I've presented the three Ds of robotics as the quintessential test to determine whether automation should be applied to any task. But, it's not. It's a useful test, but it's not the end of the story. There are a whole lotta other considerations that make or break the value of automation for any task.

One of the most obvious to engineers - especially test engineers - is precision. Automated systems can provide levels of precision unachievable with manual systems.

Let's face it, placing something exactly where you intend it is one of the most difficult things the human mechanism can do. I know from experience as a graphic artist. Yeah, one of the things I do when I'm not writing about technology is standing at an easel hand painting images. If you don't believe me, check out the "Graphic Arts" section of my website at www.cgmasi.com.

Most of my time is spent covering up little globs of paint that didn't go precisely where I intended them. That's okay when creating a one-of-a-kind piece of art. It don't cut it, however, when manufacturing something like a ball bearing, or a microchip. Even modern electronic assemblies cannot be hand-made anymore. Without robotics, cellphones would be impossible. The old wrap-the-wire-around-the-post-and-melt-solder-onto-it technique I mastered fifty years ago couldn't possibly produce any modern electronic device.

That precision requirement has grown to encompass nearly every technologically advanced product, from wrist watches to automobiles.

A few years ago, I wrote an article for Vision Systems Design profiling a system used to apply mold-release agent to green tires. Green tires aren't some kind of eco-friendly bicycle wheel. They're the gloppy guts of every "rubber" tire before they're vulcanized in a tire mold, which gives them their final shape.

Once that process is complete, the tire manufacturer has to get the stupid thing out of the mold. That's easier said than done, because the vulcanized surface wants to bond to the mold. You have to coat the surface of the green tire with a mold-release agent that prevents the tire from bonding to the mold. You've got to coat it before putting the mess into the mold to solidify it by vulcanization.

The release agent has to be applied precisely - too much and the tire surface comes out as a mess; to little and the tire surface doesn't come out at all.

Tire production-system developers found that the best way to do this was to surround the green tire with a bunch of robot arms doing different jobs in concert. While one robot holds a green tire up to be sprayed, a machine-vision system measures precisely how that particular tire sagged when picked up, followed by other robots to move the spray guns in the precise way needed to get just the right coating at each spot on that particular tire held in that particular way - that time.

Try doing that by hand.

C.G Masi