Splan8

I'm sure this won't be available for a while, but an interesting application of electromagnetism.

http://www.bose.com/controller;jsessionid=BvorzMXNunDZeMJ1liBSvrghYhhF Vbl1wg9en3fedppHJG2mRLs6!1879924776!-373760557?event=VIEW_STATIC_PAGE_EVENT&url=/learning/project_sound/suspension_challenge.jsp&pageName=/learning/project_sound/suspension_results.jsp

shelleys_man_06

Um, you're linky is messed up.

Splan8

I can't get the link to the BOSE site to work here, so...

How about this one...

http://www.pcmag.com/article2/0,1759,1640050,00.asp

or this one

http://www.bose.com/pdf/technologies...ion_system.pdf

shelleys_man_06

Bose Technology Re-imagines Auto Suspension
By Bill Howard
August 26, 2004

Maybe your dream car has an 11-speaker Bose entertainment system in the cabin. Well, the next performance car of your dreams could have a Bose suspension system under the sheet metal. Seriously. The Framingham, Massachusetts, company best known for audio systems and speakers, has developed a revolutionary computer-controlled suspension system that replaces the traditional shocks and springs with electronic actuators. The result is a ride that's absolutely flat over the bumpiest of roads and around sharp corners. In theory, a car could even bank into turns, as do planes and high-speed trains.

"This is the first time a suspension system is the same for a sports car and for a luxury car," says company founder, Amar Bose, whose interest in better car suspensions dates to a 1957 Pontiac with a primitive air suspension and a 1967 Citroen with a constantly leaky hydraulic suspension. In 1980, Bose embarked on a five-year study of alternatives and decided electromagnetic suspensions would be markedly superior once technology could catch up with his mathematical model that called for better linear electromagnetic motors, power amplifiers, control algorithms, and processor power. He set a small team of engineers to work on improving the first three in the mid-1980s and waited for Moore's Law to help on the fourth. Bose jokes that the effort was code-named Project Sound because even at a privately held company bearing his name, a 24-year investment made the accountants nervous.

The Car that CouldThe suspension module is an oval tube slightly thicker than the spring that coils around a shock absorber in current systems, which it replaces. Processing power is supplied by a 750-MHz Intel Pentium III running at a quarter of its capability in the test vehicle, a 1994 Lexus LS400. When the car senses a bump, the linear motor actuator retracts or extends the wheel and tire almost instantly—many times faster than a standard suspension. The action is so quick that occupants sense no motion at all if the bump is less than the actuator's travel of up to 20 cm (about 8 inches).

The system can reduce body roll in a turn or even allow a car to bank into a turn, but research showed that passengers find the result discomforting because they expect some roll. (Studies done outside Bose found that banking makes drivers try to defy the laws of physics when turning, producing dangerous results.) While the unit draws a good deal of power—one-third as much as a car air conditioner, which is not minor—it has the ability to regenerate and store energy created when a bump drives the wheel up. That energy is wasted in conventional shock absorbers. Bose says there's a limp-home mode in case of electrical failure, and the car responds like a softly damped luxury car.

Bose expects his company to choose one automaker, "a car company who has an absolute dedication to performance," within a year. Typical lead times for automakers would result in the Bose Suspension System, as it's called, being available late in the decade. Likely suspects are the luxury/sports makers that have reasonable market share and cars that can stand the weight—Acura, Audi, BMW, Cadillac, Infiniti, Lexus, and Mercedes. Customers could order the cars with standard or electromagnet suspensions. Vehicles without the Bose Suspension System would be the same, otherwise.

The company refused to project the cost, but cars with current computer-aided hydraulic or mechanical body roll control include a $2,000 upcharge, which would be incorporated by the Bose system. Bose says it believes its system would add 200 pounds, or about 5 percent, to the weight of a luxury/sports sedan.

