Easy ride: Bose Corp. uses speaker technology to give cars adaptive suspension
W. D. Jones · IEEE Spectrum · 2005
Bose Corp. has developed an automobile active suspension system that uses speaker technology to provide a more smooth ride. The Bose system equips each wheel with its own linear electromagnetic motor, similar to those that propel modern roller coasters. The motor works not by revolving but by telescoping up or down to do what shocks and springs do, but much faster. Algorithms manage the car as a whole, preventing body roll during turns and keeping the car from dipping forward when it stops. The company drew on its experience with sound reproduction. The voice-coil technology that drives Bose speakers proved perfect for driving the linear motors, because both applications modulate high-frequency electrical pulses in response to randomly occurring events. Indeed, the suspension's motors may be regarded as the world's strongest quadraphonic speakers, even though they hardly make a sound.