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Nuno Ferreira

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University of Zagreb

Uppsala University

University of East London

Armando Marques-Guedes

UNL - New University of Lisbon

University of Leicester

Gwen Robbins Schug

University of North Carolina at Greensboro

Gabriel Gutierrez-Alonso

University of Salamanca

Macquarie University

Universidade Federal do Rio Grande do Sul

Swansea University

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Papers by Nuno Ferreira

Data Acquisition from the Integration of Kinect Quaternions and Myo Armband EMG Sensors to Aid Equinus Foot Treatment

Proceedings of the 12th International Joint Conference on Biomedical Engineering Systems and Technologies

This paper shows the advantage of using different sensors such the Microsoft Kinect and Myo Armba... more This paper shows the advantage of using different sensors such the Microsoft Kinect and Myo Armband to acquire movement description of the plantarflexion and dorsiflexion of the foot with the help of the quaternions and the EMG Myo sensor. For the integration of these devices, it was chosen Python to develop the algorithm and create an interface to aid the signal acquisition. This integration, enabling an accurate motion description as well as a scale of EMG signal, allow the possibility of quantifying the treatment of the people with equinus foot.

Cloud-Based Framework for Robot Operation in Hospital Environments

Lecture Notes in Electrical Engineering, 2020

The robotics field is widely used in the industrial domain, but nowadays several other domains co... more The robotics field is widely used in the industrial domain, but nowadays several other domains could also take advantage of it. This interdisciplinary branch of engineering requires the use of human interfaces, efficient communication systems, high storage and processing capabilities, among other issues, to perform complex tasks. This paper aims to propose a cloud-based framework platform for robot operation in a hospital environment, addressing some challenges, such as communications security and processing/storage features. The recent developments in the artificial intelligence field and cloud resources sharing are allowing the penetration of robots in unstructured environments. However, some new challenges and solutions need to be tested in real environments. Our main contribution is to decrease the time-consumption related to processing and storage costs, associated with the physical processing resources of the robots. Also, the proposed methods provide an increase of the processing variables that are not yet present in the physical resources, such as in the case of robots with limited processing time or storage capabilities. This paper presents a platform based on Cloud Computing with services to support processing, storage and analytics applied to hospital environments. The proposed platform enables to achieve a decrease in the timeconsumption, especially when it is intended to retrieve information about all robot activities.

On the Design, Construction and Calibration of Dual-Probe Heat-Pulse Soil Moisture Sensor: Towards an Industrial Solution

There is a need for a multi-functional probe for smallscale measurements of different soil proper... more There is a need for a multi-functional probe for smallscale measurements of different soil properties measured within identical soil volumes. Dual Probe Heat Pulse (DPHP) sensors are an economical solution for this since they measure simultaneously temperature, volumetric water content, and soil thermal properties: diffusivity and volumetric heat capacity. However, all DPHP sensors to date have very complex manufacturing processes. This paper aims to design and build a DPHP sensor based only on a Printed Circuit Board (PCB) board, which comprises the probes and all supporting electronics leading to a low cost and simple manufacturing process. The proposed system includes signalprocessing circuits, a microcontroller, and communicates by a Serial Digital Interface at 1200 baud protocol (SDI-12). The sensor needs a one-time two calibrations: distance from heater to temperature sensor calibration using agar solution; and sensor calibration in soil using Tottori Dune sand. Both calibrati...

Classiﬁcation of Images of Childhood Pneumonia using Convolutional Neural Networks

Proceedings of the 12th International Joint Conference on Biomedical Engineering Systems and Technologies, 2019

In this paper we describe a comparative classification of Pneumonia using Convolution Neural Netw... more In this paper we describe a comparative classification of Pneumonia using Convolution Neural Network. The database used was the dataset Labeled Optical Coherence Tomography (OCT) and Chest X-Ray Images for Classification made available by (Kermany, 2018) with a total of 5863 images, with 2 classes: normal and pneumonia. To evaluate the generalization capacity of the models, cross-validation of k-fold was used. The classification models proved to be efficient compared to the work of (Kermany et al., 2018) which obtained 92.8 % and the present work had an average accuracy of 95.30 %.

