Active suspension from Bose
Active suspension from Bose
(OP)
From http://TheCarConnection.com
Bose Sounds Off on Suspension
While it's become one of the auto industry's Tier One suppliers, Bose Corp., is normally a name one associates with in-car entertainment. But a not-so-new project championed by the company's founder, Amar T. Bose, could make the Framingham, Mass., firm a key player in automotive suspension systems.
It's not easy to keep secrets in the auto industry, but Bose has been quietly working on "Project Sound" for more than 24 years. The intentionally misleading codename "had nothing to do with sound," Dr. Bose acknowledged with a broad smile during a recent background briefing. What the company unwrapped was, in fact, a prototype of an active suspension system. The project is not as out-of-place as it might first seem. Some of Bose Corp.'s first products were power amplification systems. Audio technology followed, eventually becoming the Massachusetts firm's public face. But Bose has continued to produce the sophisticated recuperative power hardware at the heart of its suspension design.
Conventional suspensions use springs and shocks to compensate for bumps and turns. Active suspension technology use magnets and motors to react to road inputs and driving forces, and on paper, such systems could yield a smoother ride while enhancing vehicle control. Active suspensions have been around for awhile. Infiniti offered a version on its first Q45 sedan back in 1989. But so far, the technology has fallen far short of expectations. Part of the problem is the amount of power required to operate the motors and electromagnets. But Bose uses its recuperative technology to recapture energy, much the way hybrid cars reuse energy normally lost during braking and coasting. According to Dr. Bose, the system requires barely a third the power of an auto air conditioner.
While Bose would not provide a vehicle for independent testing, it staged a demonstration of its suspension system, using a retrofitted Lexus LS400 sedan. Even when driven at moderate speed over a severely bumpy course, the cabin of the vehicle remained virtually motionless. Compared to a conventional LS400, the modified vehicle was notably more stable in aggressive slalom maneuvers. To drive home the system's capability, the Bose car literally crouched and leapt across a piece of lumber blocking its path on a parking lot course.
"We hope to achieve the benefits of a luxury car and a sports car with the same vehicle," noted Bose engineer Larry Knox. Company officials declined to say exactly how long before the system might be ready for production, though Dr. Bose suggested it was fast approaching that phase. "Within the next six months, our intent is to take 50 percent of the weight out, and significantly reduce the cost." He hinted the firm he founded is now beginning talks with the auto industry. And TheCarConnection.com has been told by a Big Three source - who asked not to be identified by name or company -that preliminary testing is now underway. That automaker would clearly expect that a marketable version would need cost less than the $5000 price for the Q45 active suspension. -Paul A. Eisenstein
http://www.bose.com/controller;jsessionid=BvuZs3VPUrdCMzkgp41wqGGW2Ul7FhYVntUEyiPvFom1DtSv0LH7!-373760557!1879924776?event=VIEW_STATIC_PAGE_EVENT&url=/learning/project_sound/bose_suspension.jsp&pageName=/learning/index.jsp
Bose Sounds Off on Suspension
While it's become one of the auto industry's Tier One suppliers, Bose Corp., is normally a name one associates with in-car entertainment. But a not-so-new project championed by the company's founder, Amar T. Bose, could make the Framingham, Mass., firm a key player in automotive suspension systems.
It's not easy to keep secrets in the auto industry, but Bose has been quietly working on "Project Sound" for more than 24 years. The intentionally misleading codename "had nothing to do with sound," Dr. Bose acknowledged with a broad smile during a recent background briefing. What the company unwrapped was, in fact, a prototype of an active suspension system. The project is not as out-of-place as it might first seem. Some of Bose Corp.'s first products were power amplification systems. Audio technology followed, eventually becoming the Massachusetts firm's public face. But Bose has continued to produce the sophisticated recuperative power hardware at the heart of its suspension design.
