Exploració per autor "Thomas, Federico"
Ara es mostren els items 71-87 de 87
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Sensor localization from distance and orientation constraints
Porta Pleite, Josep Maria; Rull Sanahuja, Aleix; Thomas, Federico (2016)
Article
Accés obertThe sensor localization problem can be formalized using distance and orientation constraints, typically in 3D. Local methods can be used to refine an initial location estimation, but in many cases such estimation is not ... -
Simplified Voronoi diagrams for motion planning of quadratically-solvable Gough-Stewart platforms
Vaca Alzate, Rubén Hernando; Aranda López, Juan; Thomas, Federico (Springer, 2012)
Text en actes de congrés
Accés obertThe obstacles in Configuration Space of quadratically-solvable Gough-Stewart platforms, due to both kinematic singularities and collisions, can be uniformly represented by a Boolean combination of signs of 4×4 determinants ... -
Singularity-free computation of quaternions from rotation matrices in E4 and E3
Sarabandi, Soheil; Pérez Gracia, Alba; Thomas, Federico (2018)
Text en actes de congrés
Accés obertA 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 ... -
Singularity-invariant families of line-plane 5-SPU platforms
Borràs Sol, Júlia; Thomas, Federico; Torras, Carme (2011-10)
Article
Accés obertA 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)
Text en actes de congrés
Accés obertIn 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)
Text en actes de congrés
Accés obert -
Singularity-invariant leg substitutions in pentapods
Borràs Sol, Júlia; Thomas, Federico (2010)
Text en actes de congrés
Accés obertA 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)
Text en actes de congrés
Accés obertAn 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 ... -
The distance geometry of the generalized lobster’s arm
Thomas, Federico; Porta Pleite, Josep Maria (Springer, 2022)
Text en actes de congrés
Accés restringit per política de l'editorialThis paper proposes a distance-based formulation to solve the inverse kinematics of what is known as the generalized Lobster's arm: a 6R serial chain in which all consecutive revolute axes intersect. Since the solution of ... -
The forward kinematics of 3-RPR planar robots: a review and a distance-based formulation
Rojas Libreros, Nicolás Enrique; Thomas, Federico (2011)
Article
Accés obertThe standard forward kinematics analysis of 3-RPR planar parallel robots boils down to computing the roots of a sextic polynomial. There are many different ways to obtain this polynomial but most of them include exceptions ... -
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)
Text en actes de congrés
Accés obertA 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 ... -
The inverse kinematics of lobster arms
Thomas, Federico; Porta Pleite, Josep Maria (2024-03-21)
Article
Accés obertThe roots of the closure polynomial associated with a given mechanism determine its assembly modes. In the case of 6R closed-loop mechanisms, these polynomials are usually expressed in the half-angle tangent of one of its ... -
The octahedral manipulator revisited
Rojas Libreros, Nicolás Enrique; Borràs Sol, Júlia; Thomas, Federico (IEEE, 2012)
Text en actes de congrés
Accés obertIn most practical implementations of the Gough- Stewart platform, the octahedral form is either taken as it stands or is approximated. The kinematics of this particula r instance of the Gough-Stewart platform, commonly ... -
The univariate closure conditions of all fully parallel planar robots derived from a single polynomial
Rojas Libreros, Nicolás Enrique; Thomas, Federico (2013-06)
Article
Accés restringit per política de l'editorialThe real roots of the univariate polynomial closure condition of a planar parallel robot determine the solutions of its forward kinematics. This paper shows how the univariate polynomials of all fully parallel planar robots ... -
The univariate closure conditions of all fully parallel planar robots derived from a single polynomial
Rojas Libreros, Nicolás Enrique; Thomas, Federico (2013)
Article
Accés obertThe real roots of the univariate polynomial closure condition of a planar parallel robot determine the solutions of its forward kinematics. This paper shows how the univariate polynomials of all fully parallel planar robots ... -
Yet a better closed-form formula for the 3D nearest rotation matrix problem
Wu, Jin; Sarabandi, Soheil; Porta Pleite, Josep Maria; Liu, Ming; Thomas, Federico (2021)
Report de recerca
Accés obertThis technical report complements the results recently presented in [1] showing that they can be extended to define an efficient and robust method to determine the rotation matrix nearest to an arbitrary 3 × 3 matrix. This ... -
Yet another approach to the Gough-Stewart platform forward kinematics
Porta Pleite, Josep Maria; Thomas, Federico (2018)
Text en actes de congrés
Accés obertThe 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 ...