Jerk analysis of a six-degrees-of-freedom three-legged parallel manipulator

2012 ◽  
Vol 28 (2) ◽  
pp. 220-226 ◽  
Author(s):  
Jaime Gallardo-Alvarado
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Six Degrees Of Freedom

Construction of a Six-Degrees-of-Freedom Parallel Manipulator With Three Planarly Actuated Links

1996 ◽  
Author(s):  
Ronen Ben-Horin ◽  
Moshe Shoham
Keyword(s):  
Parallel Manipulator ◽  
High Performance ◽  
Degrees Of Freedom ◽  
Parallel Robot ◽  
Simple Design ◽  
Output Link ◽  
Coordinated Motion ◽  
Six Degrees Of Freedom ◽  
Work Volume ◽  
New Type

Abstract The construction of a new type of a six-degrees-of-freedom parallel robot is presented in this paper. Coordinated motion of three planar motors, connected to three fixed-length links, produces a six-degrees-of-freedom motion of an output link. Its extremely simple design along with much larger work volume make this high performance-to-simplicity ratio robot very attractive.

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.

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.

On the optimum design of Stewart platform type parallel manipulators

Robotica ◽  
1995 ◽  
Vol 13 (2) ◽  
pp. 133-140 ◽  
Author(s):  
Soumya Bhattacharya ◽  
H. Hatwal ◽  
A. Ghosh
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Axial Loading ◽  
Parallel Manipulators ◽  
Stewart Platform ◽  
Parallel System ◽  
Design Parameters ◽  
Programming Technique ◽  
Six Degrees Of Freedom ◽  
Static Rigidity

SummaryThis paper studies the static rigidity behaviour of a parallel manipulator with legs modelled as elastic members under axial loading. Structurally, a parallel module is more rigid compared to a serial module and is expected to take heavier payloads. Therefore, a guidance for design of such parallel manipulators is needed which leads to maximum rigidity over the workspace. In the present work, the authors propose the concept of the flexibility ellipsoid for a parallel system. Various scalar measures of rigidity are formulated on the basis of the proposed ellipsoid. An algorithm, involving multiple objective nonlinear programming technique, is implemented to decide upon some important design parameters of a generalised six degrees of freedom Stewart platform type parallel manipulator. It is observed that irrespective of the other parameters, parallel manipulators with the legs pairwise joined at the top platform possess the highest rigidity. Moreover, there exists certain kinematic dimensions for which the designed parallel system is completely free from all sorts of singularity.

A Novel Six Degree-of-Freedom Parallel Manipulator With Three Legs

2004 ◽  
Author(s):  
Mohammad Vakil ◽  
Hodjat Pendar ◽  
Hassan Zohoor
Keyword(s):  
Numerical Method ◽  
Nonlinear Equations ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Active Joint ◽  
Six Degrees Of Freedom ◽  
Transformation Matrices ◽  
Passive Joint ◽  
Moving Platform ◽  
Six Degree Of Freedom

In this paper, a novel six degrees-of-freedom (6-DOF) parallel manipulator actuated by three base-mounted partial spherical actuators is proposed. The parallel manipulator consists of a base, a moving platform and three connecting legs. Each leg has spherical (S), prismatic (P) and universal (U) joints (SPU) in serial manner. The spherical joints are partially actuated due to the fact that the actuators of each leg are used only to specify its leg’s direction. The inverse and forward pose kinematics as well as the singularity points of the aforementioned mechanism is described in the article. In the inverse pose kinematics, active joint variables could be calculated with no need for the evaluation of passive joint variables. It will be shown that the inverse pose kinematics has sixty-four (64) solutions (64 different configurations exists for the inverse pose problem). In the forward pose kinematics, instead of twelve nonlinear equations derived by equaling the transformation matrices of each leg through Denavit-Hartenberg notation, only three nonlinear equations with less nonlinearity could be solved via numerical method, and therefore the numerical method converges more rapidly to the answer. Finally two different sets of singularity points with different natures are obtained.

Jacobian Analysis of Limited-DOF Parallel Manipulators

2002 ◽  
Vol 124 (2) ◽  
pp. 254-258 ◽  
Author(s):  
Sameer A. Joshi ◽  
Lung-Wen Tsai
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Jacobian Matrix ◽  
Parallel Manipulators ◽  
Six Degrees Of Freedom

This paper presents a methodology for the Jacobian analysis of limited degrees-of-freedom (DOF) parallel manipulators. A limited-DOF parallel manipulator is a spatial parallel manipulator which has less than six degrees-of-freedom. It is shown that a 6×6 Jacobian matrix, which provides information about both architecture and constraint singularities, can be derived by making use of the theory of reciprocal screws. The 3-UPU and 3-RPS parallel manipulators are used as examples to demonstrate the methodology.

scholarly journals Inverse dynamics and trajectory tracking control of a new six degrees of freedom spatial 3-RPRS parallel manipulator

2017 ◽  
Vol 8 (2) ◽  
pp. 235-248 ◽  
Author(s):  
Santhakumar Mohan ◽  
Burkhard Corves
Keyword(s):  
Trajectory Tracking ◽  
Tracking Control ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Virtual Prototype ◽  
Trajectory Tracking Control ◽  
Six Degrees Of Freedom ◽  
Control Scheme ◽  
Computer Based

Abstract. This paper presents the complete dynamic model of a new six degrees of freedom (DOF) spatial 3-RPRS parallel manipulator. The geometry parameters of the manipulator are optimized for a given constant orientation workspace. Further, a robust task-space trajectory tracking control is also designed for the manipulator along with a nonlinear disturbance observer. To demonstrate the efficacy and show the complete performance of the proposed controller, virtual prototype experiments are executed using one of the multibody dynamics software namely MSC Adams. The computer-based virtual prototype experiment results show that the manipulator tracking performance is satisfactory with the proposed control scheme. In addition, the controller parameter sensitivity and robustness analyses are also accomplished.

Modelling and Design of an Airship Crane

2018 ◽  
Author(s):  
Naoufel Azouz ◽  
Mahmoud Khamlia ◽  
Fida Benabdallah ◽  
Fatma Guesmi
Keyword(s):  
Dynamic Modeling ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Main Function ◽  
Precise Control ◽  
Six Degrees Of Freedom ◽  
Loading And Unloading ◽  
Position And Orientation

This paper presents the design and the dynamic modeling of a Smart Crane called CHAYASC, designed to equip wide-body airship, which has to carry out loading and unloading operations from a certain altitude. The main function of this crane is to lift, stabilize, maneuver and position large loads by having precise control of the position and orientation of these loads according to the six degrees of freedom. The CHAYASC is based in particular on a Cable Driven Parallel Manipulator and will have a dual mission: 1) deposit and arrange the containers in the hold of the airship, 2) lift and stabilize the containers suspended during a sudden movement of the airship under the effect of a gust of wind.

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