Comparative Study of Compression Techniques Applied in Different Biomedical Signals

Proceedings of the 12th International Joint Conference on Biomedical Engineering Systems and Technologies, 2019

This paper aims to compare the compression of electro-oculographic signals, based on the (EOG) fr... more This paper aims to compare the compression of electro-oculographic signals, based on the (EOG) from MIT / BIH database, and the electromyographic signals, based on the (EMG) from MIT / BIH database, for that purpose, two compression techniques that can be used in electro-oculograms and electromyograms was approached, the two techniques mentioned above, were, the discrete cosine transform and Fast Walsh Hadamard Transform. For statistic the methods used was, the Mean squared error, mean absolute error, signal-to-noise ratio and peak signal-to-noise ratio as well, and for results, the techniques and they performance on each tested signal.

Single-objective front optimization

Proceedings of the 10th annual conference on Genetic and evolutionary computation, 2008

This paper proposes a new algorithm which promotes well distributed non-dominated fronts in the p... more This paper proposes a new algorithm which promotes well distributed non-dominated fronts in the parameters space when a single-objective function is optimized. This algorithm is based on ǫ-dominance concept and maxmin sorting scheme. Besides that, the paper also presents the results of the algorithm when it is used in the automated synthesis of optimum performance CMOS radiofrequency and microwave binary-weighted differential switched capacitor arrays (RFDSCAs). The genetic synthesis tool optimizes a fitness function which is based on the performance parameter of the RFDSCAs. To validate the proposed design methodology, a CMOS RFDSCA is synthesized, using a 0.25 µm BiCMOS technology.

$Research paper thumbnail of Introducing the fractional order robotic Darwinian PSO$

Introducing the fractional order robotic Darwinian PSO

AIP Conference Proceedings, 2012

Resistive plate chambers in positron emission tomography

The European Physical Journal Plus, 2013

Resistive plate chambers (RPC) were originally deployed for high energy physics. Realizing how th... more Resistive plate chambers (RPC) were originally deployed for high energy physics. Realizing how their properties match the needs of nuclear medicine, a LIP team proposed applying RPCs to both preclinical and clinical positron emission tomography (RPC-PET). We show a large-area RPC-PET simulated scanner covering an axial length of 2.4 m-slightly superior to the height of the human body-allowing for whole-body, single-bed RPC-PET acquisitions. Simulations following NEMA (National Electrical Manufacturers Association, USA) protocols yield a system sensitivity at least one order of magnitude larger than present-day, commercial PET systems. Reconstruction of whole-body simulated data is feasible by using a dedicated, direct time-of-flight-based algorithm implemented onto an ordered subsets estimation maximization parallelized strategy. Whole-body RPC-PET patient images following the injection of only 2 mCi of 18-fluorodesoxyglucose (FDG) are expected to be ready 7 minutes after the 6 minutes necessary for data acquisition. This compares to the 10-20 mCi FDG presently injected for a PET scan, and to the uncomfortable 20-30 minutes necessary for its data acquisition. In the preclinical field, two fully instrumented detector heads have been assembled aiming at a four-head-based, small-animal RPC-PET system. Images of a disk-shaped and a needle-like 22 Na source show unprecedented sub-millimeter spatial resolution.

Benchmark of swarm robotics distributed techniques in a search task

Robotics and Autonomous Systems, 2014

Benchmark of swarm robotics distributed techniques in a search task, Robotics and Autonomous Syst... more

Interacção com um Robô através de Linguagem Natural Falada

Electrónica e Telecomunicações, Nov 30, 2012

Resumo O desenvolvimento de um sistema capaz de interagir com um ser humano através da voz é algo... more Resumo O desenvolvimento de um sistema capaz de interagir com um ser humano através da voz é algo que tem sido alvo de muitos estudos e projectos. Este tipo de sistemas são aliciantes pois permitem ao Homem, através de uma forma simples e intuitiva, comunicar com a máquina. A interface de voz com um robô–o Carl-, em desenvolvimento no âmbito do projecto CARL, é apresentada neste artigo. Apresenta-se sobretudo astecnologias existentes, as ferramentas disponíveis e ainterligação de todos os subsistemas ...

Two Cooperating Manipulators with Fractional Controllers

International Journal of Advanced Robotic Systems, 2009

This paper analyzes the dynamic performance of two cooperative robot manipulators. It is studied ... more This paper analyzes the dynamic performance of two cooperative robot manipulators. It is studied the implementation of fractional-order algorithms in the position/force control of two cooperating robotic manipulators holding an object. The simulations reveal that fractional algorithms lead to performances superior to classical integer-order controllers.

