El grup estudia el comportament dels mecanismes articulats i la planificació, simulació i el control eficient i segur dels moviments d'aquests sistemes. Tots aquests aspectes són esencials per poder desenvolupar els robots cada vegada més complexos d'avui en dia, que s'han de dissenyar de forma que operin en els espais de treball pre-establerts, que han de manipular objectes de forma destra i que han d'evitar en tot moment les configuracions singulars i les col·lisions amb l'entorn.

Recent Submissions

  • 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 ...
  • Yet another approach to the Gough-Stewart platform forward kinematics 

    Porta Pleite, Josep Maria; Thomas, Federico (2018)
    Conference report
    Open Access
    The forward kinematics of the Gough-Stewart platform, and their simplified versions in which some leg endpoints coalesce, has been typically solved using variable elimination methods. In this paper, we cast doubts on whether ...
  • Randomized planning of dynamic motions avoiding forward singularities 

    Bordalba Llaberia, Ricard; Ros Giralt, Lluís; Porta Pleite, Josep Maria (Springer International Publishing, 2018)
    Conference report
    Open Access
    Forward singularities, also known as direct, or actuator singularities, cause many problems to the planning and control of robot motions. They yield position errors and rigidity losses of the robot, and generate unbounded ...
  • Randomized kinodynamic planning for constrained systems 

    Bordalba Llaberia, Ricard; Ros Giralt, Lluís; Porta Pleite, Josep Maria (Institute of Electrical and Electronics Engineers (IEEE), 2018)
    Conference report
    Open Access
    Kinodynamic RRT planners are considered to be general tools for effectively finding feasible trajectories for high-dimensional dynamical systems. However, they struggle when holonomic constraints are present in the system, ...
  • Accurate computation of quaternions from rotation matrices 

    Sarabandi, Soheil; Thomas, Federico (Springer International Publishing, 2018)
    Conference report
    Open Access
    The main non-singular alternative to 3×3 proper orthogonal matrices, for representing rotations in R3, is quaternions. Thus, it is important to have reliable methods to pass from one representation to the other. While ...
  • A reconfigurable asymmetric 3-UPU parallel robot 

    Sarabandi, Soheil; Grosch Obregon, Patrick John; Porta Pleite, Josep Maria; Thomas, Federico (2018)
    Conference report
    Open Access
    Parallel robots with three UPU legs have received a lot of attention due to the possibility of assembling these legs so that the robot performs either a pure translational or a pure rotational motion. Nevertheless, some ...
  • 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 ...
  • Randomized kinodynamic planning for cable-suspended parallel robots 

    Bordalba Llaberia, Ricard; Porta Pleite, Josep Maria; Ros Giralt, Lluís (Springer, 2017)
    Conference report
    Open Access
    This paper proposes the use of a randomized kinodynamic planning technique to synthesize dynamic motions for cable-suspended parallel robots. Given two mechanical states of the robot, both with a prescribed position and ...

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