ABSTRACT
The chapter discusses problems related to the diagnosis of structural health of rail vehicles for rapid transportation. It presents fundamentals of diagnosing theory for mechanical systems and an example of its application in monitoring structural health of technical objects such as HSR vehicles. A basic parameter of the diagnosing process is a diagnostic signal, which must satisfy appropriate requirements in order to be employed in the diagnosing process; the requirements are related to sensitivity, uniqueness, stability and informative content with respect to a change of the structural health of the object. Satisfying these conditions is decisive in accepting a diagnostic method and a model, which are adequate for the real object being diagnosed.
An example of a monitoring system for rail vehicles is presented later in the text. The following are discussed: assumptions accepted at the stage of designing the system, structure of the system and a monitoring procedure. Besides, the process of building, testing and investigating a system prototype in laboratory and real conditions is described. The system has been built in two versions: a version for light rail vehicles, such as a tramway, and a version for passenger rail vehicles. Both versions of the system have been enhanced by introducing a capability of diagnosing the structural health of the track on the basis of the recorded signals representing accelerations at the axle-boxes of the wheelsets. Diagnostics of the structural health of the vehicles and the track is realized in on-line mode. The second version of the system was installed in a vehicle type of ED74 electric train unit. This is a passenger vehicle manufactured by Polish manufacturer PESA Bydgoszcz Company Ltd. It is designed for interregional transport at the maximal speed of 160 km/h. The text presents exemplary results of the tests as well as results of a current monitoring of the structural health of the vehicle and the track, performed during regular operational rides, along selected rail routes of the Polish State Railways, Inc. (PKP S.A.).
The developed systems and the installed software make impossible to manage signals and to comprehensively identify events, which took place along the route, while riding under operational conditions. Identification of the events makes it possible to answer the following questions: where a given event took place (with a desired accuracy), what is the structural health of the track at that spot, and how the vehicle behaved along the route (with respect to its dynamics, ride comfort or other parameters decisive in safety of the passengers) prior to an ensuing event. The system is also capable of sending a warning signal to the operator of the vehicle or a manager of the railway traffic.
