Ground Extraction from 3D Lidar Point Clouds

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works Pomares, A., Martínez, J.L., Mandow, A., Martínez, M.A., Morán, M., Morales, J. Ground extraction from 3D lidar point clouds with the Classification Learner App (2018) 26th Mediterranean Conference on Control and Automation, Zadar, Croatia, June 2018, pp.400-405. DOI: PendingGround extraction from three-dimensional (3D) range data is a relevant problem for outdoor navigation of unmanned ground vehicles. Even if this problem has received attention with specific heuristics and segmentation approaches, identification of ground and non-ground points can benefit from state-of-the-art classification methods, such as those included in the Matlab Classification Learner App. This paper proposes a comparative study of the machine learning methods included in this tool in terms of training times as well as in their predictive performance. With this purpose, we have combined three suitable features for ground detection, which has been applied to an urban dataset with several labeled 3D point clouds. Most of the analyzed techniques achieve good classification results, but only a few offer low training and prediction times.This work was partially supported by the Spanish project DPI 2015- 65186-R. The publication has received support from Universidad de Málaga, Campus de Excelencia Andalucía Tech

Slide-Down Prevention for Wheeled Mobile Robots on Slopes

Wheeled mobile robots on inclined terrain can slide down due to loss of traction and gravity. This type of instability, which is different from tip-over, can provoke uncontrolled motion or get the vehicle stuck. This paper proposes slide-down prevention by real-time computation of a straightforward stability margin for a given ground-wheel friction coefficient. This margin is applied to the case study of Lazaro, a hybrid skid-steer mobile robot with caster-leg mechanism that allows tests with four or five wheel contact points. Experimental results for both ADAMS simulations and the actual vehicle demonstrate the effectiveness of the proposed approach.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Herramienta para el Aprendizaje del Lenguaje Dactilológico Mediante Visión Artificial

Aguilar, I.; Reina, A. J.; Mandow, A., "Herramienta para el Aprendizaje del Lenguaje Dactilológico Mediante Visión Artificial," Actas de las XXXVI Jornadas de Automática, pp.127-133, Bilbao, SpainEl artículo aborda el uso de técnicas de visión artificial como herramienta didáctica para el aprendizaje de la lengua de signos para sordos. En particular, se propone una solución para el reconocimiento del alfabeto dactilológico con una cámara 2D. Con este fin, se presenta un conjunto características visuales que permiten la clasificación de los signos obtenidos mediante un árbol de decisión. Este sistema de reconocimiento se ha integrado en una herramienta interactiva de aprendizaje que permite el dictado mediante gestos a la vez que puntúa, a modo de juego, la correcta realización de los signos. El artículo presenta resultados experimentales preliminares tanto del reconocimiento de signos como de su aplicación educativa.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Optimizing Scan Homogeneity for Building Full-3D Lidars based on Rotating a Multi-Beam Velodyne Rangefinder

Multi-beam lidar (MBL) scanners are compact, light, and accessible 3D sensors with high data rates, but they offer limited vertical resolution and field of view (FOV). Some recent robotics research has profited from the addition of a degree-of-freedom (DOF) to an MBL to build rotating multi-beam lidars (RMBL) that can achieve high-resolution scans with full spherical FOV. In a previous work, we offered a methodology to analyze the complex 3D scan measurement distributions produced by RMBLs with a rolling DOF and no pitching. In this paper, we investigate the effect of introducing constant pitch angles in the construction of the RMBLs with the purpose of finding a kinematic configuration that optimizes scan homogeneity with a spherical FOV. To this end, we propose a scalar index of 3D sensor homogeneity that is based on the spherical formulation of Ripley's K function. The optimization is performed for the widely used Puck (VLP-16) and HDL-32 sensors by Velodyne.This work was partially funded by the Spanish project {DPI2015-65186-R}. The publication has received support from Universidad de Málaga, Campus de Excelencia Andalucía Tech

Sistemas de documentación y elaboración de textos científicos: Una asignatura para aprender a publicar en ingeniería

Hoy en día, la elaboración y presentación de informes de investigación resulta indispensable para muchos profesionales de la ingeniería. En este artículo se describe una asignatura de máster universitario cuyo principal objetivo es proporcionar los conocimientos necesarios para poder escribir y exponer resultados de investigación en ingeniería mecatrónica. De esta manera, se complementa la formación de los ingenieros para que puedan desenvolverse con éxito en el complejo mundo de la investigación.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Project-Based Learning of Scientific Writing and Communication Skills for Postgraduate Students

