This paper investigates the stiffness characteristics of spherical parallel manipulators. By virtue of singular value decomposition, the 6×6 dimensionally inhomogeneous Cartesian stiffness matrix is transformed into two homogeneous ones, i.e., the rotational and translational stiffness matrices. The decomposed singular values and the corresponding vectors indicate the directions of high/weak st...

This paper presents a new approach to optimized motion planning for industrial robot arms with six degrees of freedom in an on-line given 3D environment. The method is based on the A*-search algorithm and needs no essential off-line computations. The algorithm works in an implicitly discrete configuration space. Collisions are detected in the cartesian workspace by hierarchical distance computa...

For the collision avoidance with a medical robot with 6 DOF a virtual simulation system is presented. Manipulator and obstacles are modelled by geometric primitives. Collisions are detected in the Cartesian workspace by hierarchical distance computation based on the given CAD model. The application initially being addressed is maxillofacial surgery, where the safety of the patient is the main r...

Two Visual Servoing controls respectively of the Position Based and Image Based type have been developed to govern a parallel translating manipulator with an eye-in-hand configuration. The robot must be able to reach and grasp a special target randomly positioned in the workspace; the control must be adaptive to compensate motions of the target in the 3D space. The implemented trajectory planni...

dimensional synthesis of a parallel robot may be the initial stage of its design process, which is usually carried out based on a required workspace. since optimization of the links lengths of the robot for the workspace is usually done, the workspace computation process must be run numerous times. hence, importance of the efficiency of the algorithm and the cpu time of the workspace computatio...

Pointing to a remembered visual target involves the transformation of binocular visual information into an appropriate motor output. Errors generated during pointing tasks may indicate the reference frames used by the CNS for the transformation and storage of the target position. Previous studies have proposed eye-, shoulder-, or hand-centered reference frames for various pointing tasks, depend...

The aim of this paper is to characterize the notion of aspect in the workspace and in the joint space for parallel manipulators. In opposite to the serial manipulators, the parallel manipulators can admit not only multiple inverse kinematic solutions, but also multiple direct kinematic solutions. The notion of aspect introduced for serial manipulators in [1], and redefined for parallel manipula...

The aim of this paper is to characterize the notion of aspect in the workspace and in the joint space for parallel manipulators. In opposite to the serial manipulators, the parallel manipulators can admit not only multiple inverse kinematic solutions, but also multiple direct kinematic solutions. The notion of aspect introduced for serial manipulators in [1], and redefined for parallel manipula...

The paper is focusing on the material handling devices operation environment 3D-type presentation based on laser scanning systems and point of cloud data approach. Main attention was fixed at overhead travelling cranes and their operation space zone with determined and random character factor influences the workspace spatial volume. Supervising the transport means workspace get possibility mark...

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 ration further by allowing a change of assembly mode without internal link collisions or collisions between the links and end-effector. The reconfigurable Gantry-Tau kinematic design obtained by multi-objective optimisation a...