Electromagnetic Automobile Suspension Demonstrated

cylonlover writes "Last December at the Future of Electric Vehicles conference in San Jose, a representative from The Netherlands' Eindhoven University of Technology presented research that his institution had been doing into a novel type of electromagnetic vehicle suspension. Now that a test car equipped with the suspension is about to appear at the AutoRAI exhibition in Amsterdam, the university has released some more details about the technology. For starters, it is not only electromagnetic but also active, meaning that it doesn't just mechanically respond to bumps in the road, but is controlled by an onboard computer. It is claimed to improve the overall ride quality of cars by 60 percent." That seems an awfully exact figure — I'm not sure any two people would ever agree even about the exact same car's "overall ride quality."

Bose

[lcampagn]

I'm pretty sure Bose did this at least 4 years ago: http://www.bose.com/controller?url=/automotive/bose_suspension/index.jsp [bose.com]

Re:Bose

[lcampagn]

...and here's a patent filed in 1988: http://ip.com/patent/US4892328 [ip.com]

Re:Supercars

[Tx]

Even cars such as my VW Scirocco GT have similar systems (VW calls it Adaptive Chassis Control [volkswagen.co.uk]), it's not the preserve of supercars anymore. However according to the article, existing systems use hydraulic actuators, this system is apparently electromagnetic only, reacts faster and uses less power. Yes, I know, it's almost cheating to RTFA.

Re:Fine for gas or diesel,

[pthisis]

but if I had a hybrid/electric car I'm pretty sure I would rather that electricity go to turning the wheels, not keeping my chassis away from them.

According to TFA, the system actually draws less power than hydraulic shock systems:
With a peak consumption of 500 watts, the suspension uses about a quarter of the power of hydraulic systems. It also stretches its battery life by using road vibrations to generate electricity. The designers believe that with refinements, the suspension's energy-efficiency could be improved even further.

Re:Supercars

[subreality]

Negative. This is not that system. There are a number of cars that let you adjust the shock absorbers on the fly: at the entry level, this involves servos adjusting the shock valving; at the high end (such as the F599) they use electromagnets to adjust the viscosity of the fluid in the shocks, which can be done much faster.

This system is altogether different: there is no shock absorber. They have a linear motor in its place. This gives advanced capabilities that adjustable shocks cannot.

For instance, say you turn hard left. The car wants to lean right. Soft springs are good for comfort, but allow the car to tilt more. This system lets you use soft springs, and then actively counter the body roll by pushing on one side and pulling on the other. The net result is you have the best of both worlds: the smooth ride of a luxury car's soft springs combined with the fast response and stiff anti-roll characteristics of a sports car.

You need a very strong linear actuator to make a meaningful improvement, but those are expensive and require a hefty electrical system to power them, further increasing the price. Bose did some fantastic demos of these some years back, but I don't think they managed to get any manufacturers interested, probably due to cost. Hopefully these guys have improved in that regard.

Re:Err : "improve the overall RIDE QUALITY by 60%

[williegeorgie]

Actually us pavement engineer types do this all the time. Basically the input to the function is the profile of the pavement measured by a pavement profilometer which essentially captures pavement elevation about every 6 in or so. (http://www.dynatest.com/functional-rsp.php) Then this profile is fed through an algorithm that models the response of a hypothetical "quarter car" (basically a spring above a tire to simulate the amount of movement experienced by something on the axle). This measurement is called the International Roughness Index and it has been correlated to "Ride Quality" perceived by highway users. It is not a perfect measurement but it is used quite frequently to help decide pavement projects. if you are more interested.... http://en.wikipedia.org/wiki/International_Roughness_Index [wikipedia.org] http://www.umtri.umich.edu/content/LittleBook98R.pdf [umich.edu] So for this thing they would need some other model to calculate the "movement" induced by road profile on the vehicle much like IRI. Once you have that you could correlate it to Ride Quality, have they done that? That is the question...