Page "Control engineering" Paragraph 8

In contrast, modern control theory is carried out in the state space, and can deal with multi-input and multi-output ( MIMO ) systems.

This overcomes the limitations of classical control theory in more sophisticated design problems, such as fighter aircraft control, with the limitation that no frequency domain analysis is possible.

In modern design, a system is represented to the greatest advantage as a set of decoupled first order differential equations defined using state variables.

Nonlinear, multivariable, adaptive and robust control theories come under this division.

Matrix methods are significantly limited for MIMO systems where linear independence cannot be assured in the relationship between inputs and outputs.

Being fairly new, modern control theory has many areas yet to be explored.

Scholars like Rudolf E. Kalman and Aleksandr Lyapunov are well-known among the people who have shaped modern control theory.