José Luis Martín

• PhD
• Professor (Full) at University of the Basque Country

Robotic inspection is advancing in performance capabilities and is now being considered for industrial applications beyond laboratory experiments. As industries increasingly rely on complex machinery, pipelines, and structures, the need for precise and reliable inspection methods becomes paramount to ensure operational integrity and mitigate risks....

Unmanned underwater vehicles (UUVs) are key technologies to conduct preventive inspection and maintenance tasks in offshore renewable energy plants. Making such vehicles autonomous would lead to benefits such as improved availability, cost reduction and carbon emission minimization. However, some technological aspects, including the powering of the...

Neutral point voltage control converters (NPVCC) are being considered for AC drive applications, where their additional degree of freedom can be used for different purposes, such as fault tolerance or common mode voltage (CMV) reduction. For every PWM-driven converter, the CMV is an issue that must be considered since it can lead to shaft voltages...

One of the most common issues in inverters are open-circuit faults (OPF). In this scenario, a proper fault-tolerant technique must be used to improve the motor performance. Although basic fault-tolerant modulation techniques are normally preferred, this paper proposes a discontinuous pulse-width modulation algorithm (HD-PWM) to operate five-phase i...

In the automotive industry, the design and implementation of power converters and especially inverters, are at a turning point. Silicon (Si) IGBTs are at present the most widely used power semiconductors in most commercial vehicles. However, this trend is beginning to change with the appearance of wide‐bandgap (WBG) devices, particularly silicon ca...

Abstract The shorter switching times of silicon carbide (SiC) MOSFETs enable power converters to operate at higher frequencies than with silicon IGBTs. However, because SiC MOSFET die sizes are still relatively small, several devices have to be connected in parallel to cope with the high current ratings demanded. For the total current to be evenly...

Star-connected multiphase AC drives are being considered for electromovility applications such as electromechanical actuators (EMA), where high power density and fault tolerance is demanded. As for three-phase systems, common-mode voltage (CMV) is an issue for multiphase drives. CMV leads to shaft voltages between rotor and stator windings, generat...

Information about the position of entities is very valuable in many fields. People, animals, robots and sensors are some examples of entities that have been targeted as nodes of interest for localization purposes. Technical advances in ubiquitous computing and wireless communications properties are very valuable means to obtain localization informa...

The characterization of human interaction at different levels has been a matter of interest in many disciplines. So far, social networking through the Internet has been the main source to infer human beings’ relations. Nevertheless, due to the irruption of wearable devices with wireless communication capabilities, initiatives that use them to measu...

This paper highlights the challenges to be taken into consideration when Bluetooth is used as a radio technology to capture proximity traces between people. Our study analyzes the limitations of Bluetooth-based trace acquisition initiatives carried out until now in terms of granularity and reliability. We then propose an optimal configuration for t...

On-board Energy Storage Systems (ESS) are a promising solution to reduce energy consumption in transportation systems. The combination of supercapacitors and batteries would increase the efficiency of the overall ESS and its operability and durability. Two topologies are analyzed and simulated against standard testing track profiles for railways. T...

This paper presents a novel technique to evaluate the electric power losses in MVAC and HVAC three-core XLPE cables. The proposed formulation allows to evaluate these losses without power flow simulations by shaping it either in a spreadsheet or in algorithmic form. The formulation can be easily set out within wider methods such as those used to ev...

The current situation of the offshore wind market is characterized, among other things, by two opposing forces. On the one hand, there are a few already tested solutions that can be considered almost industrialized under certain conditions of sea bed depth and distance from shore, and investors interested in the offshore wind business will generall...

Ultracapacitors are entering into applications dominated by batteries. The complementary features of ultracapacitors and batteries may allow in certain applications to combine them enhancing the performance of the overall energy storage system. In other applications, the advantages of ultracapacitors may allow to completely displaced batteries avoi...

Offshore wind power is attracting the interest of experts in a range of disciplines such as electricity, electronics, mechanics, materials, control, project management and financing. The objectives are bold. On the one hand, with the fossil era showing slight signs of decay, renewable sources of electricity are seen as a realistic supply of energy...

