Lara del Val | Universidad de Valladolid (original) (raw)

Papers by Lara del Val

Research paper thumbnail of Acoustic echo modeling of people in acoustic arrays using LIDAR

INTER-NOISE and NOISE-CON Congress and Conference Proceedings

In the field of human detection using acoustic arrays, the design of beamforming and detection al... more In the field of human detection using acoustic arrays, the design of beamforming and detection algorithms is of vital importance. Evidently, the acoustic echo is directly dependent on the ergonomic characteristics of the people, as well as on the clothes they are wearing. Traditional techniques use a large set of people to characterize the system and evaluate the detection and false alarm probabilities. This work proposes a different approach, where a reduced set of people is selected and a cluster of points with their ergonomic data is obtained by means of a 2D LIDAR. From this data and using a classical reflection model, the signals that would be received in an acoustic array are calculated and, using conformation techniques, the 3D acoustic image is obtained. The work compares these synthesized acoustic images with real acoustic ones.

Research paper thumbnail of Translation of existing impact sound insulation descriptors into new proposed ones, based on a large set of in situ measurements Translation of existing impact sound insulation descriptors into new proposed ones, based on a large set of in situ measurements

The need for revision and harmonization of sound insulation descriptors is generally accepted amo... more The need for revision and harmonization of sound insulation descriptors is generally accepted among most building acoustics specialists. Undoubtedly, if all countries used the same descriptors, it would be a great advantage to all the sectors related to the building construction industry, legislators and final users.Concerning sound insulation regulations, the most common impact sound insulation descriptors used are L' nT,w and L' n,w. In some countries, the spectral adaptation term C I is also considered, including different frequency ranges, which widens the choices for impact sound insulation descriptors used in regulations. The purpose of this paper is to determine, based on a large set of in situ measurements, how existing impact sound insulation descriptors relate to new proposed ones, in order to be able to make empirical translations of descriptors. The effect of the spectral adaptation term C I and the effect of the building system (heavy/light floors) are also anal...

Research paper thumbnail of Article A Configurable Sensor Network Applied to Ambient Assisted Living

Research paper thumbnail of Fault Detection Methodology for a Fan Matrix Based on SVM Classification of Acoustic Images

Applied Condition Monitoring, 2019

A methodology to detect if a fan matrix is working properly has been designed and is presented in... more A methodology to detect if a fan matrix is working properly has been designed and is presented in this paper. This methodology is based on a Support Vector Machine (SVM) classifier that uses geometrical parameters of the acoustic images of the fan matrix. These acoustic images have been obtained using a 16 × 16 planar array of MEMS microphones working at different frequencies. A fan matrix that is not working properly implies that some of its fans have failed, that is, it does not work. The designed fault detection methodology supposes that these fans fail one by one. If one of the fans is not working, this fact can be detected rapidly with the purposed methodology, and the fan can be repaired or replaced by a new one. Although it is really unusual that more than one fan fails at the same time, this paper also studies how this methodology works if the number of faulty fans increases, in order to know if the methodology is robust enough in the presence of unexpected situations.

Research paper thumbnail of Modal Identification of Structures During Static Load Testing: Interaction Effects

Research paper thumbnail of Comparison of Methodologies for the Detection of Multiple Failures Using Acoustic Images in Fan Matrices

Shock and Vibration, 2020

This paper presents the comparison of three methodologies to detect if some fans in a matrix are ... more This paper presents the comparison of three methodologies to detect if some fans in a matrix are not working properly. These methodologies are based on detecting fan failures by analysing acoustic images of the fan matrix, obtained using a planar array of MEMS microphones. Geometrical parameters of these acoustic images for different frequencies are then used to train a support vector machine (SVM) classifier, in order to detect the fan failures. One of the methodologies is based on the detection of the faulty fan in the matrix, under the hypothesis that only one fan can fail. Other methodology is based on the detection of the specific working situation of the matrix. And finally, the third methodology that is compared is based on determining individually if each of the fans of the matrix is working properly or not. The comparison shows that this third methodology is the most reliable.

