.
It has always occurred to me that the car industry doesntprioritisee a smooth ride or this would be much more widely used.
The ABC system does more than the earlier hydropneumatic systems of Citroen etc. Those earlier systems have a slow response that can compensate for things like ride height, not to actually move the struts up and down rapidly like the ABC system.
For example see the "rodeo test" where the car moves each corner up and down to test the system. ABC involves active feedback control of the body and rapidly adjusts force/displacement of individual struts, just like what the Bose system does with electric actuators.
https://youtu.be/391IPl3LJOs
For example see the "rodeo test" where the car moves each corner up and down to test the system. ABC involves active feedback control of the body and rapidly adjusts force/displacement of individual struts, just like what the Bose system does with electric actuators.
https://youtu.be/391IPl3LJOs
I have a "road" (just concrete slabs which never graduated into a proper road) where I would love to test that.
If this technology becomes common place, what is the future of speed bumps?
It seems as if speed bumps are a rather questionable approach to traffic calming, as larger vehicles (which should be a priority for calming) are less affected.
It seems as if speed bumps are a rather questionable approach to traffic calming, as larger vehicles (which should be a priority for calming) are less affected.
We use chicanes (of a sort) and single lane bottlenecks in the UK. Forcing the vehicle to turn is a pretty easy way to get people to slow down and people complain less because it's friendlier on their suspension. In my home town there's one road that was clearly experimental? where the whole (one way) road gently zigzags for maybe 500m.
I've never understood speed bumps as a concept. Almost every car has at least 4in of travel, so you can hit them at significant speed and not damage anything. In fact the faster you hit them or the more load you're carrying the better the suspension handles it because you open up the high speed compression valves. If there's no one around and it's an empty remote rural access road I'll often hit them at 30mph+ with no issue. Rolling over them at a slower speed where your shocks stay uncompressed forces your whole car to go up and then down again, instead of absorbing the energy in the shocks.
> so you can hit them at significant speed and not damage anything.
That’s the point. They’re not supposed to damage the car. They’re supposed to be a little uncomfortable if you’re going too fast.
It’s more reminder than a physical stopper.
> In fact the faster you hit them or the more load you're carrying the better the suspension handles it because you open up the high speed compression valves.
This is a case of knowing just enough about a topic to be dangerous.
Entering the higher shaft velocity part of the damper curve doesn’t mean the suspension is handling it “better”. The high speed behavior of the valving simply means the damping forces aren’t increasing linearly with shaft velocity. They trade extra travel for reduced peak forces.
Make no mistake, though. The faster you go, the higher the forces. The high speed valving (if the OEM dampers are even digressive) isn’t changing that.
If the speed bump is tall enough and the bump stops get completely compressed you could bottom out the damper, which is not good for it.
> I'll often hit them at 30mph+ with no issue.
Just because nothing immediately breaks doesn’t mean you’re reducing the life of the OEM dampers. Repeated high speed impacts and will shorten the life. Getting the wheels bumped up into the range where you’re compressed bump stops transfers a lot of energy into the bushings and other components.
> Rolling over them at a slower speed where your shocks stay uncompressed forces your whole car to go up and then down again, instead of absorbing the energy in the shocks.
That’s the ideal way to do it. This is better than the sudden sharp impact of high speed crossing. You’re not doing your car any favors by driving quickly over speed bumps. Fortunately for you, OEM replacement dampers aren’t too expensive but replacing prematurely worn bushings is kind of a pain.
That’s the point. They’re not supposed to damage the car. They’re supposed to be a little uncomfortable if you’re going too fast.
It’s more reminder than a physical stopper.
> In fact the faster you hit them or the more load you're carrying the better the suspension handles it because you open up the high speed compression valves.
This is a case of knowing just enough about a topic to be dangerous.
Entering the higher shaft velocity part of the damper curve doesn’t mean the suspension is handling it “better”. The high speed behavior of the valving simply means the damping forces aren’t increasing linearly with shaft velocity. They trade extra travel for reduced peak forces.
