Jesús Ureña

• PhD
• Professor (Full) at University of Alcalá

The calculation of division and square root is widely used in edge computing related to image processing, clustering, recognition, and reconstruction, among others. Their common multi-stage serial calculation takes longer, and requires a higher latency, and more redundant hardware resources for multi-dimensional parallel computations. This work pro...

The massive deployment of smart meters in most Western countries in recent decades has allowed the creation and development of a significant variety of applications, mainly related to efficient energy management. The information provided about energy consumption has also been dedicated to the areas of social work and health. In this context, smart...

Many indoor positioning applications related to accurate monitoring and tracking targets require centimeter precision. Infrared- and ultrasound-based systems represent a feasible approach providing high robustness against interference. Furthermore, their combination may achieve better performance by mitigating their complementary drawbacks, coverin...

Las redes eléctricas inteligentes están transformando la relación de los usuarios con la electricidad de diferentes maneras. En este artículo se resumen algunas potenciales aplicaciones que se desarrollarán en los próximos años bajo este marco conceptual, las cuales tienen como denominador común el uso de técnicas de monitoreo no intrusivo de carga...

The research interest on indoor Location-Based Services (LBS) has increased during the last years, especially using LED lighting, since they can deal with the dual functionality of lighting and localization with centimetric accuracy. There are several positioning approaches using lateration and angular methods. These methods typically rely on the p...

Ultrasonic local positioning systems (ULPS) have been brought to the attention of researchers as one of the possibilities that can be used for indoor localization. Acoustic systems combine a suitable trade-off between precision, ease of development, and cost. This work proposes a method for measuring the time of arrival of encoded emissions from a...

The research interest on location-based services has increased during the last years ever since 3D centimetre accuracy inside intelligent environments could be confronted with. This work proposes an indoor local positioning system based on LED lighting, transmitted from a set of beacons to a receiver. The receiver is based on a quadrant photodiode...

Indoor positioning systems have become a feasible solution for the current development of multiple location-based services and applications. They often consist of deploying a certain set of beacons in the environment to create a coverage volume, wherein some receivers, such as robots, drones or smart devices, can move while estimating their own pos...

Optical indoor positioning systems have experienced an increasing research interest during last years as they can provide 3D centimeter accuracy using LED lighting. In the case of having several LEDs emitting simultaneously and a receiver (e.g. the tag to be localized), these systems face important challenges, such as very high dynamic ranges with...

Indoor positioning remains a challenge and, despite much research and development carried out in the last decade, there is still no standard as with the Global Navigation Satellite Systems (GNSS) outdoors. This paper presents an indoor positioning system called LOCATE-US with adjustable granularity for use with commercial mobile devices, such as sm...

Smart grids are a concept that is becoming a concrete reality in developed countries, and is only just emerging in developing countries. In both cases, they are transforming the customers' relationship with electricity in unexpected ways. In this work, it is shown an overview of some functionalities that will be developed within the smart grids, wh...

In recent years the development and deployment of commercial Smart Meters in most households in developed countries have spread the appearance of certain applications and methods, mainly related to the fields of Smart Grids and Internet of Things, where Non-Intrusive Load Monitoring (NILM) is one of the most well-known. It takes advantage of the ca...

Nowadays, there is an increasing interest in smart systems, e.g., smart metering or smart spaces, for which active sensing plays an important role. In such systems, the sample or environment to be measured is irradiated with a signal (acoustic, infrared, radio-frequency…) and some of their features are determined from the transmitted or reflected p...

Resumen-En las últimas décadas, con el desarrollo a nivel mundial de las redes inteligentes de energía, los contadores inteligentes (Smart Meters) se han convertido en una pieza clave en un gran número de aplicaciones y servicios finales ofrecidos a los usuarios, principalmente debido a su capacidad para medir en tiempo real la energía consumida en...

Indoor location and positioning systems (ILPS) are used to locate and track people, as well as mobile and/or connected targets, such as robots or smartphones, not only inside buildings with a lack of global navigation satellite systems (GNSS) signals but also in constrained outdoor situations with reduced coverage. Indoor positioning applications a...

For a broken rail detection system based on ultrasonic guided waves (UGW), the multimodal and dispersion of UGW degrade signal-to-noise ratio (SNR) and range resolution. To improve SNR of the received signals and range resolution, the pulse compression technique based on 13-bit Barker code is presented in this work. Through a PSpice model of the pi...

Visible Light Positioning Systems (VLPS) are a feasible alternative to local positioning systems thanks to the technology improvement and massive use of Light Emitting Diodes (LED). Compared to other technologies, VLPSs can provide significant advantages, such as the achieved accuracy, although they still present some issues, mainly related to the...