Research paper thumbnail of Analysis of the feasibility of an array of MEMS microphones to machinery condition monitoring or fault diagnosis

The Journal of the Acoustical Society of America, 2017

During the last decades, vibration analysis has been used to evaluate condition monitoring and fa... more During the last decades, vibration analysis has been used to evaluate condition monitoring and fault diagnosis of complex mechanical systems. The problem associated with these analysis methods is that the employed sensors must be in contact with the vibrant surfaces. To avoid this problem, the current trend is the analysis of the noise, or the acoustic signals, which are directly related with the vibrations, to evaluate condition monitoring and/or fault diagnosis of mechanical systems. Both, acoustic and vibration signals, obtained from a system can reveal information related with its operation conditions. Using arrays formed by digital MEMS microphones, which employ acquisition/processing systems based on FPGA, allows creating systems with a high number of sensors paying a reduced cost. This work studies the feasibility of the use of acoustic images, obtained by an array with 64 MEMS microphones (8x8) in a hemianechoic chamber, to detect, characterize, and, eventually, identify fai...

Research paper thumbnail of Characterization of a virtual array based on MEMS microphones for the analysis of acoustic sources

The Journal of the Acoustical Society of America, 2017

Using arrays with digital MEMS microphones and FPGA-based acquisition/processing systems allows t... more Using arrays with digital MEMS microphones and FPGA-based acquisition/processing systems allows to build systems with hundreds of sensors at a reduced cost. This work analyzes the performance of a virtual array with 6400 MEMS (80 × 80) microphones. The system is composed by a 2D positioning system that places a physical array of 64 microphones (8 × 8) in a grid with 8 x 8 positions, obtaining a spatial aperture of 2 x 2 meters. The measured beampattern is compared with the theoretical one for several frequencies and pointing angles. The beampattern of the physical array is also estimated for each one of the 64 positions used by the positioning system. Also, the measured beampattern and the focusing capacity are analyzed, since beamforming algorithms assume spherical wave due to the large dimensions of the array. Finally, frequency and spatial responses for a set of different acoustic sources are obtained showing angular resolutions of the order of tenths of degree.

Research paper thumbnail of Translation between existing and proposed harmonized impact sound insulation descriptors and alignment within a proposed common acoustic classification scheme for buildings

Applied Acoustics, 2018

An international standard defining a common acoustic classification scheme for dwellings is under... more An international standard defining a common acoustic classification scheme for dwellings is under development by ISO TC43/SC2/WG29, based on the outcomes of the European project COST Action TU0901. The proposal offers an opportunity for countries to establish building acoustic requirements using a harmonized set of descriptors. This harmonized set considers the possibility of using impact sound insulation descriptors including the impact spectrum adaptation term C I or not. Furthermore, it also considers the possibility of using different frequency ranges for the impact spectrum adaptation term, C I50 and C I100. In order to evaluate the potential effect of such changes, it is necessary to provide translation equations between existing and proposed harmonized descriptors. The main objective of this paper is to provide, based on a statistical analysis of a large experimental data set, a translation equation for each pair (existing/proposed) of selected impact sound insulation descriptors. Additionally, the paper aims at investigating if the obtained translation equations are independent of the building type, so the same statistical analysis has been performed with two separated databases including either only heavy floors or only light floors. From the first results, it is concluded that the obtained translation equations are dependent on the building type when different assessment frequency range and rating methods are considered in both descriptors. In spite of this conclusion and in order to provide a tool for estimating the potential consequences of adopting a different impact sound insulation descriptor, the existing impact sound insulation national requirements have been translated into two proposed harmonized descriptors (L 0 nT,w and L 0 nT,50) using the translation equation obtained using the full data set, that is, not considering the building type. Additionally, the translated requirements have been aligned within the acoustic classification scheme, which is being developed by ISO TC43/SC2/WG29. The results show that, if the proposed common acoustic classification scheme is adopted, the existing requirements would lie, as expected, mainly within classes C and D, although, in some countries with more permissive requirements, the new built dwellings would be ranked class E or even class F. There is only one country where the requirements are such that the new build dwellings would be classified as B, concerning impact sound performance.

