This paper proposes a classification of three-revolute orthogonal manipulators that have at least one of their DH parameters equal to zero. This classification is based on the topology of their workspace. The workspace is characterized in a half-cross section by the singular curves. The workspace topology is defined by the number of cusps and nodes that appear on these singular curves. The mani...

This paper studies the workspace of a six-degrees-of-freedom parallel manipulator of the general three-PPSR (prismaticprismatic-spheric-revolute) type. It is known that a drawback of parallel manipulators is their limited workspace. To develop parallel mechanisms with a larger workspace is of use to potential applications. The mechanism of a three-PPSR manipulator and its variations are briefly...

We consider in this paper a Gough-type parallel robot whose leg lengths values are constrained to lie within some fixed ranges and for which there may be mechanical limits for the motion of the passive joints. The purpose of this paper is to present algorithms to determine: • the constant orientation workspace: all the possible locations of the center of the platform which can be reached with a...

This paper presents the kinematic analysis and the development of a 4-degree-of-freedom serial-parallel mechanism for large commercial vehicle driving simulators. The degrees of freedom are selected according to the target maneuvers and the structure of human motion perception organs. Several kinematic properties of parallel part of the mechanism under study are investigated, including the inve...

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...

This paper presents a new approach to generate the workspace of planar redundant manipulators based on the workspace density of a single link. The workspace density of planar serial redundant manipulators can be computed efficiently by using the concept of the Fourier transform for the group of rigid-body motions of the plane and the convolution theorem. For manipulators using discrete actuatio...

In this paper, the kinematic workspace characteristics of a crab-like legged vehicle are investigated using a 2-D model. The alternative kinematic configurations and their corresponding workspace constraints are discussed, and the vehicle configuration of most interest identified. It is shown that, for constant vehicle body attitude, only two parameters affect the kinematic workspace, foot over...

This paper describes the OpenADE (Open Assembly Design Environment) project, a framework that is addressing issues relating to the development of information-exchange standards for the next generation of assembly-oriented design tools. The OpenADE architecture itself is based on a design workspace that is shared between a variety of agents. These agents interact with the design workspace using ...

The wrench-closure workspace of parallel cable-driven mechanisms is the set of poses of their mobile platform for which the cables can balance any external wrench. The determination of this workspace is an important issue since the cables can only pull and not push on the mobile platform. This paper deals with the wrench-closure workspace of six-degrees-of-freedom (DOF) parallel mechanisms driv...

One of the main advantages of the Gantry-Tau machine is a large accessible workspace/footprint ratio compared to many other parallel machines. The Gantry-Tau improves this ratio by allowing a change of assembly mode without internal link collisions or collisions between the links and the moving TCP platform. This paper introduces the geometric approach for the unreachable workspace area for the...