Gaston Lefranc

Pontificia Universidad Católica de Valparaiso, Chile, Escuela De Ingeniería Eléctrica, Faculty Member

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David Seamon

Kansas State University

Murat Cemal Yalcintan

Msgsu

Remo Caponi

University of Cologne

Evangelos Papadopoulos

National Technical University of Athens

Michael Shanks

Stanford University

Fabio Cuzzolin

Oxford Brookes University

Lisa Fusco

University of Washington

Ugo Rossi

Gran Sasso Science Institute

Andrea Cherubini

LIRMM

Jaydip Sen

Praxis Business School

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Papers by Gaston Lefranc

$Research paper thumbnail of Inverted pendulum stabilization by means of fractional order PID controllers$

Inverted pendulum stabilization by means of fractional order PID controllers

2017 CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON)

A simulated study of three different control strategies to stabilize an inverted pendulum on a ca... more A simulated study of three different control strategies to stabilize an inverted pendulum on a cart is presented in this paper. Linear Quadratic Regulator (LQR), Integer order PID (IOPID) and Fractional order PID (FOPID) are designed, applied and compared. A nonlinear model of the cart-pendulum system is first derived and used later in the simulation of the control strategies aforementioned. The tuning parameters of all three controllers are obtained using Particle Swarm Optimization (PSO) technique, using the Integral of the Squared Error (ISE) index as fitting function, when a sequence of step reference inputs is applied. The simulation results, when applying a sequence of step references, show a better performance for the LQR, when using the cost function of the LQR as performance index. However, in the more general case of a sinusoidal references, the FOPID is the one that exhibits the best behavior.

Android App to Monitor the Position of a Group of Robots in a Hospital

2022 IEEE International Conference on Automation/XXV Congress of the Chilean Association of Automatic Control (ICA-ACCA)

Cobots in automation and at home

2022 IEEE International Conference on Automation/XXV Congress of the Chilean Association of Automatic Control (ICA-ACCA)

Vision System for a Kuka KR-5 Industrial Manipulator

2019 IEEE CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON)

In this article, we present the design of a vision system to take objects without previous knowle... more In this article, we present the design of a vision system to take objects without previous knowledge. It is considered that these objects do not have a certain position. The manipulation will be carried out by an industrial robot Kuka KR 5, which does not have a vision system, so a Microsoft Kinect camera is used, as well as the PCA (Principal Component Analysis) algorithm to estimate the position and orientation of the objects within the robot's workspace. Among the tasks to be developed is the communication between the camera and the manipulator, the integration of additional components such as; ROS (Robot Operating System), Open CV, Solidworks and MatLab-SimMechanics. In the first stage, the design of the system as whole is presented. In a following work, the manipulative task (pick and place) is carried out with the manipulator robot.

Architecture of a Rover and its Navigation System Based on Artificial Vision

2019 IEEE CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON)

Purpose of this work is to present the design of a Rover and its autonomous navigation system bas... more Purpose of this work is to present the design of a Rover and its autonomous navigation system based in the StereoLSD SLAM algorithm for reconstruction of 3D environments using solely artificial vision and its implementation in the rover type mobile robot for lunar surface exploration named Dereumbot. Other objectives of this work are to describe the systems architecture of such rover and its performance in significant tests, such as NASA competitions and analogue simulations. Finally, encountered challenges and future work for this development is described.

Analysis of Kinesiological Rehabilitation Technologies in patients with Stroke Vascular

2021 IEEE International Conference on Automation/XXIV Congress of the Chilean Association of Automatic Control (ICA-ACCA)

Stroke (CVA) is the second leading cause of death and the third leading cause of disability in th... more Stroke (CVA) is the second leading cause of death and the third leading cause of disability in the world. A large proportion of adults who survive such an accident can recover; however, this is achieved after going through a long process of kinesiology rehabilitation. In recent times, there are numerous advances in medical equipment, systems and applications that allow a progressive recovery from the consequences caused by this type of accident. The purpose of this work is to analyze the state of the art in which kinesiological rehabilitation technologies are found, through a systematic review of the literature, which also allows to determine the effectiveness of the application of these technologies in the recovery of patients. Motor rehabilitation technologies, based on virtual reality environments and robotic equipment, were identified for adult patients who present hemiparesis or hemiplegia. A great variation was found in the treatments and scales used for its evaluation, in the motor functionality of the upper and lower limb. In the case of robotic technologies, improvements in the range of motion of the limbs, gait and functionality of the upper limbs and muscular endurance stood out. Also, it highlights the adherence of patients to therapies with virtual reality technologies, since these were partly stimulating and enhanced positive aspects such as self-esteem. The work represents a contribution to engineers, who are interested in specializing in patient rehabilitation technologies.

