Abstract: The modelling, optimization issues and stiffness for several types of three degrees-of-freedom parallel robotic manipulators, i.e., 3-DOF pure translational, 3-DOF pure rotational and 3-DOF mixed motion types, are studied in this paper. First of all, the kinematics and Jacobian for the robotic manipulators are determined through different approaches; secondly, objective functions mode...

In this paper, we introduce the generalized Stewart platform consisting of two rigid bodies connected with six distance and/or angular constraints between six pairs of points, lines and/or planes in the base and moving platform respectively, which could be considered as the most general form of parallel manipulators with six DOF in certain sense. We prove that there exist 3850 possible forms of...

In this paper, a novel four-degree-of-freedom (4-DOF) hybrid parallel platform manipulator is presented. The movable platform of the parallel manipulator can translate along two directions and rotate around two axes respectively. The kinematics model is formulated, which describes the inverse kinematic transformation and forward kinematic transformation. A 5-axis parallel machine tool based on ...

The workspace of a spatial 6‐DOF electro‐ hydraulic parallel manipulator is strongly coupled, due to its multi‐closed‐loop kinematic structure and the coupling complicates motion planning and control of the parallel manipulator. This paper clearly analyses the strong dynamic coupling property in the workspace of a spatial 6‐DOF parallel manipulator, using modal decouplin...

The development of serial or parallel manipulator robots is constantly increasing due to the need for faster productivity and higher accuracy. Therefore, researchers have turned combining both mechanisms, sharing advantage from vice versa. This paper proposes a new configuration design serial-parallel hybrid (SPHM) using industrial robotic KUKA Kr6 R900 3-DOF spherical mechanism. has six degree...

This paper presents the control of ARCHI, a 3-dof over-actuated parallel mechanism, designed as a subpart of a 5-axis hybrid machining robot. Control strategies of the parallel sub-mechanism (3 dof / 4 actuators) managing the internal constraint on the mechanism are proposed and experimental results are discussed.

After Gough [1] and Stewart [2] in the 50's and 60's introducing the idea of ‘hexapods’ (6-dof) [3][4], Clavel and his Delta structure [5] in the late 80's opened a new era with machines able to reach extremely high performances, used first for pick-and-place operations, and more recently for 3 or 5-axis machining. Considering the machining of complex shape objects, the solution often proposed ...