Methods for fault diagnosis in rail vehicle traction and braking systems

A number of techniques are available for improving reliability and avoiding unplanned maintenance in rail vehicle traction and braking systems. In this paper, the most relevant techniques, from classical monitoring to the more recent model-based methods, are reviewed. Although available for some years, many of the classical methods are often not used because of the added instrumentation cost. With increasingly tighter slip and slide control requirements, more sophisticated control strategies, many of which make use of state variable observers, are being used. As a result, the use of modern fault detection algorithms are enabled at little extra cost. Possibilities for observer design for fault tolerant control in the face of sensor failures are also explored. (13 pages)