IEEE Robotics & Automation Magazine - June 2013 - 114

Petar Kokotovic, a Contemporary of Vukobratovic´,
on the Early Days of Robotics in Yugoslavia
"There were many amputees, you know, former partisans and resistance fighters,
and many amputees also from bombings, just the war victims. So there was a
big need, especially for artificial arms and legs. And the artificial arms were a big
challenge, not only in Yugoslavia, but people were trying in Germany and other
places to develop them with the growth of electronics. Transistors just appeared
and some miniaturization was possible. Several motors became sufficiently small
for wartime applications. And the idea that maybe artificial arms could be created
motivated many people. Belgrade had this project called the Belgrade Arm,
organized by Professor Tomovic´. This developed into bigger robotics projects, a
bigger robotics operation. There was a section in the Pupin Institute for a while
supervised by Tomovic´ and then taken over, continued by Vukobratovic´. [These first
three or four years] were sort of an enthusiastic start, maybe not always realistic.
You know, fantasy and dreams very often propel you, especially if you are in a less
than super developed country. When a country is developed, it sobers you, it shows
also what is impossible. When you are not so developed, when you are young,
you have all sorts of heroic ideas that transfer into technology. Some of them
sometimes succeed."
-Petar Kokotovic,
University of California, Santa Barbara [6]

in Vukobratović's work, prosthetics to
help the many casualties of WW2
became an important area of development, as did industrial manipulators that could support the rapidly
growing domestic economy (see
"Petar Kokotovic, a Contemporary of
Vukobratović, on the Early Days of
Robotics in Yugoslavia"). Vukobratovic´ thus started his career at a time of
scarce resources and great enthusiasm and belief in scientific and technological progress for the betterment
of human lives.
Vukobratović himself cites work in
the area of prosthetics as "one of the
global incentives to begin with robotics activities in the institute, as well as
in Yugoslavia" [3, p. 5]. Yugoslavia was
at the forefront of early developments
in this field and well known for the socalled Belgrade Hand, developed
between 1963 and 1968 by Tomović,
the founder of the Robotics Labora-

tory at MPI and Vukobratović's predecessor as its director. The Belgrade
Hand, which was the first five-fingered
robotic hand, was partially financed by
the U.S. Veteran Administration and
was later improved in the 1980s with
the participation of George Bekey's
group at the University of Southern
California (USC) to create the Belgrade/USC hand. Although the Belgrade Hand never achieved wide
practical application, it put Yugoslavia
on the international map of robotics
research. After taking over the Robotics Lab from Tomović, Vukobratović
and his colleagues at MPI continued to
work on problems related to issues in
rehabilitation, designing several prototypes of active leg orthotic devices,
as well as the world's first working
active exoskeleton for restoring basic
locomotion functions to paraplegics
and the world's first active orthotic
arm for dystrophic people.

From Practice to ZMP
"Vukobratovic´ once told me how he came to think of the ZMP. One day, he was
sitting with his wife, and he was sitting on his legs. When he wanted to stand up to
take something, he almost fell down. Then he started thinking what was happening.
The leg was there, all the sensors were there, the control unit was there, but he
could not walk. Then he realized that he had lost the sense of force, and that got
him thinking about how to use force in motion."
-Branislav Borovac, MPI,
at the Humanoids 2012 Memorial
Workshop for Miomir Vukobratovic´

114

IEEE ROBOTICS & AUTOMATION MAGAZINE

june 2013

The Zero-Moment Point Is Born
The Springer Handbook of Robotics
refers to the zero-moment point (ZMP)
as "one of the most famous technical
terms born in the robotics community"
[1, p. 371]. When Honda's ASIMO took
its first public steps in 2000, it did so
using ZMP-based dynamical control.
Numerous other bipeds have applied
the ZMP to walk, including the
Humanoid Robot Project (HRP) series
humanoids and robotic dinosaur developed by the National Institute for
Advanced Industrial Science and
Technology (AIST), Sony's QRIO, and
Waseda's WABIAN. The idea of the
ZMP was developed in two seminal
papers by Vukobratović (see "From
Practice to ZMP") [4], [5]. It has taken
almost 30 years for this pioneering work
in legged locomotion to be implemented widely in the robotics community (see Figure 2).
Vukobratovic´ was in many ways a
man ahead of his time (see Figure 2).
The ZMP was just one of the pioneering ideas he developed in his long and
productive scientific career, during
which he made contributions to
fields as diverse as aeronautics, dynamical systems, and theoretical and
applied robotics. What made this
interdisciplinary work possible was the
combination of Vuk's mastery of mathematics and physics with an engineer's
attention to the practical applications
of his work. His ability to traverse with
ease between diverse systems such as
flying machines, walking devices, and
industrial robots allowed him to identify commonalities and interconnections that led to ground-breaking
ideas. Vuk was not only able to identify
novel and challenging problems but
also to propose innovative solutions to
them. Perhaps even more importantly,
he knew how to attract and motivate
the young researchers who worked in
his laboratory and colleagues from all
over the world to pursue difficult problems in robotics. Under Vukobratovic´'s
tutelage, the Robotics Laboratory at the
MPI in Belgrade, where he spent the
greater part of his career, became
a world-renowned center for theoretical and practical research in robotics

Table of Contents for the Digital Edition of IEEE Robotics & Automation Magazine - June 2013