Steady state

A steady state, and steady state refers to the state in the theory of stability of a system which is free from initial or non-stationary input signals. A system is in a steady state, so it is always stable. By intervening in the system is also this stable state and the system changes can no longer be regarded as settled.

Under input signals signals or actions are meant (more precisely, the state variables ) manipulate the state of the system. For example, the striking or the deflection of a string from hibernation is such an input signal. If the vibration of the string is no longer of deflection ( initial condition ) or striking ( input pulse ) depends on the system state has settled. The string (the system ) is therefore in the steady state.

Non-stationary signals are not constant over time. An example of this would be playing on the string: there is no clear rule as to when the string is struck how much and in what frequency. The state of the system can therefore be referred to as non-stationary. Are the factors of such signals subsided, so the system returns to a steady state.