Page 22 -

1.2 Commercial Robot Configurations and Types 3
workcell is ideally suited to emerging HMLV conditions in manufacturing
and elsewhere.
The rising popularity of robotic workcells has taken emphasis away from
hardware design and placed new emphasis on innovative software techniques
and architectures that include planning, coordination, and control (PC&C)
functions. A great deal of research into robot controllers has been required
to give robots the flexibility, precision, and functionality needed in modern
flexible workcells. The remainder of this book details such advanced control
techniques.

1.2 Commercial Robot Configurations and Types

Much of the information in this section was prepared by Mick Fitzgerald,
who was then Manager at UTA’s Automation and Robotics Research Institute
(ARRI).
Robots are highly reliable, dependable and technologically advanced
factory equipment. The majority of the world’s robots are supplied by
established companies using reliable off-the-shelf component technologies.
All commercial industrial robots have two physically separate basic
elements—the manipulator arm and the controller. The basic architecture of
most commercial robots is fundamentally the same, and consists of digital
servocontrolled electrical motor drives on serial-link kinematic machines,
usually with no more than six axes (degrees of freedom). All are supplied
with a proprietary controller. Virtually all robot applications require
significant design and implementation effort by engineers and technicians.
What makes each robot unique is how the components are put together to
achieve performance that yields a competitive product. The most important
considerations in the application of an industrial robot center on two issues:
manipulation and integration.
Manipulator Performance

The combined effects of kinematic structure, axis drive mechanism design,
and real-time motion control determine the major manipulation performance
characteristics: reach and dexterity, pay load, quickness, and precision.
Caution must be used when making decisions and comparisons based on
manufacturers’ published performance specifications because the methods
for measuring and reporting them are not standardized across the industry.
Usually motion testing, simulations, or other analysis techniques are used to
verify performance for each application.
Reach is characterized by measuring the extent of the workspace described
by the robot motion and dexterity by the angular displacement of the

Copyright © 2004 by Marcel Dekker, Inc.