Now showing items 1-20 of 21

  • A distance-based formulation of the octahedral manipulator kinematics 

    Rojas Libreros, Nicolás Enrique; Borràs Sol, Júlia; Thomas, Federico (2010)
    Conference report
    Open Access
    In most practical implementations of the Gough-Stewart platform, the octahedral form is either taken as it stands or is approximated. The kinematics of this particular instance of the Gough-Stewart platform, commonly known ...
  • A family of quadratically-solvable 5-SPU parallel robots 

    Borràs Sol, Júlia; Thomas, Federico; Torras, Carme (2010)
    Conference report
    Open Access
    A 5-SPU robot with collinear universal joints is well suited to handling an axisymmetric tool, since it has 5 controllable DoFs and the remaining one is a free rotation around the tool. The kinematics of such a robot having ...
  • A reconfigurable 5-DoF 5-SPU parallel platform 

    Borràs Sol, Júlia; Thomas, Federico; Ottaviano, Erika; Ceccarelli, Marco (2009)
    Conference report
    Open Access
    This paper presents a 5-SPU platform whose base leg attachments can be easily reconfigured, statically or dynamically, without altering its singularity locus. This permits to adapt the platform’s geometry to particular ...
  • Analysing the singularities of 6-SPS parallel robots using virtual legs 

    Borràs Sol, Júlia; Thomas, Federico; Torras, Carme (LIRMM, 2008)
    Conference report
    Open Access
    A virtual leg in a 6-SPS parallel robot is defined as a leg whose length is determined by the lengths of a subset of the actual legs of the robot. This necessarily implies that this subset of legs defines a rigid subassembly. ...
  • Architectural singularities of a class of pentapods 

    Borràs Sol, Júlia; Thomas, Federico; Torras, Carme (2011)
    Article
    Open Access
    A pentapod is usually defined as a 5-degrees-of-freedom fully-parallel manipulator with an axial spindle as moving platform. This kind of manipulators has revealed as an interesting alternative to serial robots handling ...
  • Architecture singularities in flagged parallel manipulators 

    Borràs Sol, Júlia; Thomas, Federico; Torras, Carme (IEEE, 2008)
    Conference report
    Open Access
    Flagged manipulators are of interest because they are the only Stewart-Gough platforms for which a cell decomposition of their singularity loci is available. Here we show that the known family of such manipulators can be ...
  • Direct position analysis of a large family of spherical and planar parallel manipulators with four loops 

    Borràs Sol, Júlia; Gregorio, Raffaele di (LIRMM, 2008)
    Conference report
    Open Access
    The direct position analysis (DPA) of a manipulator is the computation of the end-effector poses (positions and orientations) compatible with assigned values of the actuated-joint variables. Assigning the actuated-joint ...
  • Experiència pràctica de comunicació de Matemàtiques a la ciutadania i a secundària – 2a fase 

    Alberich Carramiñana, Maria; Barja Yáñez, Miguel Ángel; Borràs Sol, Júlia; Plans Berenguer, Bernat; Quer Bosor, Jordi; Thomas, Federico; Torras, Carme; Xambó Descamps, Sebastián (Universitat Politècnica de Catalunya. Institut de Ciències de l'Educació, 2013-02-08)
    Conference report / Conference lecture
    Restricted access - author's decision
    El projecte implementa experiències pràctiques dels estudis universitaris de matemàtiques (grau, llicenciatura i màsters) en l'àmbit de la docència i la divulgació científica. La finalitat divulgativa pretén fomentar ...
  • Kinematics of line-plane subassemblies in Stewart platforms 

    Borràs Sol, Júlia; Thomas, Federico (IEEE, 2009-05-31)
    Conference report
    Open Access
    When the attachments of five legs in a Stewart platform are collinear on one side and coplanar on the other, the platform is said to contain a line-plane subassembly. This paper is devoted to the kinematics analysis of ...
  • New geometric approaches to the analysis and design of Stewart-Gough platforms 

