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One of the key figures behind Japan's resurgent control industry
is a mild-mannered college professor who just recently took up residency in the
United States to pursue advanced control technology. In 1948, as a neophyte in
the control field, Yasundo Takahashi imported the technique of frequency
response to his native island. Over the next eight years, he taught it, and
applied it to industrial control, with such effect that an energetic young
industry was born.
Takahashi has combined academic training in heat transfer with
an interest in automatic control. As a serious student at Tokyo Imperial
University, he majored in mechanical engineering, earned his degree of
Ko-gakushi (a Japanese rank that falls somewhere between the American BS and MS
degrees) in 1935. His first industrial experience, with the Japanese National
Railways designing railway rolling stock, lacked the intellectual challenge
that young Takahashi wanted, so he switched to a more demanding academic life,
teaching and researching heat power systems. First, he was a lecturer at the
Yokohama Technical College, then an assistant professor at Nagoya Imperial
University. In 1946, his work in heat transfer systems earned him a doctorate
degree.
By this time, of course, World War II had ended. Takahashi was
hard hit psychologically, like many Japanese, and at a loss as to what to do
for the future. He accepted a chair of dynamics of ma chinery at his alma
mater, Tokyo Imperial University (whose name was promptly changed in postwar
enthusiasm to University of Tokyo), although he had little experience in this
area.
At this time, Takahashi was strongly influenced by the
far-sighted chairman of Japan's National Science Council, Professor Kankuro
Kaneshige, who told Takahashi that "automatic control would someday be the most
important area of mechanical engineering". Takahashi took this suggestion to
heart, launched a course in automatic control.
Putting together his first. lecture notes was a herculean task.
Most of the Japanese technical libraries had been destroyed by bombings; and
contact with the outside was almost impossible. Still, Takahashi pieced
together his notes by writing to control engineers in the U.S. and England,
then combining their replies with technical papers. For the first four years,
he spent practically all his working hours outside the classrooms going over
papers from the U.S. and England.
In this way, he grasped the frequency-response technique
developed at MIT, and from 1948 this became the backbone of his courses and his
research. He put it to work in the industrial application of conventional
control.
(Takahashi points out that the evolution of modern control
technology in Japan has not paralleled developments in the U.S. Mechanical
engineers pioneered Japanese control, not electrical engineers. The reason: a
postwar ban on such things as fire-control systems stultified the development
of servos and servo theory. EE's concentrated on such tasks as rebuilding
power-generating and distribution systems using conventional
approaches.) |
At the university, Takahashi also concentrated on the transfer
function analysis of heat exchange processes; and this was the subject of the
first paper he prepared for presentation outside Japan. It was published in
1952 in England.
The diminutive control engineer has been a frequent contributor
to Japanese scientific publications. In addition, he has written three books
that are an important part of any Japanese control engineer's library. The
trio: Automatic Control published in 1949, and Theory of Automatic Control and
Automatic Control Manual, both published in 1954.
Takahashi's propensity to correspondence with foreign control
engineers and his contributions to Japanese literature finally won him an
international reputation. In 1954, he was awarded a grant to study control
engineering at MIT as a Fulbright research scholar. The one-year stay in Boston
was particularly welcome to Takahashi, because it gave him a chance to meet,
and work with, some of the engineers who had introduced him to frequency
response via the mail. Among them: Hank Paynter and Don Campbell.
At the end of his stay at MIT, Takahashi was invited to teach at
the University of California as a visiting professor. In 1956, he went back to
Tokyo, to the university and also as a consultant on the instrumentation for
the Ajinomoto Co.'s new chemical plant and on nuclear power systems for the
Mitsubishi Heavy Industry Co.
In February 1958, Takahashi returned to the United States, this
time as a permanent member of the University of California faculty. In the Div.
of Heat Power Systems, Dept. of Mechanical Engineering, at Berkeley,
'I'akahashi is now pushing a couple of favorite projects that can be traced
back to his early association with heat-power systems. He's studying the
dynamic aspects of heat flow in heat exchangers, because he feels the knowledge
may be a key to some kind of computing control that will permit optimizing the
heat transfer process. And he's interested in sample data systems: how they
might be applied to optimalizing thermal processes.
Teaching at an American University, Takahashi finds, is a lot
different than teaching at a Japanese school. For one thing, U.S. students ask
questions, lots of them. And this Japanese professor, who now speaks fluent
English, likes the chance for discussion with his students. Takahashi also
likes the idea of homework in the U.S. educational system (though much abused
of late), feels it is much more effective than merely attending classes, as is
done in Japan.
At Berkeley, Takahashi is building a first-rate process-control
laboratory, a place where students can tinker with hardware; though he is the
first to admit that he is a theoretician. "To me," says the man who brought
frequency-response techniques to Japan, "controllers are just little black
boxes." But his eyes sparkle when the conversation gets back to
frequency-response techniques and how they can be applied to his favorite
study-thermal processes. |