The Concept of Robot Society: Evidence Taken From Multi-Robot SLAM

Comparison of Classification Methods for Golf Putting Performance Making

Computational Intelligence and Decision Making - Trends and Applications, From Intelligent Systems, Control and Automation: Science and Engineering Bookseries, 2012

This paper presents a comparative case study on the classification accuracy between 5 methods for... more This paper presents a comparative case study on the classification accuracy between 5 methods for golf putting performance analysis. In a previous work, a digital camera was used to capture 30 trials of 6 expert golf players. The detection of the horizontal position of the golf club was performed using a computer vision technique followed by the estimation algorithm Darwinian Particle Swarm Optimization (DPSO) in order to obtain a kinematical model of each trial. In this paper, the estimated parameters of the models are used as sample and training data of five classification algorithms: 1) Linear Discriminant Analysis (LDA); 2) Quadratic Discriminant Analysis (QDA); 3) Naïve Bayes with Normal (Gaussian) distribution (NV); 4) Naïve Bayes with Kernel Smoothing Density Estimate (NVK) and 5) Least Squares Support Vector Machines with Radial Basis Function Kernel (LS-SVM). The 5 classification methods are then compared through the analysis of the confusion matrix and the area under the Receiver Operating Characteristic curve (AUC).

Helicopter System Modelling and Control With Matlab��

This paper presents the modelling and control of a laboratory helicopter system with MatLab. In t... more This paper presents the modelling and control of a laboratory helicopter system with MatLab. In this perspective, students are motivated to investigate the dynamics, trajectory planning and control. Based on this experience, further studies on helicopter system, using more sophisticated concepts, are, then, more attractive from the students point of view.

Multi-Robot Exploration based on Swarm Optimization Algorithms

The Darwinian Particle Swarm Optimization (DPSO) is an evolutionary algorithm that extends the we... more The Darwinian Particle Swarm Optimization (DPSO) is an evolutionary algorithm that extends the well-known Particle Swarm Optimization (PSO) using natural selection, or survival-of-the-fittest, to enhance the ability to escape from local optima. In this paper, it is explored the effectiveness of using a modified version of both PSO and DPSO, respectively named as R-PSO and R-DPSO, on groups of simulated robots performing a distributed exploration task.

Manipulability analysis of two-arm robotic systems

  Many tasks involving manipulation require cooperation between robots. Meanwhile, it is necess... more   Many tasks involving manipulation require cooperation between robots. Meanwhile, it is necessary to determinate the adequate values for the robot parameters to obtain a good performance. This paper discusses several aspects related with the manipulability of two cooperative robots when handling objects with different lengths and orientations. In this line of thought, a numerical tool is developed for the calculation and the graphical visualization of the manipulability measure.

Cooperative Transportation of an Object based on Fractional Order Controllers

Advanced control techniques have been used in simulations to overcome nonlinear phenomena in orde... more Advanced control techniques have been used in simulations to overcome nonlinear phenomena in order to describe the performance of robots with two rotational (RR) degrees-of-freedom (dof). Given the current state-of-the-art, fractional order algorithms lead to better performance when compared to integer order controllers. Also, the development of simulation platforms allows evaluating the best control methodology. In this context, the use of RR robots attached to mobile platforms, denoted in this paper as RR mobile robots, demonstrates a remarkable ability in manipulating and transporting objects. The present work aims to study two cooperative RR mobile robots by analyzing the manipulator's trajectory and the forces applied to the common load. Are considered two robotic platforms based on an 8-bit microcontroller with inverse kinematics based on the Denavit-Hartenberg formulation and fractional order PID controllers inspired in the Grünwald-Letnikov definition.

Statistical Significance Analysis of the R-DPSO Towards an Understanding of the Relationship Between the Population of Robots and the Maximum Communication Distance

This paper presents a statistical significance analysis of a modified version of the Particle Swa... more This paper presents a statistical significance analysis of a modified version of the Particle Swarm Optimization (PSO) on groups of simulated robots performing a distributed exploration task, denoted as R-DPSO (Robotic DPSO). This work aims to evaluate this novel exploration strategy studying the performance of the algorithm under communication constraints while increasing the population of robots. Experimental results show that there is no linear relationship between the number of robots and the maximum communication range. In general, the decreased performance by the developed algorithm under communication constraints can be overcome by slightly increasing the number of robots as the maximum communication range is decreased.

