I recently revisited some texts on control theory. In some textbooks the term compensator is used, seemingly interchangeably with controller (see e.g. The Control Handbook by Levine, chapter 14 on classical control system design methods).
This confuses me. In my field (aerospace engineering), we always talked about controllers. Since it's some time since my days at university I may have missed/forgotten some subtle differences...
Please help me to understand the difference:
- What is the (technical) difference between a compensator and a controller?
- When do you call it one way or the other?