Now showing items 21-40 of 63

    • Clifford’s identity and generalized Cayley-Menger determinants 

      Thomas, Federico; Porta Pleite, Josep Maria (Springer Nature, 2020)
      Conference report
      Open Access
      Distance geometry is usually defined as the characterization and study of point sets in Rk, the k-dimensional Euclidean space, based on the pairwise distances between their points. In this paper, we use Clifford’s identity ...
    • Closed-form position analysis of variable geometry trusses 

      Porta Pleite, Josep Maria; Thomas, Federico (2017-03-01)
      Article
      Open Access
      Variable geometry trusses are composed, in general, of unit cells which can be modeled as bars connected by spherical joints. Under mild conditions, it has been shown that the only feasible cells are topologically equivalent ...
    • Closure polynomials for strips of tetrahedra 

      Thomas, Federico; Porta Pleite, Josep Maria (Springer, 2016)
      Conference report
      Open Access
      A tetrahedral strip is a tetrahedron-tetrahedron truss where any tetrahedron has two neighbors except those in the extremes which have only one. Unless any of the tetrahedra degenerate, such a truss is rigid. In this case, ...
    • Complete maps of molecular-loop conformational spaces 

      Porta Pleite, Josep Maria; Ros Giralt, Lluís; Thomas, Federico; Corcho Sánchez, Francisco José; Cantó Silva, Josep; Pérez, Juan J. (John Wiley & Sons, Inc., 2007)
      Article
      Open Access
      This paper presents a numerical method to compute all possible conformations of distance-constrained molecular loops, i.e., loops where some interatomic distances are held fixed, while others can vary. The method is general ...
    • Concise proof of Tienstra's formula 

      Porta Pleite, Josep Maria; Thomas, Federico (2009)
      Article
      Open Access
      The resection problem consists in finding the location of an observer by measuring the angles sub-tended by lines of sight from this observer to three known stations. Many researchers and practitioners recognize that ...
    • Distance bound smoothing under orientation constraints 

      Rull Sanahuja, Aleix; Porta Pleite, Josep Maria; Thomas, Federico (Institute of Electrical and Electronics Engineers (IEEE), 2015)
      Conference report
      Open Access
      Distance Bound Smoothing (DBS) is a basic operation originally developed in Computational Chemistry to determine point configurations that are within certain pairwise ranges of distances. This operation consist in the ...
    • Distance geometry in active structures 

      Porta Pleite, Josep Maria; Rojas Librero, Nicolás Enrique; Thomas, Federico (Springer, 2018)
      Part of book or chapter of book
      Open Access
      Distance constraints are an emerging formulation that offers intuitive geometrical interpretation of otherwise complex problems. The formulation can be applied in problems such as position and singularity analysis and path ...
    • Efficient asymptotically-optimal path planning on manifolds 

      Jaillet, Leonard Georges; Porta Pleite, Josep Maria (2013)
      Article
      Open Access
      This paper presents an efficient approach for asymptotically-optimal path planning on implicitly-defined configuration spaces. Recently, several asymptotically-optimal path planners have been introduced, but they typically ...
    • EG-RRT: Environment-guided random trees for kinodynamic motion planning with uncertainty and obstacles 

      Jaillet, Leonard Georges; Hoffman, Judy; Van den Berg, Jur; Abbeel, Pieter; Porta Pleite, Josep Maria; Goldberg, Ken (2011)
      Conference report
      Open Access
      Existing sampling-based robot motion planning methods are often inefficient at finding trajectories for kinodynamic systems, especially in the presence of narrow passages between obstacles and uncertainty in control and ...
    • Exploring ambiguities for monocular non-rigid shape estimation 

      Moreno-Noguer, Francesc; Porta Pleite, Josep Maria; Fua, Pascal (Springer, 2010)
      Conference report
      Open Access
      Recovering the 3D shape of deformable surfaces from single images is difficult because many different shapes have very similar projections. This is commonly addressed by restricting the set of possible shapes to linear ...
    • Exploring the energy landscapes of flexible molecular loops using higher-dimensional continuation 

