ClearMotion founder here! Wanted to share some insights that might answer questions from other commenters and clarify what we've developed.
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.
> 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.
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.
"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]"
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
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.
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.
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.
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.
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.
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.
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.
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.
> 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 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.
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.
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.
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.
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
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.
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.
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.
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).
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.
> 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.
Even though they're the cream of the crop of a country of over a billion people, those silly engineers at BYD don't know what they're doing. We'd all be better off if they took tips about this problem they've spent years developing from random guy on the internet.
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.
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)
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.
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.
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.
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.
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.
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.
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.
Allow me to cordially invite you to test out a speed bump set up at exactly 51.201580°N, 16.972742°E. It's not visible in Street View yet, which adds to the surprise.
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.
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.
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.
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.
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.
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
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..
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
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.
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.
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.
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
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.
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.
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.
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.
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.
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.
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.
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'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?
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.
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.
ClearMotion founder here! Wanted to share some insights that might answer questions from other commenters and clarify what we've developed.
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.
Impressive, but is it as stylish and smooth as the 1978 Royal Deluxe II?
https://www.youtube.com/watch?v=vnOwHu_wchg
> 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.
> 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.
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.
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]"
They should have just lobbied the government instead.
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
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.
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.
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...
I've had automatic inertial valve adjustment in my mountain bike for 10+ years as well.
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.
> I've spent all morning doing a FEA analysis of their valve.
You did a finite element analysis analysis?
I knew someone was going to be pedantic when I wrote that.
I don't know if it's pedantic, I also have no clue what it stands for
RAS syndrome is not actually a problem, it's never actually misunderstood, in fact it usually adds clarity as redundancy in language usually does.
This looks similar to Porsche Active Ride Suspension discussed here https://news.ycombinator.com/item?id=39739404.
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.
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.
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.
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.
> 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 :)
> 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.
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.
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.
Precision, repeatability, responsiveness.
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.
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.
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
> 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...
> 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 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.
nit: 20 years ago is ~2000s now, not 80s
that was the joke
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
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
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.
> 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.
Even though they're the cream of the crop of a country of over a billion people, those silly engineers at BYD don't know what they're doing. We'd all be better off if they took tips about this problem they've spent years developing from random guy on the internet.
Actually
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.
> 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.
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)
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.
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.
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
I have a "road" (just concrete slabs which never graduated into a proper road) where I would love to test that.
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.
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.
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.
They just tried something like this in some city in Minnesota (I think) and had to revert after a month from the public outcry.
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.
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.
Allow me to cordially invite you to test out a speed bump set up at exactly 51.201580°N, 16.972742°E. It's not visible in Street View yet, which adds to the surprise.
Thanks mate, I tested plenty in Belarus :)
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.
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.
Off-road trucks have better bump handling ability as their suspensions aren't configured like load handling trucks.
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.
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.
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.
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.
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..
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
Dan Ackroyd is the spokesperson for the project too -- circa 1979.
https://vimeo.com/312218800
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
So these systems depend, in part, on memorizing road data. I.e. another privacy issue in the making.
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
Like the Honda Civic?
Interesting, wonder how reliable it is and what its failure modes are like.
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.
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.
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.
> CVT transmissions
Well, you can take money out of an ATM machine to pay for that. Just try to remember your PIN number.
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?
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
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 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.
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.
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.
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.
Roundabouts can be implemented in small spaces, here in Vancouver there are some connecting single lanes.
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.
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.
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.
> 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.
> I've heard they aren't common in America.
They are in the Northeast. But they don't always keep bad drivers away.
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?
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.
Yes I dream of them. Just imagine cars at 4 way intersection all being able to move!
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.