This paper characterizes geometrically the singularities of limited DOF parallel manipulators. The geometric conditions associated with the dependency of six Plücker vector of lines (finite and infinite) constituting the rows of the inverse Jacobian matrix are formulated using GrassmannCayley algebra. Manipulators under consideration do not need to have a passive spherical joint somewhere in ea...

Introduction Over the past decades, with the large development of parallel structures, more attention has been paid to their kinematic, kinetostatic and dynamic properties, and in particular, to their singularities. Several papers deal with singularity analysis of parallel manipulators [111]. Most of them present the analysis of singular configurations from a kinematic point of view [1-5]. Alge...

Tracking control of the direct-drive robot manipulators in high-speed is a challenging problem. The Coriolis and centrifugal torques become dominant in the high-speed motion control. The dynamical model of the robotic system including the robot manipulator and actuators is highly nonlinear, heavily coupled, uncertain and computationally extensive in non-companion form. In order to overcome thes...

This paper addresses the problem of identifying the property of the singularity loci of a class of 3/6‐ Gough‐Stewart manipulators for general orientations in which the moving platform is an equilateral triangle and the base is a semiregular hexagon. After constructing the Jacobian matrix of this class of 3/6‐Gough‐Stewart manipulators according to the screw theory, a...

In this paper, we will discuss the potential benefits Magneto-Rheological fluids can bring to the field of human friendly manipulators. For several decades now, the robotics industry has postulated the emergence of a new breed of manipulators capable of safely interacting with humans. The integration of robots into human environments has always possessed a unique set of challenges. The primary ...

joint flexibility is a very important factor to consider in the controller design for robot manipulators if high performance is expected. most of the research works on control of flexible-joint robots in literature have ignored the actuator dynamics to avoid complexity in controller design. the problem of designing nonlinear controller for a class of single-link flexible-joint robot manipulator...

the control law (3) does not only improves the transient performance, but also provides smoother outputs. It is important to stress that a better performance can still be achieved with (28) and (30). However, as discussed in Remark IV.1, increasing gains would not only cause more peaks in the outputs, but it might also yield saturation, especially for 2. V. CONCLUSION The tracking control probl...