In order to successfully perform visual servoing of robot manipulators the control algorithm must account for the physical limitations of the manipulator. These constraints de ne the robot workspace boundary. Any visual servoing control algorithm must avoid this boundary if stability of motion is to be ensured. In this paper, a method is developed by which a desired object path can be interpola...

This paper presents Workspace-based Connectivity Oracle (WCO), a new sampling strategy for probabilistic roadmap planning. WCO uses both domain knowledge—specifically, workspace geometry—and sampling history to construct a dynamic sampling distribution. WCO is composed of many component samplers, each based on a geometric feature of a robot. Each component sampler updates its distribution, usin...

The aim of this paper is to present a new six degree-of-freedom (dof) haptic device using two parallel mechanisms. The first one, called orthoglide, provides the translation motions and the second one produces the rotational motions. These two motions are decoupled to simplify the direct and inverse kinematics, as it is needed for real-times control. To reduce the inertial load, the motors are ...

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...

The purpose of the paper is to investigate the effect of small variations (uncertainties) and large variations in design parameters on the size and shape of the workspace of the wire-actuated parallel manipulators. The static force/moment balance equations, taking into account the null space of the Jacobian matrix, are used for the workspace analysis. The parameters examined include: the windin...

The apparent mass of haptic device end-effector depends on its position inside the workspace. This paper presents a recursive algorithm to detect effective direction of gravity force, and to automatically estimate the apparent mass of the end-effector when placed at the vertices of a cubic grid contained into the device workspace. Then an on-line technique is proposed to actively compensate gra...

− In this paper, we study the design and workspace of a 6-6 cable-suspended parallel robot. The workspace volume is characterized as the set of points where the centroid of the MP (MP) can reach with tensions in all suspension cables at a constant orientation. This paper attempts to tackle some aspects of optimal design of a 6DOF cable robot by addressing the variations of the workspace volume ...

This paper proposes a method to calculate the largest Regular Dextrous Workspace (RDW) of some types of threerevolute orthogonal manipulators that have at least one of their DH parameters equal to zero. Then a new performance index based on the RDW is introduced, the isocontours of this index are plotted in the parameter space of the interesting types of manipulators and finally an inspection o...

Two optimization studies on the design of a three degree of freedom translational parallel platform are conducted and the results are compared. The objective function of the rst study maximizes total volume of the manipulator workspace without regard to the quality of the workspace. The second study optimizes the total volume of well conditioned workspace by maximizing a global condition index....

Let S be a planar n-point set. Classically, one can find the Voronoi diagram VD(S) for S in O(n log n) time and O(n) space. We study the situation when the available workspace is limited: for s ∈ {1, . . . , n}, an s-workspace algorithm has read-only access to an input array with the points from S in arbitrary order, and it may use only O(s) additional words of Θ(log n) bits for reading and wri...