Abstract: A method and device for detecting a derailment state of a rail vehicle, wherein at least one kinematic variable is respectively measured via first and second sensors with respect to first and second wheelset end portions and corresponding measurement signals are formed, processed and evaluated, where values of first and second falling velocities y with respect to the first and second wheelset end portions are respectively calculated from the measurement signals via a computing unit and a derailment state of the rail vehicle is detected via a first comparison operation of the first falling velocity and the second falling velocity with a first falling velocity limit value and a second falling velocity limit value, which has a greater magnitude than the first falling velocity limit value such that a high level of certainty in the detection of derailment states is achieved.

Abstract: A method detects a defect in an acceleration sensor. In order to be able to reliably detect a defect in an acceleration sensor, the acceleration sensor generates a signal which is checked during a test as to whether a variable dependent on the signal fulfills a predefined condition with respect to a reference value and, on the basis of the test, it is determined whether the acceleration sensor is defective.

Abstract: A method and a device for the recognition of a derailment state of a wheel (RAD) of a rail vehicle. The acceleration of the wheel (RAD) is measured perpendicularly to a rail plane (?) with at least one acceleration sensor (SEN), whereby from an acceleration signal (BSI) generated by the acceleration sensor (SEN) by means of simple integration (INT) over a time window of predeterminable magnitude, one determines a fall speed (FAG) of the wheel (RAD) in the direction of the rail plane (?), and whereby on the basis of the determined fall speed (FAG), one examines whether a derailed state exists.