Orthogonal frequency division multiplexing (OFDM) plays an important role in power-line communications (PLC), due to its robustness to frequency-selective channels. Nevertheless, it also presents some persistent drawbacks over the years, some of them related to the synchronization and channel estimation and equalization, whose features are a key as...

The ongoing deployment of smart meters and different commercial devices has made electricity disaggregation feasible in buildings and households, based on a single measure of the current and, sometimes, of the voltage. Energy disaggregation is intended to separate the total power consumption into specific appliance loads, which can be achieved by a...

With the growing of smart systems connected to Internet, the concern about locating those systems is also increasing to provide an accurate position in certain spaces, typically for people, mobile robots or objects. In this line, 3D positioning is becoming more and more significant due to the relevance of certain applications in commercial centers,...

This paper proposes an algorithm for calibrating the position of beacons which are placed on the ceiling of an indoor environment. In this context, the term calibration is used to estimate the position coordinates of a beacon related to a known reference system in a map. The positions of a set of beacons are used for indoor positioning purposes. Th...

Electricity disaggregation is the process of separating the total electrical load of a single household into appliance specific loads. This can be achieved either by intrusive monitoring of each appliance via individual device load meters or by employing Non-Intrusive Load Monitoring (NILM) techniques, that perform a detailed analysis of the curren...

The use of drones in several areas such as agriculture, security, cinema, sports, enjoyment, and rescue task, to name a few, has grown considerably in recent years. Likewise, the use of drones with autonomous flight is common nowadays. During the drone’s flight, especially autonomous flight in forest, the blades of the rotor may be damaged, scratch...

We report a novel open competition aimed at evaluating accurate robot position tracking in indoor environments. The competition was organized within the IPIN 2016 (Indoor Positioning and Indoor Navigation international Conference). Here, we describe the competition, the competitors and their final results. The challenges of this new competition inc...

With the grow of smart devices connected to Internet there is also an increasing interest in positioning systems that can provide an accurate and trusted position of such smart devices in particular volumetric spaces. In structured indoor environments, ultrasonic systems can provide some advantages over others in terms of accuracy, low-cost and roo...

Acoustic local positioning systems (ALPSs) are an interesting alternative for indoor positioning due to certain advantages over other approaches, including their relatively high accuracy, low cost, and room-level signal propagation. Centimeter-level or fine-grained indoor positioning can be an asset for robot navigation, guiding a person to, for in...

The necessity of navigation in people and mobile robots (MR) through specific environments (indoors or outdoors) has become more and more relevant nowadays. For indoors, generally speaking, the positioning systems can be divided into 2D (two dimensions) or 3D (three dimensions) approaches, where Ultrasonic Local Positioning Systems (ULPS) are often...

This paper proposes a multipath compensation algorithm (MCA) to enhance the performance of an ultrasonic local positioning system under adverse multipath conditions. The proposed algorithm is based on the accurate estimation of the environment impulse response from which the corresponding line of sight for each channel is obtained. Experimental res...

This paper proposes a Simultaneous Calibration and Navigation (SCAN) algorithm of a multiple Ultrasonic Local Positioning Systems (ULPSs) that cover an extensive indoor area. The idea is the development of the same concept than SLAM (Simultaneous Localization and Mapping), in which a Mobile Robot (MR) estimates the map while it is navigating. In ou...

This work describes a classifier designed to identify rail breakages in double-track railway lines, completing the electronic equipment carried out by authors. The main objective of this proposal is to guarantee the integrity of tracks before the railway traffic starts working. In addition, it facilitates maintenance tasks providing information abo...

Ultrasonic Local Positioning Systems ULPS are used with mobile robots (MR) as an absolute positioning system that allows MRs to be positioned inside their working area. Usually such systems are developed for 2D positioning as the MRs are expected to navigate on the floor. There are other kind of applications that need a 3D positioning as, for insta...

The massive deployment of smart meters and other customized meters has motivated the development of nonintrusive load monitoring (NILM) systems. This is the process of disaggregating the total energy consumption in a building into individual electrical loads using a single-point sensor. Most literature is oriented to energy saving. Nevertheless, ac...

The ageing of the population has raised the interest in homecare monitoring systems and assisted living in recent years. Most studies pursue non-intrusiveness and scalability to meet the requirements of this ever-growing community. Nonetheless, they are still limited by the technique: wearables need to be carried and sensor networks imply installat...