Research paper thumbnail of Translation between existing impact sound insulation descriptors, based on a large set of in situ measurements

Proceedings of Meetings on Acoustics, 2016

The need for revision and harmonization of sound insulation descriptors is generally accepted amo... more The need for revision and harmonization of sound insulation descriptors is generally accepted among most building acoustics specialists. Undoubtedly, if all countries used the same descriptors, it would be a great advantage to all the sectors related to the building construction industry, legislators and final users. Concerning sound insulation regulations, the most common impact sound insulation descriptors used are L' nT,w and L' n,w. In some countries, the spectral adaptation term C I is also considered, including different frequency ranges, which widens the choices for impact sound insulation descriptors used in regulations. The purpose of this paper is to determine, based on a large set of in situ measurements, how existing impact sound insulation descriptors relate to new proposed ones, in order to be able to make empirical translations of descriptors. The effect of the spectral adaptation term C I and the effect of the building system (heavyweight/lightweight floors) are also analyzed. Based on the translation equations found, one of the main conclusions is that heavy and light floors yield different empirical translation equations and that it would not be correct to use the same translation equation for all types of floors.

Research paper thumbnail of A robot controlled by blinking for ambient assisted living

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2009

This article presents a system which allows interaction between a physically disabled person and ... more This article presents a system which allows interaction between a physically disabled person and his environment. It contributes to achieve an Ambient Assisted Living (AAL). This system is controlled by voluntary muscular movements, particularly the orbicular ones. These movements are translated into instructions which are sent by means of a wireless link to a mobile robot that executes them. This

Research paper thumbnail of InGenias: Women as a Precursor to Technological and Scientific Vocations

Distributed Computing and Artificial Intelligence, Special Sessions, 17th International Conference, 2020

A very significant decline in technological and scientific vocations is being experienced in Euro... more A very significant decline in technological and scientific vocations is being experienced in Europe, especially regarding the female sector. In this context, the InGenias Project was born, with the aim of making female university students and teachers protagonists of future technological vocations. They promote these vocations among secondary students showing a more social and human perspective of technology in society and how technology can improve the quality of life of citizens.

Research paper thumbnail of Feasibility of Discriminating UAV Propellers Noise from Distress Signals to Locate People in Enclosed Environments Using MEMS Microphone Arrays

Sensors, 2020

Detecting and finding people are complex tasks when visibility is reduced. This happens, for exam... more Detecting and finding people are complex tasks when visibility is reduced. This happens, for example, if a fire occurs. In these situations, heat sources and large amounts of smoke are generated. Under these circumstances, locating survivors using thermal or conventional cameras is not possible and it is necessary to use alternative techniques. The challenge of this work was to analyze if it is feasible the integration of an acoustic camera, developed at the University of Valladolid, on an unmanned aerial vehicle (UAV) to locate, by sound, people who are calling for help, in enclosed environments with reduced visibility. The acoustic array, based on MEMS (micro-electro-mechanical system) microphones, locates acoustic sources in space, and the UAV navigates autonomously by closed enclosures. This paper presents the first experimental results locating the angles of arrival of multiple sound sources, including the cries for help of a person, in an enclosed environment. The results are ...

Research paper thumbnail of Radar Task Schedulers Based On Multiple Queue

There are very complex communication systems, as the multifunction radar, MFAR (Multi-Function Ar... more There are very complex communication systems, as the multifunction radar, MFAR (Multi-Function Array Radar), where functions are integrated all together, and simultaneously are performed the classic functions of tracking and surveillance, as all the functions related to the communication, countermeasures, and calibration. All these functions are divided into the tasks to execute. The task scheduler is a key element of the radar, since it does the planning and distribution of energy and time resources to be shared and used by all tasks. This paper presents schedulers based on the use of multiple queue. Several schedulers have been designed and studied, and it has been made a comparative analysis of different performed schedulers. The tests and experiments have been done by means of system software simulation. Finally a suitable set of radar characteristics has been selected to evaluate the behavior of the task scheduler working.

