Mobile parallel mechanisms (MPMs), which are with moveable bases, have previously been proposed to resolve the limited workspace of conventional mechanisms. However, most previous studies on subject focused kinematic analysis some specific MPMs and did not discuss a type synthesis method for MPMs. With this in mind, we propose screw theory-based find out possible 6-degrees-of-freedom (DOF) MPM ...

INSTRUCTIONS Precision nano-positioning techniques have become very important for biomedical science, optics and microscopy. PZT and flexure compliant mechanisms are widely used in these various fields and applications within these fields. Compliant mechanisms are flexible structures, which can generate the desired motions by undergoing elastic deformation instead of through rigid linkage/joint...

In this paper a new procedure for type synthesis of low-DoF parallel robots based on screw theory is presented. The motivation of these work is that for many industrial applications, in particular in the machine-tool field, less than 6 degree of freedom (6-DoF) may be needed to complete the task. For example, for milling operation in the machine-tool domain, the rotation of the platform around ...

The subject of this paper is the optimal design of a parallel mechanism intended for three-axis machining applications. Parallel mechanisms are interesting alternative designs in this context but most of them are designed for threeor six-axis machining applications. In the last case, the position and the orientation of the tool are coupled and the shape of the workspace is complex. The aim of t...

The two translational degrees-of-freedom (DOF) and one rotational DOF (2T1R) planar parallel mechanisms (PMs) have the characteristics of simple structures, kinematic dynamic models, ease control allow for a variety application prospects. This paper concentrates on derivations 5-DOF hybrid manipulators based synthesized mechanisms. To understand effect constraint motion rigid body clearly, meth...

A reactionless machine will not apply reaction forces and moments on the mounting base during motion. This article presents the theory for design of a reactionless planar parallel mechanism. The salient features of this design are: (i) it uses auxiliary parallelograms to locate the center of mass of each leg at the base, (ii) choice of geometric and inertial parameters to satisfy the reactionle...

In this paper, a systematic approach is developed for the structural synthesis of a class of four-degrees-of-freedom (4-DoF) and 5-DoF overconstrained parallel manipulators with identical serial limbs. The theory of screws and reciprocal screws is employed for the analysis of the geometric conditions that must be met by the limbs of such parallel manipulators. Limb structures that can be used f...

In this paper, the design and dynamic balancing of a novel 3DOF parallel mechanism referred to as parallelepiped mechanism are addressed. Two types of actuation schemes of the mechanism are considered. The balancing equations are derived by imposing that the center of mass of the mechanism is fixed and that the total angular momentum is constant with respect to a fixed point. Optimization is pe...

This paper deals with an efficient application of a model-based predictive control scheme in parallel mechanisms. A predictive functional control strategy based on a simplified dynamic model is implemented. Experimental results are shown for the H4 robot, a fully parallel structure providing 3 degrees of freedom (dof) in translation and 1 dof in rotation. Predictive functional control, computed...