Störungswert

Störungswert is a term used in German engineering, metrology and signal processing to denote the value of a disturbance that affects a system, signal or measurement. It represents the part of a measured quantity that does not reflect the true quantity of interest, but rather results from external or internal perturbations such as interference, drift, or noise.

In practice, the concept is closely related to the ideas of disturbances and noise. The true or desired quantity is often called the Sollwert or target value, while the actual measurement is the Istwert. The Störungswert describes the deviation induced by disturbances from the intended signal. Störungen can be external (electromagnetic interference, temperature fluctuations, mechanical vibrations) or internal (sensor bias, aging, nonlinearities).

Modeling and handling of the Störungswert are central to control theory and signal processing. Disturbances are frequently modeled as a stochastic process or as a deterministic input w(t) that affects the plant or measurement. Depending on the application, assumptions about the disturbance—such as bounds, statistical properties, or frequency content—guide the design of estimators, filters, and controllers intended to reject or attenuate the disturbance’s impact.

Examples include a temperature sensor reading influenced by nearby equipment, where the Störungswert adds to the true temperature, or a control system where external vibrations perturb the actuator signal. Reducing the influence of Störungswert typically involves shielding, calibration, filtering, and feedback control strategies.

Overall, the Störungswert is a key concept for understanding and mitigating measurement and control errors arising from disturbances in technical systems.