Ara es mostren els items 13-28 de 28

    • Learning rules from cause-effects explanations 

      Agostini, Alejandro Gabriel; Celaya Llover, Enric; Torras, Carme; Wörgötter, Florentin (2008)
      Report de recerca
      Accés obert
      In this work we propose a learning system to learn on-line an action policy coded in rules using natural human instructions about cause-effect relations in currently observed situations. The instructions only on currently ...
    • Model predictive control for a Mecanum-wheeled robot navigating among obstacles 

      Moreno Caireta, Iñigo; Celaya Llover, Enric; Ros Giralt, Lluís (Elsevier, 2021)
      Text en actes de congrés
      Accés obert
      Mecanum-wheeled robots have been thoroughly used to automate tasks in many different applications. However, they are usually controlled by neglecting their dynamics and relying only on their kinematic model. In this paper, ...
    • Natural landmark detection for visually-guided robot navigation 

      Celaya Llover, Enric; Albarral, José L.; Jiménez Schlegl, Pablo; Torras, Carme (Springer, 2007)
      Capítol de llibre
      Accés obert
      The main difficulty to attain fully autonomous robot navigation outdoors is the fast detection of reliable visual references, and their subsequent characterization as landmarks for immediate and unambiguous recognition. ...
    • Natural landmark detection for visually-guided robot navigation 

      Celaya Llover, Enric; Albarral Garcia, Jose Luis; Jiménez Schlegl, Pablo; Torras, Carme (2007)
      Text en actes de congrés
      Accés obert
      The main difficulty to attain fully autonomous robot navigation outdoors is the fast detection of reliable visual references, and their subsequent characterization as landmarks for immediate and unambiguous recognition. ...
    • On-line learning of macro planning operators using probabilistic estimations of cause-effects 

      Agostini, Alejandro Gabriel; Wörgötter, Florentin; Celaya Llover, Enric; Torras, Carme (2008)
      Report de recerca
      Accés obert
      In this work we propose an on-line learning method for learning action rules for planning. The system uses a probabilistic approach of a constructive induction method that combines a beam search with an example-based search ...
    • Online EM with weight-based forgetting 

      Celaya Llover, Enric; Agostini, Alejandro Gabriel (2015)
      Article
      Accés obert
      In the on-line version of the EM algorithm introduced by Sato and Ishii (2000), a time-dependent discount factor is introduced for forgetting the effect of the old posterior values obtained with an earlier, inaccurate ...
    • Online reinforcement learning using a probability density estimation 

      Agostini, Alejandro Gabriel; Celaya Llover, Enric (The MIT Press. Massachusetts Institute of Technology, 2017-01-01)
      Article
      Accés obert
      Function approximation in online, incremental, reinforcement learning needs to deal with two fundamental problems: biased sampling and nonstationarity. In this kind of task, biased sampling occurs because samples are ...
    • Probability density estimation of the Q Function for reinforcement learning 

      Agostini, Alejandro Gabriel; Celaya Llover, Enric (2009)
      Report de recerca
      Accés obert
      Performing Q-Learning in continuous state-action spaces is a problem still unsolved for many complex applications. The Q function may be rather complex and can not be expected to fit into a predefined parametric model. In ...
    • Reinforcement learning for robot control using probability density estimations 

      Agostini, Alejandro Gabriel; Celaya Llover, Enric (INSTICC Press. Institute for Systems and Technologies of Information, Control and Communication, 2010)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      The successful application of Reinforcement Learning (RL) techniques to robot control is limited by the fact that, in most robotic tasks, the state and action spaces are continuous, multidimensional, and in essence, too ...
    • Reinforcement learning with a Gaussian mixture model 

      Agostini, Alejandro Gabriel; Celaya Llover, Enric (2010)
      Text en actes de congrés
      Accés obert
      Recent approaches to Reinforcement Learning (RL) with function approximation include Neural Fitted Q Iteration and the use of Gaussian Processes. They belong to the class of fitted value iteration algorithms, which use a ...
    • Robot task specification and execution through relational positioning 

      Rodríguez Tsouroukdissian, Adolfo; Basañez Villaluenga, Luis; Celaya Llover, Enric (IFAC, 2007)
      Text en actes de congrés
      Accés obert
      This paper presents a relational positioning methodology for flexibly and intuitively specifying offline programmed robot tasks, and for assisting the execution of teleoperated tasks featuring precise or repetitive movements. ...
    • Second order collocation 

      Celaya Llover, Enric (2021)
      Report de recerca
      Accés obert
      Collocation methods for optimal control commonly assume that the system dynamics is expressed as a first order ODE of the form dx/dt = f(x, u, t), where x is the state and u the control vector. However, in many cases, the ...
    • Solution intervals for variables in spatial RCRCR linkages 

      Celaya Llover, Enric (2019-03-01)
      Article
      Accés obert
      An analytic method to compute the solution intervals for the input variables of spatial RCRCR linkages and their inversions is presented. The input-output equation is formulated as the intersection of a single ellipse with ...
    • Stochastic approximations of average values using proportions of samples 

      Agostini, Alejandro Gabriel; Celaya Llover, Enric (2011)
      Report de recerca
      Accés obert
      In this work we explain how the stochastic approximation of the average of a random variable is carried out when the observations used in the updates consist in proportion of samples rather than complete samples.
    • Visually-guided robot navigation: from artificial to natural landmarks 

      Celaya Llover, Enric; Albarral Garcia, Jose Luis; Jiménez Schlegl, Pablo; Torras, Carme (2007)
      Text en actes de congrés
      Accés obert
      Landmark-based navigation in unknown unstructured environments is far from solved. The bottleneck nowadays seems to be the fast detection of reliable visual references in the image stream as the robot moves. In our research, ...
    • Visually-guided robot navigation: From artificial to natural landmarks 

      Celaya Llover, Enric; Albarral, José L.; Jiménez Schlegl, Pablo; Torras, Carme (Springer, 2007)
      Capítol de llibre
      Accés obert
      Landmark-based navigation in unknown unstructured environments is far from solved. The bottleneck nowadays seems to be the fast detection of reliable visual references in the image stream as the robot moves. In our research, ...