Carlos De Marziani

• Electronics PhD
• Professor (Full) at National University of Patagonia San Juan Bosco

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...

Complementary sets of sequences (CSS) are widely used in communications field due to their good correlation properties. The use of multilevel CSS reduces the binary CSS limitations in length and number of sequences per set, giving more flexibility in their applications, but with a higher computational complexity in the implementation of the generat...

Complementary Set of Sequences (CSS) are being widely used in communications due to the ideal correlation properties and the availability of efficient correlators that significantly reduce the number of computations in the detection process. In this paper, the performance of the acoustic signals encoded by multilevel CSS in an underwater horizontal...

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...

The computation of relative positions among mobile objects is a useful information when are not constrained to a specific environment and they cannot depend on an external infrastructure to obtain their location information. The resolution of this kind of problems cannot be treated separately for each object. Thus, it is necessary to use ranging me...

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...

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...

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...

In this paper the design of an underwater acoustic link using the model for a short vertical channel is presented. From the specifications of the link, it is possible to determine the optimum operating frequency, modulation scheme and transmit power, information that will be useful to perform a selection of the appropriate acoustic transducer. For...

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...

The underwater channel is a highly variable medium due to the influence of several effects on the acoustic signal, and the physical variability of the environment. This behavior makes the underwater channel a very difficult one to model, and also a complex environment to work with. In acoustic-based positioning or sonar systems, where it is importa...

In this paper a propagation model of acoustic signals in an underwater channel is analyzed. This one is applied to a short vertical communication link. In this way, it's possible to predict the transmission loss, the noise level, the propagation delay and the general shapes of the used acoustic signals. These parameters can be used to design an eff...

This paper presents the design of a novel receiver for a broadband ultrasonic Local Positioning System (LPS). As in other devices based on matched filtering of the transmitted encoded signals, this receiver features high robustness to noise and multiple access capability. Unlike previous solutions, the proposed receiver is capable of detecting beac...

In relative positioning systems, with the aim of estimating object positions, distances among them are computed in a cooperative way, usually by measuring times-of-flight from the signals that they emit. These emissions are often synchronized with additional signals or suitable hardware that acts as a temporal reference. In this paper, a ranging sy...

This paper presents a new architecture for the correlation of orthogonal complementary sets of sequences (OCSS) and their performance in an ultrasonic local posi-tioning system (U-LPS). OCSS are sets of sequences whose addition of correlation functions has ideal properties, that makes interference-free code-division multiple access (CDMA) possible....

In this work, an acoustic relative positioning system is presented, based on pseudorandom coded acoustic signals that are emitted underwater and detected by matched filtering processes. With this configuration the system is independent of GPS technology, being able to work even in low coverage regions. It is easier to deploy that LBL systems, and t...

The great variability usually found in underwater media makes modeling a challenging task, but helpful for better understanding or predicting the performance of future deployed systems. In this work, an underwater acoustic propagation model is presented. This model obtains the multipath structure by means of the ray tracing technique. Using this mo...

In this article, a time-of-flight detection technique in the frequency domain is described for an ultrasonic local positioning system (LPS) based on encoded beacons. Beacon transmissions have been synchronized and become simultaneous by means of the DS-CDMA (direct-sequence code Division multiple access) technique. Every beacon has been associated...

The development of positioning systems using underwater acoustic is a new research field. One of the main advantages of such a positioning system over absolute ones is that an external infraestructure is not needed, because only the distances between the buoys are used to obtain their positions. In this work, a relative positioning system using und...

Underwater acoustic channel modeling keeps being an active field of research, despite the fact that the physical effects are known since decades ago. The great variability that is found in this kind of channel makes modeling a difficult task, being highly dependent on a particular environment. For high frequencies, ray tracing is a simple and relia...

Sensor networks have experienced a fast development and extended their fields of application since their appearance for military uses. The monitoring of physical parameters in natural habitats is a typical application for assessing the risks of worsening the ecosystem. Among natural environments with scientific interest, there are the coastlines in...

This paper presents a new recursive algorithm to directly obtain the sum of the autocorrelation functions of the M sequences belonging to a Complementary Set of Sequences (M-CSS). The proposed algorithm allows a digital filter with only one stage to be obtained, what significantly reduces the total number of memory requirements, multiplications and...

Loosely Synchronized codes, which have gained considerable interest in CDMA-based wireless communications and sensory systems, can be constructed from a set of mutually orthogonal complementary sets of sequences. In this paper a new architecture is provided for the correlation of such codes. It demands less memory and number of operations than prev...