Research paper thumbnail of Measurement of Acceleration Response Functions with Scalable Low-Cost Devices. An Application to the Experimental Modal Analysis

Sensors, 2021

One of the most popular options in the Structural Health Monitoring field is the tracking of the ... more One of the most popular options in the Structural Health Monitoring field is the tracking of the modal parameters, which are estimated through the frequency response functions of the structure, usually in the form of accelerances, which are computed as the ratio between the measured accelerations and the applied forces. This requires the use of devices capable of synchronously recording accelerations at several points of the structure at high sampling rates and the subsequent computational analysis using the recorded data. To this end, this work presents and validates a new scalable acquisition system based on multiple myRIO devices and digital MEMS (Micro-Electro-Mechanical System) accelerometers, intended for modal analysis of large structures. A simple form of this system was presented by the authors in a previous work, showing that a single board with some accelerometers connected to it got to obtain high quality measurements in both time and frequency domains. Now, a larger sys...

Research paper thumbnail of Feasibility of Using a MEMS Microphone Array for Pedestrian Detection in an Autonomous Emergency Braking System

Sensors, 2021

Pedestrian detection by a car is typically performed using camera, LIDAR, or RADAR-based systems.... more Pedestrian detection by a car is typically performed using camera, LIDAR, or RADAR-based systems. The first two systems, based on the propagation of light, do not work in foggy or poor visibility environments, and the latter are expensive and the probability associated with their ability to detect people is low. It is necessary to develop systems that are not based on light propagation, with reduced cost and with a high detection probability for pedestrians. This work presents a new sensor that satisfies these three requirements. An active sound system, with a sensor based on a 2D array of MEMS microphones, working in the 14 kHz to 21 kHz band, has been developed. The architecture of the system is based on an FPGA and a multicore processor that allow the system to operate in real time. The algorithms developed are based on a beamformer, range and lane filters, and a CFAR (Constant False Alarm Rate) detector. In this work, tests have been carried out with different people and in diff...

Research paper thumbnail of Design and Validation of a Scalable, Reconfigurable and Low-Cost Structural Health Monitoring System

Sensors, 2021

This paper presents the design, development and testing of a low-cost Structural Health Monitorin... more This paper presents the design, development and testing of a low-cost Structural Health Monitoring (SHM) system based on MEMS (Micro Electro-Mechanical Systems) triaxial accelerometers. A new control system composed by a myRIO platform, managed by specific LabVIEW software, has been developed. The LabVIEW software also computes the frequency response functions for the subsequent modal analysis. The proposed SHM system was validated by comparing the data measured by this set-up with a conventional SHM system based on piezoelectric accelerometers. After carrying out some validation tests, a high correlation can be appreciated in the behavior of both systems, being possible to conclude that the proposed system is sufficiently accurate and sensitive for operative purposes, apart from being significantly more affordable than the traditional one.

Research paper thumbnail of First steps on fan matrix condition monitoring and fault diagnosis using an array of digital MEMS microphones

Proceedings of Meetings on Acoustics, 2017

Research paper thumbnail of Acoustic Biometric System Based on Preprocessing Techniques and Linear Support Vector Machines

Sensors, 2015

Drawing on the results of an acoustic biometric system based on a MSE classifier, a new biometric... more Drawing on the results of an acoustic biometric system based on a MSE classifier, a new biometric system has been implemented. This new system preprocesses acoustic images, extracts several parameters and finally classifies them, based on Support Vector Machine (SVM). The preprocessing techniques used are spatial filtering, segmentation-based on a Gaussian Mixture Model (GMM) to separate the person from the background, masking-to reduce the dimensions of images-and binarization-to reduce the size of each image. An analysis of classification error and a study of the sensitivity of the error versus the computational burden of each implemented algorithm are presented. This allows the selection of the most relevant algorithms, according to the benefits required by the system. A significant improvement of the biometric system has been achieved by reducing the classification error, the computational burden and the storage requirements.

