By Jean Jennings
Project Sound reinvents the automotive suspension system
We have just returned from The Mountain (AKA Bose Corporation Headquarters in Framingham, Massachusetts) where we witnessed the first mega-breakthrough in car suspensions since the gas-pressurized shock. Is that hyperbolic enough for you? Well, it's impossible to overstate what the brilliant Fulbright Scholar and longtime MIT professor Dr. Amar Bose and his engineers have accomplished in the black magic arts of ride and handling.
The premise was simple: Develop a suspension system that would offer the magic carpet ride of a fine luxury automobile, yet provide the crisp handling of a high-performance sports car. Simple premise, yet seemingly insurmountable (and senseless) task given that the active suspension systems designed by savvy engineers at companies such as Lotus, Infiniti, and Mercedes-Benz in the past two decades have all since been discontinued.
While other, lesser systems have come and gone, the Bose Corporation, known more for its ubiquitous Wave radio and blessed acoustic noise-canceling headphones than for automotive engineering, has beavered away in virtual secrecy for an impossibly long twenty-four years on its own version of the active suspension. (Let's pause a moment to appreciate that any company would have a well of optimism deep enough to sustain a research project for more than two decades. "I would have been fired several times," chortles Dr. Bose, chairman and chief technical officer of the privately-held company into which he has always plowed 100% of profits back into development and growth.)
Behind it all is Dr. Bose's lifelong fascination with air and hydraulic suspensions, which grew from a Pontiac he bought in 1957, to a Citroen he bought in Paris in 1967, to finally formalizing suspension research at BOSE in 1980. "I gave that Citroen suspension system as a quiz in acoustics to my students," Dr. Bose says. "The same mathematic principles apply."
Apply them, they did. Having decided after five years of mathematical research that suspensions could be improved dramatically enough to make the journey worth it, Bose soldiered on, focusing on electromagnetics as the key to success. Never mind that high-efficiency, fast, high-power linear motors did not exist. Never mind that high-efficiency, high-power amplifiers to drive those non-existent motors would need to be developed. Never mind that control algorithms would need to be developed to stabilize the motors. Never mind that the super-quick microcomputers needed to run the whole shooting match also didn't exist. Bose took on the first three daunting tasks and bet on the industry to come up with the fourth.
The patents have now been filed. Project Sound is very nearly ready for prime time, and it is nothing short of revolutionary.
The heart of the Bose suspension system is a linear electromagnetic motor installed at each wheel in a modified McPherson strut arrangement. When electricity is fed to wire coils inside, the motor expands and contracts so quickly and forcefully that it prevents pitch and roll during times when the car is driven hard, all the while maintaining passenger car isolation from the sort of wheel impacts that would typically slam your head to the ceiling. Anti-roll bars are no longer necessary. The bobbing-head dog for the parcel shelf is obsolete.
The new design is modular, allowing Bose engineers to easily retrofit existing cars with four independent modules (fronts incorporate a two-piece lower control arm, wheel damper mounted inside the wheel, and torsion bar; rears include wheel dampers and suspension links, with electromagnetic motors laid out more in double-wishbone fashion) mounted in aluminum cradles directly to original suspension sub-system attachment points. A belt-driven alternator powers the system and its twelve-volt battery.
o witness the miracle, we were strapped into a retrofitted Lexus LS400 perched atop a Bose-designed ride simulator (itself an engineering tour de force that will most likely replace the towering three-story edifices currently used by car companies around the world). The initial experience programmed into the simulator emulated a terribly choppy road with a whole lot of high frequency energy "exciting" the wheels. Butts wiggled and stomachs hopped up and down. It was a buckboard. A martini shaker. The research engineers working the controls were just a little too jolly watching the journalists shaken, not stirred.
Next, in Bose mode, we attacked the same horrid road, but inside the passenger compartment, we were sailing along on a cruise ship. The teensiest of cradle rock. Looking at a mirror on an adjacent wall of the garage, we could see our LS400's tires chattering and bashing along, as if they belonged to another car, not the one in which we were blissfully rocking along. It was mind-boggling, unbelievably astonishing, no less than earth shattering.
Outside, we witnessed two test drivers take a basic LS400 and a Bose-retrofitted LS400 through a series of side-by-side tests that allowed us to see the performance angle of the equation. In a double lane-change maneuver, going through a bump course, and being thrown aggressively into a deep corner, the Bose-equipped Lexus remained unnervingly flat, with not a hint of body pitch or roll.
Then the Bose Lexus rushed up to a curb in the middle of the lot and jumped through the air, hurdling it neatly. The crowd roared. The driver got out and bowed. The empty car next to him bowed, too. Body pitch (and its opposite!) on demand, as it were. The wonders of mathematics.
The patents have been filed, and the engineering continues, with Bose promising a weight reduction of fifty percent in the next six months.
When will it be ready? "In 1990, I said two years," remembers Dr. Bose. "Within the next six to ten months, I'll be in a position to select a manufacturer, only one, to team with. We have to focus on its perfection. But don't anticipate it coming down to a low-priced car. They're low-priced for a reason.
"But Bose will manufacture it. It is an enormous amount of technology and we want to follow it through."
How much went into developing the Bose system? "You want me to get fired?" shouts Dr. Bose. "I'm embarrassed to say! You can imagine!"
What you can't imagine is the astonishingly silken ride and the remarkable level of handling achievable without compromise in the same vehicle.