Mandow, A; Martínez, J. L.; García-Cerezo, A.; , "Project-Based Learning of Scientific Writing and Communication Skills for Postgraduate Students," IEEE Frontiers in Education Conference (FIE), pp.210-213, Oct. 2014 doi: 10.1109/FIE.2014.7044022This paper addresses education on scientific publication skills for post-graduate engineering students. In particular, a project-based learning strategy is proposed to lead students through the preparation a research paper. Expected learning outcomes are related to finding and evaluating the quality of references, editing and formatting text in \LaTeX, writing scientific papers with appropriate style and structure, peer reviewing, and making technical presentations. This approach has been developed to increase the internationalization and visibility of young researchers by improving the quality standards of their published works. The purpose of this innovative practice is that students confront the major challenges of the publication process in the classroom, which is in contrast with the traditional self-taught approach experienced by the authors and many senior researchers. The proposed strategy is being applied as a required course in the Master in Mechatronics Engineering of the University of Malaga. This paper offers preliminary results from this experience.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This work has been partially supported by projects DPI 2011-22443 (Spanish CICYT) and PIE 13-155 (Universidad de Málaga, proyecto de innovación educativa `Aprendizaje basado en proyectos para mejorar la excelencia de publicaciones científicas y transferencia del conocimiento en ingeniería")

Mobile Robot Lab Project to Introduce Engineering Students to Fault Diagnosis in Mechatronic Systems

This document is a self-archiving copy of the accepted version of the paper. Please find the final published version in IEEEXplore: http://dx.doi.org/10.1109/TE.2014.2358551This paper proposes lab work for learning fault detection and diagnosis (FDD) in mechatronic systems. These skills are important for engineering education because FDD is a key capability of competitive processes and products. The intended outcome of the lab work is that students become aware of the importance of faulty conditions and learn to design FDD strategies for a real system. To this end, the paper proposes a lab project where students are requested to develop a discrete event dynamic system (DEDS) diagnosis to cope with two faulty conditions in an autonomous mobile robot task. A sample solution is discussed for LEGO Mindstorms NXT robots with LabVIEW. This innovative practice is relevant to higher education engineering courses related to mechatronics, robotics, or DEDS. Results are also given of the application of this strategy as part of a postgraduate course on fault-tolerant mechatronic systems.This work was supported in part by the Spanish CICYT under Project DPI2011-22443

Construction and Calibration of a Low-Cost 3D Laser Scanner with 360◦ Field of View for Mobile Robots

Navigation of many mobile robots relies on environmental information obtained from three-dimensional (3D) laser scanners. This paper presents a new 360◦ field-of-view 3D laser scanner for mobile robots that avoids the high cost of commercial devices. The 3D scanner is based on spinning a Hokuyo UTM- 30LX-EX two-dimensional (2D) rangefinder around its optical center. The proposed design profits from lessons learned with the development of a previous 3D scanner with pitching motion. Intrinsic calibration of the new device has been performed to obtain both temporal and geometric parameters. The paper also shows the integration of the 3D device in the outdoor mobile robot Andabata.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

SAR Nets: An Evaluation of Semantic Segmentation Networks with Attention Mechanisms for Search and Rescue Scenes.

This paper evaluates four semantic segmentation models in Search-and-Rescue (SAR) scenarios obtained from ground vehicles. Two base models are used (U-Net and PSPNet) to compare different approaches to semantic segmentation, such as skip connections between encoder and decoder stages and using a pooling pyramid module. The best base model is modified by including two attention mechanisms to analyze their performance and computational cost. We conduct a quantitative and qualitative evaluation using our SAR dataset defining eleven classes in disaster scenarios. The results demonstrate that the attention mechanisms increase model performance while minimally affecting the computation time.This work has been partially funded by the Spanish Ministerio de Ciencia, Innovación y Universidades, Gobierno de España, project PID2021-122944OB-I00. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Planificador estratégico para operaciones de rescate mediante vehículos terrestres no tripulados

El despliegue de plataformas robóticas como apoyo a la gestión de situaciones de emergencia constituye un reto que persigue mejorar la eficiencia en misiones de búsqueda y rescate. Este artículo propone un planificador estratégico para el rescate de víctimas mediante un equipo de robots terrestres. Este sistema inteligente permitirá planificar las trayectorias para acceder a las víctimas de acuerdo con su ubicación y prioridad de asistencia médica (triaje). Para la planificación se propone una nueva variante del algoritmo “ fast marching method” (FMM). En este trabajo se ofrecen resultados preliminares mediante un ejemplo de aplicación en condiciones simuladas.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Proyecto nacional DPI2015-65186-R. Ayuda BES-2016-077022 del Fondo Social Europeo FSE