Optical signal processing for fiber Bragg grating based wear sensors

In this study, we propose a simplified signal processing scheme for fiber Bragg grating (FBG) based wear sensing. Instead of using a chirped FBG and detecting the bandwidth, we use uniform gratings as sensors and measure the optical power reflected by the sensing grating to determine the length of the sensor grating, hence detect the wear. We demonstrate by the experiments that the proposed method is feasible and practical. The advantage of the proposed method lies in the fact that structure of the wear sensing system is simplified and therefore the cost can be significantly reduced. The principle of the proposed method, the design of the wear sensor, and the experiments are described

On line estimation of rolling resistance for intelligent tires

The analysis of a rolling tire is a complex problem of nonlinear elasticity. Although in the technical literature some tire models have been presented, the phenomena involved in the tire rolling are far to be completely understood. In particular, small knowledge comes even from experimental direct observation of the rolling tire, in terms of dynamic contact patch, instantaneous dissipation due to rubber-road friction and hysteretic behavior of the tire structure, and instantaneous grip. This paper illustrates in details a new powerful technology that the research group has developed in the context of the project OPTYRE. A new wireless optical system based on Fiber Bragg Grating strain sensors permits a direct observation of the inner tire stress when rolling in real conditions on the road. From this information, following a new suitably developed tire model, it is possible to identify the instant area of the contact patch, the grip conditions as well the instant dissipation, which is the object of the present work

A multisensing setup for the intelligent tire monitoring

The present paper offers the chance to experimentally measure, for the first time, the internal tire strain by optical fiber sensors during the tire rolling in real operating conditions. The phenomena that take place during the tire rolling are in fact far from being completely understood. Despite several models available in the technical literature, there is not a correspondently large set of experimental observations. The paper includes the detailed description of the new multi-sensing technology for an ongoing vehicle measurement, which the research group has developed in the context of the project OPTYRE. The experimental apparatus is mainly based on the use of optical fibers with embedded Fiber Bragg Gratings sensors for the acquisition of the circumferential tire strain. Other sensors are also installed on the tire, such as a phonic wheel, a uniaxial accelerometer, and a dynamic temperature sensor. The acquired information is used as input variables in dedicated algorithms that allow the identification of key parameters, such as the dynamic contact patch, instantaneous dissipation and instantaneous grip. The OPTYRE project brings a contribution into the field of experimental grip monitoring of wheeled vehicles, with implications both on passive and active safety characteristics of cars and motorbikes

Photonic sensors based on flexible materials with FBGs for use on biomedical applications

This chapter is intended for presenting biomedical applications of FBGs embedded into flexible carriers for enhancing the sensitivity and to provide interference-free instrumentation.This work was fully supported by the Algoritmi’s Strategic Project UI 319-2011-2012, under the Portuguese Foundation for Science and Technology grant Pest C/EEI/UI0319/2011

Smart Textiles Production

The research field of smart textiles is currently witnessing a rapidly growing number of applications integrating intelligent functions in textile substrates. With an increasing amount of new developed product prototypes, the number of materials used and that of specially designed production technologies are also growing. This book is intended to provide an overview of materials, production technologies, and product concepts to different groups concerned with smart textiles. It will help designers to understand the possibilities of smart textile production, so that they are enabled to design this type of products. It will also help textile and electronics manufacturers to understand which production technologies are suitable to meet certain product requirements

Generator Insulation-Aging On-Line Monitoring Technique Based on Fiber Optic Detecting Technology

The relationship between insulation aging and generator lifespan using fiber optic sensors (FOSs) is explored to ultimately improve asset lifespan through smart choices in running conditions and maintenance. Insulation aging is a major factor that causes generator failure. FOS provides the rare opportunity of being installed up close to the insulation, monitoring degradations that are otherwise difficult to detect. FOSs, unlike purely electrical transducers, are immune to high voltage (HV) and strong electromagnetic (EM) fields. They are small and have a proven long life by their deployment in the Telecom industry. The proposed FOS is a Fabry-Perot cavity made up of two identical fiber Bragg gratings (FBGs) using light wave interference as the working principle. Such architecture delivers simultaneous vibration (10 Hz–1 kHz) and temperature (0.1°C resolution) monitoring, both helping to spot irregular vibration patterns (signatures) and hot-spots inside the generator stator slots. The signal processing unit equipped with a gateway device can help to connect the large volume of sensor data, allowing correlation with the supervisory control and data acquisition (SCADA) system data of the plant. This chapter also elaborates on the field test jointly conducted with Calpine Corporation and Oz Optics, Ltd. (Ottawa, Ontario, Canada)