Complementary sequences are currently being applied to multiple fields of engineering not only when an active signal must be coded to obtain large noise immunity (proportional to the sequences length) but also when multiuser or multisensory operations need to be conducted (because of their orthogonality properties). The orthogonality between comple...

On current railway systems, it is becoming ever more necessary to install safety elements to avoid accidents. One of the causes that can provoke serious accidents is the existence of obstacles on the tracks, either fixed or mobile. In this paper, a multisensory system that can inform the monitoring system about the existence of obstacles is propose...

A new approach for the efficient correlation of loosely synchronised (LS) codes, when they are generated from Golay pairs, is presented. By employing this new approach, the total number of operations to be performed in the correlation is notably decreased, if compared with existing proposals based on classical efficient Golay correlators or straigh...

This work presents an intelligent system which allows the detection of obstacles on railways. The sensory system is based on one barrier of infrared emitters and another of receivers, placed on opposing sides of the railway. Obstacle detection is achieved by a lack of reception in the detectors. The efficiency of the system is improved with the geo...

Las redes de sensores han experimentando un gran desarrollo desde su aparición en aplicaciones militares, extendiendo su campo de aplicación a diversos ámbitos como es el caso de los hábitats naturales donde resulta de interés el monitoreo de diferentes variables físicas a fin de evaluar el riesgo de deterioro del ecosistema circundante. Entre los...

A new sensor array based on the EMFi material is presented in this work to perform 3D localization of reflectors. This operation is accomplished by means of an algorithm that performs spherical trilateration using the Time-Of-Flight (TOF) of the emissions from every sensor. An accurate measurement of these TOFs is obtained by encoding the emissions...

In this work, an acoustic sensor network for a relative localization system is analyzed by reporting the accuracy achieved in the position estimation. The proposed system has been designed for those applications where objects are not restricted to a particular environment and thus one cannot depend on any external infrastructure to compute their po...

Loosely Synchronous (LS) codes improves the performance of Local Positioning Systems (LPS) in terms of noise immunity, capability of simultaneous measurements and precision in the location, provided that the multipath spread and the relative time offset between the codes are within the zero correlation zone (ZCZ) that they achieve in their correlat...

This paper presents three novel methods to efficiently generate and correlate sequence pairs with three zero correlation zones in the sum of their aperiodic correlation functions. These sequences have achieved great importance in communications systems when the maximum transmission delay is less than the length of these zones, because the multiple...

In this work, several code division multiple access encoding schemes are evaluated for their application in ultrasonic sensory systems based on the determination of times-of-flight. Proper encoding improves the performance of such systems in terms of noise immunity, capability of simultaneous measurements and precision in the distance measurements....

Airborne sonar is a robust sensing modality that has gained its popularity as a reliable and inexpensive means of determining the range to the closest obstacle. Nevertheless, it is impossible to extract bearing information from a single transducer if classical Time-of-Flight (TOF) measurements are used. For this reason, many sensors have been propo...

Sensory systems for localization and mapping based on ranging allows to obtain not only the position of a mobile object but also the position of the beacons or landmarks. Using only ranging, the beacon positions are often calculated without needing to compute all the spatial relations among them. In this work, a preliminary study about the use of r...

An advanced adaptive sonar module is described, capable of being configured to different circumstances and distances according to reflectors found in the environment. Thanks to the sensory distribution, it is possible to identify three basic types of reflector (planes, edges and corners). Furthermore, a heuristic map of the environment is built. Th...

An advanced adaptive sonar module is described, capable of being configured to different circumstances and distances according to reflectors found in the environment. Thanks to the sensory distribution, it is possible to identify three basic types of reflector (planes, edges and corners). Furthermore, a heuristic map of the environment is built. Th...

This paper presents a novel method to correlate loosely synchronized (LS) codes generated from mutually orthogonal complementary sets of sequences (CSS). The proposed correlator significantly reduces the total number of multiplications and additions to be performed, in comparison with straightforward correlators. This fast correlator, together with...

A prototype of an ultrasonic transducer based on electromechanical film (EMFi) is presented, as well as its electronic driving and receiving blocks. The electromechanical film provides a wide bandwidth response, showing enough of a level of sensitivity to allow echo-pulse measurement in the most frequency ranges for robotics applications. Emission...