Make no mistake, though. The faster you go, the higher the forces. The high speed valving (if the OEM dampers are even digressive) isn’t changing that.
If the speed bump is tall enough and the bump stops get completely compressed you could bottom out the damper, which is not good for it.
> I'll often hit them at 30mph+ with no issue.
Just because nothing immediately breaks doesn’t mean you’re reducing the life of the OEM dampers. Repeated high speed impacts and will shorten the life. Getting the wheels bumped up into the range where you’re compressed bump stops transfers a lot of energy into the bushings and other components.
> Rolling over them at a slower speed where your shocks stay uncompressed forces your whole car to go up and then down again, instead of absorbing the energy in the shocks.
That’s the ideal way to do it. This is better than the sudden sharp impact of high speed crossing. You’re not doing your car any favors by driving quickly over speed bumps. Fortunately for you, OEM replacement dampers aren’t too expensive but replacing prematurely worn bushings is kind of a pain.
>This is a case of knowing just enough about a topic to be dangerous.
>Entering the higher shaft velocity part of the damper curve doesn’t mean the suspension is handling it “better”. The high speed behavior of the valving simply means the damping forces aren’t increasing linearly with shaft velocity. They trade extra travel for reduced peak forces.
>If the speed bump is tall enough and the bump stops get completely compressed you could bottom out the damper, which is not good for it.
Oh the irony!
In practice none of the suspension parts on any car are in any danger until you run out of up travel and determining where the deflection will happen becomes a competition between the air in your tire and the suspension components.
No automotive suspension is designed so that the damper bottoms out. You'll have an external bump stop somewhere, sometimes on the damper shaft, in any case the damper itself isn't bottoming out, you'd know, probably even hear it specifically if it did.
Regularly traveling rough roads, hitting rumble strips, comically out of round tires or anything else that creates oscillation is going to be way, way, way worse for component longevity (dampers, bushings, etc) than a hard bump from time to time.
Source: live it
>Entering the higher shaft velocity part of the damper curve doesn’t mean the suspension is handling it “better”. The high speed behavior of the valving simply means the damping forces aren’t increasing linearly with shaft velocity. They trade extra travel for reduced peak forces.
>If the speed bump is tall enough and the bump stops get completely compressed you could bottom out the damper, which is not good for it.
Oh the irony!
In practice none of the suspension parts on any car are in any danger until you run out of up travel and determining where the deflection will happen becomes a competition between the air in your tire and the suspension components.
No automotive suspension is designed so that the damper bottoms out. You'll have an external bump stop somewhere, sometimes on the damper shaft, in any case the damper itself isn't bottoming out, you'd know, probably even hear it specifically if it did.
Regularly traveling rough roads, hitting rumble strips, comically out of round tires or anything else that creates oscillation is going to be way, way, way worse for component longevity (dampers, bushings, etc) than a hard bump from time to time.
Source: live it
Yeah 100% to all of this.
You're not going to hit your bump stops until you max out the travel, which a 4in speed bump is likely not doing unless you're in a fairly low car.
> The faster you go, the higher the forces.
The higher the forces into the dampers, yes, but the whole point is that if you're in the right section of the damping curve they spread it out and turn most of it into heat. With well tuned suspension that means lower peak force on the rest of the car, which means less rattling of every single part other than the unsprung bits.
> If the speed bump is tall enough
Those are a rare exception on pubic roads. All the points you make are about pushing your car beyond max travel, which obviously will start to break things. I'm talking only about bumps below your max travel, which I argue you can hit at significant speed with minimal wear to anything sprung.
> This is a case of knowing just enough about a topic to be dangerous.
I mean I do race off road competitively so I've had plenty of experience testing these assumptions and witnessing real-world wear on my components as a result. If you ride washerboards all day in high heat you'll see plenty of blown shock seals, but with well tuned suspension a single speed bump at 30mph wont harm a thing on the average car. It just makes a "thud" that sounds like damage to people, and I guess that's a good deterrent.
