US-based start-up Clearmotion has developed a fully active suspension system that could be fitted to almost any car – and it is set to appear in future Porsches.
Fully active suspension – where the car can control both the extension and compression strokes using an actuator or motor – has been the stuff of dreams for chassis engineers for a long time.
Whereas passive or semi-active suspension (adaptive dampers and/or air suspension) can only ever react to inputs from the road, an active system can effectively pull the wheel up for a bump and push it back down when the road dips, as well as compensate for body pitch and roll in order to keep the car’s body perfectly level. In this way, it can theoretically isolate occupants from what is going on underneath. It can also control the load on the four contact patches individually to improve roadholding without compromising the ride.
In a lineage that includes Citroën’s hydropneumatic suspension, Mercedes’ Active Body Control and the Ferrari Purosangue’s Multimatic set-up, active systems have always had compromises, such as cost, reliability, functionality or all of the above.
Porsche’s Active Ride is arguably the best seriesproduction system so far, but it is very expensive and power-hungry, which means it can only be fitted to cars with a high-voltage electrical system (plug-in hybrids and EVs).
Clearmotion’s solution, as demonstrated on Chinese EV maker Nio’s ET9 flagship, looks remarkably similar to a normal combination of a spring (either air or coil, depending on the application) with a remote-reservoir damper. This compactness and relative simplicity allows it to be installed in many existing cars with minimal modification. It runs on 48V, but a converter allows 12V cars to use it too.
Clearmotion technical fellow Marco Giovanardi said: “We are a different kind of supplier from the ZFs of this world. We didn’t already have a mature product, so we couldn’t wait for someone to design a vehicle for us.”
Key to the system is a rotary electric motor with its own control unit, which powers a hydraulic pump that forces fluid in or out of the damper. There’s one for each corner of the car, rather than a central one, thus eliminating metres of pipework.
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I used to go over speed bumps - without slowing down - in a 2cv, and you couldn't feel them. Modifying one of those using parts from a Xantia Activa, I'd wager you could come up with something that'll match what they're doing. Describing how good it is that they've removed so much pipe work, and hoping you've forgotten the 4 electric motors, while talkign about reliability.
Headline: "UK firm reveals..."
First sentence: "US-based start-up....."
C'mon guys, this is a bit ridiculous. The only UK connection I can see from the article is that they have a tech centre in the UK. Misleading headline.
Illya - don't forget the Jaguar I Pace with air suspension and 'adaptive dynamics' (= adaptive dampers) for comparison. From as long ago as 2018! I Pace forums on Facebook and Pistonheads speak very favourably of the I Pace so equipped.
I agree comment about big wheels/small sidewalls as way of worsening the ride of almost any vehicle. Many reviews say the bigger wheels of the more expensive models in a range are actually a negative.