A funny thing happened about forty or fifty years ago. Engineers, as a group, made one of the most important discoveries of the twentieth century. The odd thing is that no one ever talks about it. They don't teach about it in engineering school. Yet most technical progress in the latter half of the twentieth century depends upon it. The reason no one talks about it directly is that it's kind of embarrassing. In the process of building ever more sophisticated hardware we found out we weren't smart enough.
When I was working on my Bachelors degree in physics, I made ends meet by shuffling paper in a large hospital part time. We used a database that ran on a mysterious mainframe computer in another building. We talked to the mainframe by means of these big Burroughs computer terminals. I still remember looking through the air vents on one of the terminals and marvelling at the complexity. I saw several printed circuit boards, each about a foot square. Each board was studded with hundreds of mysterious electronic doodads. Colorful little resistors, diodes, capacitors, and those mysterious black integrated circuits looking, for all the world, like little stylized insects. At the time I thought to myself that the electrical engineers who designed those terminals must have been like gods. I just couldn't imagine how human beings could have ever managed to design something so complex. I figured they must be the brightest people in the world and there was no point in someone as stupid as me trying to figure it out. I felt like a dog trying to understand a remote control for a VCR.
When it was time to graduate, I decided I didn't want to get a real job. Instead I started looking into doing graduate work. Of all things I fell into electrical engineering. Despite being initially intimidated, I was surprised to find it was not all that hard. Why the change of heart? I learned a secret...
It's not a secret people are hiding. It's just one that nobody ever talks about. Electrical engineering at the beginning of the 20th century was practically anti-intellectual in its rejection of mathematical methods. People like Oliver Heaviside were ridiculed for trying get people to apply transform theory. But like many things, the revolutionary ideas became orthodoxy by the 1940s.
The 40s and 50s were a golden age for control theory. Huge progress was made. The standard texts by D'azzo & Houpis, Truxal, and Gibson were written.
Control theory in many ways became the heart of electrical engineering. And where it wasn't directly applicable, like in finite automata, the lessons of functional compartmentalization were taken to heart.
So what's the problem? Control theory reached its zenith in the 1950s and what is mostly taught and published is mathematical garbage. The key to success in academia is publishing papers, Nice complicated mathematical papers. The problem is, there isn't much worth saying after what was developed forty years ago. That minor rub will not stop people of course who are trying to make their marks. Hence we have Optimal Controls, Fuzzy Controls, Modern Controls, and other mathematical marvels that in all fairness add very little to actually making things that work.
Why? Because the dirty little secret of control theory is this:
Mind you, there are systems which are so nasty and unstable (like helicopters) that complex high order analysis is essential. However, systems like these are rare, far between and most engineers will never have to deal with them.
So? Control system design is mostly low order analysis coupled with common sense to deal with non-linearities. You don't need anything more modern than Gibson's Nonlinear Automatic Control published forty years ago. Sadly very few profs want to admit this or, heaven forbid, actually teach it that way. Ah well...