My Thoughts

It's a nice to see Bose stretching its arms in suspension technology. The Corvette has employed magnetic ride selection in recent years. Magnetic suspensions today will never outrun hydraulics. Give developers time, and hydraulics will be phased out. Electromagnetism is much stronger than hydraulics, any time, any day.

MrWigggles

My next car WILL have some sort of electronic suspension.

I think the limitations in the past have been more mechnical. The problem with accuators has been size and ability. It looks like Bose might have fixed that.

On a test track everything should work great. Real life is a different story. We have more irregular bumps than simple speed bumps.

The system is also going to need some sophisticated sensors to tell the car when a bump should be absorbed and when it should not be.

For instance if you are about to hit a 4 inch bump the system pick the wheels up and absorb it 100%. If you are going to hit a high curb during some sort emergency, the system needs to not absorb everything, the car needs to go upwards somewhat to get over the curb.

Another example is the difference between a speed bump and a road hump. If the car treats a road hump as bump, the suspension could be doing some funny things.

Anyway, I wish Bose the best, but I have to warn that Mercedes is also currently working on this and Infiniti as well as Toyota had systems like this a while back. The patent issues could be extensive.

Well, you know what they say. "No highs, no lows, must be Bose." now has a positive conotation.

-Mr. Wigggles

globi

I believe the Corvettes C6 electronic suspension system just adapts the resistance of the dampers. It doesn't actually use linear actuators as Bose does. (By the way the Mazda 929 built in the 80's had an auto adaptable suspension as well. Who knows why the stopped selling that system?)

The only advantage of the Bose system is that it can reuse part of the energy. It probably can't compete against an hydraulic active suspension regarding speed and weight and therefore wouldn't be useful in race or even sports car applications. But maybe useful on luxury vehicles. (Since the power to operate the system is generated remotely, the hydraulic actuators in comparison to linear electric actuators can be kept light and small - less unsprung weight). Besides a hydraulic active suspension doesn't need any extra shockabsorbers since the actuator is extremely fast. I don't really understand why the Bose system still requires shockabsorbers, since that's partly what you're trying to substitute. (Well maybe it's just a back up thing?)
Let's face it: Bose is developing an 'electric/electronic suspension' because they know about electric actuators not because its superior to hydraulic, hydro pneumatic or pneumatic suspension.

Citroën's hydro pneumatic suspension doesn't require shock absorbers as well. Heck, it doesn't even require coil springs!
http://www.citroen.mb.ca/citroenet/html/h/hydro.html

Lotus developed a very sophisticated hydraulic active suspension in the 80's. And Lotus belongs to GM. I wonder why they've never offered it on a Corvette? (Oh well, probably because customers only ask for HP and don't really care about suspension. At least wouldn't be willing to pay an extra few grand on such an option.)

Liquid Rhino

Fresh! Tekmology Rules!... and all this time i've been lining my tires with cotton... who woulda thought?

Gord96BRG

Yes, GM's system (used by Cadillac as well as Corvette) uses a shock absorber fluid that changes it's viscosity based on a current being passed through it. No current, and the fluid is thin and flows easily, so the shocks are soft. Full current, and the fluid is thick as molasses and the shocks are very firm. A great system, as you point out it doesn't require any mechanical actuators or valving.

Mazda's system (also available on the 80s 626) used a few different hole sizes in the shock shaft and piston, with actuators to adjust between them. It was very expensive to replace when the shocks were worn, and that's likely the reason Mazda dropped it.

GM bought Lotus in 1986, but the only model to come out during their ownership was the M100 Elan (front wheel drive). It was originally intended to be Toyota powered, but after GM took control the engine was changed to an Isuzu unit! GM sold Lotus entirely in 1993 to Bugatti Industries, owned by Romano Artioli. He funded the development of the Elise (named after his daughter), but sold Lotus to the Malaysian auto manufacturer Proton in 1996. Proton still own all of Lotus.

So, GM hasn't owned Lotus for over a decade. They'd have to pay Lotus big consulting money to get access to their old active suspension systems!

Regards,
Gordon