Railway switch and crossing (S&C) systems have a very complex structure that requires not only a large number of components (such as rails, check rails, switches, crossings, turnout bearers, slide chair, etc.) but also different types of components and technologies (mechanical devices to operate switches, electrical and/or electronic devices for control, etc.). This complexity of railway S&C systems makes them vulnerable to failures and malfunctions that can ultimately cause delays and even fatal accidents. Thus, it is crucial to develop suitable condition monitoring techniques to deal with fault detection and diagnosis (FDD) in railway S&C systems. The main contribution of this paper is to present a comprehensive review of the existing FDD techniques for railway S&C systems. The aim is to overview the state of the art in rail S&C and in doing so to provide a platform for researchers, railway operators, and experts to research, develop and adopt the best methods for their applications; thereby helping ensure the rapid evolution of monitoring and fault detection in the railway industry at a time of the increased interest in condition based maintenance and the use of high-speed trains on the rail network.

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This paper proposes a model-based fault detection (FD) method with application to railway switch & crossing (S&C) systems. These systems are safety critical assets in the rail network and they daily exposed to harsh working conditions and severe environment, which make them more vulnerable to failures and breakdowns. Therefore, it is critical to implement a condition monitoring (CM) technique to enhance the reliability and the availability of these S&C systems. To-the-end of reducing the scheduled maintenance process and decreasing the possible number of delays and/or accidents. This paper thus, proposes a simple model-based technique, a modified residual-based technique, which can be implemented in the real rail network for FD with application to railway electro-mechanical switch system.

This paper presents a global characterization and an analytical model of the static flow stage of an electro-pneumatic proportional valve FESTO MPYE-5-M5-010-B. This study is useful for linear or nonlinear control synthesis in our application for medical robotics. Firstly, the experimental measurements are carried out using 3D graphs where a set of curves gives the output mass flow rate as a function of the electrical input of the electronic stage for different values of the output pressure. The exhaust and supply pressures, during these tests, are assumed to be constant. Moreover, 2D classical curves given by some constructors can be reconstructed, such as mass flow gain, pressure gain and mass flow characterization. Secondly, an approximation of the mass flow stage characteristics of this five-way proportional valve by a polynomial function is described. The model elaborated enables a good reproduction of the pressure gain and the global mass flow characterization curves to be obtained.