INTO THE 21ST YEAR
This is the year of the 7th IFAC Congress, and it is the year when IFAC advances into maturity--if transition from its 20th to 21st year may be compared with that of human growth. To commemorate this event, a special article has been compiled for this issue by Professor Pieter Eykhoff, a member of the IFAC Executive Council and a former Honorary Editor of IFAC, and it is called "IFAC, 20 Years Old, 20 Years Young". It provides a brief history of IFAC, its birth, evolution, and the principles on which it was founded. It also contains a brief glimpse of some personalities which helped make IFAC a successful international organization.
Soon after IFAC was founded, some rather revolutionary scientific and engineering changes occurred which directly and indirectly began to affect the development of automatic control and of IFAC itself. Within a few weeks after IFAC was founded, in the first week of October 1957, Sputnik, the first orbiting satellite, was launched, and the next year, on October 26, 1958, the first commercial jet flight across the Atlantic began, and distances around the world were effectively halved. In his contribution to the special anniversary article, first IFAC President Harold Chestnut notes that the operation and success of IFAC was considerably enhanced by the latter event.
Only a short time later, the reliability and availability of large digital computers increased to the point where solutions to previously unsolvable control systems problems could be found by a large number of researchers. To a considerable extent this encouraged the development of new mathematical control theory particularly with respect to optimal filtering and the control of large scale systems. Thus, during the early 1960's, emphasis was placed on theory and analysis techniques which involved state vector and matrix representations of systems having multiple inputs and outputs. Actual applications of control theory were not given much emphasis in the literature although new types of control systems using on-line digital computers and data processors were being developed experimentally.
Actually, the ever present, but necessary, gap between control theory and its application appeared to increase rapidly in the early 1960's, not only because of the introduction of mathematics and terminology, completely new to engineers, but also because problems were formulated in precise mathematical language and conditions for