> The faster you go, the higher the forces.
The higher the forces into the dampers, yes, but the whole point is that if you're in the right section of the damping curve they spread it out and turn most of it into heat. With well tuned suspension that means lower peak force on the rest of the car, which means less rattling of every single part other than the unsprung bits.
> If the speed bump is tall enough
Those are a rare exception on pubic roads. All the points you make are about pushing your car beyond max travel, which obviously will start to break things. I'm talking only about bumps below your max travel, which I argue you can hit at significant speed with minimal wear to anything sprung.
> This is a case of knowing just enough about a topic to be dangerous.
I mean I do race off road competitively so I've had plenty of experience testing these assumptions and witnessing real-world wear on my components as a result. If you ride washerboards all day in high heat you'll see plenty of blown shock seals, but with well tuned suspension a single speed bump at 30mph wont harm a thing on the average car. It just makes a "thud" that sounds like damage to people, and I guess that's a good deterrent.
Properly built speed bumps are most comfortable to traverse at posted speed, but are very well felt when you're speeding. In my experience they build them well in Northern Europe, less so in Eastern.
Not in any parts of northern Europe where I drive. You are usually (exceptions exist) supposed to reduce speed very much below posted speed limit before passing the bump. For example, posted speed is 50kmh but speed bump is designed to be crossed at no more than 20kmh. If you drive a less comfort oriented car, make that 5kmh instead of 20kmh.
I drive mainly in Norway but hadn't noticed any difference in Sweden or Denmark. If you drive the posted speed here you can count that your wheels won't be knocked off. If you have to reduce speed (say around schools or near poor visibility crossing) then there is a sign for different speed, as simple as that.
You won't lose your wheels going at the posted limit, if it is a 30kmh road. For comfort you probably do want to reduce down to 15-20 in an average car.
If you encounter a warning sign for speedbumps on a 50kmh or 70kmh road you better start braking if you dont't fancy getting airborne.
There are some weird deadlocks in Swedish road regulations that make it unreasonable difficult to change the speed limit in some situations. They sometimes work around that by actively making it impossible to drive the posted limit.
If you encounter a warning sign for speedbumps on a 50kmh or 70kmh road you better start braking if you dont't fancy getting airborne.
There are some weird deadlocks in Swedish road regulations that make it unreasonable difficult to change the speed limit in some situations. They sometimes work around that by actively making it impossible to drive the posted limit.
OK, maybe that's a thing in Sweden after all, certainly not here. Just drove a whole bunch of speed bumps on the way to work today anywhere from 30km/h to 50. You'll never encounter a speed bump in a 70 km/h zone here.
>I've never understood speed bumps as a concept. Almost every car has at least 4in of travel, so you can hit them at significant speed and not damage anything.
They only work because the average consumer doesn't know this.
They only work because the average consumer doesn't know this.
Speed bumps are already almost meaningless with modern suspensions. Next time you have a rental car hit a few at speed and you might be surprised how well an average car handles it.
If it's the posted speed that's exactly how the bumps are designed. You aren't supposed to brake.
[deleted]
They’re already too small for the idiot monster trucks everybody drives nowadays. Not sure this will change that.
Speed bumps are much rougher in my idiot monster truck than they are on my Mercedes station wagon, idiot monster truck spring rates and damping are engineered to tow heavy loads/carry heavy payloads so especially when unloaded speed bumps are quite jarring compared to a passenger car.
Except for the fact that the in the average case the monster truck is probably being driven by someone who'll full send it (which minimizes the bump) and the Mercedes is being driven by someone who'll inevitably crawl over it at 2mph.
But yeah, swap the average drivers and the Mercedes is gonna do way better.
But yeah, swap the average drivers and the Mercedes is gonna do way better.
Just hit them significantly faster, it'll do the same thing as going slow with a heavy load. There's a reason the faster you ride motocross the harsher you tune your spring and damping rates.
