A hybrid type manipulation system is a combination of closed-chain and open-chain mechanisms or it is a sequence of parallel mechanisms. Parallel manipulators have high stiffness and large load capacity, but suffer from a very limited workspace volume. The hybrid manipulators overcome the limited workspace of the parallel manipulators and at the same time they have high stiffness. The determina...

—In this paper, the failure of wire­actuated parallel manipulators is examined considering their failure modes. A methodology for investigating the effect of actuator/wire failures on the force/moment capability of manipulators is presented, and the criteria for full and partial recovery from these failures are established. The methodology is also applicable for the cases that the minimum norm ...

A parallel manipulator provides an alternative design to serial manipulators, and can be found in many applications such as mining machines (Arai et al., 1991). Through the design of active joints such that actuators are fixed to the manipulator base, the mass of moving components of the parallel manipulator is greatly reduced, and high speed and high acceleration performance may be achieved. P...

In this paper, a method to compute joint space singularity surfaces of 3-RPR planar parallel manipulators is first presented. Then, a procedure to determine maximal joint space singularity-free boxes is introduced. Numerical examples are given in order to illustrate graphically the results. This study is of high interest for planning trajectories in the joint space of 3-RPR parallel manipulator...

Mechanical structure of a cable-based parallel manipulator consists of a moving platform, witch is called end-effector, and a base. These two elements are connected by multiple cables. Indeed, the end-effector is operated by motors that can extend or retract cables. Cable-based parallel manipulators are structurally similar to parallel ones but they have some advantages, if compared to classica...

The aim of this paper is to characterize the uniqueness domains in the workspace of parallel manipulators, as well as their image in the joint space. The notion of aspect introduced for serial manipulators in [Borrel 86] is redefined for such parallel manipulators. Then, it is shown that it is possible to link several solutions to the direct kinematic problem without meeting a singularity, thus...

Introduction Over the past decades, with the large development of parallel structures, more attention has been paid to their kinematic, kinetostatic and dynamic properties, and in particular, to their singularities. Several papers deal with singularity analysis of parallel manipulators [111]. Most of them present the analysis of singular configurations from a kinematic point of view [1-5]. Alge...

This paper addresses the problem of identifying the property of the singularity loci of a class of 3/6‐ Gough‐Stewart manipulators for general orientations in which the moving platform is an equilateral triangle and the base is a semiregular hexagon. After constructing the Jacobian matrix of this class of 3/6‐Gough‐Stewart manipulators according to the screw theory, a...