Research paper thumbnail of Assistance System for Disabled People: A Robot Controlled by Blinking and Wireless Link

Communications in Computer and Information Science, 2010

Disabled people already profit from a lot of technical assistance that improves their quality of ... more Disabled people already profit from a lot of technical assistance that improves their quality of life. This article presents a system which will allow interaction between a physically disabled person and his environment. This system is controlled by voluntary muscular movements, particularly those of face muscles. These movements will be translated into machine-understandable instructions, and they will be sent by

Research paper thumbnail of Acoustic echo modeling of people in acoustic arrays using LIDAR

INTER-NOISE and NOISE-CON Congress and Conference Proceedings

In the field of human detection using acoustic arrays, the design of beamforming and detection al... more In the field of human detection using acoustic arrays, the design of beamforming and detection algorithms is of vital importance. Evidently, the acoustic echo is directly dependent on the ergonomic characteristics of the people, as well as on the clothes they are wearing. Traditional techniques use a large set of people to characterize the system and evaluate the detection and false alarm probabilities. This work proposes a different approach, where a reduced set of people is selected and a cluster of points with their ergonomic data is obtained by means of a 2D LIDAR. From this data and using a classical reflection model, the signals that would be received in an acoustic array are calculated and, using conformation techniques, the 3D acoustic image is obtained. The work compares these synthesized acoustic images with real acoustic ones.

Research paper thumbnail of Translation of existing impact sound insulation descriptors into new proposed ones, based on a large set of in situ measurements Translation of existing impact sound insulation descriptors into new proposed ones, based on a large set of in situ measurements

The need for revision and harmonization of sound insulation descriptors is generally accepted amo... more The need for revision and harmonization of sound insulation descriptors is generally accepted among most building acoustics specialists. Undoubtedly, if all countries used the same descriptors, it would be a great advantage to all the sectors related to the building construction industry, legislators and final users.Concerning sound insulation regulations, the most common impact sound insulation descriptors used are L' nT,w and L' n,w. In some countries, the spectral adaptation term C I is also considered, including different frequency ranges, which widens the choices for impact sound insulation descriptors used in regulations. The purpose of this paper is to determine, based on a large set of in situ measurements, how existing impact sound insulation descriptors relate to new proposed ones, in order to be able to make empirical translations of descriptors. The effect of the spectral adaptation term C I and the effect of the building system (heavy/light floors) are also anal...

Research paper thumbnail of Article A Configurable Sensor Network Applied to Ambient Assisted Living

Research paper thumbnail of Fault Detection Methodology for a Fan Matrix Based on SVM Classification of Acoustic Images

Applied Condition Monitoring, 2019

A methodology to detect if a fan matrix is working properly has been designed and is presented in... more A methodology to detect if a fan matrix is working properly has been designed and is presented in this paper. This methodology is based on a Support Vector Machine (SVM) classifier that uses geometrical parameters of the acoustic images of the fan matrix. These acoustic images have been obtained using a 16 × 16 planar array of MEMS microphones working at different frequencies. A fan matrix that is not working properly implies that some of its fans have failed, that is, it does not work. The designed fault detection methodology supposes that these fans fail one by one. If one of the fans is not working, this fact can be detected rapidly with the purposed methodology, and the fan can be repaired or replaced by a new one. Although it is really unusual that more than one fan fails at the same time, this paper also studies how this methodology works if the number of faulty fans increases, in order to know if the methodology is robust enough in the presence of unexpected situations.

Research paper thumbnail of Modal Identification of Structures During Static Load Testing: Interaction Effects

Research paper thumbnail of Comparison of Methodologies for the Detection of Multiple Failures Using Acoustic Images in Fan Matrices

Shock and Vibration, 2020

This paper presents the comparison of three methodologies to detect if some fans in a matrix are ... more This paper presents the comparison of three methodologies to detect if some fans in a matrix are not working properly. These methodologies are based on detecting fan failures by analysing acoustic images of the fan matrix, obtained using a planar array of MEMS microphones. Geometrical parameters of these acoustic images for different frequencies are then used to train a support vector machine (SVM) classifier, in order to detect the fan failures. One of the methodologies is based on the detection of the faulty fan in the matrix, under the hypothesis that only one fan can fail. Other methodology is based on the detection of the specific working situation of the matrix. And finally, the third methodology that is compared is based on determining individually if each of the fans of the matrix is working properly or not. The comparison shows that this third methodology is the most reliable.