My riding skill improved so much the day I fully grokked "lean back and twist the throttle" to handle obstacles (I did it by accident and thought I was going to die)
what's the reason? it surely isn't ride smoothness, it's control.
similar to a race car -- you don't compensate the speed with damping and spring rates in order to maximize a smooth ride , you do it to more quickly transfer the movement energy OUT of your car, into the ground and traction patch so that the car can remain dynamic for the next force.
this does not equate to ride quality, most race cars (and bikes) are bone-shakers.
similar to a race car -- you don't compensate the speed with damping and spring rates in order to maximize a smooth ride , you do it to more quickly transfer the movement energy OUT of your car, into the ground and traction patch so that the car can remain dynamic for the next force.
this does not equate to ride quality, most race cars (and bikes) are bone-shakers.
ride smoothness in the medium frequency range = control. if you're bouncing all over then you're weighting and de-weighting constantly, which is terrible for control.
high performance cars are mostly bone shakers at slow speeds when not in their ideal operating range. at high speeds they should level on top of it all, just watch a rally truck go over dunes or the video of an F1 wheel well stabilized to the frame of the car. sure you have low-frequency high-g-force weight transfer during acceleration/deceleration, and you have high frequency signal from the road texture, but medium frequency parking-lot-speedbump-style bouncing should not be happening at all or you're going to lose the race.
high performance cars are mostly bone shakers at slow speeds when not in their ideal operating range. at high speeds they should level on top of it all, just watch a rally truck go over dunes or the video of an F1 wheel well stabilized to the frame of the car. sure you have low-frequency high-g-force weight transfer during acceleration/deceleration, and you have high frequency signal from the road texture, but medium frequency parking-lot-speedbump-style bouncing should not be happening at all or you're going to lose the race.
See also: unladen vs laden commercial truck, same exact principals apply just at way different speeds and weights.
Off-road trucks have better bump handling ability as their suspensions aren't configured like load handling trucks.
My first thought. It's the ultimate American invention, something to let you fly straight over the speed bumps people have installed to keep their streets safe, neatly tying up the infatuation with car culture with a complete disdain for all life outside the car.
Very cool that these folks appear to be betting that L4 is going to be things we sleep in or something, at least that's the vision I'm getting from their prod page on this tech, also neat they seem to have reduced stopping distance by a considerable amount (although no speed listed). https://clearmotion.com/cm1
Makes sense. I like to feel the road when I'm driving, but if the car is driving, I'd prefer the ride to be as smooth as possible.
Perfect for the daily 7 hour commute once we’re reduced to a handful of global megacities with vehemently enforced RTO.
The Lexus LS400 was a great quality car. What's the closest equivalent these days? (A 10 year old Lexus?)
it was a great car. the 1UZ-FE was one of the few motors in a consumer-available car that had a flight-rated version AND a marine-rated version . It was one of the first 300+ WHP sedans. Bullet-proof. Great.
If you don't mind old cars you could explore the rest of the lineup that touched the 1UZ/2UZ motor/3UZ; they're all pretty good. SC430,GS430,GS400,LS430,LS400. [0]
As far as modern Toyota goes.. I couldn't make a recommendation. I like the newer Prius, but it's a different market and I wouldnt vouch for the reliability, although i've had good luck.
[0]: https://en.wikipedia.org/wiki/Toyota_UZ_engine
If you don't mind old cars you could explore the rest of the lineup that touched the 1UZ/2UZ motor/3UZ; they're all pretty good. SC430,GS430,GS400,LS430,LS400. [0]
As far as modern Toyota goes.. I couldn't make a recommendation. I like the newer Prius, but it's a different market and I wouldnt vouch for the reliability, although i've had good luck.
[0]: https://en.wikipedia.org/wiki/Toyota_UZ_engine
I’ve always dreamed of this technology applied to buses, especially trolley buses which have plenty of capacity to supply a power-hungry electromagnetic suspension. If this could convert a bouncy and squeaky bus into a smooth light rail equivalent, wowsers
More stuff to go wrong. Can someone please make an affordable simple car?