During past decades, local positioning systems (LPSs) have become more and more important for different robotic and automation applications, as well as for service-oriented developments. One of the emerging technologies for that purpose is ultrasounds, since they provide positioning errors in the range of centimeters with low-cost deployments. Neve...

The ageing of the population, and their increasing wish of living independently, are motivating the development of welfare and healthcare models. Existing approaches based on the direct heath-monitoring using body sensor networks (BSN) are precise and accurate. Nonetheless, their intrusiveness causes non-acceptance. New approaches seek the indirect...

This work presents the FPGA design of a DC/AC pulse width modulated converter for teaching purposes. The design allows to change in real time the PWM modulation scheme, the amplitude and frequency of the desired first harmonic, as well as the harmonic spectrum depending on the requirements of the application. Therefore, a teaching platform to be us...

Near-optimal states estimation in dynamic systems with Gaussian noise has been extensively applied in research using Kalman Filtering (KF). This method is especially useful in technological applications that use noisy data from several sensors or need the estimation of an optimal state vector in systems with multiple observations. A particular situ...

In this paper we present an Android application, called LOCATE-US, that allows accurate indoor positioning of mobile devices by processing the ultrasonic signals coming from a local positioning system (LPS). The LPS operates around 41KHz, and an external hardware based on an ultrasonic microphone digitizes the incoming signals and send them to the...

This paper describes the design, measurement methodology, and experimental validation of an electronic system for monitoring the electrical discontinuity in rails of double-track railway lines in order to detect the rail breakage. The electronic system is based on an emitter node and on the two receiver nodes. The three nodes, together with the fou...

This paper presents a characterization of an underwater positioning system based on surface nodes equipped with GPS and acoustic transducers. The positioning system calculates the coordinates of an underwater vehicle in one of the surface nodes or beacons, by the emission, detection, and reply of acoustic encoded signals. The characterization of th...

Due to the continuous development of the high-speed railway lines and the growth of automatic systems, it is becoming more and more necessary to install safety elements to prevent accidents. One of these elements is the so-called obstacle fall detector on the tracks, in charge of detecting the sudden appearance of dangerous objects in the safety ar...

In the last years, indoor positioning systems have become an ubiquitous part of smart spaces. The use of coded ultrasonic indoor positioning systems leads to accurate position estimation at reduced cost as the low propagation speed of sound allows the use of analog-to-digital converters at low sampling frequencies. In these systems, coding schemes...

Los conjuntos de secuencias complementarias (CSS) han sido de gran utilidad en los últimos años en diversas aplicaciones, ya sea en sistemas de sensado activo multiusuario, como sistemas de comunicación OFDM, o CDMA cuasi-síncronos (QS-CDMA), hasta para la realización de ensayos no destructivos (NDT). Esto se debe principalmente a las propiedades i...

En este artículo se propone el análisis y modelado de una estructura sensorial ultrasónica empleando un algoritmo de procesamiento que utiliza un conjunto de macro-secuencias y técnicas de correlación para obtener respuestas impulsivas de canales de transmisión de forma simultánea. La estructura sensorial está formada por múltiples transductores ul...

This paper presents the different levels of signal processing applied to an extensive Ultrasonic Local Positioning System (ULPS) intended for mobile robot (MR) indoor navigation. The working area is covered using several single LPSs, each of them composed of a set of closely arranged ultrasonic beacons. Low-level signal processing deals with the si...

Ocean noise is a complex phenomenon in underwater environments. Different processes such as shipping traffic, wind, rain or animals contribute with a different signature to the background noise, which can worsen underwater systems performance. However, in the simulation of underwater systems the common approach is to consider an additive white Gaus...

New coding schemes are increasingly being developed to adapt multisensor and communication systems to the requirements of the current technological environment. In some cases, the practical implementation of these schemes involves a great amount of signal processing operations. In order to achieve and make suitable their use in different platforms,...

This work presents a SOC-based (system-on-chip) architecture for ultrasonic imaging systems in airborne transmission which uses macro-sequences derived from complementary sets of sequences (CSS) to achieve simultaneous beam steering in several directions. By means of CSS concatenation and zero padding, a new macro-sequence can be obtained which ach...

Golay complementary pairs have been widely used in signal coding and pulse compression systems due to the ideal sum of their aperiodic correlation functions. Furthermore, they can be used as basic building blocks for the generation of novel encoding schemes with zero correlation zones. In a recent work, algorithms for the efficient generation and c...

In those positioning systems based on the detection of acoustic signals, an accurate detection of the arrival times is crucial for a correct estimation of the distance between nodes, and therefore, for the precise estimation of the node that wants to be located. In order to obtain this arrival time more accurately, acoustic signals can be coded usi...

