Pantopteron: a New Fully-Decoupled 3-DOF Translational Parallel Robot for Pick-and-Place Applications

International audienceIn this paper, a novel 3-DOF fully decoupled translational parallel robot, called the Pan-topteron, is presented. This manipulator is similar to the Tripteron Cartesian parallel manipulator, but due to the use of three pantograph linkages, an amplification of the ac-tuators displacements is achieved. Therefore, equipped with the same actuators, the mobile platform of the Pantopteron moves many-times faster than that of the Tripteron. This amplification is defined by the magnification factor of the pantograph linkages. The kinematics, workspace and constraint singularities of the proposed parallel robot are studied in detail. Design considerations are also discussed and a possible prototype is illustrated.

Structural compliance effects on the accuracy and safety of a R-CUBE haptic device

28th International Conference on Robotics in Alpe-Adria-Danube Region, RAAD 2019; Kaiserslautern; Germany; 19 June 2019 through 21 June 2019This paper addresses the contribution of structural compliance on stiffness and safety of a R-CUBE Haptic Device. Structural compliance is determined in several poses via FEM analysis and addressed by referring to local and global indices of performance. Results are also compared with evidences from experimental tests. Comparison of numerical and experimental data allows to identify and separate the contributions to the overall compliance that are due to the structural stiffness, and other contributions such as joint clearance, pose and loading conditions.Axis IT and T (20/01.09.2016), European Regional Development Fun

Pantopteron-4: a New 3T1R Decoupled Parallel Manipulator for Pick-and-Place Applications

International audienceIn this paper, a novel 4-DOF decoupled parallel manipulator with Schoenflies motions, called the Pantopteron-4, is presented. This manipulator is able to perform the same movements as the Isoglide4 or the Quadrupteron, but, due to its architecture which is made of three pantograph linkages, an amplification of the movements between the actuators and the platform displacements is achieved. Therefore, having the same actuators for both robots, the Pantopteron-4 displaces (theoretically) many-times faster than the Isoglide4 or the Quadrupteron, depending on the magnification factor of the pantograph linkages. Thus, this mechanism is foreseen to be used in applications where the velocities and accelerations have to be high, as in pick-and-place. First, the kinematics of the Pantopteron-4 is presented. Then, its workspace is analyzed. Finally, a prototype of the mechanism is shown and conclusions are given

Cable Robot Performance Evaluation by Wrench Exertion Capability

Although cable driven robots are a type of parallel manipulators, the evaluation of their performances cannot be carried out using the performance indices already developed for parallel robots with rigid links. This is an obvious consequence of the peculiar features of flexible cables-a cable can only exert a tensile and limited force in the direction of the cable itself. A comprehensive performance evaluation can certainly be attained by computing the maximum force (or torque) that can be exerted by the cables on the moving platform along a specific (or any) direction within the whole workspace. This is the idea behind the index-called the Wrench Exertion Capability (WEC)-which can be employed to evaluate the performance of any cable robot topology and is characterized by an efficient and simple formulation based on linear programming. By significantly improving a preliminary computation method for the WEC, this paper proposes an ultimate formulation suitable for any cable robot topology. Several numerical investigations on planar and spatial cable robots are presented to give evidence of the WEC usefulness, comparisons with popular performance indices are also provided

An innovative machine for Fused Deposition Modeling of metals and advanced ceramics

The design of a new additive manufacturing (AM) system based on extrusion and 3D deposition of a mixture of metal (or advanced ceramic) powder and polymeric binder is described in this paper. The proposed system is totally innovative in terms of combination of deposited work material, extrusion system (head and nozzle), and deposition work table, which is based on a 5-axes parallel kinematics machine (PKM). The extrusion head and nozzle have been designed in order to be able to extrude high viscosity mixtures with low polymeric content. The 5-axes PKM is aimed at obtaining a good surface quality of the deposited work and reducing the need for supports during deposition. After the deposition, the material is de-binded and sintered to nearly the density of the solid material as-cast. The design and kinematics of the machine and especially the PKM table is described in this paper, the main design issues are discussed and some preliminary extrusion and sintering results are presented