Control system

Summary

A control system is a dynamical system whose evolution depends on an input that can be chosen, the control. For systems governed by ordinary differential equations it has the form $x' = f(x, u)$, where $x$ is the state and $u$ is the control. It is the basic object of control theory. That theory asks which states can be reached, how to steer the system, and how to do so in the best way.