Slate’s plan looks promising:
https://news.ycombinator.com/item?id=43792849
https://news.ycombinator.com/item?id=43792849
Like the Honda Civic?
I'm thinking more like a 1980s Toyota Corolla. Or an original VW Beetle.
[deleted]
Hydractive 3+ is now 20 years old. Bose is late in the game and reinventing the wheel.
Citroen has been leading active suspension tech since 1954. Mercedes, BMW, others have adopted it later.
Citroen has been leading active suspension tech since 1954. Mercedes, BMW, others have adopted it later.
Dan Ackroyd is the spokesperson for the project too -- circa 1979.
https://vimeo.com/312218800
https://vimeo.com/312218800
sigh. Somewhat like the flying car, and the fusion..
Similar title, 7 years ago: https://news.ycombinator.com/item?id=17108828
Still keep fingers crossed it would make it.
btw, one possible side effect of mass-adoption of this will be that roads will be left to deteriorate and become worse - with much more potholes and what-not - as cars will not need it. Or such will be the excuse..
Similar title, 7 years ago: https://news.ycombinator.com/item?id=17108828
Still keep fingers crossed it would make it.
btw, one possible side effect of mass-adoption of this will be that roads will be left to deteriorate and become worse - with much more potholes and what-not - as cars will not need it. Or such will be the excuse..
Interesting, wonder how reliable it is and what its failure modes are like.
I indeed have zero faith in a video demo of a digital system with super evenly placed bumps placed in a linear fashion.
It would be so easy to just code up the perfect reaction in advance, & it not be representative at all of the conditions in the streets where the machine actually has to detect and respond dynamically to the conditions of the road
It would be so easy to just code up the perfect reaction in advance, & it not be representative at all of the conditions in the streets where the machine actually has to detect and respond dynamically to the conditions of the road
Normally, in semi active suspension, the failure mode is an overdamped vehicle, which is safer but also harsh and uncomfortable.
Reliable? What a quaint idea for a modern car. Mercedes and BMW in particular have been designing cars that fail just after the initial lease period (think plastic water pumps, timing chains at the back of the engine, wet rubber timing belts, CVT transmissions).
Some crazy, unfixable magnetic suspension that lasts 3 years and requires $5000 a corner shocks is par for the course these days.
Some crazy, unfixable magnetic suspension that lasts 3 years and requires $5000 a corner shocks is par for the course these days.
> CVT transmissions
Well, you can take money out of an ATM machine to pay for that. Just try to remember your PIN number.
Well, you can take money out of an ATM machine to pay for that. Just try to remember your PIN number.
timing chains at the back of the engine
Smallblock Chevys have a timing chain at the front but it's basically never a failure point. I agree with your other points, however; the trend is to optimise for short-term efficiency and cost, resulting in complex and relatively fragile designs.
Smallblock Chevys have a timing chain at the front but it's basically never a failure point. I agree with your other points, however; the trend is to optimise for short-term efficiency and cost, resulting in complex and relatively fragile designs.
The flip side: is it beneficial to anyone to have cars junked at 200k miles with water pumps that have another 500k miles on them? Overengineering has costs, in both price and weight.
Yeah, I'm adding Audi to the list. Car just totaled for a blown engine with no determining reason a few months out of warranty. Audi won't touch it. Not worth the engine replacement cost.
Not sure it would make sense to design cars to fail right when they get them back from the lessee?
So these systems depend, in part, on memorizing road data. I.e. another privacy issue in the making.
Do you want traffic circles? Because this is how you get traffic circles.
(I used to live in a neighborhood full of them and I liked them but very many people disagreed with me. If you make speed bumps not work then they will all be replaced with slaloms or circles.
(I used to live in a neighborhood full of them and I liked them but very many people disagreed with me. If you make speed bumps not work then they will all be replaced with slaloms or circles.
I had to look up what a traffic circle is, but apparently it just means roundabout. And yes, I do want roundabouts, who wouldn't?
Is there any serious argument against them? I've heard they aren't common in America.
Is there any serious argument against them? I've heard they aren't common in America.
