The condition monitoring of an overhead contact line (OCL) is investigated by developing an innovative monitoring system for a pantograph on an electrical multiple unit of a regional line. Kinematic and dynamic modelling of the pantograph is conducted to support the designed monitoring system. The modelling is proved through rigorous test-rig experiments, while the proposed methodology is then validated through extensive field tests. The field tests serve a dual purpose: First, to validate the monitoring system using benchmark measurements of the tCat (R) trolley, and second, to assess the reproducibility of measurements in a realistic case. This paper presents the OCL monitoring system developed in the framework of the H2020 project SIA. The accuracy of our results is not far from that of other commercial systems, with just 12 mm of absolute error in the height measurement. Therefore, they provide reliable information about trends in various key performance indicators (KPIs) that facilitates the early detection of failures and the diagnosis of anomalies. The results highlight the importance of model calibration and validation in enabling novel health monitoring capabilities for the pantograph. By continuously monitoring the parameters and tracking their degradation trends, our approach allows for optimized scheduling of maintenance tasks for the OCL.

In recent years, the integration of Digital Twins (DT) for the adoption of smarter maintenance strategies has grown exponentially in different industrial sectors. New IoT and edge computing systems are being developed for this purpose, however, there are still some open issues and challenges to be solved. Firstly, this paper presents new approaches to the initial dependencies of the studied solution and make a new proposal to improve the interoperability of the presented system. Secondly, this paper provides a methodology applicable to similar developments of edge-based AI (Artificial Intelligence) solution, which comprises of four phases: the presentation of the multi-objective problem and the pre-selection of AI-based models, the description of the evaluation architecture, the profiling of the different models for the selection of the most suitable one and explainable AI strategies for getting insights of the selected model. Finally, it presents a use case of an edge-solution for the railway catenary geometry diagnostic (stagger amplitude of the overhead wire), saving the interoperability of the message exchange with other systems is provided.

This paper deals with the stability analysis of two haptically-coupled devices. It describes how to model this kind of systems and shows how to obtain stable linking impedances. The approach is applied to an experimental setup that consists of a bimanual driving system in which both devices are haptically coupled. Four different cases depending on system dynamics are considered: 1) identical rigid devices, 2) different rigid devices, 3) different devices with vibration modes, and 4) mechanically-linked devices with vibration modes. The theoretical analysis is validated with experiments carried out on a driving simulation platform. The influence of the human operator is also experimentally discussed. Results can be extended to other applications where two haptic devices are used to hold virtual objects.

The stability of haptic rendering is affected by many factors that limit the range of impedances that can be applied to virtual objects. This paper addresses the effect of the vibration modes of the haptic interface on the stability of the impedance control loop. It is well known that experimental stability boundaries present complex shapes, making it difficult to predict the final Z-width of the haptic system. This paper shows how the vibration modes of the mechanical interface highly affect the size of the Z-width, causing a sudden reduction in the critical virtual stiffness K if the virtual damping B is increased beyond a certain value. The inclusion of the most significant vibration modes in the theoretical model of the haptic system-together with the viscous damping, time delay and sampling rate-makes it possible to obtain the stable impedances associated with the haptic device. A PHANToM Premium 1.0 haptic interface was used as a test bed to validate this paper. Although results have been tested only on this device, this paper proposes a methodology for obtaining the Z-width that can be generalized for any other haptic system.

This paper presents a new mechatronic system that combines the capabilities of the steering wheel, the throttle and brake pedals in a single all-encompassing device. A two degreeof-freedom mechanism allows controlling all driving functionalities together in a very ergonomic and original way. The system uses drive-by-wire technology with haptic feedback for an outstanding driving experience. The device has been tested in a simulation platform, showing similar performance to conventional set of steering wheel and pedals, and very good acceptance among users. This work also surveys current drive-by-wire systems in the automotive industry and the use of haptic technology to assist drivers.