Gravity compensation of parallel kinematics mechanism with revolute joints using torsional springs

2019 ◽  
Vol 48 (1) ◽  
pp. 27-47 ◽  
Author(s):  
Abdur Rosyid ◽  
Bashar El-Khasawneh ◽  
Anas Alazzam
Keyword(s):  
Gravity Compensation ◽  
Parallel Kinematics ◽  
Revolute Joints

Static Balancing of a Parallel Kinematics Machine With Linear-Delta Architecture

2014 ◽  
Author(s):  
Alberto Martini ◽  
Marco Troncossi ◽  
Marco Carricato ◽  
Alessandro Rivola
Keyword(s):  
General Theory ◽  
Closed Loop ◽  
Parallel Robot ◽  
Design Solution ◽  
Robot Design ◽  
Gravity Compensation ◽  
Parallel Kinematics ◽  
Static Balancing ◽  
Milling Operation ◽  
Working Performance

The study deals with the compensation of gravity loads in closed-loop mechanisms as a possible strategy for enhancing their working performance. This work focuses on the Orthoglide 5-axis, a prototypal parallel robot for milling operation, characterized by linear-delta architecture with two further serial DOFs. Starting from a general theory formerly proposed by the authors, gravity compensation of the mechanism is analytically carried out. The statically balanced Orthoglide 5-axis can be obtained by installing on one leg a proper set of extension springs and a simple additional linkage. A feasible design solution for developing the device in practice is presented. The proposed balancing device can be implemented with minor modifications of the original robot design, thus appearing a profitable solution to be possibly extended to other machinery with similar architecture.

scholarly journals Modeling and Validation of a Passive Truss-Link Mechanism for Deployable Structures Considering Friction Compensation with Response Surface Methods

2022 ◽  
Vol 12 (1) ◽  
pp. 451
Author(s):  
Han-Sol Choi ◽  
Dong-Yeon Kim ◽  
Jeong-Hoon Park ◽  
Jae Hyuk Lim ◽  
Tae Seong Jang
Keyword(s):  
Response Surface ◽  
Degrees Of Freedom ◽  
Large Scale ◽  
Frictional Torque ◽  
Gravity Compensation ◽  
Deployable Structures ◽  
Response Surface Methods ◽  
Revolute Joints ◽  
Link Mechanism ◽  
History Of

In this study, a passive truss-link mechanism applicable to large-scale deployable structures was designed to achieve successful deployment in space. First, we simplified the selected truss-link mechanisms to the two-dimensional geometry and calculated the degrees of freedom (DOF) to determine whether a kinematic over-constraint occurs. The dimensions of the truss-link structure were determined through a deployment kinematic analysis. Second, a deployment simulation with the truss-link was conducted using multibody dynamics (MBD) software. Finally, a deployment test was performed considering gravity compensation, and the results were compared with those of MBD simulation. The results of the deployment simulations were confirmed to be slightly faster than those of the deployment test due to friction effects existing in the joints and gravity compensation devices. To address this issue, inverse identification of the equivalent frictional torque (EFT) at the revolute joints in the deployment test was conducted through response surface methods (RSM) combined with the central composite design technique. As a result, we confirmed that the deployment angle history of the deployment simulation was similar to that of the deployment test.

Performance Analysis of a Novel 6-DOF Parallel-Kinematics Machine with Decoupled Motion Characteristics

2006 ◽  
Vol 505-507 ◽  
pp. 1177-1182
Author(s):  
Gui Lin Yang ◽  
Yun Hua Li
Keyword(s):  
Performance Analysis ◽  
Vertical Direction ◽  
Parallel Kinematics ◽  
Reachable Workspace ◽  
Revolute Joints ◽  
Prismatic Joints ◽  
Decoupled Motion ◽  
Motion Characteristics ◽  
Assembly Tasks ◽  
Machine Structure

This paper is focused on the performance analysis of a newly developed 6-DOF Parallel-Kinematics Machine (PKM). The design related analysis issues such as the instantaneous kinematics, manipulability, accuracy, and stiffness are addressed. This new PKM has three identical RPRS legs to support the moving platform. Since all joint axes, excluding the three spherical joints at the leg-ends, are parallel to each other and perpendicular to the base plane, this 6-DOF 3RPRS PKM exhibits decoupled motion characteristics such that translation along the vertical direction and rotation about horizontal axes are only driven by the three active-prismatic joints, while translation in horizontal planes and rotation about vertical axes are mainly driven by the three active-revolute joints. The PKM also has a large cylindrical reachable workspace and high stiffness in vertical directions. These features make it a promising 6-DOF machine structure for light machining and heavy parts assembly tasks.

