Branches of Control Engineering

Here we are going to give a brief listing of the various different methodologies within the sphere of control
engineering. Oftentimes, the lines between these methodologies are blurred, or even erased completely.

Classical Controls
Control methodologies where the ODEs that describe a system are transformed using the Laplace, Fourier,
or Z Transforms, and manipulated in the transform domain.

Modern Controls
Methods where high-order differential equations are broken into a system of first-order equations. The
input, output, and internal states of the system are described by vectors called "state variables".

Robust Control
Control methodologies where arbitrary outside noise/disturbances are accounted for, as well as internal
inaccuracies caused by the heat of the system itself, and the environment.

Optimal Control
In a system, performance metrics are identified, and arranged into a "cost function". The cost function is
minimized to create an operational system with the lowest cost.

Adaptive Control
In adaptive control, the control changes it's response characteristics over time to better control the system.

Nonlinear Control
The youngest branch of control engineering, nonlinear control encompasses systems that cannot be
described by linear equations or ODEs, and for which there is often very little supporting theory available.

Game Theory
Game Theory is a close relative of control theory, and especially robust control and optimal control
theories. In game theory, the external disturbances are not considered to be random noise processes, but
instead are considered to be "opponents". Each player has a cost function that they attempt to minimize,
and that their opponents attempt to maximize.