This paper investigates the stiffness modelling of a 3-DOF parallel manipulator with two additional legs. The stiffness model in six directions of the 3-DOF parallel manipulator with two additional legs is derived by performing condensation of DOFs for the joint connection and treatment of the fixed-end connections. Moreover, this modelling method is used to derive the stiffness model of the ma...

In this paper we introduce two new posture-dependent performance indices for 6dof UPS and 3-dof RPR parallel manipulators. One is based on an object-oriented metric in the workspace (end-effector dependent) and the other one takes the angular velocities of the passive joints into consideration (end-effector independent). Both newly defined indices are invariant under rigid-body motions and simi...

This paper deals with the design and analysis of a two-translation and one-rotation (2T1R) mechanism for a novel cooking robot. Firstly the motions involved in stir-fry, the most representative operation in the cooking processes used in Chinese cuisine, are analyzed in details. Then the featured motions are decomposed into four main movements that are used as a design base for a wok motion mech...

Driven by the significant demand for space control mechanism in development of national field, topology synthesis method hybrid based on finite and instantaneous screw (FIS theory) is studied this paper. The number types degrees freedom (DOF) required capturing, detumbling, screwing plugging tasks are analyzed depth, simplest mathematical expression continuous motion corresponding to formed. Ac...

This paper presents the kinematic design of a translational parallel mechanism (PM) named Vari-Orthoglide by means workspace superposition, according to sub-kinematic chain (SKC) based PM composition principle. The main topological characteristics manipulator with two SKCs under study, such as position and orientation (POC) characteristics, degree freedom (DOF) coupling are analyzed, which turn...

Abstract: This paper deals with an efficient application of a model based predictive control in parallel machines. A receding horizon control strategy based on a simplified dynamic model is implemented. Experimental results are shown for the H4 robot, a fully parallel structure providing 3 degrees of freedom (dof) in translation and 1 dof in rotation. The model based predictive control and the ...

This paper deals with the experimental identification of the dynamic parameters of parallel machines. The dynamic parameters are estimated by using the weighted least squares solution of an over determined linear system obtained from the sampling of the dynamic model along a closed loop exciting trajectory. Experimental results are exhibited for the H4 robot, a fully parallel structure providin...

In previous works, the authors showed that using robot-assisted steerable electrode array insertions can significantly reduce the insertion forces compared to non-steerable electrode arrays. In addition to steering the electrode array, it is possible to change its angle of approach with respect to the scala tympani. This paper focuses on determining the relevance of changing the angle of approa...

A recursive dynamic modeling of a three-DOF parallel robot, namely, threeRevolute-Prismatic-Spherical (3-RPS) parallel manipulator is reported in this work. Euler parameters are utilized to define the 3-DOF orientation of its moving platform, because the coordinates are free of singularity. For the dynamic modeling, the concept of the Decoupled Natural Orthogonal complement (DeNOC) matrices is ...