Control perspectives
In control perspectives, we’ll take the typical engineering approach to feedback structures, where there are three basic components of a feedback system: a sensing mechanism (something that senses a change), an actuation mechanism (something that is triggered), and a computation
(something that compares the output to the input and determines the controls).
Example applications
Engineers typically use feedback structures to read the input and ‘control’ the output, such as in amplifiers, robots controlled by servos, thermostats that control air conditioners or cruise control that adjusts the throttle in your car. Most systems could be improved by improving the sensing mechanism in a feedback structure. A good example of this is a washing machine cycle - modern machines will weigh the load to estimate how long the wash cycle will take. Note that they are probably measuring the wrong thing, and a better feedback structure might look at how dirty the clothes actually are!
Basics
Identify the input and output signals, what the control mechanism is, and how the signals are measured in the sensor mechanism. A key way to improve the output of the system (other than changing the structure) is to increase the sampling rate, but this often comes at the expense of processing power.
Key concepts
- an explanation of a control system, and the key elements within it
- an example that conceptually walks through a relevant control system and identifies the key mechanisms
- advice to the student engineer on how to optimise one aspect of the control system
Core resources
A great overview of engineering control systems is in:
- Astrom, KJ and RM Murray (2009) Feedback Systems: An Introduction for Scientists and Engineers, Princeton University Press. See Chapter 1 (PDF)
There are also some great examples of engineering control systems in Chapter 3.
Similar tools…
Control systems can even be seen in social systems. System Dynamics modelling, the basis of ENGN3410 Engineering Sustainable Systems, explores this approach.