Page 231 - Concise Encyclopedia of Robotics

Open-Loop System
(V 1, V 2, V 3, and V 4 in this example) are constantly input to the micro-
computer. The microcomputer “knows” the robot’s coordinates at any
moment, based on this information.
See also COMPUTER MAP and DISPLACEMENT TRANSDUCER.
OFFLOADING
It has been said that a machine is something that makes people’s work
easier. This is especially true of robots and smart computers. These devices
can do many of the tedious or dangerous jobs that were done by humans
in the past. As robotic technology advances, this process can be expected
to continue. The replacement of human workers by robots and/or smart
computers is called robotization, automation, or computerization. On a per-
sonal level, the use of robots and smart computers for mundane chores is
called offloading, a term coined by futurist Charles Lecht.
According to Lecht, there is still much room for improvement in
our lives. Even in our advanced, highly technological society, we spend
time buying groceries, washing clothes, and vacuuming the floor. Cre-
ative people, in particular, often regard these things as a waste of time.
But if the chores don’t get done, people go hungry, wear dirty clothes,
suffer with unsanitary living conditions. Some people hire servants to
do their mundane chores, but not many people can afford a butler or
a maid.
Robots can take over some routine daily chores. Lecht believes they
eventually will, and that they will be affordable for almost everybody.
This will free people to do more fun and creative things, Lecht says, such
as paint pictures, write books, compose music, or play golf.
See also PERSONAL ROBOT.
OPEN-LOOP SYSTEM
The term open-loop system refers to any machine that does not incorpo-
rate a servomechanism. For this reason, open-loop robots are often called
nonservoed robots. This type of robot depends, for its positioning accuracy,
on the alignment and precision of its parts. There is no means for cor-
recting positioning errors. The robot operates blind; it cannot compare
its location or orientation with respect to its surroundings.
Open-loop systems can work faster than closed-loop,or servoed,robotic
systems. This is because there is no feedback in an open-loop system,
and therefore, no time is needed to process feedback signals and make
positioning corrections. Open-loop systems are also less expensive than
closed-loop systems. However, in tasks that require extreme accuracy,
open-loop systems are not precise enough. This is especially true when a
robot must make many programmed movements, one after the other. In

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