Method and apparatus for determining changes in the longitudinal dynamic behavior of a railway vehicle

An apparatus for determining changes in the longitudinal-dynamic behavior, in particular of an undercarriage, of a railway vehicle for identifying a current driving condition of the railway vehicle, comprising:

• a control unit and at least one sensor unit for providing a respective measuring signal, wherein the control unit is configured to reconstruct and evaluate variables, which cannot be measured and which characterize the longitudinal-dynamic behavior, via a system model of the railway vehicle by means of a cybernetic observer from a known or metrologically determined input signal and the at least one measuring signal of the observed railway vehicle as an observed real reference system,
• wherein the control unit is further configured to compare the at least one measuring signal of the observed railway vehicle and a corresponding reconstructed measuring signal of the system model and to recursively track, with a regulator, the deviation determined by comparison so that the determined deviation is minimized.