Research paper thumbnail of Analysis of the feasibility of an array of MEMS microphones to machinery condition monitoring or fault diagnosis

The Journal of the Acoustical Society of America, 2017

During the last decades, vibration analysis has been used to evaluate condition monitoring and fa... more During the last decades, vibration analysis has been used to evaluate condition monitoring and fault diagnosis of complex mechanical systems. The problem associated with these analysis methods is that the employed sensors must be in contact with the vibrant surfaces. To avoid this problem, the current trend is the analysis of the noise, or the acoustic signals, which are directly related with the vibrations, to evaluate condition monitoring and/or fault diagnosis of mechanical systems. Both, acoustic and vibration signals, obtained from a system can reveal information related with its operation conditions. Using arrays formed by digital MEMS microphones, which employ acquisition/processing systems based on FPGA, allows creating systems with a high number of sensors paying a reduced cost. This work studies the feasibility of the use of acoustic images, obtained by an array with 64 MEMS microphones (8x8) in a hemianechoic chamber, to detect, characterize, and, eventually, identify fai...

Research paper thumbnail of Characterization of a virtual array based on MEMS microphones for the analysis of acoustic sources

The Journal of the Acoustical Society of America, 2017

Using arrays with digital MEMS microphones and FPGA-based acquisition/processing systems allows t... more Using arrays with digital MEMS microphones and FPGA-based acquisition/processing systems allows to build systems with hundreds of sensors at a reduced cost. This work analyzes the performance of a virtual array with 6400 MEMS (80 × 80) microphones. The system is composed by a 2D positioning system that places a physical array of 64 microphones (8 × 8) in a grid with 8 x 8 positions, obtaining a spatial aperture of 2 x 2 meters. The measured beampattern is compared with the theoretical one for several frequencies and pointing angles. The beampattern of the physical array is also estimated for each one of the 64 positions used by the positioning system. Also, the measured beampattern and the focusing capacity are analyzed, since beamforming algorithms assume spherical wave due to the large dimensions of the array. Finally, frequency and spatial responses for a set of different acoustic sources are obtained showing angular resolutions of the order of tenths of degree.

Research paper thumbnail of Translation between existing and proposed harmonized impact sound insulation descriptors and alignment within a proposed common acoustic classification scheme for buildings

Applied Acoustics, 2018

An international standard defining a common acoustic classification scheme for dwellings is under... more An international standard defining a common acoustic classification scheme for dwellings is under development by ISO TC43/SC2/WG29, based on the outcomes of the European project COST Action TU0901. The proposal offers an opportunity for countries to establish building acoustic requirements using a harmonized set of descriptors. This harmonized set considers the possibility of using impact sound insulation descriptors including the impact spectrum adaptation term C I or not. Furthermore, it also considers the possibility of using different frequency ranges for the impact spectrum adaptation term, C I50 and C I100. In order to evaluate the potential effect of such changes, it is necessary to provide translation equations between existing and proposed harmonized descriptors. The main objective of this paper is to provide, based on a statistical analysis of a large experimental data set, a translation equation for each pair (existing/proposed) of selected impact sound insulation descriptors. Additionally, the paper aims at investigating if the obtained translation equations are independent of the building type, so the same statistical analysis has been performed with two separated databases including either only heavy floors or only light floors. From the first results, it is concluded that the obtained translation equations are dependent on the building type when different assessment frequency range and rating methods are considered in both descriptors. In spite of this conclusion and in order to provide a tool for estimating the potential consequences of adopting a different impact sound insulation descriptor, the existing impact sound insulation national requirements have been translated into two proposed harmonized descriptors (L 0 nT,w and L 0 nT,50) using the translation equation obtained using the full data set, that is, not considering the building type. Additionally, the translated requirements have been aligned within the acoustic classification scheme, which is being developed by ISO TC43/SC2/WG29. The results show that, if the proposed common acoustic classification scheme is adopted, the existing requirements would lie, as expected, mainly within classes C and D, although, in some countries with more permissive requirements, the new built dwellings would be ranked class E or even class F. There is only one country where the requirements are such that the new build dwellings would be classified as B, concerning impact sound performance.

