June,25,2014 SANTA CLARA, Calif.--Holistic system design coupled with gradual design evolution and sensor fusion will put autonomous vehicles in every driveway. Some day. At least that was my takeaway from a recent presentation by Nathaniel Fairfield, the technical lead on Google > src="http://community.cadence.com/CSSharedFiles/blogs/fullerview/Google-fully-autonomous-car.jpg" />

The challenge is to design a human-like solution that isn't human and to do so in a noisy chaotic real-world environment at an affordable cost with reasonable compute requirements. No problem, right?

For the time being, both the first Prius- and Lexus-based generations of Google autonomous vehicles and the more recent , but that turns out not to be such an issue. In the Lexus case, "they use a standard equivalent of a desktop computer," Fairfield said. "It doesn't need a lot because it's on the freeway and there's a lot of structure (via mapping) we can exploit."

Atop the vehicles sit Velodyne Lidar systems to complement other sensors and cameras. Can those be replaced with, say, a number of additional (and less costly) cameras?

Although Google is looking into reducing sensor costs, replacing the Lidar is not realistic, Fairfield said:

"Cameras are fantastic for some purposes but the laser is great--for example, at night. It just sees in the dark. Otherwise you'd have to surround the car with spotlights. I don't see one (type) of sensor replacing another. I see us getting better at integrating them and building that combined system. I really do think they're all important."

One attendee probed Fairfield about the sensor architecture to understand where the filtering and processing is managed. He kept it close to the vest:

"Because we are computationally limited, the sort of theoretically awesome, dump-it-into-one-massive filter that sorts it all out, that's not really tractable. We build simpler systems to combine the information and then infuse it at a higher level."

Asked whether the roadmap (pardon the pun) will reduce reliance on maps, Fairfield replied, "I'd love to. Longer term that's a good direction (and) it can be a gradual process. But we have no plans to do it (soon). "

Another attendee asked about how to mitigate interference among lasers. Fairfield said:

"The radars--off-the-shelf radars-are designed not to interfere with each other. With the lasers, we have detected interference...it was still less than interference you get from the sun and other sparkly stuff you get in the world."

If, like me, you're dying to buy one of these driverless cars to ease your mind during lousy commutes and long hauls, you're just going to have to be patient. In the meantime, we can satisfy ourselves by watching a really amazing design evolution happen before our eyes.

Brian Fuller

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