Object Detection Algorithms and Implementation in a Robot of Service

2018 IEEE International Conference on Automation/XXIII Congress of the Chilean Association of Automatic Control (ICA-ACCA), 2018

The recognition of objects and the proper handling of them is a common problem in service robots.... more The recognition of objects and the proper handling of them is a common problem in service robots. This article presents a set of computational vision algorithms to improve an object detection system using an RGBD sensor. Within this set of algorithms is the computational vision algorithm to identify a plane, a second algorithm to determine the position of an object and a third algorithm that performs the Principal Components Analysis to identify the orientation of the objects and to perform a correct manipulation. Several tests are presented that validate our approach. This group of algorithms is used by the service robot Justina at the upcoming RoboCup 2018 international tournament [1].

Recognition and simulation of a vision system for a KUKA KR-5 industrial manipulator

2021 IEEE CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON), 2021

The objective of this article is to have a computer vision system capable of recognizing various ... more The objective of this article is to have a computer vision system capable of recognizing various objects in a given plan, so that a KUKA KR-5 industrial robot can perform manipulation tasks with said objects. Three algorithms are evaluated to improve the performance of this vision system, with the ability to recognize multiple objects and their positions. A Microsoft Kinect 2.0 sensor is used as an input device to a system with a KUKA KR-5 industrial robotic manipulator. Object recognition is done by two algorithms; FastOrb and Brisk, while a third Ransac-PCA algorithm is used for object detection. With the combination of these algorithms, it is possible to recognize more than two objects in a three-dimensional working environment. Finally, the Moveit algorithm is used to obtain trajectories and calculate the inverse kinematics and Gazebo to obtain the simulation of the KUKA KR-5 industrial manipulator.

Probabilistic Minimal Loss Reconfiguration for Electric Power Distribution Control

2018 IEEE International Conference on Automation/XXIII Congress of the Chilean Association of Automatic Control (ICA-ACCA), 2018

Although it is well-known that electric demand is a random variable, the reconfiguration theory s... more Although it is well-known that electric demand is a random variable, the reconfiguration theory still approaches this problem from a deterministic point of view; i.e., most of the network losses optimization problems solutions are built primarily for a specific profile of demand. Even if there are many random behaviors involved in this subject, the main proposal of this paper is a didactic line of attack for a probabilistic minimal loss reconfiguration problem, that takes into account the randomness of load variations of electric distribution systems. The method is based on the Monte Carlo (MC) technique to assign a random load level in each node of the system. The statistical behavior of the loads is modeled using uniform probability density functions. The model defines a useful stochastic index for medium and long-term operation planning reconfiguration. The optimization problem of reconfiguration is solved using a Genetic Algorithm (GA). Principal contributions of this paper are: a) a didactic way to understand a complex electric distribution control theme b) the idea of “expected or characteristic topologies” controlling the influence of wide random load variations on the system configuration and c) a modal topology (in statistical sense) corresponding to the reconfiguration solution for the average demand values. Preceding outcomes are very important: 1) from the realistic modeling point of view, 2) the decision-making strategies and 3) a simple understanding of the topic.

Variables control of a modular greenhouse

2017 CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON), 2017

In this work, the design and implementation of a system to control a greenhouse is presented. Thi... more In this work, the design and implementation of a system to control a greenhouse is presented. This system is a control of the temperature, relative humidity, soil moisture and lighting variables inside a greenhouse. With these variables, a system is configured for a specific type of crops, using sensors, a micro controller Arduino and actuators selected by the user. The system allows maintaining the variables in an appropriate way.

Biomedical engineering projects to support the elderly

2017 CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON), 2017

Several studies and projects carried out at the University of Valparaiso are focused on the condi... more Several studies and projects carried out at the University of Valparaiso are focused on the condition of the elderly, particularly those who present conditions of vulnerability and deterioration. In this context, the actions of the academy are consistent with the policies defined by Chilean Government. This is generated by the current conditions of demographic and epidemiological transition, which on the one hand extend people's lives and on the other hand increase morbidity and deterioration in a more chronic than acute way. The potential of biomedical engineering can be proved by through the problem solving of the older adult in subjects of prostration, disability, monitoring of chronic diseases, and in the monitoring of treatments adherence (drugs); together with the development of technical aids for daily living; besides, due the relevance of professional work in several lines such as telemedicine, Home Care, new type of instrumentation specifically for adults, and the management of technologies, greatly impacts the diagnosis, care, treatment and support to a healthy and active aging, of a population sector at a time of greater presence and importance.