A novel multi-robot exploration approach based on Particle Swarm Optimization algorithms

9th IEEE International Symposium on Safety, Security, and Rescue Robotics, SSRR 2011, 2011

This paper proposes two extensions of Particle Swarm Optimization (PSO) and Darwinian Particle Sw... more This paper proposes two extensions of Particle Swarm Optimization (PSO) and Darwinian Particle Swarm Optimization (DPSO), respectively named as RPSO (Robotic PSO) and RDPSO (Robotic DPSO), so as to adapt these promising biologicalinspired techniques to the domain of multi-robot systems, by taking into account obstacle avoidance. These novel algorithms are demonstrated for groups of simulated robots performing a distributed exploration task. The concepts of social exclusion and social inclusion are used in the RDPSO algorithm as a "punish-reward" mechanism enhancing the ability to escape from local optima. Experimental results obtained in a simulated environment show that biological and sociological inspiration can be useful to meet the challenges of robotic applications that can be described as optimization problems (e.g. search and rescue).

Ensuring ad hoc connectivity in distributed search with Robotic Darwinian Particle Swarms

9th IEEE International Symposium on Safety, Security, and Rescue Robotics, SSRR 2011, 2011

This paper presents an enforcing multi-hop network connectivity algorithm experimentally validate... more This paper presents an enforcing multi-hop network connectivity algorithm experimentally validated using a modified version of the Darwinian Particle Swarm Optimization (DPSO), denoted as RDPSO (Robotic DPSO) on groups of simulated robots performing a distributed exploration task. This work aims to overcome limitations of multi-robot systems (MRS) in difficult scenarios (e.g., search and rescue) concerning the need and the ability to actively maintain an available inter-robot communication channel, through the development of effective multi-robot cooperation without relying on a preexisting communication network. Although there is no linear relationship between the number of robots (i.e., nodes) and the maximum communication range, experimental results show that the decreased performance by the developed algorithm under communication constraints can be overcome by slightly increasing the number of robots as the maximum communication range is decreased.

Data Acquisition from the Integration of Kinect Quaternions and Myo Armband EMG Sensors to Aid Equinus Foot Treatment

Proceedings of the 12th International Joint Conference on Biomedical Engineering Systems and Technologies

This paper shows the advantage of using different sensors such the Microsoft Kinect and Myo Armba... more This paper shows the advantage of using different sensors such the Microsoft Kinect and Myo Armband to acquire movement description of the plantarflexion and dorsiflexion of the foot with the help of the quaternions and the EMG Myo sensor. For the integration of these devices, it was chosen Python to develop the algorithm and create an interface to aid the signal acquisition. This integration, enabling an accurate motion description as well as a scale of EMG signal, allow the possibility of quantifying the treatment of the people with equinus foot.

Cloud-Based Framework for Robot Operation in Hospital Environments

Lecture Notes in Electrical Engineering, 2020

The robotics field is widely used in the industrial domain, but nowadays several other domains co... more The robotics field is widely used in the industrial domain, but nowadays several other domains could also take advantage of it. This interdisciplinary branch of engineering requires the use of human interfaces, efficient communication systems, high storage and processing capabilities, among other issues, to perform complex tasks. This paper aims to propose a cloud-based framework platform for robot operation in a hospital environment, addressing some challenges, such as communications security and processing/storage features. The recent developments in the artificial intelligence field and cloud resources sharing are allowing the penetration of robots in unstructured environments. However, some new challenges and solutions need to be tested in real environments. Our main contribution is to decrease the time-consumption related to processing and storage costs, associated with the physical processing resources of the robots. Also, the proposed methods provide an increase of the processing variables that are not yet present in the physical resources, such as in the case of robots with limited processing time or storage capabilities. This paper presents a platform based on Cloud Computing with services to support processing, storage and analytics applied to hospital environments. The proposed platform enables to achieve a decrease in the timeconsumption, especially when it is intended to retrieve information about all robot activities.

