800-521-0600 UNIVERSITE DE MONTREAL Counter-Current and Flooding in Vertical and Horizontal Tubes with and wit hout Obstructions

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Visualisation of Configuration Spaces of Polygonal Linkages

Abstract. Using Morse theory, the configuration space of a 4-gonal (respectively 5-gonal) linkage in the plane or on the unit-sphere can be visualised as a curve i

A Family of New Parallel Architectures with Four Degrees of Freedom

This paper describes a novel parallel kinematic chain with 4 DoF. Three of the freedoms of the platform are rotational and only one is translational. The position and velocity kinematics of the mechanism are analyzed with different choices of the actuated joints. Methods for singularity analysis of the proposed mechanisms are also presented

. FACULTÉ DES SCIENCES ET DE GÉNIE

à la Faculté des études supérieures de l'Université Laval dans le cadre du programme de doctorat en génie mécanique pour l'obtention du-grade de PhilosophiaeDoctor (Ph.D.

Generation of Architecturally Singular 6-SPS Parallel Manipulators with Linearly Related Planar Platforms

An architecturally singular parallel manipulator is a parallel manipulator with architectural singularities spanning the whole workspace. It should be abandoned in the design process. This paper deals with the generation of architecturally singular 6-SPS parallel manipulators with linearly related planar platforms. The forward displacement analysis of the 6-SPS parallel manipulator with linearly related planar platforms is performed at first. All the architecturally singular 6-SPS parallel manipulators with linearly related planar platforms are then generated. It is found that a 6-SPS parallel manipulator with linearly related planar platforms is architecturally singular if and only if all the spherical joints on the base (or moving platform ) are located on a conic section. At last, self-motion analysis of the architecturally singular 6-SPS parallel manipulators with linearly related planar platforms is addressed

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The static balancing of spherical three-degree-of-freedom (DoF) parallel mechanisms and manipulators is addressed in this paper. Static balancing is defined here as the set of conditions on mechanism dimensional and inertial parameters which, when satisfied, ensure that the weight of the links does not produce any torque (or force) at the actuators for any configuration of the mechanism, under static conditions. First, the static balancing of a single body mounted on a spherical joint is studied. It is shown that it is possible to balance such a mechanism with springs, and that complete balancing can be achieved even with a single spring. Geometric conditions for the location of the spring attachments are given. Then, the results are applied to the balancing of two types of 3-DoF spherical parallel mechanisms. The first mechanism is a 9R manipulator, while the second one is referred to as the 3-6-6 spherical mechanism. Fo