Page 30 - Sensing, Intelligence, Motion : How Robots and Humans Move in an Unstructured World

INTRODUCTION 5

robotics on such lines is an extremely successful and cost-effective proposition,
in spite of their high cost.
Unfortunately, some tasks—in fact, the great majority of tasks we face every
day—differ in some fundamental ways from those on the automotive assembly
line. We live in the world of uncertainty. We deal with unstructured tasks,tasks
that take place in an unstructured environment. Because of unpredictable or
changing nature of this environment, motions that are needed to do the job
are not amenable to once-and-for-all calculation or to honing via direct iterative
improvement. Although some robots in the structured automotive environment
are of great complexity, and functionally could be of much use in unstructured
tasks, their use in an unstructured environment is out of the question without
profound changes in their design and abilities. Analyzing this fact and finding
ways of dealing with it is the topic of this book.
Sometime in the late 1950s John McCarthy, from Stanford University [who
is often cited as father of the field of artificial intelligence (AI)], was quoted as
saying that if the AI researchers had as much funding as NASA was given at
the time to put a man on the moon, then within 10 years robot taxi cabs would
roam the streets of San Francisco. McCarthy continued talking about “auto-
matic chauffeurs” until at least the late 1990s. Such loyalty to the topic should
certainly pay off eventually because the automatic cab drivers will someday
surely appear.
Today, over 40 years since the first pronouncement, we know that such a robot
cannot be built yet—at any cost. This statement is far from trivial—so it is not
surprising that many professional and nonprofessional optimists disagree with
it. Not only it is hard to quantify the difficulties that prevent us from building
such machines, but these difficulties have been consistently underestimated. As
another example, in 1987, when preparing an editorial article for the special issue
on robot motion planning for the IEEE Transactions on Robotics and Automation,
this author was suggested to take off from the Foreword a small paragraph saying
that in the next 10 years—that is, between 1987 and 1997—we should not expect
a robot capable of, say, tying one’s shoelaces or a necktie. The text went on to
suggest that the main bottleneck had less to do with lacking finger kinematics
and more with required continuous sensing and accompanying continuous sensor
data processing. “This sounds too pessimistic; ten years is a long time; science
and technology move fast these days,” the author was told. Today, almost two
decades later, we still don’t have robots of this level of sophistication—and not
for a lack of trying or research funding. In fact, we can confidently move the
arrival of such robots by at least another decade.
One way to avoid the issue is to say that a task should be “well engineered.”
This is fine except that no task can be likely “well engineered” unless a technician
has a physical access to it once or twice a day, as in any automotive assembly
line. Go use this recipe with a robot designed to build a large telescope way out
in deep space!
Is the situation equally bleak in other areas of robotics? Not at all. In recent
years robotics has claimed many inroads in factory automation, including tasks