Research paper thumbnail of Translation between existing impact sound insulation descriptors, based on a large set of in situ measurements

Proceedings of Meetings on Acoustics, 2016

The need for revision and harmonization of sound insulation descriptors is generally accepted amo... more The need for revision and harmonization of sound insulation descriptors is generally accepted among most building acoustics specialists. Undoubtedly, if all countries used the same descriptors, it would be a great advantage to all the sectors related to the building construction industry, legislators and final users. Concerning sound insulation regulations, the most common impact sound insulation descriptors used are L' nT,w and L' n,w. In some countries, the spectral adaptation term C I is also considered, including different frequency ranges, which widens the choices for impact sound insulation descriptors used in regulations. The purpose of this paper is to determine, based on a large set of in situ measurements, how existing impact sound insulation descriptors relate to new proposed ones, in order to be able to make empirical translations of descriptors. The effect of the spectral adaptation term C I and the effect of the building system (heavyweight/lightweight floors) are also analyzed. Based on the translation equations found, one of the main conclusions is that heavy and light floors yield different empirical translation equations and that it would not be correct to use the same translation equation for all types of floors.

Research paper thumbnail of A robot controlled by blinking for ambient assisted living

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2009

This article presents a system which allows interaction between a physically disabled person and ... more This article presents a system which allows interaction between a physically disabled person and his environment. It contributes to achieve an Ambient Assisted Living (AAL). This system is controlled by voluntary muscular movements, particularly the orbicular ones. These movements are translated into instructions which are sent by means of a wireless link to a mobile robot that executes them. This

Research paper thumbnail of InGenias: Women as a Precursor to Technological and Scientific Vocations

Distributed Computing and Artificial Intelligence, Special Sessions, 17th International Conference, 2020

A very significant decline in technological and scientific vocations is being experienced in Euro... more A very significant decline in technological and scientific vocations is being experienced in Europe, especially regarding the female sector. In this context, the InGenias Project was born, with the aim of making female university students and teachers protagonists of future technological vocations. They promote these vocations among secondary students showing a more social and human perspective of technology in society and how technology can improve the quality of life of citizens.

Research paper thumbnail of Feasibility of Discriminating UAV Propellers Noise from Distress Signals to Locate People in Enclosed Environments Using MEMS Microphone Arrays

Sensors, 2020

Detecting and finding people are complex tasks when visibility is reduced. This happens, for exam... more Detecting and finding people are complex tasks when visibility is reduced. This happens, for example, if a fire occurs. In these situations, heat sources and large amounts of smoke are generated. Under these circumstances, locating survivors using thermal or conventional cameras is not possible and it is necessary to use alternative techniques. The challenge of this work was to analyze if it is feasible the integration of an acoustic camera, developed at the University of Valladolid, on an unmanned aerial vehicle (UAV) to locate, by sound, people who are calling for help, in enclosed environments with reduced visibility. The acoustic array, based on MEMS (micro-electro-mechanical system) microphones, locates acoustic sources in space, and the UAV navigates autonomously by closed enclosures. This paper presents the first experimental results locating the angles of arrival of multiple sound sources, including the cries for help of a person, in an enclosed environment. The results are ...

Research paper thumbnail of Radar Task Schedulers Based On Multiple Queue

There are very complex communication systems, as the multifunction radar, MFAR (Multi-Function Ar... more There are very complex communication systems, as the multifunction radar, MFAR (Multi-Function Array Radar), where functions are integrated all together, and simultaneously are performed the classic functions of tracking and surveillance, as all the functions related to the communication, countermeasures, and calibration. All these functions are divided into the tasks to execute. The task scheduler is a key element of the radar, since it does the planning and distribution of energy and time resources to be shared and used by all tasks. This paper presents schedulers based on the use of multiple queue. Several schedulers have been designed and studied, and it has been made a comparative analysis of different performed schedulers. The tests and experiments have been done by means of system software simulation. Finally a suitable set of radar characteristics has been selected to evaluate the behavior of the task scheduler working.