Within the emerging new technologies in Smart Grids, the concern about Non-Intrusive Load Monitoring (NILM) techniques has increased over the last five years. These techniques aim to disaggregate the energy consumption on a household or commercial building into individual appliances from the use of a single-point sensor. Most efforts attempt to dis...

This paper presents the design and implementation of a System-on-Chip (SoC) based on a FPGA (Field-Programmable Gate Array) device to control and configure an ultrasonic beacon array for an extensive ultrasonic Local Positioning System (LPS). The SoC is based on a MicroBlaze microprocessor and some advanced peripherals. Among them, it is possible t...

Smartphone capabilities can significantly enhance mobile and context-aware applications that depend on location information. Whereas outdoor Location Based Services (LBS) are highly developed thanks to GPS, indoor LBS still demand a positioning technology that provides accurate location data. In this paper, an ultrasonic signal acquisition module f...

This paper describes a first prototype of an airborne ultrasonic array that combines pulse-compression techniques with localization algorithms in order to achieve accurate determination of the position of the reflectors placed in front of the array. The new sensory system is based on an array with four independently controlled emitters and a receiv...

This paper presents a flexible deployment of ultrasonic position sensors and a novel positioning algorithm suitable for the navigation of mobile robots (MRs) in extensive indoor environments. Our proposal uses several independently-referenced local positioning systems (LPS), which means that each one of them operates within its own local reference...

In this paper, a digital filter for the generation/correlation of binary Golay pairs of sequences of length 2^N · 10^M · 26^P (N, M and P are non-negative integers) is proposed. It is carried out by means of a novel Golay kernel 26 decomposition, also introduced in this paper, combined with building blocks of Golay kernels 2 and 10, presented in pr...

Generalized Pairwise Complementary (GPC) sequences are increasingly being used in many applications due to their properties, which allow uncorrelated sequences generation from a base pair. The generation of these sequences is conducted by iterative algorithms developed to be implemented in hardware platforms. However, in order to reduce even furthe...

The use of Ultra -WideBand (UWB) techniques is considered an attractive solution for indoor Local Positioning Systems (LPS). In this case, the positioning is usually performed by hyperbolic trilateration techniques measuring the time difference of arrival (TDOA) between the received signals coming from the beacons placed in the environment. The det...

This paper presents an improved navigation system for Mobile Robots (MR) in extensive areas using different Ultrasonic Local Positioning Systems (ULPS) and the complement of Isolated Beacons (IB) in regions without LPS coverage. Each single LPS has a high accuracy in positioning but a limited coverage area. The proposal of this paper is the use of...

Accurate distance estimation is a key part for certain active sensing systems as ultrasonic Indoor Positioning Systems (IPSs). In these systems, receive filters play a key role for the achievement of robust and accurate position estimations. For that reason, this paper carries out the performance comparison of different receive filters, namely matc...

Underwater Wireless Sensor Network applications require the design of efficient communications links due to the rough environment. Acoustic signals make feasible the data transmission based on Direct Sequence Code Division Multiple Access (DS-CDMA) techniques, because compensates the multipath effect and allow receivers to simultaneously distinguis...

SUMMARY This paper presents a new methodology to obtain the line impedance of current railway tracks by using only short-circuit measurements. Open-circuit measurements required by conventional methodologies are discarded, since they cannot be carried out for railway tracks in service (electrically continuous and indefinite length). The mathematica...

This paper presents an Extensive Local Positioning System for mobile robots (MRs) that fuses the information from a mobile robot (MR) internal odometer sensor and the measurements of distances from two external systems: an Ultrasonic Local Positioning System (ULPS) with high accuracy but a short coverage area and a set of WiFi beacons that create a...

One of the challenges of phased array (PA) ultrasonic imaging systems is their limited capability to deal with real-time applications, such as echocardiography and obstetrics. In its most basic outline, these systems require emitting and receiving with the entire array for each image line to be acquired; therefore, with many image lines, a higher a...

In this paper we present a privacy-oriented Ultrasonic Local Positioning System (U-LPS) allowing users with portable devices, such as smartphones or tablets, to accurately determine their position in indoor environments. Indoor U-LPSs have been widely used to provide location information with centimeter or even sub-centimeter level accuracy at high...

In Ultra-Wideband (UWB) Local Positioning Systems (LPS), Inter-Symbol Interference (ISI), Multiple-Access Interference (MAI) and near-far effect are significant issues that can limit system performance. This paper presents a DS-UWB (Direct Sequence UWB) LPS based on FPGAs (Field-Programmable Gate Array) and on commercially available Radio-Frequency...