Now showing items 1-12 of 21

    • 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 ...
    • A space decomposition method for path planning of loop linkages 

      Porta Pleite, Josep Maria; Cortés, Juan; Ros Giralt, Lluís; Thomas, Federico (2007)
      Conference report
      Open Access
      This paper introduces box approximations as a new tool for path planning of closed-loop linkages. Box approximations are finite collections of rectangloids that tightly envelop the robot's free space at a desired resolution. ...
    • Visually-guided robot navigation: from artificial to natural landmarks 

      Celaya Llover, Enric; Albarral Garcia, Jose Luis; Jimenez Schlegl, Pablo; Torras, Carme (2007)
      Conference report
      Open Access
      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, ...
    • Natural landmark detection for visually-guided robot navigation 

      Celaya Llover, Enric; Albarral Garcia, Jose Luis; Jimenez Schlegl, Pablo; Torras, Carme (2007)
      Conference report
      Open Access
      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. ...
    • Exploiting single-cycle symmetries in branch-and-prune algorithms 

      Ruiz de Angulo García, Vicente; Torras, Carme (2007)
      Conference report
      Open Access
      As a first attempt to exploit symmetries in continuous constraint problems, we focus on permutations of the variables consisting of one single cycle. We propose a procedure that takes advantage of these symmetries by ...
    • Singularity-free computation of quaternions from rotation matrices in E4 and E3 

      Sarabandi, Soheil; Pérez Gracia, Alba; Thomas, Federico (2018)
      Conference report
      Open Access
      A real orthogonal matrix representing a rotation in E4 can be decomposed into the commutative product of a left-isoclinic and a right-isoclinic rotation matrix. The double quaternion representation of rotations in E4 follows ...
    • A fast branch-and-prune algorithm for the position analysis of spherical mechanisms 

      Shabani, Arya; Sarabandi, Soheil; Porta Pleite, Josep Maria; Thomas, Federico (Springer, 2019)
      Conference report
      Open Access
      Different branch-and-prune schemes can be found in the literature for numerically solving the position analysis of spherical mechanisms. For the prune operation, they all rely on the propagation of motion intervals. They ...
    • Forward kinematics of the general triple-arm robot using a distance-based formulation 

      Rojas, Nicolas; Thomas, Federico (Springer, 2017)
      Conference report
      Open Access
      Distance-based formulations have successfully been used to obtain closure polynomialsfor planar mechanisms without relying, in most cases, on variable eliminations. The methods re-sulting from previous attempts to generalize ...
    • A new insight into the coupler curves of the RCCC four-bar linkage 

      Thomas, Federico; Pérez Gracia, Alba (Springer, 2017)
      Conference report
      Open Access
      Based on the condition for four points to lie on the unit sphere, derived using Distance Geometry, a new mathematical formulation for the coupler curves of the RCCC linkage is presented. The relevance of this formulation ...
    • A singularity-robust LQR controller for parallel robots 

      Bordalba Llaberia, Ricard; Porta Pleite, Josep Maria; Ros Giralt, Lluís (Institute of Electrical and Electronics Engineers (IEEE), 2018)
      Conference report
      Open Access
      Parallel robots exhibit the so-called forward singularities, which complicate substantially the planning and control of their motions. Often, such complications are circumvented by restricting the motions to singularity-free ...
    • The forward kinematics of doubly-planar Gough-Stewart platforms and the position analysis of strips of tetrahedra 

      Porta Pleite, Josep Maria; Thomas, Federico (Springer, 2018)
      Conference report
      Open Access
      A strip of tetrahedra is a tetrahedron-tetrahedron truss where any tetrahedron has two neighbors except those in the extremes which have only one. The problem of finding all the possible lengths for an edge in the strip ...
    • Grasping unknown objects in clutter by superquadric representation 

      Makhal, Abhijit; Thomas, Federico; Pérez Gracia, Alba (Institute of Electrical and Electronics Engineers (IEEE), 2018)
      Conference report
      Open Access
      In this paper, a quick and efficient method is presented for grasping unknown objects in clutter. The grasping method relies on real-time superquadric (SQ) representation of partial view objects and incomplete object ...