I worked in I&C for several years - both as a project engineer with a systems integrator and as a plant engineer - before going to graduate school. I found no shortage of challenges on the job. The field is very interdisciplinary, and you could find yourself designing a simple control system for HVAC control one day and setting up a OPC/ODBC connection between a data historian and an ERP system the next. Depending on the area of control they work in, controls engineers should have a good understanding of mathematics (uncertainty analysis, statistics and statistical process control), control and systems theory, along with:
mechanical engineering topics (kinematics, thermodynamics, heat transfer, fluid flow, hydraulics/pneumatics, mechanical equipment selection (e.g., valves, drive train parts), unit operations (e.g., HXs, compressors, chillers, boilers, pumps, blowers, turbines) etc.)
electrical/computer engineering topics (power systems and circuit protection, grounding and shielding, digital logic, analog systems theory, networking/communications, programming, database administration, PLC/DCS programming, instrumentation selection, etc.)
chemical engineering topics (chemical reactions, pH control and neutralization, process unit operations (e.g., reactors, distillation columns, separators, dryers), etc.)
I have found, though, that too many colleges focus too much on theory and not enough on application, especially at the graduate school level. Many of the advanced techniques for control I've learned are used in only a small selection of the applications, though I believe there is a lot of room for improvement in this area.
To paraphrase an anecdote I've read: a fairly new chemical engineering professor was taking his first sabbatical, and found a position with a company to gain practical experience. When he told them he taught process control, they put a drawing in front of him and told him to design a control system for the equipment on it. Not only did he not know where to start, he couldn't even read the standard industrial diagram. His knowledge of systems theory (transfer functions, Bode plots, root locus design, etc.) was sound, but he had not learned how to apply it to a real system. He realized this was the case for most students as well, going back generations.
Another story: a EE controls professor at my university had students figure out PID tuning parameters on a midterm. He gave them a transfer function and asked them to use Routh-Hurwitz analysis to find the gain at which the system would oscillate as well as its period of oscillation. Then they could use Ziegler-Nichols tuning formulas to come up with the parameter values. When I explained to him that many controls engineers in industry do not know the transfer function of the system they're working with, he was amazed. He asked how PID tuning was performed, and I told him that I either increased the gain of the controller with the integral and derivative turned off until I got oscillations, or I formed a first-order lag plus delay model by looking at a step response and calculated the tuning parameters given the model parameters. He looked dumbfounded. (Of course, this is the professor who asked if a PLC was an integrated circuit.)
Anyway, to wrap up this ramble, I think I&C is a fascinating field requiring a wide knowledge base and a lot of keeping up with new technology and products. I highly recommend it if you like to learn, but take what you learn in school with a grain of salt and gain all the practical experience you can from outside of school and books on practical (as opposed to theoretical) control systems design. Oh, and I have never found trouble finding a job with my skills.
xnuke
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