scholarly journals Design of a 4-DoF (degree of freedom) hybrid-haptic device for laparoscopic surgery

2021 ◽  
Vol 12 (1) ◽  
pp. 155-164
Author(s):  
Houssem Saafi ◽  
Med Amine Laribi ◽  
Said Zeghloul
Keyword(s):  
Laparoscopic Surgery ◽  
Degrees Of Freedom ◽  
Haptic Device ◽  
Haptic Interface ◽  
Gravity Compensation ◽  
Parallel Kinematics ◽  
Dimensional Synthesis ◽  
Parallel Chain ◽  
Serial Chain ◽  
Kinematic Performance

Abstract. This paper presents a novel kinematics architecture with 4 DoFs (degrees of freedom) intended to be used as a haptic interface for laparoscopic surgery. The proposed architecture is a result of an association of serial and parallel kinematics chains, with each one handling a part of the whole device DoF. The serial chain allows one to handle the translation and self-rotation and the parallel chain handles the two tilt motions, and this in a disjoint way as the natural gesture of the surgeon. The proposed hybrid-haptic device (HH device) benefits from the split DoF to ensure a good kinematic performance, large workspace, as well as gravity compensation. The kinematics study of the HH device is presented and followed by the optimal dimensional synthesis and the gravity compensation model.

Adaptronic Revolute Joints for Parallel Robots Based on Simultaneous Quasi-Statical Axial and Radial Clearance Adjustment

2008 ◽  
Author(s):  
Nenad Pavlovic ◽  
Ralf Keimer ◽  
Hans-Joachim Franke
Keyword(s):  
Laboratory Tests ◽  
Dynamic Performance ◽  
Parallel Robots ◽  
Radial Clearance ◽  
Parallel Kinematics ◽  
Robot System ◽  
Friction Characteristic ◽  
Revolute Joints ◽  
Overall Performance ◽  
Goal Conflicts

Robots based on parallel kinematics feature low moved masses, allowing for better dynamic performance compared to serial mechanisms. Otherwise, the known drawbacks, like occurrence of singularities or bad radio of work space to installation area, hinder their fully industrial establishment. In order to overcome some of these drawbacks, development of specific and optimized robot components, like rods or joints, becomes necessary. Development of joints for parallel robots is determined by numerous contradictory requirements which cause different goal conflicts. In this work, possibilities for dissolving of such goal conflicts by means of adaptronic joints (joints with integrated piezo-actuators) are discussed. To deal with these complex issues this paper focuses on three major areas: firstly, conventional joint concepts, including their main flaws; secondly, new, adaptronic joint concepts based on quasi-statical clearance adjustment with two laboratory prototypes and their improvements over the old solutions; thirdly and finally, some of possible consequences of the new joint concepts for the overall performance of parallel robots. By drawing on experimental results derived from laboratory tests, it is possible to show how implementation of the developed joint prototypes could influence friction characteristic of the whole robot system.

scholarly journals Modeling in ADAMS of a 6R industrial robot

2018 ◽  
Vol 184 ◽  
pp. 02006
Author(s):  
Mariana Ratiu ◽  
Alexandru Rus ◽  
Monica Loredana Balas
Keyword(s):  
Dynamic Analysis ◽  
Industrial Robot ◽  
Kinematic Model ◽  
Future Research ◽  
Robot Motion ◽  
Cad Model ◽  
3D Cad ◽  
Revolute Joints ◽  
Real Model ◽  
Articulated Robot

In this paper, we present the first steps in the process of the modeling in ADAMS MBS of MSC software of the mechanical system of an articulated robot, with six revolute joints. The geometric 3D CAD model of the robot, identical to the real model, in the PARASOLID format, is imported into ADAMS/View and then are presented the necessary steps for building the kinematic model of the robot. We conducted this work, in order to help us in our future research, which will consist of kinematic and dynamic analysis and optimization of the robot motion.

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