Towards learning contact states during peg-in-hole assembly with a dual-arm robot

2017 CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON), 2017

The use of dual arm robots for human like operations such as the peg-in-hole tasks can be facilit... more The use of dual arm robots for human like operations such as the peg-in-hole tasks can be facilitated by learning contact states during manipulation. In this paper, we propose a control scheme that includes the learning of contact states during operations. The approach includes the use of a Motoman SDA-20 dual-arm robot equipped with two three-fingered gripper and a force/torque sensing capability. A real operation using the assembly of an automotive starter motor is used as a case of study. Several patterns are generated and classified during the stages of the starter assembly. Three categories were considered during operations: moving both arms simultaneously and moving the right arm while keeping the left arm static and vice versa. Contact states were generated using the robot and learned by an Artificial Neural Network (ANN) Fuzzy ARTMAP architecture. The output of the ANN has been envisaged to be a motion command to diminish the constrained forces while moving the arm in the assembly direction. Results during contact state classification have shown that manipulative forces can be recognized by the Neural Network Controller (NNC) so that a valid motion command can be issued to the arm robot favoring the assembly task.

Evaluation of the Degree of Knowledge and Implementation of Information Security Management Systems, based of the NCh-ISO 27001 Standard, in Health Institutions

2018 IEEE International Conference on Automation/XXIII Congress of the Chilean Association of Automatic Control (ICA-ACCA), 2018

Several companies and organizations are being violated and affected by threats, attacks or theft ... more Several companies and organizations are being violated and affected by threats, attacks or theft of information or money from their computer systems. Among them, health institutions, which handle confidential and sensitive data. There is a standard, NCh-ISO 27001, which defines the requirements to establish, implement, maintain and continuously improve an Information Security Management System. The article analyzes the advances in this area in the health sector in Chile; and presents a research, based on surveys, on the degree of knowledge and the degree of implementation of NCh-ISO 27001 in the establishments and Health Services of the country. The results obtained are analyzed, and there is evidence of the urgent need to implement and complete internal processes conducive to having an appropriate, efficient and effective information security management system.

Smart semaphore using image processing

2017 CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON), 2017

The article presents an intelligent traffic light system that allows optimal flow in a car crossi... more The article presents an intelligent traffic light system that allows optimal flow in a car crossing composed of two one-way streets. To achieve this purpose, real-time image processing is used to obtain the counting and space occupied by the vehicles. The algorithms of Backgroud Subtraction and KNN (K-Nearest Neighbor) are used, to determine the congestion vehicular in a street; the libraries of OpenCV are used. The results obtained give a greater ease and response time.

NETE Recommendations of Experts to advise students on ubiquitous learning experiences: Method and Validation

IEEE Latin America Transactions, 2018

Ubiquitous learning systems have proved to behelpful in many learning situations. These systems a... more Ubiquitous learning systems have proved to behelpful in many learning situations. These systems are contextaware,so considering only student’s profiles to offer personalizedrecommendations it is not enough. It is also necessary to take intoaccount contextual characteristics. We proposed a method togenerate automatics recommendations of experts to advisestudents. The method considers previous experiences of theseexperts with other students and recommends expert that areavailable and physically close to the student; and experts that areavailable and online. This work presents the method and describesthe experiments carried out to validate it using simulationtechniques. The precision value obtained demonstrate that themethod produces results that are fit-for-purpose.

The thermal impedance of new power semiconductor modules using AlN substrates

Conference Record of 1998 IEEE Industry Applications Conference. Thirty-Third IAS Annual Meeting (Cat. No.98CH36242)

Increasing operating voltages of IGBT modules result in higher dissipation heat as well as additi... more Increasing operating voltages of IGBT modules result in higher dissipation heat as well as additional requirements on the insulation and partial discharge. The most important part affected here is the substrate. AlN ceramic with a thermal conductivity of typically λ=180 W/mK is clearly superior to the conventional Al2O3 ceramic at λ=27 W/mK. The thermal and thermomechanical properties of AlN substrates

NETE Predictive Control Strategies Operating at Fixed Switching Frequency for Input Filter Resonance Mitigation in an Indirect Matrix Converter

IEEE Latin America Transactions, 2018

The classic model predictive control leads to avariable switching frequency which could produce r... more The classic model predictive control leads to avariable switching frequency which could produce resonances inthe input filter of the matrix converter, affecting the performanceof the system. This paper proposes two methods to mitigate theresonance of the input filter to solve this issue. The first methodconsists in a hybrid combination of model predictive currentcontrol with instantaneous reactive power minimization and anactive damping method which consists in emulating a virtualresistor in parallel to the input filter’s capacitor. The secondmethod imposes a sinusoidal source current instance to minimizethe instantaneous reactive power at the input side. Both methodscan be further enhanced with fixed switching frequencyoperations. Simulated results confirm the feasibility of theproposal demonstrating that the performance of the system isimproved with source and load currents showing a significantreduction in the harmonic distortion produced by the filterresonance.

