The conventional way of studying corrosion in marine environments is by installing corrosion coup... more The conventional way of studying corrosion in marine environments is by installing corrosion coupons. Instead, this paper presents an experimental field study using an unattended corrosion sensor developed on the basis of ultrasound (US) technology to assess the thickness loss caused by general atmospheric corrosion on land close to the sea (coastal region). The system described here uses FPGA, low-power microcontroller, analog front-end devices in the sensor node, and a Beaglebone black wireless board for posting data to a server. The overall system is small, operates at low power, and was deployed at Gran Canaria to detect the thickness loss of an S355 steel sample and consequently estimate the corrosion rate. This experiment aims to demonstrate the system’s viability in marine environments and its potential to monitor corrosion in offshore wind turbines. In a day, the system takes four sets of measurements in 6 hour intervals, and each set consists of 5 consecutive measurements. ...
As large wind farms are now often operating far from the shore, remote condition monitoring and c... more As large wind farms are now often operating far from the shore, remote condition monitoring and condition prognostics become necessary to avoid excessive operation and maintenance costs while ensuring reliable operation. Corrosion, and in particular uniform corrosion, is a leading cause of failure for Offshore Wind Turbine (OWT) structures due to the harsh and highly corrosive environmental conditions in which they operate. This paper reviews the state-of-the-art in corrosion mechanism and models, corrosion monitoring and corrosion prognostics with a view on the applicability to OWT structures. Moreover, we discuss research challenges and open issues as well strategic directions for future research and development of cost-effective solutions for corrosion monitoring and prognostics for OWT structures. In particular, we point out the suitability of non-destructive autonomous corrosion monitoring systems based on ultrasound measurements, combined with hybrid prognosis methods based on...
These data have been obtained using the CEIT ultrasound testbed exciting a PZT piezoelectric sens... more These data have been obtained using the CEIT ultrasound testbed exciting a PZT piezoelectric sensor with a +/-15 volts pulse located over a 5 mm bare steel sample. The testbed receives the ultrasound response and estimates the TOF measuring the distance between two consecutive echoes. The aim is to develop an embedded system to measure the loss of thickness produced by corrosion.
In this paper, we propose a flexible Fog Computing architecture in which the main features are th... more In this paper, we propose a flexible Fog Computing architecture in which the main features are that it allows us to select among two different communication links (WiFi and LoRa) on the fly and offers a low-power solution, thanks to the applied power management strategies at hardware and firmware level. The proposed Fog Computing architecture is formed by sensor nodes and an Internet of Things (IoT) gateway. In the case of LoRa, we have the choice of implementing the LoRaWAN and Application servers on the cloud or on the IoT gateway, avoiding, in this case, to send data to the Cloud. Additionally, we have presented an specific setup and methodology with the aim of measuring the sensor node’s power consumption and making sure there is a fair comparison between the different alternatives among the two selected wireless communication links by varying the duty cycle, the size of the payload, and the Spreading Factor (SF). This research work is in the scope of the STARPORTS Interconnecta...
Structural health monitoring is a critical part of the maintenance procedures of an aircraft. Mos... more Structural health monitoring is a critical part of the maintenance procedures of an aircraft. Most of the problems that arise from structural elements are detected by trained personnel using visual inspection. Moreover, the places at which these structural elements are located are frequently very difficult to access. This makes inspections time consuming and potentially very costly. In this paper we are presenting the design principles that must be taken into account in order to successfully deploy a wireless sensor network in an aircraft. We will discuss the relations between sampling duration, power consumption, energy harvesting and storage, wireless communication and network architecture in order to successfully deploy the system. In order to consider the trade-offs between different design issues we have designed a sensor node equipped with an accelerometer, a temperature and humidity sensor and a strain gauge sensor. The sensor node has an energy harvester from a thermo-electrical generator and a battery storage element. Wireless communications are based on Zigbee protocol and the sensor node is controlled from a low power microcontroller.
The time required for system analysis and verification has invariably become the bottleneck of th... more The time required for system analysis and verification has invariably become the bottleneck of the development process as designs become more complex. Methodologies involving configurable hardware have proven to be the only ones to break the inverse relationship between accuracy in simulation and performance in verification. In this work we present a Hardware-in-the-Loop based platform that substantially reduces the time required for system verification and parameter fine tuning. The verification platform has been used to evaluate the performance of the physical layer of a WLAN 802.11a compliant transceiver. Compared to a software RTL simulation this platform reduces simulation time by a factor of at least 103.