      Porta Pleite, Josep Maria; Jaillet, Leonard Georges (2013)
      Article
      Open Access
      The conformational space of a flexible molecular loop includes the set of conformations fulfilling the geometric loop-closure constraints and its energy landscape can be seen as a scalar field defined on this implicit set. ...
    • Finding all valid hand configurations for a given precision grasp 

      Rosales Gallegos, Carlos; Porta Pleite, Josep Maria; Suárez Feijóo, Raúl; Ros Giralt, Lluís (IEEE, 2008)
      Conference report
      Open Access
      Planning a precision grasp for a robot hand is usually decomposed into two main steps. First, a set of contact points over the object surface must be determined, ensuring they allow a stable grasp. Second, the inverse ...
    • Finding all valid hand configurations for a given precision grasp 

      Rosales Gallegos, Carlos; Porta Pleite, Josep Maria; Suárez Feijóo, Raúl; Ros Giralt, Lluís (2008)
      Conference report
      Open Access
      Planning a precision grasp for a robot hand is usually decomposed into two main steps. First, a set of contact points over the object surface must be determined, ensuring they allow a stable grasp. Second, the inverse ...
    • Further characterization of the zebrafish model of acrylamide acute neurotoxicity: gait abnormalities and oxidative stress 

      Faria, Melissa; Valls Brusco, Arnau; Prats Miravitllas, Eva; Bedrossiantz, Juliette; Orozco, Manuel; Porta Pleite, Josep Maria; Gómez Oliván, Leobardo Manuel; Raldúa Pérez, Demetrio José (Nature, 2019-05-08)
      Article
      Open Access
      Occupational, accidental, or suicidal exposure to acrylamide (ACR) may result in a neurotoxic syndrome. Development of animal models of acrylamide neurotoxicity is necessary for increasing our mechanistic understanding of ...
    • Global optimization of robotic grasps 

      Rosales Gallegos, Carlos; Porta Pleite, Josep Maria; Ros Giralt, Lluís (The MIT Press. Massachusetts Institute of Technology, 2011)
      Conference report
      Open Access
      This paper presents a procedure to optimize the quality of robotic grasps for objects that need to be held and manipulated in a specific way, characterized by a number of tight contact constraints. The main difficulties ...
    • Grasp optimization under specific contact constraints 

      Rosales Gallegos, Carlos; Porta Pleite, Josep Maria; Ros Giralt, Lluís (2013)
      Article
      Open Access
      This paper presents a procedure to synthesize highquality grasps for objects that need to be held and manipulated in a specific way, characterized by a pre-specified set of contact constraints to be satisfied. Due to the ...
    • Information-based compact Pose SLAM 

      Ila, Viorela Simona; Porta Pleite, Josep Maria; Andrade-Cetto, Juan (2010)
      Article
      Open Access
      Pose SLAMis the variant of simultaneous localization and map building (SLAM) is the variant of SLAM, in which only the robot trajectory is estimated and where landmarks are only used to produce relative constraints between ...
    • Kinodynamic planning on constraint manifolds 

      Bordalba Llaberia, Ricard; Porta Pleite, Josep Maria; Ros Giralt, Lluís (2017)
      External research report
      Open Access
      This report presents a motion planner for systems subject to kinematic and dynamic constraints. The former appear when kinematic loops are present in the system, such as in parallel manipulators, in robots that cooperate ...
    • Numerical computation of manipulator singularities 

      Bohigas Nadal, Oriol; Zlatanov, Dimiter; Ros Giralt, Lluís; Manubens Ferriol, Montserrat; Porta Pleite, Josep Maria (IEEE, 2012)
      Conference report
      Open Access
      This paper provides a method to compute all types of singularities of non-redundant manipulators with non-helical lower pairs and designated instantaneous input and output speeds. A system of equations describing each ...
    • On the symmetric molecular conjectures 

      Porta Pleite, Josep Maria; Ros Giralt, Lluís; Schulze, Bernd; Sljoka, Adnan; Whiteley, Walter (Springer, 2013)
      Conference report
      Open Access
      A molecular linkage consists of a set of rigid bodies pairwise connected by revolute hinges where all hinge lines of each body are concurrent. It is an important problem in biochemistry, as well as in robotics, to efficiently ...