Control concept,which includes all state variables which influence the system's behaviour in the (e.g. positions, pressures, velocity, acceleration, amongst others).
For example, for a closed loop position control system, this means that it is underlain by the velocity and acceleration in minor loops.
The state controller is therefore particularly well suited to controlled subsystems that are hard to stabilise or subsystems with a low natural damping, as it generates sufficient damping at higher loop gains.
The state controller is different to a cascaded (multi loop) control system in that all branches are fed back to an addition point and are jointly optimised (Figure Z 10).
If the state variables cannot be measured for technical reasons, they can be introduced by status monitors.
In the case of the closed loop position control systems in fluid technology it has been shown that a combined feedback of the velocity and acceleration produces the best results in terms of pilot control behaviour and interference response (Figure Z 11).
The observer control technology can also be used in the case of non-linear controllers (Figure Z 12).
Figure Z 10: State controllers
Figure Z 11: Step response in the case of a state controller with observer
Figure Z 12: Status monitors in the case of non-linear controllers