On the Design, Construction and Calibration of Dual-Probe Heat-Pulse Soil Moisture Sensor: Towards an Industrial Solution

There is a need for a multi-functional probe for smallscale measurements of different soil proper... more There is a need for a multi-functional probe for smallscale measurements of different soil properties measured within identical soil volumes. Dual Probe Heat Pulse (DPHP) sensors are an economical solution for this since they measure simultaneously temperature, volumetric water content, and soil thermal properties: diffusivity and volumetric heat capacity. However, all DPHP sensors to date have very complex manufacturing processes. This paper aims to design and build a DPHP sensor based only on a Printed Circuit Board (PCB) board, which comprises the probes and all supporting electronics leading to a low cost and simple manufacturing process. The proposed system includes signalprocessing circuits, a microcontroller, and communicates by a Serial Digital Interface at 1200 baud protocol (SDI-12). The sensor needs a one-time two calibrations: distance from heater to temperature sensor calibration using agar solution; and sensor calibration in soil using Tottori Dune sand. Both calibrati...

Classiﬁcation of Images of Childhood Pneumonia using Convolutional Neural Networks

Proceedings of the 12th International Joint Conference on Biomedical Engineering Systems and Technologies, 2019

In this paper we describe a comparative classification of Pneumonia using Convolution Neural Netw... more In this paper we describe a comparative classification of Pneumonia using Convolution Neural Network. The database used was the dataset Labeled Optical Coherence Tomography (OCT) and Chest X-Ray Images for Classification made available by (Kermany, 2018) with a total of 5863 images, with 2 classes: normal and pneumonia. To evaluate the generalization capacity of the models, cross-validation of k-fold was used. The classification models proved to be efficient compared to the work of (Kermany et al., 2018) which obtained 92.8 % and the present work had an average accuracy of 95.30 %.

Comparative Study of Compression Techniques Applied in Different Biomedical Signals

Proceedings of the 12th International Joint Conference on Biomedical Engineering Systems and Technologies, 2019

This paper aims to compare the compression of electro-oculographic signals, based on the (EOG) fr... more This paper aims to compare the compression of electro-oculographic signals, based on the (EOG) from MIT / BIH database, and the electromyographic signals, based on the (EMG) from MIT / BIH database, for that purpose, two compression techniques that can be used in electro-oculograms and electromyograms was approached, the two techniques mentioned above, were, the discrete cosine transform and Fast Walsh Hadamard Transform. For statistic the methods used was, the Mean squared error, mean absolute error, signal-to-noise ratio and peak signal-to-noise ratio as well, and for results, the techniques and they performance on each tested signal.

Single-objective front optimization

Proceedings of the 10th annual conference on Genetic and evolutionary computation, 2008

This paper proposes a new algorithm which promotes well distributed non-dominated fronts in the p... more This paper proposes a new algorithm which promotes well distributed non-dominated fronts in the parameters space when a single-objective function is optimized. This algorithm is based on ǫ-dominance concept and maxmin sorting scheme. Besides that, the paper also presents the results of the algorithm when it is used in the automated synthesis of optimum performance CMOS radiofrequency and microwave binary-weighted differential switched capacitor arrays (RFDSCAs). The genetic synthesis tool optimizes a fitness function which is based on the performance parameter of the RFDSCAs. To validate the proposed design methodology, a CMOS RFDSCA is synthesized, using a 0.25 µm BiCMOS technology.

$Research paper thumbnail of Introducing the fractional order robotic Darwinian PSO$

