Piezoelectric sensors and actuators are the bridge between electronic and mechanical systems in structures. This type of sensor is a key element in the integrity monitoring of aeronautic structures, bridges, pressure vessels, wind turbine blades, and gas pipelines. In this paper, an all-in-one system for Structural Health Monitoring (SHM) based on ultrasonic waves is presented, called Phased Array Monitoring for Enhanced Life Assessment. This integrated instrument is able to generate excitation signals that are sent through piezoelectric actuators, acquire the received signals in the piezoelectric sensors, and carry out signal processing to check the health of structures. To accomplish this task, the instrument uses a piezoelectric phased-array transducer that performs the actuation and sensing of the signals. The flexibility and strength of the instrument allow the user to develop and implement a substantial part of the SHM technique using Lamb waves. The entire system is controlled using configuration software and has been validated through functional, electrical loading, mechanical loading, and thermal loading resistance tests.

The goal of the research presented in this paper is to design and incorporate new technologies into railway bogie-mounted sensors. It is often impossible to connect the mounted systems to physical wires due to their location in an inaccessible position or the distance to the energy source. Therefore, another power source must be used to solve this problem. Energy harvesting technology is an increasingly popular solution that extracts energy from the ambient environment and transforms it into electrical energy. Using piezoelectric transducers, it is possible to transform the vibrations experienced by the bogie into energy that can be used to power the sensors. A prototype with multiple piezoelectric transducers has been designed, built and subjected to tests to validate the technology. The experimental results for all of the different configurations tested and levels of energy collected are presented.

This Note introduces a novel methodology to analyze the time performance of Bluetooth gateways in multi-hop networks, known as scatternets. The methodology is focused on distinguishing between the processing time and the time that each communication between nodes takes along an implemented scatternet. This technique is not only valid for Bluetooth networks but also for other wireless networks that offer access to their middleware in order to include beacons in the operation of the nodes. We show in this Note the results of the tests carried out on a Bluetooth scatternet in order to highlight the reliability and effectiveness of the methodology. The results also validate this technique showing convergence in the results when subtracting the time for the beacons from the delay measurements.

The goal of this paper is to present both the development of an intelligent sensor that can be used to obtain information about the existence of rolling contact fatigue cracks created by wheel-rail interactions and also the data obtained in a real-world study performed for its validation. The design of a bogie-mounted instrumentation system to detect and measure wheel rolling in railway units is introduced, and experimental results are presented. The system is designed to analyse and compare the angular velocity of the wheels of a railway unit. It uses photodiodes to acquire information about rolling conditions and a radio frequency link to send that information to a data logger, which acquires and saves the data for post-processing and analysis.

Abstract. In this paper, the design, implementation and testing of a prototype for electric energy generation from collecting wasted ambient power sources coming from the mechanic vibrations (Piezoelectric Energy Harvesting PEH) is presented. This prototype has been specifically designed for applications where it is required to connect multiple transducers in order to obtain greater power levels. This design is based on a previous comparative analysis among all the existing auto-harvesting circuits. The prototype has been tested both in laboratory tests as in real field trials on board railway units, with encouraging results. It has been proved that, though achieving power levels of a few milliwatts, its application in the autonomous low-consumption devices powering systems field is a real possibility.