We present in this paper a new mechanical architecture for a parallel manipulator. We address the problem of the determination of the singular configurations of this architecture. Then we show that the direct kinematic problem has at most 16 solutions and exhibit an algorithm to find all the solutions.

This paper presents a new method to analyze the closedform kinematics of a generalized three-degree-of-a-freedom spherical parallel manipulator. Using this analytical method, concise and uniform solutions are achieved. Two special forms of the three-degree-of-freedom spherical parallel manipulator, i.e. right-angle type and a decoupled type, are also studied and their unique and interesting pro...

In this paper, 3-PPR planar parallel manipulators with ∆or U-shape base are compared with respect to their workspace size and kinematic sensitivity to joint clearances. First, the singularities and workspace of a general 3-PPR planar parallel manipulator are analyzed. Then, an error prediction model applicable to both serial and parallel manipulators is developed. As a result, two nonconvex qua...

Twice (Tilting device with WIde Capacity) a new amplification device able to double the tilting angle of a parallel mechanism is presented. A singularity analysis is carried out: it proves that Twice can give a huge tilting angle to Parallel Kinematic Machines (PKM). Finally, practical implementation features are discussed.

Shaking forces and shaking moments in high speed parallel manipulators are a significant cause of base vibrations. These vibrations can be eliminated by designing the manipulator to be shaking-force balanced and shaking-moment balanced. In this article an approach for the design and for the evaluation of high speed dynamically balanced parallel manipulators is presented and applied for a compar...

This paper presents the feasibility study of an under-actuated parallel manipulator with 6-PUS topology, destined to handle work-tables in CNC machine tools. The proposed device exploits the fact that, in such an application, the path between the initial and final poses of the mobile platform is not assigned to reduce the number of actuators to only one.

The design of a novel prismatic drive is reported in this paper. This transmission is based on Slide-O-Cam, a cam mechanism with multiple rollers mounted on a common translating follower. The design of Slide-O-Cam was reported elsewhere. This drive thus provides pure-rolling motion, thereby reducing the friction of rack-and-pinions and linear drives. Such properties can be used to design new tr...

The geometry of a 3D octahedral parallel robot manipulator system is specified in terms of two rigid octahedral structures (the fixed and moving platforms) and six actuation legs. The symmetry of the system is exploited to determine the behaviour of (a new version of) the quality index for various motions. The main results are presented graphically.