This work describes the design of a ultrasonic local positioning system (ULPS) with large covered area. The beacons have been designed with a cylindrical PVDF transducer (piezofilm transducer) to which a conical reflector has been connected to enlarge the covered area and to guarantee 3D indoor positioning. The proposed ULPS for mobile robots (MR)...

This work presents the development of a local positioning system (LPS), based on the transmission of ultrasonic signals, which have been previously encoded by loosely synchronous (LS) codes. The LPS consists of several ultrasonic emitters located at known positions in the environment, and of a portable receiver that computes its position by measuri...

This work presents the development and implementation of a Local Positioning System (LPS) based on the transmission of ultrasonic signals, proposed for indoor positioning of mobile robots. The LPS consists of several ultrasonic beacons located in the environment, all of them emitting periodically and simultaneously. A portable receiver collects all...

This paper presents a prototype of an ultrasonic transducer based on electromechanical film (EMFi). This electromechanical film provides a wide bandwidth response, useful for robotic applications. Furthermore, its sensitivity is constant enough to allow echo-pulse measurement in the desired frequency range. The emission patterns are obtained for di...

This work describes the design of a reflector for a PVDF-based ultrasonic transducer (Piezofilm transducer) to carry out a ultrasonic beacon system, where the covered area be improved and a 3D indoor positioning be guaranteed. The proposed Local Positioning System (LPS) for Mobile Robots (MR) uses simultaneous emissions from ultrasonic beacons. In...

This work presents the development and implementation of an acoustic sensor network mainly proposed for relative positioning of mobile robots and autonomous modules. The system consists of several objects to be located, each one of them with an acoustic sensor node. Every node has the required technology in order to compute its position, by using o...

Golay sequences and complementary sets of sequences have been long studied for their application in multisensor and communication systems. The feasibility of these systems strongly depends on the design of an efficient generator and correlator with the aim of reducing the computational load and hardware complexity. Recursive algorithms, which allow...

Some sensor systems are characterized by multiple simultaneous aperiodic emissions, with low signal-to-noise ratio and asynchronous detection. In these systems, complementary sets of sequences can be used to encode emissions, due to their suitable auto-correlation and cross-correlation properties. The transmission of a complementary set can be acco...

Signal coding and pulse compression provide ultrasonic systems with the capability to obtain accurate measurements that are nearly independent of the conditions of operation. This property, together with the high robustness to noise also achieved with these techniques, are making possible the development of high reliability systems intended for out...

In this work, the performance of an acoustic relative positioning system is studied, by a Monte-Carlo analysis, with the aim of determining the obtained accuracy and precision. The system has been designed in order to be used in the relative positioning estimation of mobile objects which are not restricted to a particular environment and cannot dep...

Ultrasonic transducers have been often used to develop local positioning systems (LPS) in the field of intelligent spaces. In these systems, it is necessary to design an ultrasonic beacon, which is distributed in the environment to cover a determined area where mobile robots or people can be located. This work describes the design and the implement...

The encoding of emissions by complementary sets of sequences is usually used in communications and multi-sensor systems where asynchronous detection is required. These sets of sequences have ideal properties in the addition of their autocorrelation and cross-correlation functions. Furthermore, it is possible to obtain efficient correlation algorith...

This work proposes several techniques to validate the detection of objects in railway environments. The system for obstacle detection is based on an infrared emitting barrier and another of receivers placed on opposing side in the railway, establishing different optical links between them. The system is located at the segments of the railroads wher...

Many mobile robots and autonomous vehicles designed for outdoor operation have incorporated ultrasonic sensors in their navigation systems, whose function is mainly to avoid possible collisions with very close obstacles. The use of these systems in more precise tasks requires signal encoding and the incorporation of pulse compression techniques tha...

Kasami sequences have been successfully used in communications, navigation and related systems due to their low cross-correlation values, compared to those from other binary sequences. In this work, different alternatives for the hardware implementation of a correlator of Kasami sequences are presented: for short sequences a combinational design is...

The determination of the relative position among mobile objects or members of a robot team is a useful information when the systems are not restricted to a particular environment and they cannot depend on an external infrastructure to obtain their location information. The solution for this kind of problems cannot be divided and treated separately...

This work proposes a data fusion technique to validate the detection of objects in railway environments. The system for obstacle detection is based on an infrared emitting barrier and another of receivers placed on opposing side in the railway, establishing different optical links between them. The interruption of one or several links in the sensor...