This paper reviews offshore wind projects with a wide perspective. The current situation of the offshore wind market is presented, pointing out the countries leading the process in terms of installed capacity and in terms of technological leadership. Feasibility studies of alternative offshore wind farms (OWFs) are interesting not only in relation...

Smart grids and distributed power will play a big role in the future power grid. In the future many DC grids will coexist with the traditional AC grids. This paper presents an efficient and low cost alternative for unidirectional or asymmetric interconnection of DC grids using MVDC transmission lines using High Frequency Transformers.

This paper proposes a procedure to assess the electrical losses in Wind Energy Conversion Systems (WECSs) with different electrical topologies. Those losses are evaluated in an annual basis considering the randomness of the wind with a Rayleigh probability distribution function. Due to the lack of specific standards, the analysis is based on standa...

The matrix converter (MC) is arousing considerable attention as an alternative for conventional ac/ac converters due to the advantages it offers. However, the control and modulation of this converter is complex. This, together with the fact that the MC usually operates at high modulation frequencies, makes the computational load of the platform to...

The matrix converter can be used in a wide range of applications. Nevertheless, it does not yet represent a sufficiently mature option for industrialization. In order to resolve this prob- lem, this paper examines the hardware of the matrix converter and identifies all the circuits that should be included in this. It also quantifies the operating c...

This paper gives an overview to the foundations, the Offshore Wind Turbines (OWTs) and the collection and transmission systems of Offshore Wind Farms (OWFs). Although for some of the components of their Electric Systems (ESs) there are different technical possibilities under consideration, under certain conditions of sea depth and distance from sho...

This paper gives an overview of several aspects of Offshore Wind Power (OWP) integration. During last year the wind market has exceed forecasts despite of the global crisis, with the offshore market offering very good numbers. Moreover, some projections presented in the paper show that OWP installed during the next five years will probably overcome...

This paper proposes a stationary-frame sequence detector (SFSD) structure for determining the positive sequence in three-phase systems. The structure includes the use of the Clarke transformation and moving average filters (MAFs). The positive-sequence phase angle can be obtained from the alpha-beta components; however, such a detection becomes ina...

Microgrids (MGs) are promising electrical systems based on Distributed Generation and with high penetration of renewable energy sources. One important feature of MGs is the islanding capability: if there is a disturbance in the main grid, the MG will be automatically disconnected. In theory, once in islanding, the MG can continue the electrical gen...

This paper presents a new three-level topology based on the neutral-point (NP)-clamped converter. An additional leg is added to the basic topology. The main purpose of this leg is to provide the converter with fault-tolerant capabilities. In addition, during normal operation mode, the fourth leg can be used to balance the NP voltage. In this way, t...

The matrix converter (MC) presents a promising topology that will have to overcome certain barriers (protection systems, durability, the development of converters for real applications, etc.) in order to gain a foothold in the industry. In some applications, where continuous operation must be insured in the case of a system failure, improved reliab...

In this paper a wave-to-wire approach to model the exploitation of ocean energy by point absorbers in heave is presented. Attention is focused on the impact that the control strategy of the Wave Energy Converter (WEC) has both on the power performance of the single device and on the grid power quality at the connection point, when point absorbers a...

This paper proposes a filtered-sequence phase-locked loop (FSPLL) structure for detection of the positive sequence in three-phase systems. The structure includes the use of the Park transformation and moving average filters (MAF). Performance of the MAF is mathematically analyzed and represented in Bode diagrams. The analysis allows a proper select...

This paper presents a study of the fault tolerance capacity of a neutral-point-clamped converter. Different faults in power semiconductors are considered, and the available postfault states of the converter are shown. In regard of the operation limits, two possible solutions are presented. In these solutions, adding a reduced number of additional c...

The matrix converter (MC) is a promising topology for various applications due to its intrinsic advantages. In this sense, this type of converter represent an alternative for small wind turbines (SWT). Simulation is necessary to validate the controllers and study the interaction of the wind farm with the grid, but this is not feasible using traditi...