The first few roundabouts I encountered were terrible. One was next to a school, yet it was too small to be navigated by the school bus. One had stop signs instead of yield at every entrance.
As a result, I hated them until years later, when I encountered one that was done correctly. After that, I completely flipped my opinion. Done right, they can completely beat a traffic light for wait time and throughput.
As a result, I hated them until years later, when I encountered one that was done correctly. After that, I completely flipped my opinion. Done right, they can completely beat a traffic light for wait time and throughput.
They are all over the Indianapolis burbs and cutting east/west across rush hour traffic is maddening because of the nonstop car trains running north/south through the roundabouts.
They take up a lot of space and they can be inconvenient and potentially unsafe to pedestrians. Unsafe for the same reason that right turns on red are unsafe: drivers are looking to their left for traffic and not to their right.
They were rare in the US before, I want to say, 15 or 20 years ago but I see them all the time now and new ones are always being installed. Good traffic devices, with the above tradeoffs in mind.
They were rare in the US before, I want to say, 15 or 20 years ago but I see them all the time now and new ones are always being installed. Good traffic devices, with the above tradeoffs in mind.
I think right turn on red is usually a reasonable trade off and designers can always put no right on red signs if they think warranted.
Where roundabouts get bad is when they’re multi-lane and can get a lot of traffic. There’s one I se fairly regularly and I’m surprised there aren’t more accidents.
Where roundabouts get bad is when they’re multi-lane and can get a lot of traffic. There’s one I se fairly regularly and I’m surprised there aren’t more accidents.
As a counterpoint, they're only slightly larger than a typical intersection and can have nice landscaping in the center. It makes for a much nicer urban environment.
Regarding pedestrian safety that seems like it should be easily solved by those flashing lights that they can trigger with a button. Or some other signal based solution.
Regarding pedestrian safety that seems like it should be easily solved by those flashing lights that they can trigger with a button. Or some other signal based solution.
A general reason: they take up a lot of space. Not a problem in most of America, but that'd be a deal killer in Japan. If you're not familiar with Japanese neighborhoods, I'd recommend spending some time on street view - it's actually kinda cool. Make note of the parabolic mirrors at the intersections.
For America specifically: they're not a great fit for places where everything is spread out and the road system is sensibly designed. I can drive from one side of Tulsa to the other (on streets, not freeways) in a fraction of the time I could drive across a similarly-sized European city. That's because the city itself is designed for cars. It has straight major streets with 40-45 mph speed limits that form a grid. Neighborhoods sit inside the grid and the streets in them curve with the landscape. In most of the city you have maybe 3-5 traffic lights per mile on the major streets, so unless it's rush hour you get minimal slowdowns. Sometimes I can drive several miles without hitting a red light.
The ideal situation is to have a straight road with no traffic directly between you and where you want to go. Obviously, that's not possible. So you have to compromise. Roundabouts suck, but they're better than almost any other option in places that have twisty narrow streets and lots of pedestrians. Many (most?) American cities aren't like that (at least to the extent European cities are), so roundabouts don't make as much sense here.
For America specifically: they're not a great fit for places where everything is spread out and the road system is sensibly designed. I can drive from one side of Tulsa to the other (on streets, not freeways) in a fraction of the time I could drive across a similarly-sized European city. That's because the city itself is designed for cars. It has straight major streets with 40-45 mph speed limits that form a grid. Neighborhoods sit inside the grid and the streets in them curve with the landscape. In most of the city you have maybe 3-5 traffic lights per mile on the major streets, so unless it's rush hour you get minimal slowdowns. Sometimes I can drive several miles without hitting a red light.
The ideal situation is to have a straight road with no traffic directly between you and where you want to go. Obviously, that's not possible. So you have to compromise. Roundabouts suck, but they're better than almost any other option in places that have twisty narrow streets and lots of pedestrians. Many (most?) American cities aren't like that (at least to the extent European cities are), so roundabouts don't make as much sense here.
