3. Controllers and controller types

The aim of control is that setpoint (reference variable w) and feedback value (controlled variable x) are identical. If this is not the case, the control difference e is not equal to zero and the controller tries to influence the controlled system using the manipulated variable y in accordance with the transfer function so that the controlled variable again approaches the reference variable.

In the following, we will introduce various controllers, their transmission behaviour and their properties.

3.2 Continuous controllers:
- Proportional controller (P)
- Proportional-Derivative controller (PD)
- Proportional-integraL controller (Pi)
- Proportional-integraL-Derivative controller (Pid)
- Direction of controller action

3.4 Discontinuous controllers
- Two-point controller
- Three-point controller

3.6 Controller setting, optimisation, quality
- Setting rules from Chien, Hrones and Reswick
- Setting rules from Ziegler-Nichols
- Empirical settings
- Assessment of control quality