Full-Mobility Three-CCC Parallel-Kinematics Machines: Kinematics and Isotropic Design

2017 ◽  
Vol 10 (1) ◽  
Author(s):  
Wei Li ◽  
Jorge Angeles
Keyword(s):  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Large Region ◽  
Parallel Kinematics ◽  
Six Degrees Of Freedom ◽  
Parallel Kinematics Machines ◽  
The Subject ◽  
Moving Platform

The subject of this paper is twofold: the kinematics and the isotropic design of six degrees-of-freedom (DOF), three-CCC parallel-kinematics machines (PKMs). Upon proper embodiment and dimensioning, the PKMs discussed here, with all actuators mounted on the base, exhibit interesting features, not found elsewhere. One is the existence of an isotropy locus, as opposed to isolated isotropy points in the workspace, thereby guaranteeing the accuracy and the homogeneity of the motion of the moving platform (MP) along different directions within a significantly large region of their workspace. The conditions leading to such a locus are discussed in depth; several typical isotropic designs are brought to the limelight. Moreover, the kinematic analysis shows that rotation and translation of the MP are decoupled, which greatly simplifies not only the kinetostatic analysis but also, most importantly, their control. Moreover, it is shown that the singularity loci of this class of mechanism are determined only by the orientation of their MP, which also simplifies locus evaluation and eases its representation.

Dynamic Analysis of a Biglide Parallel Grinder

2005 ◽  
Vol 291-292 ◽  
pp. 495-500
Author(s):  
Ping Zou
Keyword(s):  
Machine Tool ◽  
Dynamic Analysis ◽  
Degrees Of Freedom ◽  
Jacobian Matrix ◽  
Lagrangian Formulation ◽  
Dynamic Equations ◽  
Six Degrees Of Freedom ◽  
Moving Platform ◽  
Drill Point ◽  
Joint Velocity

In this paper, the moving platform of the biglide parallel grinder with six degrees of freedom will keep moving horizontally at any time using parallelograms. Besides grinding the helical drill point, this grinder also can work as drilling and welding machine tool as well as a CMM. The joint-velocity Jacobian matrix is calculated. Moreover, the dynamic equations are derived by applying the Lagrangian formulation.

A 2(3-RRPS) parallel manipulator inspired by Gough–Stewart platform

Robotica ◽  
2012 ◽  
Vol 31 (3) ◽  
pp. 381-388 ◽  
Author(s):  
Jaime Gallardo-Alvarado ◽  
Mario A. García-Murillo ◽  
Eduardo Castillo-Castaneda
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Parallel Manipulators ◽  
Forward Kinematics ◽  
Triangular Prism ◽  
Input Output ◽  
Six Degrees Of Freedom ◽  
Moving Platform

SUMMARYThis study addresses the kinematics of a six-degrees-of-freedom parallel manipulator whose moving platform is a regular triangular prism. The moving and fixed platforms are connected to each other by means of two identical parallel manipulators. Simple forward kinematics and reduced singular regions are the main benefits offered by the proposed parallel manipulator. The Input–Output equations of velocity and acceleration are systematically obtained by resorting to reciprocal-screw theory. A case study, which is verified with the aid of commercially available software, is included with the purpose to exemplify the application of the method of kinematic analysis.

Workspace Optimization of a Six Degrees of Freedom Parallel Manipulator for Micromachining

2010 ◽  
Author(s):  
Ahmet Agaoglu ◽  
Namik Ciblak ◽  
Koray K. Safak
Keyword(s):  
Numerical Analysis ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Base Plane ◽  
Six Degrees Of Freedom ◽  
Moving Platform ◽  
Workspace Optimization ◽  
Kinematic Diagram ◽  
Orientation Workspace

This work addresses the optimization of the workspace of a six degrees of freedom parallel manipulator. In this study, The topology of the manipulator is composed of three xy-tables, symmetrically positioned on a circle on a base plane, connected by three legs to a moving platform. Kinematic composition of the manipulator is introduced and kinematic diagram is illustrated. Orientation workspace is investigated using three different orientation representations. XYZ fixed angles representation is selected considering the benefits of its visualization are considered. By using this representation, the orientation workspace is modeled and kinematic circuits of the manipulator are explored. First, optimization is performed without slider limitations. A result table is obtained based on the user defined parameters. Secondly, optimization is performed under slider limitations. The maximal orientation capability is optimized using numerical analysis. The optimized configuration of the manipulator indicates that a 330% increase in orientation capability is achieved, compared to the old configuration.

Experiments on Linear and Nonlinear Control of a Multi-DOF Parallel Mechanism

2003 ◽  
Author(s):  
Sandor Riebe ◽  
Heinz Ulbrich
Keyword(s):  
Degrees Of Freedom ◽  
Motion Tracking ◽  
Parallel Robot ◽  
Parallel Kinematics ◽  
Control Laws ◽  
Six Degrees Of Freedom ◽  
Position Accuracy ◽  
Nonlinear Approach ◽  
Linear Approach ◽  
Measurement Results

Parallel kinematics with multi degrees-of-freedom (DOF), like hexapod-systems, are mostly used in applications where high demands on position accuracy are required and/or high accelerations are needed. Adequate control concepts are essential in order to achieve the desired dynamic response. This paper deals with a comparative study of two structural different control concepts applied on a parallel robot with six degrees-of-freedom. The first one is a decentral linear approach and the second one is a multivariable nonlinear approach. The two concepts are presented and implemented on an experimental hexapod-system. In order to verify the used dynamic model comparisons between simulation and measurement results are shown. Finally, experiments have been carried out to compare the control laws with respect to their motion tracking performance.