In this paper, an Autonomous Fault Tolerant System that implements a communication gateway between a CAN bus and asynchronous communication interface is presented. This gateway has been implemented using a Triple Modular Redundancy architecture at IP core level. The system can respond to an error detected by a voter in a Triple Modular Redundancy a...

Trains have evolved from being the first practical forms of mechanized land transport to the extremely complex and sophisticated transportation systems we currently use. Modern trains systematically incorporate more and more electronic equipment and consequently, nowadays multiple manufacturers and suppliers provide electronic systems for this well...

This paper describes a novel approach to binarization techniques. It presents a way of obtaining a threshold that depends both on the image and the final application using a semantic description of the histogram and a neural network. The intended applications of this technique are high precision OCR algorithms over a limited number of document type...

Increasing the level of abstraction while designing electronic complex systems is one of the main challenges that electronic design teams are facing nowadays. This challenge is closely related to the development of virtual models of components and devices with four main objectives: 1) early software development; 2) architectural exploration; 3) Hig...

Modern digital systems demand increasing electronic resources, so the multiprocessor platforms are a suitable solution for them. This approach provides better results in terms of area, speed, and power consumption compared to traditional uniprocessor digital systems. Reconfigurable multiprocessor systems are a particular type of embedded system, im...

Modern Systems-on-Chip (SoC) development is moving toward multiprocessor-based design. Embedded systems have evolved from an uniprocessor to a multiprocessor approach, seeking better performance and less energy consumption. It is widely accepted that Multiprocessor Systems-on-Chip (MPSoC) will become the predominant class of embedded systems in fut...

Connection of winfarms to the main grid through an HVDC transmission system has many technological advantages that can help increase the amount of wind power connected in a system. The high cost of the power converters in HVDC systems is the main drawback that is holding back the use of HVDC in wind farms. HVDC systems are usually Point to Point co...

The oceans represent a huge energy reservoir. Although today all of the marine power projects are very near from the shore and they are rated at low power, the huge potential of the seas may in a not very distant future bring marine power further into the sea. Also offshore oil and gas exploration is moving into deeper waters and at longer distance...

The standardization of train communications protocols, train communication network (TCN), has created a need to design new electronic devices which can communicate according to them. Up to date, several solutions have been suggested, but every one needs additional circuits. In this article we present a novel flexible architecture which allows the m...

In this paper a configurable-system-on-programmable-chip controller for matrix converter is presented. The controller takes advantage from partial reconfiguration to interchange dynamically space-vector-modulation cores with different signal quality-switching power loses trade-off. The internal design is presented and the newest Xilinx design flow...

The present paper provides a review of the main concepts and principles involved in mixed PCBs (printed circuit board) design for electronic devices with mixed technologies, i.e. analog, RF (radio frequency) and digital components within the same PCB, such as characteristic impedance, layer stack-up and shielding.

This paper presents and discuses different PI tuning methods and control strategies for a permanent magnet synchronous machine. The machine is a part of a wind turbine generation system in which two back-to-back-connected three-level converters are the power interface to the electrical grid. It is demonstrated that, for the speed control loop, the...

The matrix converter (MC) presents a promising topology that needs to overcome certain barriers (protection systems, durability, the development of converters for real applications, etc.) in order to gain a foothold in the market. Taking into consideration that the great majority of efforts are being oriented toward control algorithms and modulatio...

This paper proposes a three-phase positive sequence detector that does not require any parameter to be adjusted. It operates in open loop and there is not any PI controller that needs to be tuned. The scheme includes the use of the Park transformation and moving average filters. Performance of the moving average filter is mathematically analyzed an...

The matrix converter (MC) presents a promising topology that needs to overcome certain barriers (protection systems, durability, the development of converters for real applications, etc.) in order to gain a foothold in the market. This article focuses on MC hardware. In order to improve the switching speed of the MC and thus obtain signals with les...

This paper presents a new low-loss modulation technique for the hybrid three-level four-leg converter. The total losses of the converter are reduced by about 18% on average compared to the standard three-leg neutral-point-clamped converter. Furthermore, the low-frequency voltage oscillation in the neutral point is completely cancelled, and the maxi...