Roundabouts can be implemented in small spaces, here in Vancouver there are some connecting single lanes.
> I've heard they aren't common in America.
They are in the Northeast. But they don't always keep bad drivers away.
They are in the Northeast. But they don't always keep bad drivers away.
> I've heard they aren't common in America
They're getting more popular in the Puget Sound area. We have been re-engineering streets to include roundabouts all over the place. I think they're a great thing, but too many people still stop at the wrong time.
They're getting more popular in the Puget Sound area. We have been re-engineering streets to include roundabouts all over the place. I think they're a great thing, but too many people still stop at the wrong time.
I live in the PNW. I like roundabouts where they fit, but near our house there's a super-busy one with multiple lanes that is just an accident magnet. People are constantly cutting across lanes while entering and exiting and sideswiping each other. It was originally a 4-way traffic light and it should have stayed that way. OTOH, we have a 4-way stop sign that is also an accident magnet during rush hour (when there's so much traffic that right-of-way is often unclear) and it should be a roundabout instead. Other than accidents from cutting across lanes during turns, the main failure mode I see in roundabouts is that they're subject to starvation while stop lights or stop signs aren't: if traffic coming one way never stops, then traffic to its right may never have a chance to go. I see this dealt with informally by folks voluntarily yielding but it's far from ideal (and unsafe because it's making an ad-hoc exception to a rule).
I'm confused, all of the traffic circles I drive through were just intersections before, no speed bumps. And all of the speed bumps I encounter are in parking lots, and can't be replaced by a traffic circle.
Are there traffic circles that are primarily about slowing traffic rather than managing intersections?
Are there traffic circles that are primarily about slowing traffic rather than managing intersections?
Yes, there are some cross intersections that are turned into very tight roundabouts as speed control. They essentially just plonk an island in the center, and maybe cut the corners a bit to sort of round it out. Most people slow down when crossing them.
Roundabouts are smaller than traffic circles and not designed the same.
Thanks. I suspect other commentators were similarly confused; I have indeed only experienced roundabouts. Traffic circles sound awful to me!
https://www.washingtoncountymn.gov/DocumentCenter/View/2296/...
https://www.washingtoncountymn.gov/DocumentCenter/View/2296/...
Most Americans don't know the difference either as they haven't experienced traffic circles/rotaries which are relatively rare and all remaining examples were implemented 100+ years ago.
I doubt most cars will be jacked up high off the ground like in the video, especially to fully handle speed bumps at higher speeds. There will be tradeoffs in such a thing.
IRL this is probably just handles small bumps and turns comfortably thing.
IRL this is probably just handles small bumps and turns comfortably thing.
Yes I dream of them. Just imagine cars at 4 way intersection all being able to move!
The ClearMotion1 system is a major leap above all tech currently on the market, with transmitted vibration reduced about 80% versus top market technologies. Here's a video comparing it on production NIO cars against luxury vehicles using semi-active (or slow active) systems others mentioned - sort of like comparing a microcontroller to a NVIDIA H100. http://bit.ly/44TDtgl
This matters especially for autonomous vehicles, where the whole point is to give people back time, and preventing motion sickness while working/reading is essential.
Our tech stack:
- Electro-hydraulic actuators that both push/pull actuate and dampen within a few milliseconds, using electric motors (not solenoid valves or special fluids). We use integrated hydraulics as a mechanical gain lever
- Predictive control software that anticipates vehicle, driver, and road dynamics
- "Infinite preview" control using crowdsourced road data with <3cm localization precision
- Software-enabled features including pre-crash posture mitigation and tire grip technology
The combination creates a "software-defined" chassis, similar to how electric power steering enabled today's driver assist features.
Our Bose acquisition was to acquire specific control software and engineering talent, but most of our IP and our production hardware/software was developed in house.
There were a few questions about durability— our system has passed 5 years of testing across millions of miles - a requirement from all of our customers like NIO and Porsche. It’s also a reason why it’s so difficult to succeed as a startup in automotive, but once you’re in, you’re locked in long-term.