Kinematic analysis and path planning of a new kinematically redundant planar parallel manipulator

Robotica ◽  
2008 ◽  
Vol 26 (3) ◽  
pp. 405-413 ◽  
Author(s):  
Iman Ebrahimi ◽  
Juan A. Carretero ◽  
Roger Boudreau
Keyword(s):  
Path Planning ◽  
Condition Number ◽  
Kinematic Analysis ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Six Degrees Of Freedom ◽  
Displacement Problem ◽  
Singular Configurations ◽  
Planar Parallel Manipulator

SUMMARYIn this work, the 3-RPRR, a new kinematically redundant planar parallel manipulator with six-degrees-of-freedom, is presented. First, the manipulator is introduced and its inverse displacement problem discussed. Then, all types of singularities of the 3-RPRR manipulator are analysed and demonstrated. Thereafter, the dexterous workspace is geometrically obtained and compared with the non-redundant 3-PRR planar parallel manipulator. Finally, based on a geometrical measure of proximity to singular configurations and the condition number of the manipulators' Jacobian matrices, actuation schemes for the manipulators are obtained. Different actuation schemes for a given path are obtained and the quality of their actuation schemes are compared. It is shown that the proposed manipulator is capable of following a path while avoiding the singularities.

Design and Analysis of a Sliding Panel Shape Morphing Mechanism System

2016 ◽  
Author(s):  
Aaron Yu ◽  
Fengfeng (Jeff) Xi
Keyword(s):  
Degrees Of Freedom ◽  
Longitudinal Direction ◽  
General Purpose ◽  
Search Method ◽  
Application System ◽  
Driving System ◽  
Six Degrees Of Freedom ◽  
Shape Morphing ◽  
Different Shapes ◽  
Moving Platform

A sliding panel shape morphing mechanism system is proposed. The said system is constructed by a number of segmented rigid panels that are allowed to slide relative to each other during shape morphing. In this paper, a method is presented for the design and analysis of the said system using a hexapod as a general-purpose driving system with six degrees-of-freedom. First, it is shown that a proper passive linkage system is required to connect a set of sliding panels to the base and moving platform of the hexapod. Each panel is made of a telescopic pair in the longitudinal direction and connected transversally with two adjacent panels through slots. Second, after modeling the entire system and formulating the constraints among the sliding panels, a search method is presented to determine the solutions that all the sliding panels can move without interference under a given hexapod motion. Further studies are also carried out to examine different shapes of the base and moving platform as well as different number of panels that can approximate a real application system, such as a morphing wing.

Six degrees of freedom parallel robots with C5 links

Robotica ◽  
1992 ◽  
Vol 10 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Y. Amirat ◽  
F. Artigue ◽  
J. Pontnau
Keyword(s):  
Automotive Industry ◽  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Parallel Architecture ◽  
Parallel Robot ◽  
Parallel Architectures ◽  
Parallel Robots ◽  
Left Hand ◽  
Six Degrees Of Freedom ◽  
Assembly Tasks

SummaryThis paper presents at first a static and kinematic analysis of closed chains mechanisms which permits to deduce different possible fully parallel architectures. Then we focus on a particular parallel architecture with C5 links designed to perform precise assembly tasks. A general modeling of this C5 parallel robot is presented. Two typical assembly tasks in the automotive industry are also proposed; the first one uses the C5 links parallel robot as a left-hand device, while the second one uses it as the terminal tool of a sequential manipulator.

Study on the Kinematics of 3-TPS Hybrid Machine Tool

2009 ◽  
Vol 16-19 ◽  
pp. 1329-1334
Author(s):  
Xiang Zhi Meng ◽  
Shu Jun Li ◽  
Ming Li
Keyword(s):  
Machine Tool ◽  
Structural Design ◽  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Jacobian Matrix ◽  
Hybrid Machine Tool ◽  
Locking Mechanism ◽  
Fixed Base ◽  
Hybrid Machine ◽  
Moving Platform

A 3-TPS(RRR) hybrid machine tool that could process vertically as well as horizontally was designed in Northeastern University. A parallel locking mechanism, equipped between the moving platform and the fixed base, is used to constrain partial degrees of freedom (DOF) of the platform. It leads that the platform has three translational DOF and a rotate DOF. The kinematic analysis was discussed in this paper. Several important issues were addressed, namely, position, velocity, acceleration, Jacobian matrix. A simulation was also carried out, which lay the base on structural design and dynamic analysis.

Multibody Analysis and Design of a Reconfigurable Parallel Kinematics Manipulator

2015 ◽  
Author(s):  
Matteo Palpacelli ◽  
Massimo Callegari ◽  
Luca Carbonari ◽  
Giacomo Palmieri
Keyword(s):  
Control Strategy ◽  
Degrees Of Freedom ◽  
Parallel Kinematics ◽  
Analysis And Design ◽  
Pure Rotation ◽  
Analytic Expressions ◽  
Robot Leg ◽  
Moving Platform ◽  
Actuation Systems ◽  
Three Degrees Of Freedom

This paper presents the design of a reconfigurable parallel kinematics machine endowed with three degrees of freedom of pure translation, or alternately of pure rotation. Such reconfigurability results from the use of lockable spherical joints, which realize the connection between each robot leg and the moving platform. Three actuated legs are used to drive the platform motion. The change of configuration occurs only at a specific pose, called home configuration. A control strategy allows to manage the shift phase and activate the two mobilities one at a time. Multibody simulations allowed to analyze the dynamic behavior of the manipulator and to verify the choices made with regard to the robot mechanics and the size of actuation systems. Position and differential kinematics of the manipulator are briefly introduced in order to demonstrate the simplicity of the analytic expressions and the mechanical feasibility of the manipulator.

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