This paper proposes a practical way to simplify large simulation platforms. A complete model with a Matrix Converter ( MC ) linked to a doubly fed induction machine ( DFIM ) is described, proving that this kind of converter is suitable for use in power regenerative rigs. Besides contributing to the study of DFIM with MC , a fast way to describe all...

Parameter variations, model inaccuracies and noise in measurements introduce rotor position estimation errors in sensorless algorithms in Doubly Fed Induction Machines. Depending on the chosen control algorithm, these position estimation errors may generate important errors on the control of active power and reactive power of the Doubly Fed Inducti...

The behavior of the matrix converter (MC) is usually studied in the stationary condition, however, turning on the MC is a very crucial moment for this device as overcurrents and overvoltages may appear, damaging the converter. In order to improve its ride-through capability, this paper focuses on matrix converter (MC) power-up protection strategies...

This paper presents the design of a network master device for the multifunction vehicle bus. An analysis of the specifications for this bus administrator reveals that the functional design can be arranged in 14 operational blocks and in a special memory for communication data known as the traffic store. System-on-a-chip strategies have been adopted...

DRM (digital radio mondiale) is a new digital audio broadcasting system used in narrow band AM bands. In order to analyze its propagation behavior, high quality receivers must be implemented. Thus, BER and C/N ratios may be measured and analyzed, enabling broadcasters to establish the best strategy to effectively cover a wide geographical area. In...

In this paper a modification of the neutral-point-clamped (NPC) converter, in which a fourth leg has been added, is presented. The main aim of this additional leg is to increase the reliability of the converter and thereby allow it to continue operating when a breakdown in one of the IGBTs occurs. In addition, during normal fault-free operation, th...

The increase of the wind power penetration in the electrical grids of Denmark, Germany, Spain and other countries and regions is challenging the stability of the system. The subject of this paper is to review the main problems of the connection of wind farms to the grid and how the grid codes must be adapted in order to integrate wind power generat...

In this work we present a self-reconfiguration control focused on multiprocessor core-based systems implemented on FPGA technology. An infrastructure of signals, protocols, interfaces and a controller is exposed to perform safe hardware/software reconfigurations. This infrastructure is part of the Tornado framework that includes other elements such...

This paper presents a study of the fault tolerance capacity of a neutral-point-clamped (NPC) converter. Furthermore, two possible solutions are presented. In these solutions, adding a reduced number of additional components, the behavior of the converter when a switch fails improves considerably. Simulations results that prove the correct operation...

This paper presents a new three-level topology based on the neutral-point-clamped converter. The new topology includes a fourth leg that provides fault tolerance to the converter. Furthermore, during normal operation mode, this leg is able to provide a stiff neutral voltage. Consequently, the low- frequency voltage oscillations that appear in the n...

In this work, the use of the Generalized Principal Components Analysis (G-PCA) to improve the segmentation of moving objects in image sequences is proposed. In order to obtain this improvement, the noise components in the image derivatives are reduced, and afterwards, a method based on linear algebra is used to make the segmentation. Furthermore th...

This paper describes a reconfigurable digital architecture to compute dense disparity maps at video-rate for stereo vision. The processor architecture is described in synthetizable VHDL and, by means of the reconfigurability, the hardware requirements are optimized for different image resolutions and matching scenarios. The configurable description...

Buses in modern trains must cope with dynamic on-board network topologies while ensuring that data are delivered in real time. This is the case of the wire train bus, in which most of the nodes are complex multi-processor gateways. In these systems, the link layer related tasks, as defined in the train communication network (TCN) standard, need all...

This paper describes a clustering technique using Self Organizing Maps and a two-dimensional histogram of the image. The two-dimensional histogram is found using the pixel value and the mean in the neighborhood. This histogram is fed to a self organizing map that divides the histogram into regions. Carefully selecting the number of regions, a schem...

Networks in trains are mobile communication systems which require, above all, safety and reliability. So, the electronic creation flow should ensure that the designed line controller (mainly coder and decoder) is secure. However, verifying the behavior and performance of such an electronic circuit is not a simple task. Most times, the receiver must...

