Automotive

Citroen prototype smooths out bumpy rides with hydraulic cushions

Citroen prototype smooths out ...
The Citroen Advanced Comfort Lab prototype vehicle is based on a C4 Cactus
The Citroen Advanced Comfort Lab prototype vehicle is based on a C4 Cactus
View 19 Images
The Citroen Advanced Comfort Lab prototype vehicle is based on a C4 Cactus
1/19
The Citroen Advanced Comfort Lab prototype vehicle is based on a C4 Cactus
The Cactus is already a smooth riding car, but Citroen has tried to make it smoother 
2/19
The Cactus is already a smooth riding car, but Citroen has tried to make it smoother 
Citroen has a history of smooth riding cars
3/19
Citroen has a history of smooth riding cars
Citroen says the system provides a smoother ride over all kinds of rough or poorly surfaced roads 
4/19
Citroen says the system provides a smoother ride over all kinds of rough or poorly surfaced roads 
The system does away with conventional bump stops
5/19
The system does away with conventional bump stops
The innards of Citroen's new hydraulic cushion suspension
6/19
The innards of Citroen's new hydraulic cushion suspension
A cutaway of Citroen's hydraulic cushion suspension, which deals with big hits in a less abrupt way than conventional bump stops
7/19
A cutaway of Citroen's hydraulic cushion suspension, which deals with big hits in a less abrupt way than conventional bump stops
Citroen has taken inspiration from the bedding industry with the seats in its latest concept
8/19
Citroen has taken inspiration from the bedding industry with the seats in its latest concept
The seats take the curve of your back into account for a better ride
9/19
The seats take the curve of your back into account for a better ride
The seats look vaguely like an expensive Patagonia puffer jacket
10/19
The seats look vaguely like an expensive Patagonia puffer jacket
The hydraulic cushion suspension doesn't crash into its bump stops, instead it can smoothly soak up big hits.
11/19
The hydraulic cushion suspension doesn't crash into its bump stops, instead it can smoothly soak up big hits.
Citroen says the technology is ready for production in cheap or expensive cars
12/19
Citroen says the technology is ready for production in cheap or expensive cars
The hydraulic cushion is designed to handle compression and rebound damping
13/19
The hydraulic cushion is designed to handle compression and rebound damping
A closer look at Citroen's hydraulic cushion suspension
14/19
A closer look at Citroen's hydraulic cushion suspension
Citroen says the system replicates its hydropneumatic suspension's ride quality at a fraction the cost 
15/19
Citroen says the system replicates its hydropneumatic suspension's ride quality at a fraction the cost 
The hydraulic cushion suspension in all its glory
16/19
The hydraulic cushion suspension in all its glory
Citroen has used a structural joining process that adds about 20 percent more rigidity to the car's body
17/19
Citroen has used a structural joining process that adds about 20 percent more rigidity to the car's body
The Cactus already has airbumps, now it's got a hydraulic suspension to absorb a different type of hit
18/19
The Cactus already has airbumps, now it's got a hydraulic suspension to absorb a different type of hit
Citroen's hydraulic cushion suspension
19/19
Citroen's hydraulic cushion suspension
View gallery - 19 images

Citroen is known for a few things, but the most prominent technological development in its history has to be the hydropneumatic suspension from the DS. It's credited with saving Charles de Gaulle's life, and makes for a magic carpet ride regardless of how rugged or rural the roads. In an attempt to inject some of this smooth-riding magic into its modern cars, the engineers at Citroen have developed a new hydraulic cushion suspension system.

Hydraulic cushions might sound like the sort of thing you'd buy on daytime television, but they're actually a clever way to stop vibrations and noise making their way into the cabin. Conventional suspension systems are generally made up of a shock absorber, a spring and mechanical bump stops. When a car reaches the end of its suspension travel and bottoms out these mechanical stops come into play abruptly, which can make for a jolting ride over big bumps and potholes.

Citroen has a history of smooth riding cars
Citroen has a history of smooth riding cars

Rather than using mechanical bump stops, Citroen's system uses a hydraulic cushion to regulate rebound and compression. When the suspension is getting close to the end of its travel, the hydraulic cushions gradually absorb the movement rather than abruptly stopping it, allowing for greater control all the way to the end of the suspension's travel.

According to the team behind it, this system helps to create a "flying carpet" effect, where the body stays isolated from any imperfections in the road surface because the suspension can be relaxed in the middle of its travel without making it loose and crashy over big imperfections.

Although this system should improve ride quality, there's more to Citroen's search for improved comfort than just clever bump stops, because the suspension doesn't work in total isolation. Instead, a car's body also plays a role in keeping you sheltered from unpleasant bumps and vibrations from the road below.

Thanks to a unique structural bonding process, Citroen engineers say they've managed to improve overall body stiffness by around 20 percent without adding any weight. This helps to isolate it from any vibrations, and in turn makes for a more refined driving experience in the cabin. Subaru has tried to do the same thing with its new platform, which is stiffer than before.

The seats take the curve of your back into account for a better ride
The seats take the curve of your back into account for a better ride

The final piece of this smooth-riding puzzle is the seats. Considering they're where you spend 100 percent of your time in the car, it seems like a good idea to dedicate some serious time to getting them right. For Citroen, that means looking to the world of bedding to create memory seats that use polyurethane, viscoelastic and textured foams for a better ride.

Although they don't go quite as far as the German Chiropractic Association approved seats in the Vauxhall Insignia, the seats in upcoming Citroens will also take into account the curve of your back for a better driving position.

All of these features show up its Advanced Comfort Lab prototype vehicle, but Citroen says they're cost effective enough to work in production models right now.

Source: Citroen

View gallery - 19 images
5 comments
yawood
Peugeot had seats that were tuned to the suspension back in the 504 from 1968 to 1983. It was exceptionally good too. French cars have always been great with ride quality.
Catweazle
Citroen have always been at the forefront of innovative suspension design, such as the very effective inertia dampers fitted to the ends of the suspension arms on early 2CVs, for example. I can vouch for their efficiency, and the reduction in suspension efficiency, especially in traction on indifferent surfaces, that ensued when they were discontinued.
sk8dad
"hydraulic cushions" is that any different from progressive damping other than spelling?
Magnetron
I've just driven around France, the home of Citroen, and didn't come across a single pothole. I'm guessing these cars are aimed at countries like England where the pot holes regularly injure people and wreck vehicles. I have lost three tyres to them this year, but most notably have had a sprained wrist due to the steering wheel 'bucking' my hands off whilst traversing a rather interesting one hidden by light surface water on a clear 60mph road with full visibility. I, like everyone else in England, have given up on personal bodily and auditory comfort when driving our medieval roads, but if Citroen were to design a system to prevent terrain-feedback injuries on light vehicles, I would surely buy one.
IvanWashington
I've always liked what they put out. too bad they show no signs of importing them here ever again.