We dispel with “street wisdom” regarding the practical implementation of Strassen’s algorithm for matrix-matrix multiplication (DGEMM). Conventional wisdom: it is only practical for very large matrices. Our implementation is practical for small matrices. Conventional wisdom: the matrices being multiplied should be relatively square. Our implementation is practical for rank-k updates, where k is...

Computer simulations aimed at assessing functional characteristics of the graphic workspace are presented. The simulations involve a 10-df kinematic model of the distal part of the writing arm, and yield the effective workspace of the pen tip under two types of kinematic constraints. The first constraint involves fixing the forearm under various pronation angles, the second governs the protrusi...

Nowadays, many teams collaborate via shared workspace environment which offer a suite of services supporting the group interaction. The needs for an effective group interaction vary over time and are dependent of the current problem and group goal. An ideal shared workspace environment has to take this into account and offer means for tailoring the offered the services to meet the current needs...

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 moving platform 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 v...

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...