Conventional suspensions use springs and shocks to compensate for bumps and turns. Active suspension technology use magnets and motors to react to road inputs and driving forces, and on paper, such systems could yield a smoother ride while enhancing vehicle control. Active suspensions have been around for awhile. Infiniti offered a version on its first Q45 sedan back in 1989. But so far, the technology has fallen far short of expectations. Part of the problem is the amount of power required to operate the motors and electromagnets. But Bose uses its recuperative technology to recapture energy, much the way hybrid cars reuse energy normally lost during braking and coasting. According to Dr. Bose, the system requires barely a third the power of an auto air conditioner.
While Bose would not provide a vehicle for independent testing, it staged a demonstration of its suspension system, using a retrofitted Lexus LS400 sedan. Even when driven at moderate speed over a severely bumpy course, the cabin of the vehicle remained virtually motionless. Compared to a conventional LS400, the modified vehicle was notably more stable in aggressive slalom maneuvers. To drive home the system's capability, the Bose car literally crouched and leapt across a piece of lumber blocking its path on a parking lot course.
"We hope to achieve the benefits of a luxury car and a sports car with the same vehicle," noted Bose engineer Larry Knox. Company officials declined to say exactly how long before the system might be ready for production, though Dr. Bose suggested it was fast approaching that phase. "Within the next six months, our intent is to take 50 percent of the weight out, and significantly reduce the cost." He hinted the firm he founded is now beginning talks with the auto industry. And TheCarConnection.com has been told by a Big Three source - who asked not to be identified by name or company -that preliminary testing is now underway. That automaker would clearly expect that a marketable version would need cost less than the $5000 price for the Q45 active suspension. -Paul A. Eisenstein
http://www.bose.com/controller;jsessionid=BvuZs3VPUrdCMzkgp41wqGGW2Ul7FhYVntUEyiPvFom1DtSv0LH7!-373760557!1879924776?event=VIEW_STATIC_PAGE_EVENT&url=/learning/project_sound/bose_suspension.jsp&pageName=/learning/index.jsp





RE: Active suspension from Bose
One can imagine how a sensor or connector failure might cause the system to become unstable, resulting in a car that leaps about uncontrollably. A system power failure would leave the car on the bump stops, while a single corner power failure would result in an asymmetric three-wheeler.
Pete.
With thanks to John Miles for his experiences with active suspension systems.
RE: Active suspension from Bose
Nothing else that Bose has ever done, apart from the marketing of his noise making devices, has impressed me quite as much as the claimed performance of this system.
I am intrigued about the cooling system for his electronics - on a rough road a suspension will be absorbing several kW. One sneaky way to absorb this energy is to 'pump' the car higher in the short term, but you can't do that for long, it upsets the handling, and you run out of strut stroke.
By the way PTwizz, I worked with Milesy on the SID car, and was on the design team from the word go, just about.
Cheers
Greg Locock
RE: Active suspension from Bose
http://www.bose.com/controller;jsessionid=BiyLINcQ...
Best,
MAPirc
Disclaimer: I work for Bose as a transducer designer, but haven't been closely associated with Project Sound.
RE: Active suspension from Bose
Using a mechanical spring is a good idea, I don't know why Lotus tended not to.
Cheers
Greg Locock
RE: Active suspension from Bose
Back to speculation about the possibility of dissipating 4kW of thermal power: 1.) the motors have lots of surface area and high emissivity, and 2.) the motors probably don't exceed very roughly 200 deg C or so internally. Whether they can hold to this limit without an auxiliary cooling system of some sort is unknown to me, and probably beyond that need-to-know threshold (sincerest apologies about that.)
Best,
Mark
RE: Active suspension from Bose
If they are still functioning as motor/generators, the system could fail a big resistor across the leads, either water cooled (this is a car, after all!) or mounted securely to the structure of the car...
Jay Maechtlen
RE: Active suspension from Bose
One can always reduce the power by reducing the force factor, thus "weakening" the motor, or by deliberating increasing the resistance in the failure-mode shunt path, as you're saying, Jay. The problem is that as the resistance is increased, average total thermal power is decreased, but so is damping action. On the narrow basis of the parameters I've presented here, then, it's a matter of trading-off operating temperature with damping force.
Best,
Mark
RE: Active suspension from Bose
Norm