2009 Digest of Technical Papers International Conference on Consumer Electronics, 2009
ABSTRACT In this paper we present a hardware architecture for a multiband OFDM (MBOA) ultra wide ... more ABSTRACT In this paper we present a hardware architecture for a multiband OFDM (MBOA) ultra wide band (UWB) transceiver designed with double data paths. The design minimizes the use of memories and is able to work with a unique clock frequency or with two clock domains. In the second case, it consumes less power and can be implemented with less expensive technologies. The proposed transceiver has been synthesized for a 120 nm CMOS technology.
I. INTRODUCTION AND IEEE 802.11A OVERVIEW IEEE WLAN 802.11 standards define the physical layer of... more I. INTRODUCTION AND IEEE 802.11A OVERVIEW IEEE WLAN 802.11 standards define the physical layer of communication systems based on OFDM. This set of standards have reached maturity over the years and are integrated in many common devices such as laptops, ...
The ultrasound technique is a well-known non-destructive and efficient testing method for on-line... more The ultrasound technique is a well-known non-destructive and efficient testing method for on-line corrosion monitoring. Wall thickness loss rate is the major parameter that defines the corrosion process in this approach. This paper presents a smart corrosion monitoring system for offshore wind turbines based on the ultrasound pulse-echo technique. The solution is first developed as an ultrasound testbed with the aim of upgrading it into a low-cost and low-power miniaturized system to be deployed inside offshore wind turbines. This paper discusses different important stages of the presented monitoring system as design methodology, the precision of the measurements, and system performance verification. The obtained results during the testing of a variety of samples show meaningful information about the thickness loss due to corrosion. Furthermore, the developed system allows us to measure the Time-of-Flight (ToF) with high precision on steel samples of different thicknesses and on coa...
IEEE Transactions on Wireless Communications, 2007
Abstract In this paper we consider the problem of estimating the signaltonoise ratio (SNR) of ... more Abstract In this paper we consider the problem of estimating the signaltonoise ratio (SNR) of the received signal in a QPSK data transmission system. This estimation must be done inservice (nondata aided), without carrier phase knowledge and without symbol timing ...
ABSTRACT Comparison is made of the area and performance of several pipeline - SDF Radix-2i IFFT/F... more ABSTRACT Comparison is made of the area and performance of several pipeline - SDF Radix-2i IFFT/FFT architectures for an MB-OFDM UWB system. Among the studied architectures, the pipeline-SDF radix-24- CSD is proposed as the most area efficient core for an MB-OFDM UWB system.
The conventional way of studying corrosion in marine environments is by installing corrosion coup... more The conventional way of studying corrosion in marine environments is by installing corrosion coupons. Instead, this paper presents an experimental field study using an unattended corrosion sensor developed on the basis of ultrasound (US) technology to assess the thickness loss caused by general atmospheric corrosion on land close to the sea (coastal region). The system described here uses FPGA, low-power microcontroller, analog front-end devices in the sensor node, and a Beaglebone black wireless board for posting data to a server. The overall system is small, operates at low power, and was deployed at Gran Canaria to detect the thickness loss of an S355 steel sample and consequently estimate the corrosion rate. This experiment aims to demonstrate the system’s viability in marine environments and its potential to monitor corrosion in offshore wind turbines. In a day, the system takes four sets of measurements in 6 hour intervals, and each set consists of 5 consecutive measurements. ...
As large wind farms are now often operating far from the shore, remote condition monitoring and c... more As large wind farms are now often operating far from the shore, remote condition monitoring and condition prognostics become necessary to avoid excessive operation and maintenance costs while ensuring reliable operation. Corrosion, and in particular uniform corrosion, is a leading cause of failure for Offshore Wind Turbine (OWT) structures due to the harsh and highly corrosive environmental conditions in which they operate. This paper reviews the state-of-the-art in corrosion mechanism and models, corrosion monitoring and corrosion prognostics with a view on the applicability to OWT structures. Moreover, we discuss research challenges and open issues as well strategic directions for future research and development of cost-effective solutions for corrosion monitoring and prognostics for OWT structures. In particular, we point out the suitability of non-destructive autonomous corrosion monitoring systems based on ultrasound measurements, combined with hybrid prognosis methods based on...
These data have been obtained using the CEIT ultrasound testbed exciting a PZT piezoelectric sens... more These data have been obtained using the CEIT ultrasound testbed exciting a PZT piezoelectric sensor with a +/-15 volts pulse located over a 5 mm bare steel sample. The testbed receives the ultrasound response and estimates the TOF measuring the distance between two consecutive echoes. The aim is to develop an embedded system to measure the loss of thickness produced by corrosion.
