Page 38 - Introduction to AI Robotics

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1.4 A Brief History of Robotics
tor had to make non-intuitive and awkward motions with their arms to get
the robot arm to perform a critical manipulation—very much like working in
front of a mirror. Likewise, the telemanipulators had challenges in providing
force feedback so the operator could feel how hard the gripper was holding
an object. The lack of naturalness in controlling the arm (now referred to as
a poor Human-Machine Interface) meant that even simple tasks for an un-
encumbered human could take much longer. Operators might take years of
practice to reach the point where they could do a task with a telemanipulator
as quickly as they could do it directly.
After World War II, many other countries became interested in producing a
nuclear weapon and in exploiting nuclear energy as a replacement for fossil
fuels in power plants. The USA and Soviet Union also entered into a nu-
clear arms race. The need to mass-produce nuclear weapons and to support
peaceful uses of nuclear energy kept pressure on engineers to design robot
arms which would be easier to control than telemanipulators. Machines that
looked more like and acted like robots began to emerge, largely due to ad-
vances in control theory. After WWII, pioneering work by Norbert Wiener
allowed engineers to accurately control mechanical and electrical devices us-
ing cybernetics.

1.4.1 Industrial manipulators

Successes with at least partially automating the nuclear industry also meant
the technology was available for other applications, especially general man-
ufacturing. Robot arms began being introduced to industries in 1956 by
Unimation (although it wouldn’t be until 1972 before the company made a
profit). 37 The two most common types of robot technology that have evolved
for industrial use are robot arms, called industrial manipulators, and mobile
carts, called automated guided vehicles (AGVs).
INDUSTRIAL An industrial manipulator, to paraphrase the Robot Institute of America’s
MANIPULATOR definition, is a reprogrammable and multi-functional mechanism that is de-
signed to move materials, parts, tools, or specialized devices. The emphasis
in industrial manipulator design is being able to program them to be able
to perform a task repeatedly with a high degree of accuracy and speed. In
order to be multi-functional, many manipulators have multiple degrees of
freedom, as shown in Fig. 1.4. The MOVEMASTER arm has five degrees
of freedom, because it has five joints, each of which is capable of a single
rotational degree of freedom. A human arm has three joints (shoulder, el-