Matrix converters present several advantages in some power electronic applications, but their control is a complicated task. Matlab-Simulink is a very useful tool for the developing of control algorithms for power converters. In this paper, an exhaustive analysis of double sided space vector modulation for a matrix converter is presented. The synth...

In this paper, two designs for the decoder of the multifunction vehicle bus (MVB) are compared. The first one follows a bottom-up methodology and the second one has been created in a top-down style. Although this latter methodology is more systematic and easy to automate, it results in a lower performance. In the case of the MVB decoder, the ratio...

Every month new applications of fuzzy logic to image processing appear. The lightly tight nature of fuzzy algorithms simulates human vision and thus, the field of applications widens. This paper implements in hardware a very popular fuzzy algorithm, the Fuzzy C-Means algorithm. The version of the algorithm allows a high degree of parallelism, which...

This paper describes the hardware implementation of a high complexity algorithm to estimate the optical flow from image sequences in real time. Optical flow estimation from image sequences has been for several years a mathematical process carried out by general purpose processors in no real time. In this work, a specific architecture for this task...

Nowadays, neural networks play a key role in many electronic applications. Software implementations are the most used ones because they require a great amount of resources. With the increasing power and capabilities of current FPGAs it is obvious that they can be translated into hardware to increase their speed and usefulness. This paper presents a...

In this paper a behavioral model of the gateway for the Train Communication Network (TCN) is presented. It has been used in a specific verification tool for TCN devices based on a commercial VHDL simulator. By means of bit level exhaustive simulation in this tool, electronic designs in VHDL language have been validated before prototypes are produce...

The multifunction vehicle bus (MVB) is a local area network for telematic applications of trains. It uses Manchester encoding in order to interchange data among field devices on board. The physical level is accurately defined since RS-485 standard is followed. So electrical signal are bipolar and the point-to-multipoint structure is the most common...

Neural networks play a key role in many electronic applications, we can find them from industrial control applications to predictive models. They are mainly implemented as software entities because they require a great amount of complex mathematical operations. With the increasing power and capabilities of current FPGAs, now it is possible to trans...

The functionality of many digital circuits is strongly dependent on high speed data exchange between data source and sink elements. In order to alleviate the main processor’s work, it is usually interesting to isolate high speed data transfers from all other control tasks. A generic architecture, based on configurable cores, has been achieved for c...

This paper describes a reconfigurable digital architecture to compute dense disparity maps at video-rate for stereo vision. The processor architecture is described in synthetizable VHDL and, by means of the reconfigurability, the hardware requirements are optimized for different image resolutions and matching scenarios. To have a configurable descr...

This paper discusses a new control method for variable-speed doubly-fed induction machine, power error vector control. The control does not depend on physical parameters of the machine and it has no need to tune parameters, so it is very simple, robust, and can be implemented in very short time. The application of different modulation strategies, n...

In complex SoC designs verification consumes more than half of the overall design effort. Design reuse is a critical element in closing the SoC design gap, but it is not enough. A generic core-based architecture for circuits that require high volume data transfer control was designed. After some experience in reusing the architecture, a key improve...

In this paper present a partial run-time reconfiguration framework focused on multiprocessor core-based systems implemented on FPGA technology. It is called Tornado, and it is composed of an infrastructure of signals, protocols, interfaces and controller to perform safe hardware/software reconfigurations.

A new electronic design for a TCN (train communication network) bus is presented in this paper. Based on top-down philosophy and focused on system on a chip strategies, various of its modules are expected to be reused in some other designs for complex communication circuits. In order to verify the Class 1 device proposed for MVB (multifunction vehi...

A secret and secure ballot is the core of every democracy. We all feel proud of being able to decide the future of our countries by making appropriate use of our right to vote in an election. However, how can we improve the efficiency of the voting process? Democratic governments should have mechanisms which ensure the integrity, security and priva...

The fuzzy approach in image processing is taking each day greater importance. It is greatly due to the fact that every new application of artificial vision is closer to human vision. This means that tightly knot algorithms are not always a good solution and a more "imprecise" and fuzzy approach is desirable. This paper describes a modified Fuzzy C-...

