A robot is a machine designed to execute one or more tasks
repeatedly, with speed and precision. There are as many different types of
robots as there are tasks for them to perform.
A robot can be controlled by a human operator, sometimes from a
great distance. But most robots are controlled by computer, and fall into
either of two categories: autonomous robots and insect robots. An autonomous
robot acts as a stand-alone system, complete with its own computer (called the
controller). Insect robots work in fleets ranging in number from a few to
thousands, with all fleet members under the supervision of a single controller.
The term insect arises from the similarity of the system to a colony of
insects, where the individuals are simple but the fleet as a whole can be
sophisticated.
Robots are sometimes grouped according to the time frame in which
they were first widely used. First-generation robots date from the 1970's and
consist of stationary, nonprogrammable, electromechanical devices without
sensors. Second-generation robots were developed in the 1980's and can contain
sensors and programmable controllers. Third-generation robots were developed
between approximately 1990 and the present. These machines can be stationary or
mobile, autonomous or insect type, with sophisticated programming, speech
recognition and/or synthesis, and other advanced features. Fourth-generation
robots are in the research-and-development phase, and include features such as artificial
intelligence, self-replication, self assembly, and nanoscale
size (physical dimensions on the order of nanometers, or units of 10-9 meter).
Some advanced robots are called androids because of their
superficial resemblance to human beings. Androids are mobile, usually moving
around on wheels or a track drive (robots legs are unstable and difficult to
engineer). The android is not necessarily the end point of robot evolution.
Some of the most esoteric and powerful robots do not look or behave anything
like humans. The ultimate in robotic intelligence and sophistication might take
on forms yet to be imagined.
The term comes from a Czech word, robota, meaning
"forced labor." The word robot first appeared in a
1920 play by Czech writer Karel Capek, R.U.R.: Rossum's Universal Robots. In
the play, the robots eventually overthrow their human creators.