Research paper thumbnail of Measurement of Acceleration Response Functions with Scalable Low-Cost Devices. An Application to the Experimental Modal Analysis

Sensors, 2021

One of the most popular options in the Structural Health Monitoring field is the tracking of the ... more One of the most popular options in the Structural Health Monitoring field is the tracking of the modal parameters, which are estimated through the frequency response functions of the structure, usually in the form of accelerances, which are computed as the ratio between the measured accelerations and the applied forces. This requires the use of devices capable of synchronously recording accelerations at several points of the structure at high sampling rates and the subsequent computational analysis using the recorded data. To this end, this work presents and validates a new scalable acquisition system based on multiple myRIO devices and digital MEMS (Micro-Electro-Mechanical System) accelerometers, intended for modal analysis of large structures. A simple form of this system was presented by the authors in a previous work, showing that a single board with some accelerometers connected to it got to obtain high quality measurements in both time and frequency domains. Now, a larger sys...

Research paper thumbnail of Feasibility of Using a MEMS Microphone Array for Pedestrian Detection in an Autonomous Emergency Braking System

Sensors, 2021

Pedestrian detection by a car is typically performed using camera, LIDAR, or RADAR-based systems.... more Pedestrian detection by a car is typically performed using camera, LIDAR, or RADAR-based systems. The first two systems, based on the propagation of light, do not work in foggy or poor visibility environments, and the latter are expensive and the probability associated with their ability to detect people is low. It is necessary to develop systems that are not based on light propagation, with reduced cost and with a high detection probability for pedestrians. This work presents a new sensor that satisfies these three requirements. An active sound system, with a sensor based on a 2D array of MEMS microphones, working in the 14 kHz to 21 kHz band, has been developed. The architecture of the system is based on an FPGA and a multicore processor that allow the system to operate in real time. The algorithms developed are based on a beamformer, range and lane filters, and a CFAR (Constant False Alarm Rate) detector. In this work, tests have been carried out with different people and in diff...

Research paper thumbnail of Design and Validation of a Scalable, Reconfigurable and Low-Cost Structural Health Monitoring System

Sensors, 2021

This paper presents the design, development and testing of a low-cost Structural Health Monitorin... more This paper presents the design, development and testing of a low-cost Structural Health Monitoring (SHM) system based on MEMS (Micro Electro-Mechanical Systems) triaxial accelerometers. A new control system composed by a myRIO platform, managed by specific LabVIEW software, has been developed. The LabVIEW software also computes the frequency response functions for the subsequent modal analysis. The proposed SHM system was validated by comparing the data measured by this set-up with a conventional SHM system based on piezoelectric accelerometers. After carrying out some validation tests, a high correlation can be appreciated in the behavior of both systems, being possible to conclude that the proposed system is sufficiently accurate and sensitive for operative purposes, apart from being significantly more affordable than the traditional one.

Research paper thumbnail of First steps on fan matrix condition monitoring and fault diagnosis using an array of digital MEMS microphones

Proceedings of Meetings on Acoustics, 2017

Research paper thumbnail of Acoustic Biometric System Based on Preprocessing Techniques and Linear Support Vector Machines

Sensors, 2015

Drawing on the results of an acoustic biometric system based on a MSE classifier, a new biometric... more Drawing on the results of an acoustic biometric system based on a MSE classifier, a new biometric system has been implemented. This new system preprocesses acoustic images, extracts several parameters and finally classifies them, based on Support Vector Machine (SVM). The preprocessing techniques used are spatial filtering, segmentation-based on a Gaussian Mixture Model (GMM) to separate the person from the background, masking-to reduce the dimensions of images-and binarization-to reduce the size of each image. An analysis of classification error and a study of the sensitivity of the error versus the computational burden of each implemented algorithm are presented. This allows the selection of the most relevant algorithms, according to the benefits required by the system. A significant improvement of the biometric system has been achieved by reducing the classification error, the computational burden and the storage requirements.

Research paper thumbnail of Assistance System for Disabled People: A Robot Controlled by Blinking and Wireless Link

Communications in Computer and Information Science, 2010

Disabled people already profit from a lot of technical assistance that improves their quality of ... more Disabled people already profit from a lot of technical assistance that improves their quality of life. This article presents a system which will allow interaction between a physically disabled person and his environment. This system is controlled by voluntary muscular movements, particularly those of face muscles. These movements will be translated into machine-understandable instructions, and they will be sent by