Modern control theory is carried out in the [[State space (controls)|state space]], and can deal with [[Multiple-input multiple-output system|multiple-input and multiple-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 equation]]s defined using [[state variables]]. [[Nonlinear control|Nonlinear]], [[multivariable control|multivariable]], [[adaptive control|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.{{Citation needed|reason=No citation or explanation on this generic claim|date=November 2019}} Being fairly new, modern control theory has many areas yet to be explored. Scholars like [[Rudolf E. Kálmán]] and [[Aleksandr Lyapunov]] are well known among the people who have shaped modern control theory.
