30. CONTINUOUS CONTROL

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A controlled system includes,

- a basic system that does not achieve objectives by normal means - for our purposes a mathematical model a such a system is very important.

- some objective for the operation of the system.

- a controller that is matched to system, and tuned to meet the control objective.

Objectives for control systems might include,

- fast response

- stability

- energy efficiency

- etc.

The systems below are often directed by control systems.

Some Notes:

- Neither of these systems have controls.

- They both have inputs, and outputs.

- The output is not always something exiting the system. eg. the water tank height

is the system state.

- We can treat these systems with `black boxes' with lumped parameters.

All of the inputs and outputs are expressed as physical quantities (as will be seen later).