Patent ID: 7412299

Claim:
A method of determining at least one condition variable from a model of an RTP system by means of at least one measurement signal, the measurement value, detected at the RTP system and having dependency upon the condition variable that is to be determined, and by means of a measurement value, the predicted value, predicted by means of the model, wherein the measurement value and the predicted value each comprise components of a constant portion and a changeable portion, the method including the steps of separately establishing at least the changeable portion by a filter to form a first difference between the changeable portion of the measurement value and the changeable portion of the measurement value predicted by the model; adapting at least one model parameter by feeding the first difference back into the model with the aim of adapting the model behavior to variable system parameters; forming a second difference from the measurement value and the predicted value, or from the measurement value corrected by the changeable portion and the predicted value corrected by the changeable portion; correcting a condition of the model system by feeding the second difference back into the model with the aim of bringing the condition of the model system into correspondence with that of the real system; and detecting at least one condition variable from the model.