Active Suspension systems
Discussion
I was happily browsing wiki randomly when i happened across Active suspension systems
http://en.wikipedia.org/wiki/Active_suspension
Anyhow,
having done a little googling, i have found that Bose are developing what looks to be a pretty impressive system.
http://www.bose.com/controller?url=/automotive/bos...
anyone know of any electronic active suspension systems that are actually available on the market to buy?
http://en.wikipedia.org/wiki/Active_suspension
Anyhow,
having done a little googling, i have found that Bose are developing what looks to be a pretty impressive system.
http://www.bose.com/controller?url=/automotive/bos...
anyone know of any electronic active suspension systems that are actually available on the market to buy?
SystemParanoia said:
The last 20 seconds of that are awesome! The rest is pretty impressive too. I wonder what happens when you go up a ramp, such as in a multistorey car park? At what point does the suspension stop trying to keep the car level and accept that it is going to go up a sharp incline? Looking at how the car reacts in that video, it would ground the nose out before actually adjusting to the gradient.
this one
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
or
http://www.pistonheads.co.uk/Gassing/topic.asp?h=0...
XM wasnt the full active but...
http://www.youtube.com/watch?v=2DN9Rbs8V88
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
or
http://www.pistonheads.co.uk/Gassing/topic.asp?h=0...
XM wasnt the full active but...
http://www.youtube.com/watch?v=2DN9Rbs8V88
I'm not aware of any aftermarket versions currently available. There have been one or two attempts to modify Citroen suspensions to suit, such as this Landrover with DS suspension.
The Kinetic hydraulic suspension as used in the MP4-12C, whilst it looks ideal for aftermarket use is only available to OEMs. The Kinetic systems H2, X, and RFS are fundamentally passive, using hydraulics to create a balanced suspension, but with additional electronic control over the hydraulics to provide varying levels of control depending on mood/use.
As I understand it, traditional spring/damper suspension has a fundamental problem when it comes to providing comfortable ride and good roll resistance, and the stiffer the chassis gets the worse it becomes. The only vehicles that really benefit from a stiff twist mode are racecars and shopping trolleys, yet modern passenger cars appear to be heading in that direction rather than away from it. I'm surprised that there's not been more research and use of this type of suspension by OEMs given how long ago hydragas was first used by BL and Citroen.
I'd love to be able to fit a balanced suspension based on the Kinetic systems to the XJS when I rebuild the front and rear subframes, but with a budget of not a lot and not enough knowledge of hydraulics, it looks as though I'll be sticking to traditional springs/dampers for now.
The Kinetic hydraulic suspension as used in the MP4-12C, whilst it looks ideal for aftermarket use is only available to OEMs. The Kinetic systems H2, X, and RFS are fundamentally passive, using hydraulics to create a balanced suspension, but with additional electronic control over the hydraulics to provide varying levels of control depending on mood/use.
As I understand it, traditional spring/damper suspension has a fundamental problem when it comes to providing comfortable ride and good roll resistance, and the stiffer the chassis gets the worse it becomes. The only vehicles that really benefit from a stiff twist mode are racecars and shopping trolleys, yet modern passenger cars appear to be heading in that direction rather than away from it. I'm surprised that there's not been more research and use of this type of suspension by OEMs given how long ago hydragas was first used by BL and Citroen.
I'd love to be able to fit a balanced suspension based on the Kinetic systems to the XJS when I rebuild the front and rear subframes, but with a budget of not a lot and not enough knowledge of hydraulics, it looks as though I'll be sticking to traditional springs/dampers for now.
Does anyone know why this, or more simply adaptive damping, is not more common in road cars? Not user switchable, but actual active suspension that responds in real time, like Williams F1 pioneered all those years ago. Even mega expensive supercars seem to avoid it, and in the case of the MP4-12C, which does use a system like this, they avoid using a true active system and use a sort of hydragas style system instead (which I heard described as 'Ron-gas' rather amusingly).
The active dampers found in the Ferrari et al are a poor relation to the active suspension in the soarer and xantia.
The Soarer and Xantia effectively add extra springing to bring the car level but leave the damping alone, the Ferrari et al stiffen up the suspension damping to reduce wallow but still allow it to roll (only prevented by the ARB and how much spring there is).
The full active systems are far more expensive and complicated plus AIUI drivers can't easily distinguish the limits when there is zero roll.
The Soarer and Xantia effectively add extra springing to bring the car level but leave the damping alone, the Ferrari et al stiffen up the suspension damping to reduce wallow but still allow it to roll (only prevented by the ARB and how much spring there is).
The full active systems are far more expensive and complicated plus AIUI drivers can't easily distinguish the limits when there is zero roll.
Fastdruid said:
The full active systems are far more expensive and complicated plus AIUI drivers can't easily distinguish the limits when there is zero roll.
There's a story of Mansell test driving the fully active Williams and coming into the pits after one lap complaining that the brakes weren't working. Apparently it was just the lack of dive in the car!I guess cost is the reason we don't see these systems on more cars then. Interesting that Citroen managed it on the Xantia and £50k saloons or £100k sports cars don't use it...
Fastdruid said:
The active dampers found in the Ferrari et al are a poor relation to the active suspension in the soarer and xantia.
The Soarer and Xantia effectively add extra springing to bring the car level but leave the damping alone, the Ferrari et al stiffen up the suspension damping to reduce wallow but still allow it to roll (only prevented by the ARB and how much spring there is).
The full active systems are far more expensive and complicated plus AIUI drivers can't easily distinguish the limits when there is zero roll.
Yes, well you answered the question. The cost and complexity of full active systems - plus the usual media back lash against using too much electronic aids in supercars can be seen as the reason why they are not used today.The Soarer and Xantia effectively add extra springing to bring the car level but leave the damping alone, the Ferrari et al stiffen up the suspension damping to reduce wallow but still allow it to roll (only prevented by the ARB and how much spring there is).
The full active systems are far more expensive and complicated plus AIUI drivers can't easily distinguish the limits when there is zero roll.
Going back to the dampers on the Ferrari, the damping is adjusted based on shaft speed, so maintaining high damping against body pitch and roll, and loosening it at higher shaft speeds when the wheels travel over undulations.
Lotus probably have some old kit knocking about somewhere :
http://www.youtube.com/watch?v=AxzrQCnCaNA
http://www.youtube.com/watch?v=AxzrQCnCaNA
Gassing Station | General Gassing | Top of Page | What's New | My Stuff