alt Hacker News> 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.
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I've had automatic inertial valve adjustment in my mountain bike for 10+ years as well.
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...
This looks similar to Porsche Active Ride Suspension discussed here https://news.ycombinator.com/item?id=39739404.
My 1991 Mitsubishi 3000gt VR4 had switched dampers stock! These were not reactive it was just high or low with a button and maybe some automatic logic. But even on stiff mode, aftermarket struts were stiffer so I replaced them.
> I've spent all morning doing a FEA analysis of their valve.
You did a finite element analysis analysis?
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.
Exactly what I came here to post. Mag fluid suspension has been mainstream for a while. Cadillacs aren't exotic.
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):
Or look the slalom at about one minute in the vid. That's not 3D.
> 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.