6 ms·

> 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 bu

by genter 1y ago

> 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.

Fade_Dance 1y ago
Exactly what I came here to post. Mag fluid suspension has been mainstream for a while. Cadillacs aren't exotic.
- neom 1y ago
  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.
  - serf 1y ago
    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.
    - neom 1y ago
      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 https://mf-topper.jp/articles/10003931
  - dahauns 1y ago
    So...more like Mercedes' system?
- brookst 1y ago
  Adjusting damping rates is very different from proactively lifting a wheel just as it reaches a bump.
nolist_policy 1y ago
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.
- deleted 1y ago
  [deleted]
- thrill 1y ago
  Precision, repeatability, responsiveness.
- yesco 1y ago
  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.
ChrisMarshallNY 1y ago
> 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.
- cgio 1y ago
  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.
- Svip 1y ago
  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.
  - branko_d 1y ago
    https://en.wikipedia.org/wiki/Moose_test 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]"
TacticalCoder 1y ago
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 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 https://www.youtube.com/watch?v=ELmY_HLtxTo
nick3443 1y ago
I've had automatic inertial valve adjustment in my mountain bike for 10+ years as well.
mikeha 1y ago
This looks similar to Porsche Active Ride Suspension discussed here https://news.ycombinator.com/item?id=39739404 https://news.ycombinator.com/item?id=39739404.
SequoiaHope 1y ago
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.
motorest 1y ago
> I've spent all morning doing a FEA analysis of their valve. You did a finite element analysis analysis?
- genter 1y ago
  I knew someone was going to be pedantic when I wrote that.
  - andrepd 1y ago
    I don't know if it's pedantic, I also have no clue what it stands for
- rcxdude 1y ago
  RAS syndrome is not actually a problem, it's never actually misunderstood, in fact it usually adds clarity as redundancy in language usually does.
- potato3732842 1y ago
  >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.
PeterStuer 1y ago
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-suspension-explained-49954.html https://www.autoevolution.com/news/citroen-hydropneumatic-su...
robocat 1y ago
> 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".

by genter 1y ago

Fade_Dance 1y ago

Exactly what I came here to post. Mag fluid suspension has been mainstream for a while. Cadillacs aren't exotic.

neom 1y ago
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.
- serf 1y ago
  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.
  - neom 1y ago
    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 https://mf-topper.jp/articles/10003931
- dahauns 1y ago
  So...more like Mercedes' system?
brookst 1y ago
Adjusting damping rates is very different from proactively lifting a wheel just as it reaches a bump.

nolist_policy 1y ago

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.

deleted 1y ago
[deleted]
thrill 1y ago
Precision, repeatability, responsiveness.
yesco 1y ago
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.

ChrisMarshallNY 1y ago

> 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.

cgio 1y ago
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.
Svip 1y ago
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.
- branko_d 1y ago
  https://en.wikipedia.org/wiki/Moose_test 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]"

TacticalCoder 1y ago

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 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 https://www.youtube.com/watch?v=ELmY_HLtxTo

nick3443 1y ago

I've had automatic inertial valve adjustment in my mountain bike for 10+ years as well.

mikeha 1y ago

This looks similar to Porsche Active Ride Suspension discussed here https://news.ycombinator.com/item?id=39739404 https://news.ycombinator.com/item?id=39739404.

SequoiaHope 1y ago

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.

motorest 1y ago

> I've spent all morning doing a FEA analysis of their valve. You did a finite element analysis analysis?

genter 1y ago
I knew someone was going to be pedantic when I wrote that.
- andrepd 1y ago
  I don't know if it's pedantic, I also have no clue what it stands for
rcxdude 1y ago
RAS syndrome is not actually a problem, it's never actually misunderstood, in fact it usually adds clarity as redundancy in language usually does.
potato3732842 1y ago
>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.

PeterStuer 1y ago

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-suspension-explained-49954.html https://www.autoevolution.com/news/citroen-hydropneumatic-su...

robocat 1y ago

> 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".