In this work a processing algorithm is presented to obtain the impulse response of the transmission channel in a MIMO ultrasonic system. In this algorithm the macro-sequences (Ms) obtained from complementary sets of M sequences are used to obtain the impulse response of the environment. The signals received by the sensorial system are demodulated a...

This paper proposes a train wheel detection system based on the use of an inductive sensor array. It allows multiple detection points and uses coded signals in order to work with low signal to noise ratios. The sensor array consists of pairs of sensor coils placed at every detection point. In this work, unlike previous work about this matter, the c...

This work presents some methods to reduce false alarms in railway obstacle detection. The sensorial system is based on one barrier of infrared emitters and another of receivers, placed on opposing sides of the railway. Obstacle detection is achieved by the lack of reception in the detectors. On the one hand, the efficiency of the system is achieved...

The use of complementary sets of sequences is especially relevant in multisensorial systems, with simultaneous emissions from different sources and low signal-to-noise ratio (SNR). There exist efficient generation and correlation algorithms that give a reduction in the computational load and complexity of a hardware implementation. In this work a n...

This work presents an intelligent system, which allows to detect obstacles in railways, based on optical emitters. The sensorial system is based on a barrier of emitters and another of receivers, placed each one of them at one side of the railway. Apart from the disposition of the sensorial system, a codification method of the emission is also pres...

The present work shows a local positioning system (LPS) for mobile robots (MR) using simultaneous emissions in the ultrasonic beacons. In order to solve the problem of the simultaneous emission of the ultrasonic beacons, the well-known technique called direct sequence code division multiple access (DS-CDMA) is used. This technique modulates the ult...

In this paper the estimation of a channel impulse response using complementary sets of sequences is considered. A direct (non-iterative) technique is presented and applied to an asynchronous system where the signals are recovered by matched filtering. The robustness of this technique is quantified in terms of the signal-to-noise ratio (SNR) obtaine...

This work deals with the use of sets to code multi-mode seasonal system, similar to code-division multiple-access (CDMA) communication ones. In multi-sensorial systems, as multi-user ones, it is necessary to avoid the multiple-access interference (MAI). We propose the use of mutually orthogonal complementary sets of sequences (MO-CSS) to avoid MAI...

This article presents a process for the simultaneous determination of distances among objects in an indoor localization system using an acoustic sensor network. The proposed technique is based on a simultaneous time-of-flight measurement for the emitted acoustic signals from every object, without needing any additional signal to be used for synchro...

The design of advanced sonar modules implies the use of more and more complex processing algorithms, in order to obtain as much information as possible from the environment. The use of simultaneous emission and reception techniques in certain transducers, that form an ultrasonic sensorial module, allows to increase the benefits and the performance...

Golay sequences and complementary sets of sequences have been long studied for applications in asynchronous Direct Sequence CDMA systems. Procedures for the generation of two or more complementary sequences make possible to have two or more orthogonal sets of sequences. However, the feasibility of these systems depends on the design of an efficient...

En este trabajo se presenta un método para estimar la respuesta impulsiva (IR) en un sistema ultrasónico MIMO usando Conjuntos Complementarios de M Secuencias (M-CSS). El sistema esta conformado por µ transductores, que emiten simultáneamente una Macro-Secuencia (M S) construida a partir de un conjunto complementario distinto y particular. Cada M S...

Resumen — La codificación de emisiones mediante secuencias complementarias es ampliamente utilizada en sistemas de comunicaciones y multi-sensor. Estos esquemas de codificación poseen propiedades ideales en sus funciones de auto-correlación y correlación cruzada que hacen muy adecuado su empleo en sistemas de detección asíncrona. Sin embargo, debid...

Systems that characterize the state of an entity or object are very im-portant in the "smart spaces" and "ubiquitous computing"; this information is usually known as the entity's "context". Those applications, which describe or characterize these entities and interact with it, are often referred as "context-aware computing". One of the most importa...

La capacidad para determinar la resistencia a las heladas de invierno de las plantas permite evaluar la viabilidad de plantación de ciertas especies en zonas climáticamente desfavorables. Para llevar a cabo experimentos de congelación en condiciones de campo, con control total de temperatura, se ha desarrollado un freezer portátil para analizar el...

Recientemente se ha demostrado la utilidad que pueden tener los polímeros celulares cuasi-piezoeléctricos en diversas aplicaciones. En este trabajo se describe la fabricación y caracterización de un transductor emisor de ultrasonidos utilizando láminas poliméricas electromecánicas. Se ha comprobado que estos transductores tienen un ancho de banda p...