摘要 |
The precision of a closed loop control system, for example of a loss-in-weight feeder, having a controlled operating section and a closed loop controlling section, is improved by adjusting the closed loop controlling section with regard to at least two stochastic precision disturbing signals. One such signal may represent disturbances that affect a sensor for ascertaining the actual weight of the scale. The other value may represent estimated bulk material density variations or disturbances. A model generator (7) provides spectra representing these disturbing values. A noise parameter estimator (17) selects those spectra most closely resembling the spectra of the disturbing values for producing an adjusting signal that is used to adapt the closed loop controlling section (5) to an optimal control. The closed loop controlling section (5) has connected thereto an evaluating circuit (14) including the model generator (7) for performing the correction or adjustment.
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