    Borràs Sol, Júlia; Thomas, Federico; Torras, Carme (Institute of Electrical and Electronics Engineers (IEEE), 2014)
    Article
    Open Access
    In general, rearranging the legs of a Stewart-Gough platform, i.e., changing the locations of its leg attachments, modifies the platform singularity locus in a rather unexpected way. Nevertheless, some leg rearrangements ...
  • New geometric approaches to the singularity analysis of parallel platforms 

    Borràs Sol, Júlia; Thomas, Federico; Torras, Carme (Escuela Superior de Ingenieros de la Universidad de Sevilla, 2011)
    Conference report
    Open Access
    In general, rearranging the legs of a Stewart- Gough platform, i.e., changing the locations of its leg attachments, modifies the platform singularity locus in a rather unexpected way. Nevertheless, some leg rearrangements ...
  • On the primal and dual forms of the Stewart platform pure condition 

    Borràs Sol, Júlia; Thomas, Federico (2012)
    Article
    Open Access
    The algebraic characterization of the singularities of a Stewart platform is usually presented as a 6 × 6 determinant, whose rows correspond to the line coordinates of its legs, equated to zero. This expression can be ...
  • On ¿-transforms 

    Thomas, Federico; Torras, Carme; Borràs Sol, Júlia (2009)
    Article
    Open Access
    Anyset of two legs in a Gough–Stewart platform sharing an attachment is defined as a Δcomponent. This component links a point in the platform (base) to a line in the base (platform). Thus, if the two legs, which are involved ...
  • Optimal design of a 6-DOF 4-4 parallel manipulator with uncoupled singularities 

    Borràs Sol, Júlia; Ottaviano, Erika; Ceccarelli, Marco; Thomas, Federico (Asociación Española de Ingeniería Mecánica, 2008)
    Conference report
    Open Access
    A 6-DOF 4-4 parallel manipulator is presented. Its forward kinematics can be solved by a sequence of three trilaterations and, as a consequence, its singularities can be described in geometric terms as the degeneration of ...
  • Polynomial solution to the position analysis of two Assur kinematic chains with four loops and the same topology 

    Borràs Sol, Júlia; Gregorio, Raffaele di (ASME PRESS, 2009)
    Article
    Restricted access - publisher's policy
    The direct position analysis (DPA) of a manipulator is the computation of the end-effector poses (positions and orientations) compatible with assigned values of the actuated-joint variables. Assigning the actuated-joint ...
  • Singularity-invariant families of line-plane 5-SPU platforms 

    Borràs Sol, Júlia; Thomas, Federico; Torras, Carme (2011-10)
    Article
    Open Access
    A 5-SPU robot with collinear universal joints is well suited to handling an axisymmetric tool, since it has 5 controllable DoFs and the remaining one is a free rotation around the tool. The kinematics of such a robot ...
  • Singularity-invariant leg rearrangements in doubly-planar Stewart-Gough platforms 

    Borràs Sol, Júlia; Thomas, Federico; Torras, Carme (2010)
    Conference report
    Open Access
    In general, rearranging the legs of a Stewart-Gough platform, i.e., changing the locations of its leg attachments, modifies the platform singularity locus in a rather unexpected way. Nevertheless, some leg rearrangements ...
  • Singularity-invariant leg rearrangements in Stewart-Gough platforms 

    Borràs Sol, Júlia; Thomas, Federico; Torras, Carme (Springer Verlag, 2010)
    Conference report
    Open Access
  • Singularity-invariant leg substitutions in pentapods 

    Borràs Sol, Júlia; Thomas, Federico (2010)
    Conference report
    Open Access
    A pentapod is usually defined as a 5-degree-offreedom fully-parallel manipulator with an axial spindle as moving platform. This kind of manipulators have revealed as an interesting alternative to serial robots handling ...
  • Straightening-free algorithm for the singularity analysis of Stewart-Gough platforms with collinear/coplanar attachments 

    Borràs Sol, Júlia; Thomas, Federico; Torras, Carme (Springer Verlag, 2009)
    Conference report
    Open Access
    An algorithm to derive the pure condition of any double-planar Stewart-Gough platform in a standard form suitable for comparison is presented. By applying the multilinear properties of brackets directly to the superbracket ...