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Tuesday, Nov 10, 2009
Evolvable hardware -- gadgets that design themselves -- can get the job done, even if humans have no idea how they do it.
Aug 12, 2004 | Paul Layzell is a specialist in the budding field of evolvable hardware. Simply put, he helps machines design themselves, using principles borrowed directly from biological evolution.
It's a job with strange and unexpected twists. Take the time three years back when he and fellow University of Sussex researcher Jon Bird attempted to build an oscillator circuit using genetic algorithms and a handful of transistors. While a few circuits came out fitting the functional profile -- steady output, steady frequency -- one circuit took a strange path to get there. Instead of building internal feedback loops to reach the desired frequency, it had simply wired itself in a way that the radiated hum of a nearby computer went straight through the circuit and into the attached oscilloscope.
In other words, it cheated. The circuit had hacked the system by becoming a radio.
"The best way I can think to describe it is a mixture of respect and humor," says Layzell, summing up his reaction. "A bit like when a child solves a common problem in an original way: It always makes you smile."
Using evolutionary processes to optimize machine performance is nothing new. Since the 1960s, artificial intelligence researchers have exploited the dynamics of Darwinian evolution to solve software problems in fields as diverse as financial investment, manufacturing and biochemistry.
What is new, however, is the application of evolutionary processes in the hardware realm. Thanks to reconfigurable devices such as the field programmable gate array (FPGA) -- the microchip designer's equivalent of an Etch A Sketch -- and increasing computational power, researchers who once performed simulations of new circuits with an eye on the clock are suddenly free to let their designs evolve for a while just to see what happens. One might not be sure that one understands how a given circuit achieves what it is supposed to, but if it works, is that really a problem?
For many engineers, the question is already the first major litmus test of the 21st century. Those who answer yes see evolutionary engineering as barely a half step above tinkering. Those who answer no, however, see it as a useful method to break through the complexity barriers limiting both software and hardware innovation.
"I see the evolved radio as an intuition pump," says Bird -- borrowing a phrase from Daniel Dennett, a Tufts University philosopher with a sizable fan base in the world of artificial intelligence research -- "a vivid thought experiment that can structure the way we think about a problem."
