Robot Mechanisms and Mechanical Devices Illustrated - Profe Saul

Introduction
xiii
There are a few terms specific to mobile robots that must be defined to
avoid confusion. First, the term robot itself has unfortunately come to
have at least three different meanings. In this book, the word robot
means an autonomous or semi-autonomous mobile land vehicle that may
or may not have a manipulator or other device for affecting its environment.
Colin Angle, CEO of iRobot Corp. defines a robot as a mobile
thing with sensors that looks at those sensors and decides on its own
what actions to take.
In the manufacturing industry, however, the word robot means a
reprogrammable stationary manipulator with few, if any sensors, commonly
found in large industrial manufacturing plants. The third common
meaning of robot is a teleoperated vehicle similar to but more sophisticated
than a radio controlled toy car or truck. This form of robot usually
has a microprocessor on it to aid in controlling the vehicle itself, perform
some autonomous or automatic tasks, and aid in controlling the manipulator
if one is onboard.
This book mainly uses the first meaning of robot and focuses on
things useful to making robots, but it also includes several references to
mechanisms useful to both of the other types of robots. Robot and
mobile robot are used interchangeably throughout the book.
Autonomous, in this book, means acting completely independent of any
human input. Therefore, autonomous robot means a self-controlled, selfpowered,
mobile vehicle that makes its own decisions based on inputs
from sensors. There are very few truly autonomous robots, and no
known autonomous robots with manipulators on them whose manipulators
are also autonomous. The more common form of mobile robot today
is semiautonomous, where the robot has some sensors and acts partially
on its own, but there is always a human in the control loop through a
radio link or tether. Another name for this type of control structure is
telerobotic, as opposed to a teleoperated robot, where there are no, or
very few, sensors on the vehicle that it uses to make decisions. Specific
vehicles in this book that do not use sensors to make decisions are
labeled telerobotic or teleoperated to differentiate them from
autonomous robots. It is important to note that the mechanisms and
mechanical devices that are shown in this book can be applied, in their
appropriate category, to almost any vehicle or manipulator whether
autonomous or not.
Another word, which gets a lot of use in the robot world, is mobility.
Mobility is defined in this book as a drive system’s ability to deal with
the effects of heat and ice, ground cover, slopes or staircases, and to
negotiate obstacles. Chapter Nine focuses entirely on comparing drive
systems’ mobility based on a wide range of common obstacles found in