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Curvature principal directions on geometric surfaces are a ubiquitous concept of Geometry Processing techniques. However they only account for order 2 differential quantities, oblivious of higher order differential behaviors. In this paper,…

Computational Geometry · Computer Science 2021-11-11 Julie Digne , Sébastien Valette , Raphaëlle Chaine , Yohann Béarzi

This article presents a new variable actuation mechanism based on the 3-RPR parallel robot. This mechanismis an evolution of the NaVARo robot, a 3-RRR parallel robot, for which the second revolute joint of the threelegs is replaced by a…

Robotics · Computer Science 2019-08-07 Damien Chablat , Luc Rolland

Workspace and joint space analysis are essential steps in describing the task and designing the control loop of the robot, respectively. This paper presents the descriptive analysis of a family of delta-like parallel robots by using…

Robotics · Computer Science 2015-05-21 R. Jha , Damien Chablat , Fabrice Rouillier , G. Moroz

We study determining the posture of an in-parallel planar manipulator, which has three connectors composed of revolute, prismatic and revolute joints, from specified active joint variables. We construct an ideal in the field of complex…

Robotics · Computer Science 2015-11-17 Sureyya Sahin

We study the unit distance and distinct distances problems over the planar hypercomplex numbers: the dual numbers $\mathbb{D}$ and the double numbers $\mathbb{S}$. We show that the distinct distances problem in $\mathbb{S}^2$ behaves…

Combinatorics · Mathematics 2020-02-18 David FitzPatrick

We present algorithms for computing strongly singular and near-singular surface integrals over curved triangular patches, based on singularity subtraction, the continuation approach, and transplanted Gauss quadrature. We demonstrate the…

Numerical Analysis · Mathematics 2024-06-24 Hadrien Montanelli , Francis Collino , Houssem Haddar

This paper focuses on the kinematic properties of a new three-degree-of-freedom hybrid manipulator. This manipulator is obtained by adding in series to a five-bar planar mechanism (similar to the one studied by Bajpai and Roth) a third…

Robotics · Computer Science 2007-05-23 Damien Chablat , Philippe Wenger , Jorge Angeles

This note is about promoting singularity subtraction as a helpful tool in the discretization of singular integral operators on curved surfaces. Singular and nearly singular kernels are expanded in series whose terms are integrated on…

Numerical Analysis · Mathematics 2013-01-31 Johan Helsing

We describe typical degenerations of quadratic differentials thus describing ``generic cusps'' of the moduli space of meromorphic quadratic differentials with at most simple poles. The part of the boundary of the moduli space which does not…

Geometric Topology · Mathematics 2014-04-07 Howard Masur , Anton Zorich

We study the geometry and codes of quartic surfaces with many cusps. We apply Gr\"obner bases to find examples of various configurations of cusps on quartics.

Algebraic Geometry · Mathematics 2014-12-23 Slawomir Rams

Cuspidal robots are robots with at least two inverse kinematic solutions that can be connected by a singularity-free path. Deciding the cuspidality of generic 3R robots has been studied in the past, but extending the study to…

Symbolic Computation · Computer Science 2022-09-20 Damien Chablat , Rémi Prébet , Mohab Safey El Din , Durgesh Salunkhe , Philippe Wenger

A differential geometric approach to singular perturbation theory is presented. It is shown that singular perturbation problems such as multiple-scale and boundary layer problems can be treated more easily on a differential geometric basis.…

Mathematical Physics · Physics 2008-11-06 F. Jamitzky

A cusp singularity is a surface singularity whose minimal resolution is a cycle of smooth rational curves meeting transversely. Cusp singularities come in naturally dual pairs. Looijenga proved in 1981 that if a cusp singularity is…

Algebraic Geometry · Mathematics 2021-11-16 Philip Engel , Robert Friedman

Singularities arise in diverse disciplines and play a key role in both exploring fundamental laws of physics and making highly-sensitive sensors. Higher-order (>3) singularities, with further improved performance, however, usually require…

This paper deals with the comparison of planar parallel manipulator architectures based on a multi-objective design optimization approach. The manipulator architectures are compared with regard to their mass in motion and their regular…

Robotics · Computer Science 2010-12-14 Damien Chablat , Stéphane Caro , Raza Ur-Rehman , Philippe Wenger

A family of reconfigurable parallel robots can change motion modes by passing through constraint singularities by locking and releasing some passive joints of the robot. This paper is about the kinematics, the workspace and singularity…

Robotics · Computer Science 2017-08-08 Damien Chablat , Xianwen Kong , Chengwei Zhang

This paper introduces a methodology to analyze geometrically the singularities of manipulators, of which legs apply both actuation forces and constraint moments to their moving platform. Lower-mobility parallel manipulators and parallel…

Robotics · Computer Science 2009-10-22 Daniel Kanaan , Philippe Wenger , Stéphane Caro , Damien Chablat

For generic maps from compact surfaces with boundary into the plane we develop an explicit algorithm for minimizing both the number of cusps and the number of components of the singular locus. More precisely, we minimize among maps with…

Geometric Topology · Mathematics 2019-02-12 Dominik Wrazidlo

This paper is concerned with the local bifurcation analysis around typical singularities of piecewise smooth planar dynamical systems. Three-parameter families of a class of non$-$smooth vector fields are studied and the tridimensional…

Dynamical Systems · Mathematics 2014-09-04 Claudio A. Buzzi , Tiago A. Carvalho , Marco A. Teixeira

We introduce and analyze a model for self-reconfigurable robots made up of unit-cube modules. Compared to past models, our model aims to newly capture two important practical aspects of real-world robots. First, modules often do not occupy…