Bayesian recursive algorithm for width estimation of freespace for a power wheelchair using stereoscopic cameras.

This paper is concerned with the estimation of freespace based on a Bayesian recursive (BR) algorithm for an autonomous wheelchair using stereoscopic cameras by severely disabled people. A stereo disparity map processed from both the left and right camera images is constructed to generate a 3D point map through a geometric projection algorithm. This is then converted to a 2D distance map for the purpose of freespace estimation. The width of freespace is estimated using a BR algorithm based on uncertainty information and control data. Given the probabilities of this width computed, a possible movement decision is then made for the mobile wheelchair. Experimental results obtained in an indoor environment show the effectiveness of this estimation algorithm

Análisis de la tecnología de posicionamiento indoor aplicada a robots autónomos móviles

La creación del presente proyecto surge de la necesidad del Departamento de Sistemas y Automática de la Universidad Carlos III de disponer de un documento que recoja las diferentes tecnologías dedicadas al posicionamiento de robot autónomos móviles en interiores. El propósito del documento es exponer de forma accesible pero rigurosa los aspectos clave de los sistemas de posicionamiento en interiores, sus usos actuales en múltiples entornos y las posibles evoluciones futuras de las diferentes tecnologías. Los principales contenidos cubiertos son: - Principales tecnologías de posicionamiento: características, ventajas e inconvenientes. - Estrategias y algoritmos usados en los sistemas de posicionamiento. - Estado de los sistemas de posicionamiento en interiores en la actualidad, tanto comerciales como en fase de desarrollo. De forma complementaria, se estudian conceptos relativos a la locomoción robótica, ya que pueden ser determinantes a la hora de analizar las estrategias de los robots autónomos móviles, y se presentan las principales tecnologías de sensores organizadas según su campo de aplicación. Finalmente, se analizan los resultados y se elaboran conclusiones en función de los requerimientos iniciales del proyecto, valorando su adecuidad para las aplicaciones propuestas.The making of this project emerges from the need of the Department of Systems and Automation at the University Carlos III to gather information in a survey about the different technologies related to the indoor positioning of self-sufficient mobile robots. The purpose of the project is to present the key aspects of the selected indoor positioning systems, their current usage in multiple surroundings and the possible future development of these different technologies in an accessible, yet rigorous way. The main content covered by the survey is: - Relevant positioning technologies: characteristics, benefits and disadvantages. - Strategies and algorithms applied by the positioning systems. - Present status of existing indoor positioning systems, considering both systems that are currently commercialized and systems in stage of development. To enrich the survey, it has been complemented by a study of concepts related to robotic locomotion, seeing that they can be decisive at the moment of analyzing the strategy of the autonomous mobile robots. Relevant sensor technologies are also presented, organized by the application area. Finally, the results are analyzed and the conclusions are made according to the requirements established in the initial phases of the project, considering the adequacy for the suggested applications.Ingeniería Técnica en Electrónic

Visual Odometry In Mobile Robots

The paper presents an application of visual odometry, through reconstruction of the path of a mobile robot, using a stereoscopic camera system. The scale invariant feature transformation algorithm (SIFT), is used to process the images and locate keypoints in a 3D euclidian coordinates space. The path of a Pioneer mobile robot is estimated using the proposed technique. © 2011 IEEE.Lower, D.G., Distinctive image features from scale-invariant keypoints (2004) International Journal of Computer VisionSmith, M.R., Estimating uncertain spatial relationships in robôics (1990) Auton. Robô Veh., 8, pp. 167-193. , PSilveira, G., Malis, E., Rives, An efficient direct approach to visual SLAM (2008) IEEE-j-ro, 24, pp. 969-979. , P. 5Silveira, G., Malis, E., Rives, (2007) An Efficient Direct Method for Improving Visual SLAM, pp. 4090-4095. , PDavison, A.J., Murray, D.W., Simultaneous localization and mapbuilding using active vision (2002) IEEE-j-pami, 24, pp. 865-880. , 7Zhu, Z., Keeping smart, omnidirectional eyes on you [adaptive panoramic stereovision] (2004) IEEE Robôics & Automation Magazine, 11, pp. 69-78. , 4Saeedi, P., Lawrence, P.D., Lowe, D.G., Vision-based 3-D trajectory tracking for unknown environments (2006) IEEE-j-ro, 22, pp. 119-136. , 1Steder, B., Visual SLAM for flying vehicles (2008) IEEE-j-ro, 24, pp. 1088-1093. , 5Paz, L.M., Large-scale 6-DOF SLAM with stereo-in-hand (2008) IEEE-j-ro, 24, pp. 946-957. , 5Mahon, I., Efficient view-based SLAM using visual loop closures (2008) IEEE-j-ro, 24, pp. 1002-1014. , 5Hebert, M., Kanade, T., 3-D vision for outdoor navigation by an autonomous vehicle (1998) Proc. Image Understanding Workshop, pp. 593-601. , San Mateo, CA, aprilKriegman, D.J., Triendl, E., Binford, T.O., Stereo vision and navigation in building for mobile robots (1989) IEEE Transaction on Robotics and Automation, 5 (6), pp. 792-803Thorpe, C.E., Hebert, M., Kanade, T., Shafer, S., Vision and navigation for the carnegie-mellon navlab (1988) IEEE Trans. Pattern Anal. Mach. Intell., 10 (3), pp. 362-373. , MarTurk, M.A., Morgenthaler, D.G., Gremban, K.D., Marra, M., VITS - A vision system for autonomous land vehicle navigation (1988) IEEE Trans. Pattern Anal. Mach. Intell., 3, pp. 342-361. , MarWaxman, A.M., A visual navigation system for autonomous land vehicles (1987) IEEE J. Robot. Autom., RA-3 (2), pp. 124-141. , AprMa, Y., Kosecká, J., Sastry, S.S., Vision guided navigation for a nonholonomic mobile robot (1999) IEEE Transactions on Robotics and Automation, 15 (3). , JunChoomuang, R., Afzulpurkar, N., Hybrid Kalman filter/fuzzy logic basead position control of autonomous mobile robot (2005) International Journal of Advanced Robotic System, 2 (3), pp. 197-208Karlsson, N., Di Bernado, E., Ostrowski, J., Gonçalves, L., Pirjanian, P., Munich, M.E., The vSLAM algorithm for robust localization and mapping (2005) IEEE, International Conference on Robotics and Automation, pp. 24-29. , Barcelona, SpainHeikkilä, J., Geometric camera calibration using circular control points (2000) IEEE Transactions on Pattern Analysis and Machine Intelligence, 22 (10), pp. 1066-1077. , OctVedaldi, A., Fulkerson, B., (2008) An Open and Portable Library of Computer Vision Algorithms, , http://www.vlfeat.org