In this paper, we propose a flexible Fog Computing architecture in which the main features are th... more In this paper, we propose a flexible Fog Computing architecture in which the main features are that it allows us to select among two different communication links (WiFi and LoRa) on the fly and offers a low-power solution, thanks to the applied power management strategies at hardware and firmware level. The proposed Fog Computing architecture is formed by sensor nodes and an Internet of Things (IoT) gateway. In the case of LoRa, we have the choice of implementing the LoRaWAN and Application servers on the cloud or on the IoT gateway, avoiding, in this case, to send data to the Cloud. Additionally, we have presented an specific setup and methodology with the aim of measuring the sensor node’s power consumption and making sure there is a fair comparison between the different alternatives among the two selected wireless communication links by varying the duty cycle, the size of the payload, and the Spreading Factor (SF). This research work is in the scope of the STARPORTS Interconnecta...
Structural health monitoring is a critical part of the maintenance procedures of an aircraft. Mos... more Structural health monitoring is a critical part of the maintenance procedures of an aircraft. Most of the problems that arise from structural elements are detected by trained personnel using visual inspection. Moreover, the places at which these structural elements are located are frequently very difficult to access. This makes inspections time consuming and potentially very costly. In this paper we are presenting the design principles that must be taken into account in order to successfully deploy a wireless sensor network in an aircraft. We will discuss the relations between sampling duration, power consumption, energy harvesting and storage, wireless communication and network architecture in order to successfully deploy the system. In order to consider the trade-offs between different design issues we have designed a sensor node equipped with an accelerometer, a temperature and humidity sensor and a strain gauge sensor. The sensor node has an energy harvester from a thermo-electrical generator and a battery storage element. Wireless communications are based on Zigbee protocol and the sensor node is controlled from a low power microcontroller.
The time required for system analysis and verification has invariably become the bottleneck of th... more The time required for system analysis and verification has invariably become the bottleneck of the development process as designs become more complex. Methodologies involving configurable hardware have proven to be the only ones to break the inverse relationship between accuracy in simulation and performance in verification. In this work we present a Hardware-in-the-Loop based platform that substantially reduces the time required for system verification and parameter fine tuning. The verification platform has been used to evaluate the performance of the physical layer of a WLAN 802.11a compliant transceiver. Compared to a software RTL simulation this platform reduces simulation time by a factor of at least 103.
2009 Digest of Technical Papers International Conference on Consumer Electronics, 2009
ABSTRACT In this paper we present a hardware architecture for a multiband OFDM (MBOA) ultra wide ... more ABSTRACT In this paper we present a hardware architecture for a multiband OFDM (MBOA) ultra wide band (UWB) transceiver designed with double data paths. The design minimizes the use of memories and is able to work with a unique clock frequency or with two clock domains. In the second case, it consumes less power and can be implemented with less expensive technologies. The proposed transceiver has been synthesized for a 120 nm CMOS technology.
I. INTRODUCTION AND IEEE 802.11A OVERVIEW IEEE WLAN 802.11 standards define the physical layer of... more I. INTRODUCTION AND IEEE 802.11A OVERVIEW IEEE WLAN 802.11 standards define the physical layer of communication systems based on OFDM. This set of standards have reached maturity over the years and are integrated in many common devices such as laptops, ...
The ultrasound technique is a well-known non-destructive and efficient testing method for on-line... more The ultrasound technique is a well-known non-destructive and efficient testing method for on-line corrosion monitoring. Wall thickness loss rate is the major parameter that defines the corrosion process in this approach. This paper presents a smart corrosion monitoring system for offshore wind turbines based on the ultrasound pulse-echo technique. The solution is first developed as an ultrasound testbed with the aim of upgrading it into a low-cost and low-power miniaturized system to be deployed inside offshore wind turbines. This paper discusses different important stages of the presented monitoring system as design methodology, the precision of the measurements, and system performance verification. The obtained results during the testing of a variety of samples show meaningful information about the thickness loss due to corrosion. Furthermore, the developed system allows us to measure the Time-of-Flight (ToF) with high precision on steel samples of different thicknesses and on coa...
IEEE Transactions on Wireless Communications, 2007
Abstract In this paper we consider the problem of estimating the signaltonoise ratio (SNR) of ... more Abstract In this paper we consider the problem of estimating the signaltonoise ratio (SNR) of the received signal in a QPSK data transmission system. This estimation must be done inservice (nondata aided), without carrier phase knowledge and without symbol timing ...
ABSTRACT Comparison is made of the area and performance of several pipeline - SDF Radix-2i IFFT/F... more ABSTRACT Comparison is made of the area and performance of several pipeline - SDF Radix-2i IFFT/FFT architectures for an MB-OFDM UWB system. Among the studied architectures, the pipeline-SDF radix-24- CSD is proposed as the most area efficient core for an MB-OFDM UWB system.
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