Störgrößen

Störgrößen, a German term, translates to "disturbance variables" or "interfering variables" in English. In the context of control systems and process engineering, Störgrößen are external influences that can negatively affect the desired output or behavior of a system. They are factors that are not directly controlled by the system's actuators but can alter the system's state.

These variables arise from the environment in which a system operates or from unpredictable internal events. Examples include variations in ambient temperature, fluctuations in power supply, mechanical vibrations, or changes in the properties of input materials. The presence of Störgrößen can lead to deviations from the setpoint or target value, potentially compromising the system's performance, accuracy, and stability.

Control systems are designed with the explicit goal of minimizing or compensating for the effects of Störgrößen. This is often achieved through feedback mechanisms. A controller monitors the system's actual output and compares it to the desired output. If a difference exists, likely due to a Störgröße, the controller adjusts the system's input to counteract the disturbance and bring the output back to the target. Techniques like feedforward control can also be employed to anticipate and mitigate the impact of known or measurable Störgrößen before they affect the system. Understanding and managing Störgrößen is fundamental to robust and reliable system design.