Partially Flagged Parallel Manipulators: Singularity Charting and Avoidance

The topology of singularities of flagged parallel manipulators

The spatial parallel manipulator can abstractly be described as two bodies, base and platform, joined by six segments (or legs) of variable lengths. The configuration space which describes all possible platform locations with respect to the base is R×SO3(R) the Euclidean motion group. It is a differentiable manifold of dimension 6, and this is why the platform and the base are joined by six leg...

Instantaneous kinematics and singularity analysis of three-legged parallel manipulators

Instantaneous kinematics and singularity analysis of a class of three-legged, 6-DOF parallel manipulators are addressed in this paper. A generic method of derivation of reciprocal screw and consequently, the instantaneous kinematics model is presented. The advantage of this formulation is that the instantaneous kinematics model possesses well-defined geometric meaning and algebraic structure. S...

Singularity Analysis, Constraint Wrenches and Optimal Design of Parallel Manipulators

Singularity Loci of Planar Parallel Manipulators with Revolute Joints

This paper addresses the problem of determining the singularity loci of 3-DOF planar parallel manipulators with revolute joints for a constant orientation of the mobile platform. The case when the base joints are actuated is of primary concern and is proved here to lead to singularity loci represented by curves of degree 42—an improved measure with respect to the one already given in the litera...

Results on Planar Parallel Manipulators with Cylindrical Singularity Surface

In this article we give first results on Stewart Gough Platforms with planar base and platform, whose singularity set for any orientation of the platform is a cylindrical surface with rulings parallel to a given fixed direction p in the space of translations. In this case the singularity set can easily be visualized as curve by choosing p as projection direction. Moreover the computation of sin...