Checking whether complex digital systems work properly is a hard, tedious and repetitive task. If this digital system involves the transmission of data through the use of communication devices, the testing becomes a hard problem to solve: signal power is low and it is prone to interference, baseband signals are complex and transmitted data is hard...

In this paper a specific verification tool for digital communication circuits is presented. Applied to devices for the train communication network (TCN) and based on bit level exhaustive simulation, electronic designs in VHDL language can be validated before prototypes are produced. For this purpose, a virtual communication network is built by mean...

This article describes a pipeline sequential fuzzy controller endowed with great flexibility and high performance. Its design allows for the possibility to implement it on programmable devices at low cost. To optimise the design and performance of the circuit, a number of simplifications over traditional fuzzy algorithms are pointed out. For the ma...

This paper presents a method for the processing and classification of electroencephalographic (EEG) signals linked to mental states (rest and motor image) using the wavelet transform of these signals as input information of an LVQ neural network. This system obtained a 70% correct qualification rate in the first recording session, a 50% rate in the...

In this paper, the authors present a real-time adaptive and reusable image enhancement architecture for video signals, based on a statistical processing of the video sequence. The main processing circuit has been implemented in a FPGA. A software test bench designed specifically for image processing applications has been used for simulation purpose...

In this paper we present a DSP-based board for control, monitoring and maintenance of a primary station of a crushing plant, which includes a feeder, a jaw crusher, and conveyor belts. The system has a LCD used for the visualization of different messages, such as the measurements acquired by the sensors and the menus required to configuring the sys...

Two of the most important problems of autonomous mobile robots are the physical implementation (sensors and actuators) and strategy definition. The objective of the paper is to describe a vehicle guidance circuit with less specific hardware as possible and with an easy way of defining the guidance strategy. The control circuit is based on a low cos...

In this paper we present a new architecture for slave node of a train communication system based on the standard TCN (train communication network). This node is used to interconnect different electronic equipment based on the MVB (multifunction vehicle bus). The architecture is based on a microcontroller for the link and network layers, and a PLD f...

The aim of this work is to design a real-time adaptive and reusable image enhancement architecture for video signals, based on a statistical processing of the video sequence. The VHDL hardware description language has been used in order to make possible a top-down design methodology. Generic design methodology has been followed by means of two feat...

This paper describes the VHDL implementation of a high complexity algorithm to estimate the optical flow from image sequences in real time. The final system will be developed with hardware that combines FPGA technology and discrete FIFO memories. By this reason in the VHDL description it is necessary to include three types of code: synthetizable on...

The aim of this work is to design a real time adaptive and parameterizable histogram equalizer for video signals. The VHDL hardware description language has been used in order to make possible a top-down design methodology. A reusable histogram equalizer has been achieved by means of a generic design strategy, which has been possible using two feat...

In this paper, the authors present a video processing circuit for a 3D machine vision system designed with an FPGA that processes images in real time and provides them through the EPP (enhanced parallel port) to a computer. The system is useful in 3D vision applications so different as robot guidance in MIG and laser soldering or control of treated...

The design of complex electronic circuits such as image processing circuits require new specific simulation and modelling tools, in order to reduce the development time. To simulate image-processing models described in VHDL an application specific test bench is needed. In this work a VHDL test bench was designed specifically for image-processing ap...

Optical flow estimation from image sequences has been for several years a mathematical process carried out by general purpose processors in no real time. A specific architecture for this task has been developed and tested with simulators of hardware description languages. This architecture can estimate the optical flow in real time and can be const...

Time gradient can be used to extract information from motion.It has been already done, but higher performances are reached if it's computed on real time. We propose an architecture to evaluate it from consecutive images in a video signa. Behind a delaying structure, a circuit operates over the neighborhood of pixels around each one: not only the ad...

The printed circuit board (PCB) is the base most commonly used for building electronic circuits. The design of the PCB is usually done by means of an adequate CAD program. The files generated by CAD programs can have different formats to describe printed circuit boards, but all formats essentially consist of the traces and the soldering pads that m...