This paper addresses the workspace analysis of two 3-DOF translational parallel mechanisms designed for machining applications. The two machines features three fixed linear joints. The joint axes of the first machine are orthogonal whereas these of the second are parallel. In both cases, the mobile platform moves in the Cartesian x−y−z space with fixed orientation. The workspace analysis is con...

We present an algorithm to determine all the possible geometries of Gough-type 6 d.o.f. parallel manipulators whose workspace has to include a desired workspace. This desired workspace is described as a set of geometric objects, limited here to points and segments, which describe the desired locations of the center of the moving platform. It is assumed that the orientation of the platform is fi...

We present a fast algorithm for solving the problem of determining if the straight line between two different postures of a parallel manipulator lie fully inside its workspace. This algorithm is based on the analysis of the algebraic inequalities describing the constraints on the workspace (link lengths range, mechanical limits on the joints, interference between the links) and enables to compu...

By using the topological structure synthesis theory and method based on POC (Position and Orientation Characteristic) equations,a novel 4-DOF 3T1R parallel manipulator (PM) with low coupling degree, 2PaRSS, is presented.First,the modeling and numerical solutions for forward and inverse position of the PM is established. Then, the workspace and rotation capacity of the PM are analyzed based on i...

In this paper, we study the design and workspace of a 6–6 cable-suspended parallel robot. The workspace volume is characterized as the set of points where the centroid of the moving platform can reach with tensions in all suspension cables at a constant orientation. This paper attempts to tackle some aspects of optimal design of a 6DOF cable robot by addressing the variations of the workspace v...

The purpose of the paper is to investigate the effect of small variations (uncertainties) and large variations in design parameters on the size and shape of the workspace of the wire-actuated parallel manipulators. The static force/moment balance equations, taking into account the null space of the Jacobian matrix, are used for the workspace analysis. The parameters examined include: the windin...

− In this paper, we study the design and workspace of a 6-6 cable-suspended parallel robot. The workspace volume is characterized as the set of points where the centroid of the MP (MP) can reach with tensions in all suspension cables at a constant orientation. This paper attempts to tackle some aspects of optimal design of a 6DOF cable robot by addressing the variations of the workspace volume ...

The apparent gravity force acting on the end-effector of an haptic device depends on its position inside the workspace. This thesis presents an offline recursive algorithm to automatically estimate the required gravity compensation terms to be applied to the end-effector at a given set of positions, corresponding to the vertices of a cubic grid contained into the device workspace. Online gravit...

In this paper, it is studied how a certain class of physical constraints can be represented by a continuous set of orientations and how this representation is especially suitable for representing the constraints imposed by revolute and spherical joints. Further, it is shown how this can be used to represent the freedom of passive joints. It is recognised that in cooperative manipulation, the re...