Introducing the fractional order robotic Darwinian PSO

AIP Conference Proceedings, 2012

Resistive plate chambers in positron emission tomography

The European Physical Journal Plus, 2013

Resistive plate chambers (RPC) were originally deployed for high energy physics. Realizing how th... more Resistive plate chambers (RPC) were originally deployed for high energy physics. Realizing how their properties match the needs of nuclear medicine, a LIP team proposed applying RPCs to both preclinical and clinical positron emission tomography (RPC-PET). We show a large-area RPC-PET simulated scanner covering an axial length of 2.4 m-slightly superior to the height of the human body-allowing for whole-body, single-bed RPC-PET acquisitions. Simulations following NEMA (National Electrical Manufacturers Association, USA) protocols yield a system sensitivity at least one order of magnitude larger than present-day, commercial PET systems. Reconstruction of whole-body simulated data is feasible by using a dedicated, direct time-of-flight-based algorithm implemented onto an ordered subsets estimation maximization parallelized strategy. Whole-body RPC-PET patient images following the injection of only 2 mCi of 18-fluorodesoxyglucose (FDG) are expected to be ready 7 minutes after the 6 minutes necessary for data acquisition. This compares to the 10-20 mCi FDG presently injected for a PET scan, and to the uncomfortable 20-30 minutes necessary for its data acquisition. In the preclinical field, two fully instrumented detector heads have been assembled aiming at a four-head-based, small-animal RPC-PET system. Images of a disk-shaped and a needle-like 22 Na source show unprecedented sub-millimeter spatial resolution.

Benchmark of swarm robotics distributed techniques in a search task

Robotics and Autonomous Systems, 2014

Benchmark of swarm robotics distributed techniques in a search task, Robotics and Autonomous Syst... more

Interacção com um Robô através de Linguagem Natural Falada

Electrónica e Telecomunicações, Nov 30, 2012

Resumo O desenvolvimento de um sistema capaz de interagir com um ser humano através da voz é algo... more Resumo O desenvolvimento de um sistema capaz de interagir com um ser humano através da voz é algo que tem sido alvo de muitos estudos e projectos. Este tipo de sistemas são aliciantes pois permitem ao Homem, através de uma forma simples e intuitiva, comunicar com a máquina. A interface de voz com um robô–o Carl-, em desenvolvimento no âmbito do projecto CARL, é apresentada neste artigo. Apresenta-se sobretudo astecnologias existentes, as ferramentas disponíveis e ainterligação de todos os subsistemas ...

Two Cooperating Manipulators with Fractional Controllers

International Journal of Advanced Robotic Systems, 2009

This paper analyzes the dynamic performance of two cooperative robot manipulators. It is studied ... more This paper analyzes the dynamic performance of two cooperative robot manipulators. It is studied the implementation of fractional-order algorithms in the position/force control of two cooperating robotic manipulators holding an object. The simulations reveal that fractional algorithms lead to performances superior to classical integer-order controllers.

The Concept of Robot Society: Evidence Taken From Multi-Robot SLAM

Comparison of Classification Methods for Golf Putting Performance Making

Computational Intelligence and Decision Making - Trends and Applications, From Intelligent Systems, Control and Automation: Science and Engineering Bookseries, 2012

This paper presents a comparative case study on the classification accuracy between 5 methods for... more This paper presents a comparative case study on the classification accuracy between 5 methods for golf putting performance analysis. In a previous work, a digital camera was used to capture 30 trials of 6 expert golf players. The detection of the horizontal position of the golf club was performed using a computer vision technique followed by the estimation algorithm Darwinian Particle Swarm Optimization (DPSO) in order to obtain a kinematical model of each trial. In this paper, the estimated parameters of the models are used as sample and training data of five classification algorithms: 1) Linear Discriminant Analysis (LDA); 2) Quadratic Discriminant Analysis (QDA); 3) Naïve Bayes with Normal (Gaussian) distribution (NV); 4) Naïve Bayes with Kernel Smoothing Density Estimate (NVK) and 5) Least Squares Support Vector Machines with Radial Basis Function Kernel (LS-SVM). The 5 classification methods are then compared through the analysis of the confusion matrix and the area under the Receiver Operating Characteristic curve (AUC).

Helicopter System Modelling and Control With Matlab��

This paper presents the modelling and control of a laboratory helicopter system with MatLab. In t... more This paper presents the modelling and control of a laboratory helicopter system with MatLab. In this perspective, students are motivated to investigate the dynamics, trajectory planning and control. Based on this experience, further studies on helicopter system, using more sophisticated concepts, are, then, more attractive from the students point of view.

Multi-Robot Exploration based on Swarm Optimization Algorithms

The Darwinian Particle Swarm Optimization (DPSO) is an evolutionary algorithm that extends the we... more The Darwinian Particle Swarm Optimization (DPSO) is an evolutionary algorithm that extends the well-known Particle Swarm Optimization (PSO) using natural selection, or survival-of-the-fittest, to enhance the ability to escape from local optima. In this paper, it is explored the effectiveness of using a modified version of both PSO and DPSO, respectively named as R-PSO and R-DPSO, on groups of simulated robots performing a distributed exploration task.

