December 1, 2010 Vol. 6, No. 24

Way back in January or so I told you about a wildly interesting truck seat emanating from a very unlikely source. Bose, a Massachusetts company we probably all know for its home and vehicle audio equipment going back a few decades, had just announced a truck-specific product that had nothing to do with sound.

What? A truck seat? True story. I’ve since had a chance to try it, and I think it’s sufficiently significant to warrant a few words here.

The Bose Ride System is a seat designed by the same guy — or more likely a bunch of engineers taking his lead — who got fed up with conventional stereo speaker design as a grad student at MIT back in the 1950s. Dr. Amar G. Bose, by name. There followed a lengthy period of research into speaker design and psychoacoustics — the perception of sound — and that led to the Bose 901 Direct/Reflecting speaker system in 1968 and later the Wave music system, among others. But Bose research activities go well beyond sound, and it now produces technologies that regulate electric power in airplanes, control fuel rods inside nuclear reactors, or test medical devices.

In fact, Dr. Bose had a serious hand in the seat’s design because I suspect it’s an offshoot of his 30-year research into car suspension systems. That began in 1980 when he did a mathematical study to determine the optimum possible performance of an automotive suspension, ignoring the limitations of any existing suspension hardware. Five years later he concluded that it was possible to go way beyond anything then available. He looked at all the conventional spring and hydraulic approaches, but he and the team couldn’t find the combination of speed, strength and efficiency necessary to provide the results they were looking for. The study identified electromagnetics as the one approach that could deliver optimal suspension characteristics, and they’ve been rolling — smoothly — down that road ever since.

The Bose suspension, says the company, required significant advancements in four key disciplines: linear electromagnetic motors, power amplifiers, control algorithms, and computation speed. Bose took on the challenge of the first three and bet that others would make good on the speed bit, which of course they did.

Prototypes of the Bose suspension system have been installed in standard production vehicles, and they’ve been tested on a wide variety of roads, on tracks and on durability courses. Have a look at this link. Very cool.

I’m trying to get back to the seat here but just a few details on the suspension. It’s utterly fascinating, and a video I recently saw shows an astonishing difference between cars with and without the Bose system. 

Things start with a linear electromagnetic motor installed at each wheel of the car, looking more or less like a simple telescoping suspension strut, along with a two-piece lower control arm. A torsion bar spring connected to one end of the lower arm supports the weight of the vehicle. But inside are magnets and coils of wire. When electrical power is applied to the coils, the motor retracts and extends, creating motion between the wheel and car body.

One key advantage of an electromagnetic approach is speed, says Bose. The linear electromagnetic motor responds quickly enough to counter the effects of bumps and potholes, maintaining a comfortable ride. The motor puts out enough force to prevent the car from rolling and pitching during aggressive driving maneuvers.

There are also ‘regenerative’ power amplifiers that deliver electrical power to the motor in response to signals from the control algorithms. They allow power to flow into and back from the electromagnetic motor. For example, when the car hits a pothole, power is used to extend the motor — acting like a strut — and isolate passengers from the bump. Once past the pothole, the motor operates as a generator and returns power back through the amplifier. In practice, says Bose, the suspension needs less than a third of the power of a typical vehicle’s air conditioner

BUT WHAT ABOUT THE SEAT? Well, I’m getting there. First off, the Bose Ride System is a direct replacement for conventional seats in heavy trucks. It’s said to install easily in about two hours in most over-the-road machines using the existing bolts and air line, plus a 12-volt power line that connects to the truck’s battery.

You get a very sophisticated suspension base and an integrated, custom-designed seat top. The company claims it provides over-the-road truckers with "an unprecedented level of protection from road-induced shocks and vibration."