4 ms·

For comparison the McLaren MP4-12C [1] has probably the most trick setup you'd see this side of a early 90s Williams F1 car [2][3]. Notice on the 12C how the re

by dmmalam 13y ago

For comparison the McLaren MP4-12C [1] has probably the most trick setup you'd see this side of a early 90s Williams F1 car [2][3]. Notice on the 12C how the rebound/compression dampers from each corner are cross connected instead of a roll bar, and the z spring at the back to resist high downforce. Considering the Williams F1 active system was developed for the 1992 season, I'm kinda disappointed that no fully active system has ever hit a production car. The best we've seen is active damping on several cars. Bose had a pretty cool prototype [4], but never hit prod. The neat thing about electromagnetic damper/springs is that they can regen for a EV. If your unfamiliar with car mechanics, then this is a good serious of short video tutorials [5]. [1] http://www.edmunds.com/car-reviews/track-tests/2012-mclaren-mp4-12c-suspension-walkaround.html http://www.edmunds.com/car-reviews/track-tests/2012-mclaren-... [2] http://vimeo.com/22195303 http://vimeo.com/22195303 [3] http://scarbsf1.com/williams_active/WilliamsF1_ACTIVE_SUSPENSION_SYSTEMS.htm http://scarbsf1.com/williams_active/WilliamsF1_ACTIVE_SUSPEN... [4] http://www.bose.com/controller?url=/automotive/bose_suspension/index.jsp http://www.bose.com/controller?url=/automotive/bose_suspensi... [5] http://www.youtube.com/playlist?list=PLE067A7397E1AF108 http://www.youtube.com/playlist?list=PLE067A7397E1AF108

incision 13y ago
Also, for an overview of all sorts of automotive engineering for the curious, I highly recommend the Bosch Automotive Handbook [1]. 1: http://www.amazon.com/Bosch-Automotive-Handbook-Robert-GmbH/dp/0837616867 http://www.amazon.com/Bosch-Automotive-Handbook-Robert-GmbH/...
ricardobeat 13y ago
Ah, I remember seeing the Bose videos and wondering when it would hit the market. I'm also waiting for those airless spoked tires! Mercedes and BMW have their own active suspension systems that are standard in the high-end models, not sure if they look as magic as Bose's.
- dmmalam 13y ago
  Pretty much all systems marketed as 'active' aren't really 'fully active'. Remember from mechanics/Differential Eqns, a suspension system is basically a damped harmonic oscillator. The two main constants are the springing and damping. The majority of cars just have electronically variable dampers. ie the same oem parts from bilstein/dephi/bosch with some silly marketing acronym on like Porsche PASM, MagneRide etc. Some have variable strength roll bars, but roll bars are really just a 'hack' anyway. Very few have used a variable springing system (Merc ABC). An air suspension can change springing and ride height, but's it's slow. In addition to low latency damping/springing adjustments/ride height, a fully active system in able to apply force into the suspension so the attitude of each corner is under complete software control, milli by milli. You can have a perfectly smooth ride, but no roll. All current non-active designs are a compromise between sporty and confort (high vs low springing/damping constants, and movements in attitude due to accelerating/braking/downforce/cornering/road surface. The main problem with fully active is that it uses quite a bit of power and is very complex. Here's some more info http://www.autozine.org/technical_school/suspension/tech_suspension3.htm http://www.autozine.org/technical_school/suspension/tech_sus...
- stplsd 13y ago
  Citroen DS had semi-active hydropneumatic suspension since 1955
deleted 13y ago
[deleted]
altcognito 13y ago
I'm confused. My understanding is there are lots of fully active suspensions out there: http://www.edmunds.com/car-technology/suspension-iii-active-suspension-systems.html?articleid=43853 http://www.edmunds.com/car-technology/suspension-iii-active-...
- dmmalam 13y ago
  that article is wrong, most of the cars listed there have semi-active systems with just the damping being electronically adjustable (see my below comment). That's pretty sloppy work by edmunds, considering all car press releases describe in detail(in marketing speak ofcourse) exactly what systems they have and how they roughly work

by dmmalam 13y ago

incision 13y ago

Also, for an overview of all sorts of automotive engineering for the curious, I highly recommend the Bosch Automotive Handbook [1]. 1: http://www.amazon.com/Bosch-Automotive-Handbook-Robert-GmbH/dp/0837616867 http://www.amazon.com/Bosch-Automotive-Handbook-Robert-GmbH/...

ricardobeat 13y ago

Ah, I remember seeing the Bose videos and wondering when it would hit the market. I'm also waiting for those airless spoked tires! Mercedes and BMW have their own active suspension systems that are standard in the high-end models, not sure if they look as magic as Bose's.

dmmalam 13y ago
Pretty much all systems marketed as 'active' aren't really 'fully active'. Remember from mechanics/Differential Eqns, a suspension system is basically a damped harmonic oscillator. The two main constants are the springing and damping. The majority of cars just have electronically variable dampers. ie the same oem parts from bilstein/dephi/bosch with some silly marketing acronym on like Porsche PASM, MagneRide etc. Some have variable strength roll bars, but roll bars are really just a 'hack' anyway. Very few have used a variable springing system (Merc ABC). An air suspension can change springing and ride height, but's it's slow. In addition to low latency damping/springing adjustments/ride height, a fully active system in able to apply force into the suspension so the attitude of each corner is under complete software control, milli by milli. You can have a perfectly smooth ride, but no roll. All current non-active designs are a compromise between sporty and confort (high vs low springing/damping constants, and movements in attitude due to accelerating/braking/downforce/cornering/road surface. The main problem with fully active is that it uses quite a bit of power and is very complex. Here's some more info http://www.autozine.org/technical_school/suspension/tech_suspension3.htm http://www.autozine.org/technical_school/suspension/tech_sus...
stplsd 13y ago
Citroen DS had semi-active hydropneumatic suspension since 1955

deleted 13y ago

[deleted]

altcognito 13y ago

I'm confused. My understanding is there are lots of fully active suspensions out there: http://www.edmunds.com/car-technology/suspension-iii-active-suspension-systems.html?articleid=43853 http://www.edmunds.com/car-technology/suspension-iii-active-...

dmmalam 13y ago
that article is wrong, most of the cars listed there have semi-active systems with just the damping being electronically adjustable (see my below comment). That's pretty sloppy work by edmunds, considering all car press releases describe in detail(in marketing speak ofcourse) exactly what systems they have and how they roughly work