Bose suspension system

[STUNO]

I had never heard of this, but it looks to be remarkable. According to my few minutes research on google it was not a commercial success, but the system is now used in truck seats.

 

https://www.youtube.com/watch?v=z3gX2HwFf5I

 

 

[They_all_do_that_sir]

So what happened to it?

[Dave_Q]

I did an assignment on active suspension systems last year.

 

The Bose system was only a prototype I believe, there was a Toyota fully active system which made it into production on the early 90s Celica and Soarer.

 

A fully active system is one where the spring and damper are replaced with a hydraulic ram or similar and inputs to the suspension are counteracted by the ram for level cornering, breaking etc.

 

Ultimately a fully active system is still too expensive for production today. The top end stuff like Mercedes ABC is a series active system where there is still a spring that controls high frequency movements like potholes, cobbles etc and the actuator works for lower frequency inputs like body roll.

[forddeliveryboy]

But the clever bit in the MB system is the magic eye which reads the road ahead and adjust things accordingly, up to about 80mph. Fully active suspension is relatively useless without the ability to see and read what's ahead - so how good is it on an autobahn? Having said that, I've ridden in an S-class with this top system and it was superb even above 80mph, if no more comfortable than a CX or DS - it just heeled noticeably less through slower corners. 

 

Problem is with all active suspension is not only the complexity but longevity and mass. I'd say the way ahead is the Kinetic system developed in Australia and bought out by the Americans (supposedly for national security reasons, among others).

 

 

 

It's beautifully simple, uses few extra moving parts, works much better than other systems and is powered by the motion of the suspension itself.

[Noel Tidybeard]

the defender was quite impressive

[RoadworkUK]

The MB system is uncanny, unless it's raining, or foggy, or dark, or you have a dirty windscreen and the camera can't see the road. But it's Version 1.0 at the moment, no doubt it'll use laser scanning or something eventually.

[Mad Cyril]

Did somebody mention active suspension? No body roll?

https://www.youtube.com/watch?v=09-C33SrJi8

[cort16]

That Bose stuff is impressive especially the bunny hop bit.

My cl500 had abc and while I wouldn't say it stopped body roll it was mega impressive

[forddeliveryboy]

So what happened to it?

 

Nobody would buy it - too bulky, too expensive, complex and not sufficiently well developed to take it to mass production without spending billions. Mercedes's own system is in the German tradition a real lash-up, but beautifully executed and refined - in the German tradition. It has a world's first with its road-scanning ability, that's the clever bit which no doubt others are struggling with. I'd love to try it out on the roads round here, though. I'm sure I could trip it up in some way or other!

 

 

 

the defender was quite impressive

 

The Kinetic set-up it had been fitted with was - a shame JLR don't use it today, perhaps they didn't want to share a system with Toyota and Lexus. Its simplicity is amazing and can very easily be made 'active' by varying the pressure in the accumulator sphere to suit the road and driving. This is what McLaren do on their road cars.

 

How does it work? Connect both sides of the reservoir in a shock absorber/damper to pipes, link the upper chambers on one side of the vehicle to the lower ones on the other, with an accumulator sphere acting as the antiroll bar spring, pressurising the circuit for the desired amount of anti-roll. 

 

It's neat on so many levels - fundamental simplicity and self-powered, no need for ECUs and sensors unless you wish to actively control roll springing rates. Throwing away the steel antiroll bar means you separate the bump and roll modes, so stiff cornering but freely articulating suspension on the straight. WRC banned it, once they found out Citroen had been using it to rack up all those Loeb wins in the 90s.

 

 

Toyota use a variation of it which progressively uncouples conventional steel arbs when pressure differences suggest this is needed - I think this allows the extremes of articulation which 4x4s need off road.