Manipulability analysis of two-arm robotic systems

  Many tasks involving manipulation require cooperation between robots. Meanwhile, it is necess... more   Many tasks involving manipulation require cooperation between robots. Meanwhile, it is necessary to determinate the adequate values for the robot parameters to obtain a good performance. This paper discusses several aspects related with the manipulability of two cooperative robots when handling objects with different lengths and orientations. In this line of thought, a numerical tool is developed for the calculation and the graphical visualization of the manipulability measure.

Cooperative Transportation of an Object based on Fractional Order Controllers

Advanced control techniques have been used in simulations to overcome nonlinear phenomena in orde... more Advanced control techniques have been used in simulations to overcome nonlinear phenomena in order to describe the performance of robots with two rotational (RR) degrees-of-freedom (dof). Given the current state-of-the-art, fractional order algorithms lead to better performance when compared to integer order controllers. Also, the development of simulation platforms allows evaluating the best control methodology. In this context, the use of RR robots attached to mobile platforms, denoted in this paper as RR mobile robots, demonstrates a remarkable ability in manipulating and transporting objects. The present work aims to study two cooperative RR mobile robots by analyzing the manipulator's trajectory and the forces applied to the common load. Are considered two robotic platforms based on an 8-bit microcontroller with inverse kinematics based on the Denavit-Hartenberg formulation and fractional order PID controllers inspired in the Grünwald-Letnikov definition.

Statistical Significance Analysis of the R-DPSO Towards an Understanding of the Relationship Between the Population of Robots and the Maximum Communication Distance

This paper presents a statistical significance analysis of a modified version of the Particle Swa... more This paper presents a statistical significance analysis of a modified version of the Particle Swarm Optimization (PSO) on groups of simulated robots performing a distributed exploration task, denoted as R-DPSO (Robotic DPSO). This work aims to evaluate this novel exploration strategy studying the performance of the algorithm under communication constraints while increasing the population of robots. Experimental results show that there is no linear relationship between the number of robots and the maximum communication range. In general, the decreased performance by the developed algorithm under communication constraints can be overcome by slightly increasing the number of robots as the maximum communication range is decreased.

A novel multi-robot exploration approach based on Particle Swarm Optimization algorithms

9th IEEE International Symposium on Safety, Security, and Rescue Robotics, SSRR 2011, 2011

This paper proposes two extensions of Particle Swarm Optimization (PSO) and Darwinian Particle Sw... more This paper proposes two extensions of Particle Swarm Optimization (PSO) and Darwinian Particle Swarm Optimization (DPSO), respectively named as RPSO (Robotic PSO) and RDPSO (Robotic DPSO), so as to adapt these promising biologicalinspired techniques to the domain of multi-robot systems, by taking into account obstacle avoidance. These novel algorithms are demonstrated for groups of simulated robots performing a distributed exploration task. The concepts of social exclusion and social inclusion are used in the RDPSO algorithm as a "punish-reward" mechanism enhancing the ability to escape from local optima. Experimental results obtained in a simulated environment show that biological and sociological inspiration can be useful to meet the challenges of robotic applications that can be described as optimization problems (e.g. search and rescue).

Ensuring ad hoc connectivity in distributed search with Robotic Darwinian Particle Swarms

9th IEEE International Symposium on Safety, Security, and Rescue Robotics, SSRR 2011, 2011

This paper presents an enforcing multi-hop network connectivity algorithm experimentally validate... more This paper presents an enforcing multi-hop network connectivity algorithm experimentally validated using a modified version of the Darwinian Particle Swarm Optimization (DPSO), denoted as RDPSO (Robotic DPSO) on groups of simulated robots performing a distributed exploration task. This work aims to overcome limitations of multi-robot systems (MRS) in difficult scenarios (e.g., search and rescue) concerning the need and the ability to actively maintain an available inter-robot communication channel, through the development of effective multi-robot cooperation without relying on a preexisting communication network. Although there is no linear relationship between the number of robots (i.e., nodes) and the maximum communication range, experimental results show that the decreased performance by the developed algorithm under communication constraints can be overcome by slightly increasing the number of robots as the maximum communication range is decreased.