NETE Editorial to Special Issue

IEEE Latin America Transactions, 2018

NETE Caw’s Walking State Recognition Based on Accelerometers and Gyroscopes Installed on Ear- Tags and Collar-Tags

IEEE Latin America Transactions, 2018

Caw’s walking detection is relevant, because thequantity of times that a caw presents this state ... more Caw’s walking detection is relevant, because thequantity of times that a caw presents this state can be associatedwith symptoms of estrus, lesions or even welfare degree. In orderto identify the characteristic movements associated with walkingactually it is common the use of inertial devices attached to theanimal's leg. The procedure of the device’s installation in theanimal’s leg entails risks to humans, animals and to the device.This paper aims to clarify if the inertial sensors installed in theanimal's collar or even in an ear-tag can be used to estimatepatterns associated with the animal’s walking. Two devices withIMU's (inertial measurement unit) were fabricated in order tocollect acceleration and gyroscope data from both, an ear-tag anda collar-tag, installed simultaneously in a caw. The data used wasunfiltered and filtered with linear and angular Kalman filters,then with each set of data, a support vector machines was trained.The best result achieved was with the ...

$Research paper thumbnail of The Associative Multifractal Process: A Novel Model for Computer Network Traffic Flows$

The Associative Multifractal Process: A Novel Model for Computer Network Traffic Flows

ArXiv, 2021

A novel constructive mathematical model based on the multifractal formalism in order to accuratel... more A novel constructive mathematical model based on the multifractal formalism in order to accurately characterizing the localized fluctuations present in the course of traffic flows today high-speed computer networks is presented. The proposed model has the target to analyze self-similar second-order time series representative of traffic flows in terms of their roughness and impulsivity.

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$Research paper thumbnail of Inverted pendulum stabilization by means of fractional order PID controllers$

Inverted pendulum stabilization by means of fractional order PID controllers

2017 CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON)

Android App to Monitor the Position of a Group of Robots in a Hospital

2022 IEEE International Conference on Automation/XXV Congress of the Chilean Association of Automatic Control (ICA-ACCA)

Cobots in automation and at home

2022 IEEE International Conference on Automation/XXV Congress of the Chilean Association of Automatic Control (ICA-ACCA)

Vision System for a Kuka KR-5 Industrial Manipulator

2019 IEEE CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON)

Architecture of a Rover and its Navigation System Based on Artificial Vision

2019 IEEE CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON)

Analysis of Kinesiological Rehabilitation Technologies in patients with Stroke Vascular

2021 IEEE International Conference on Automation/XXIV Congress of the Chilean Association of Automatic Control (ICA-ACCA)

Object Detection Algorithms and Implementation in a Robot of Service

2018 IEEE International Conference on Automation/XXIII Congress of the Chilean Association of Automatic Control (ICA-ACCA), 2018

Recognition and simulation of a vision system for a KUKA KR-5 industrial manipulator

2021 IEEE CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON), 2021

Probabilistic Minimal Loss Reconfiguration for Electric Power Distribution Control

2018 IEEE International Conference on Automation/XXIII Congress of the Chilean Association of Automatic Control (ICA-ACCA), 2018

Variables control of a modular greenhouse

2017 CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON), 2017

Biomedical engineering projects to support the elderly

2017 CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON), 2017

Towards learning contact states during peg-in-hole assembly with a dual-arm robot

2017 CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON), 2017

Evaluation of the Degree of Knowledge and Implementation of Information Security Management Systems, based of the NCh-ISO 27001 Standard, in Health Institutions

2018 IEEE International Conference on Automation/XXIII Congress of the Chilean Association of Automatic Control (ICA-ACCA), 2018

Smart semaphore using image processing

2017 CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON), 2017

NETE Recommendations of Experts to advise students on ubiquitous learning experiences: Method and Validation

IEEE Latin America Transactions, 2018

The thermal impedance of new power semiconductor modules using AlN substrates

Conference Record of 1998 IEEE Industry Applications Conference. Thirty-Third IAS Annual Meeting (Cat. No.98CH36242)

NETE Predictive Control Strategies Operating at Fixed Switching Frequency for Input Filter Resonance Mitigation in an Indirect Matrix Converter

IEEE Latin America Transactions, 2018

NETE Editorial to Special Issue

IEEE Latin America Transactions, 2018

NETE Caw’s Walking State Recognition Based on Accelerometers and Gyroscopes Installed on Ear- Tags and Collar-Tags

IEEE Latin America Transactions, 2018

$Research paper thumbnail of The Associative Multifractal Process: A Novel Model for Computer Network Traffic Flows$

The Associative Multifractal Process: A Novel Model for Computer Network Traffic Flows

ArXiv, 2021

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