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Despite his name, Hendrik Wade Bode was a genuine mid-western American, having been born in 1905 in Madison, Wisconsin, gone to school in Urbana, Illinois and graduated from the Ohio State University in 1926. He then entered the Bell Telephone Laboratories as a mathematician. Bode eventually became Vice President of the Bell Laboratories, and when he retired in 1967 he was immediately awarded a chair in Systems Engineering at Harvard University. |
In his early years at the Bell Laboratories Bode concentrated on the development of a rigorous foundation for electrical network theory, which included extensions of Nyquist's work on feedback amplifiers. Most of you will have encountered this through the 'Bode Plot', an elegant method of displaying network characteristics which he devised.
You will probably not have encountered his textbook 'Network Analysis and Feedback amplifier Design', which is no longer in print, but in my opinion is the finest textbook on electrical circuit theory ever produced. When the war started in 1939 Bode was diverted to work on Fire Control Systems. The basic problem was to use advances in technology to improve methods of shooting down enemy aircraft. To achieve this it was necessary to first detect the aircraft's position, current speed and flight direction by using the new radar systems, then to use this data to obtain a 'best estimate' of where the aircraft would be in 'x seconds' time and finally to aim and fire a gun so that its shell would arrive at the same spot at the same time. The process had to take into account possible changes in the aircraft's flight path during the x seconds involved. Because of the rapid responses needed it had to be carried out automatically, so the process involved a complex combination of information theory, data processing and control system theory.
This work was in fact the real starting point for modern control system design and was also the predecessor to the development of electronic computers.
It is a sad fact that wars are often the stimulus for major scientific advantages. The present threat of a war with Iraq might well be the stimulus for significant advances in medicine and biology, now that biological warfare is a major concern.
Bode characterised the convergence of control and communications as "a sort of shotgun marriage". He was awarded the Presidential Certificate of Merit for his work in this area in 1948.
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