Diagnosis of broken bar fault in three-phase induction motors using fibre bragg grating strain sensors assisted by an algorithm

Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do ParanáIn this study, we developed an algorithm for identifying failures caused by broken bars in the rotors of three-phase induction motors through the analysis of their dynamic deformation using fibre optic Bragg gratings (FBGs) as sensing elements. The analysis of dynamic deformation enables the detection and diagnosis of various mechanical faults, such as misalignment, imbalance, bearing failures, and mechanical looseness. Furthermore, it allows for the identification of electrical faults, such as fractures or cracks in the rotor rings or bars To measure the dynamic deformation, we employed FBG-based sensors known for their key features, including high multiplexing capability, electromagnetic radiation immunity, and long-distance operation. Experimental tests were conducted on a small-scale induction motor (3 HP) to validate the method and explore its applicability to medium and large-scale machines. The motor was powered by two different supply sources: the utility power grid and a controled power sources, under load conditions of 75% and 100% of the rated load. During the tests, we used a rotor without any bar defects and subsequently a rotor with a broken bar. The presence of a broken bar was successfully identified under both load conditions and across all two power supply sources. The fault caused by the broken bar in the rotor was detected in two frequency regions obtained from the three sets of experiments. The first region was centred around the mechanical rotational frequency of the rotor, while the second region was approximately twice the electrical frequency of the power supply. The system demonstrated high sensitivity with a good signal-to-noise ratio and showcased advantages over conventional methods and sensors commonly used for identifying broken bar faults in induction motors.Neste estudo, desenvolvemos um algoritmo para identificar falhas em barras quebradas no rotor de motores de indução trifásicos por meio da análise da deformação dinâmica do estator usando grades de Bragg em fibras ópticas (FBGs) com assitência de um algoritmo. Essa análise possibilita a detecção e o diagnóstico de várias falhas mecânicas, como desalinhamento, desbalanceamento e folga mecânica. Além disso, permite a identificação de falhas elétricas, como fraturas ou rachaduras nos anéis ou barras do rotor. Para medir a deformação dinâmica, empregamos sensores baseados em FBG conhecidos por suas principais características, incluindo alta capacidade de multiplexação, imunidade à radiação eletromagnética e operação a longa distância. Testes experimentais foram conduzidos em um motor de indução em pequena escala (3 HP) para validar o método e explorar sua aplicabilidade em máquinas de médio e grande porte. O motor foi alimentado por duas fontes de alimentação diferentes: a rede elétrica de utilidade pública e por uma fonte controlada, sob condições de carga de 75% e 100% da carga nominal. Durante os testes, utilizamos um rotor sem defeitos no rotor e, posteriormente, um rotor com uma barra quebrada. A presença da barra quebrada foi identificada com sucesso em ambas as condições de carga e em todas as duas fontes de alimentação. A barra quebrada no rotor foi detectada em duas regiões de frequência obtidas a partir dos três conjuntos de experimentos. A primeira região estava centrada em torno da frequência rotacional mecânica do rotor, enquanto a segunda região era aproximadamente o dobro da frequência elétrica da fonte de alimentação. O sistema demonstrou alta sensibilidade com uma boa relação sinal-ruído e apresentou vantagens sobre os métodos convencionais e sensores comumente usados para identificar falhas em barras quebradas em motores de indução

Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology

INE/AUTC 10.0

Review on Strain Monitoring of Aircraft Using Optical Fibre Sensor

Structural health monitoring of aircraft assures safety, integrity and reduces cost-related concerns by reducing the number of times maintenance is required. Under aerodynamic loading, aircraft is subjected to strain, in turn causing damage and breakdown. This paper presents a review of experimental works, which focuses on monitoring strain of various parts of aircraft using optical fibre sensors. In addition, this paper presents a discussion and review on different types of optical fibre sensors used for structural health monitoring (SHM) of aircraft. However, the focus of this paper is on fibre bragg gratings (FBGs) for strain monitoring.  Here, FBGs are discussed in detail because they have proved to be most viable and assuring technology in this field. In most cases of strain monitoring, load conditioning and management employs finite element method (FEM). However, more effort is still required in finding the accurate positions in real time where the sensors can be placed in the structure and responds under complex deformation