Design and Modeling of a Large-Range Modular XYZ Compliant Parallel Manipulator Using Identical Spatial Modules

2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Guangbo Hao ◽  
Xianwen Kong
Keyword(s):  
Parallel Manipulator ◽  
Large Range ◽  
Parallel Manipulators ◽  
Analytical Models ◽  
Parameter Determination ◽  
Design Parameters ◽  
Element Analysis ◽  
Characteristics Analysis ◽  
Motion Range ◽  
Precision Motion

To meet the need for large-range high-precision motion stages, a design methodology of XYZ compliant parallel manipulators (CPMs) is introduced at first. A spatial double four-beam module and a compliant P (prismatic) joint, composed of two spatial double four-beam modules, are then proposed. Starting from a 3-PPPR (R: revolute) translational parallel manipulator, a large-range modular XYZ CPM with identical spatial modules is constructed using the proposed design approach. Normalized analytical models for the large-range modular XYZ CPM are further presented. As a case study, a modular XYZ CPM with a motion range of 10 mm × 10 mm × 10 mm along the positive X-, Y-, and Z-axes is presented in detail, covering the geometrical parameter determination, performance characteristics analysis, buckling check, and actuation force check. The analytical models are compared with the finite element analysis (FEA) models. Finally, the dynamics consideration, manufacturability, and merits are discussed. It is shown that the proposed large-range modular XYZ CPM has the following main merits compared with existing designs: (1) large range of motion up to 20 mm × 20 mm × 20 mm and (2) reduced number of design parameters through the use of identical spatial modules, although the manufacturability is a challenging issue.

A Novel Large-Range XY Compliant Parallel Manipulator With Enhanced Out-of-Plane Stiffness

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Guangbo Hao ◽  
Xianwen Kong
Keyword(s):  
Parallel Mechanism ◽  
Large Range ◽  
Parallel Manipulators ◽  
Analytical Models ◽  
Parameter Determination ◽  
Element Analysis ◽  
Parasitic Motion ◽  
Out Of Plane ◽  
Characteristics Analysis

There is an increasing need for compact large-range XY compliant parallel manipulators (CPMs). This paper deals with a novel large-range XY CPM with enhanced out-of-plane stiffness (LRXYCPMEOS). Unlike most of XY CPMs based on the 4-PP (P: prismatic) decoupled parallel mechanism, the LRXYCPMEOS is obtained from a 4-PP-E (E: planar) decoupled parallel mechanism by replacing each P joint with a planar double multibeam parallelogram module (DMBPM) and the E joint with a spatial double multibeam parallelogram module. Normalized analytical models for the LRXYCPMEOS are then presented. As a case study, an LRXYCPMEOS with a motion range 10 mm × 10 mm in both positive directions is presented in detail, covering the geometrical parameter determination, performance characteristics analysis, actuation force check, and buckling check. The analytical models are compared with the finite element analysis (FEA) models. Finally, dynamics consideration, manufacturability, out-of-plane stiffness, and result interpretation are discussed. It is shown that the LRXYCPMEOS in the case study has the following merits: large range of motion up to 20 mm × 20 mm, enhanced out-of-plane stiffness which is approximately 7.1 times larger than the associated planar XY CPM without the spatial compliant leg, and well-constrained parasitic motion with the parasitic translation along the Z-axis less than 2 × 10−4 mm, the parasitic rotation about the X-axis/Y-axis less than 2 × 10−6 rad, and the parasitic rotation about the Z-axis below 1 × 10−6 rad.

A 2-legged XY parallel flexure motion stage with minimised parasitic rotation

2014 ◽  
Vol 228 (17) ◽  
pp. 3156-3169 ◽  
Author(s):  
Guangbo Hao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Parallel Manipulator ◽  
Parallel Manipulators ◽  
Design Approach ◽  
Analytical Models ◽  
Geometrical Parameters ◽  
Element Analysis ◽  
Motion Range ◽  
Cross Axis

XY compliant parallel manipulators (aka XY parallel flexure motion stages) have been used as diverse applications such as atomic force microscope scanners due to their proved advantages such as eliminated backlash, reduced friction, reduced number of parts and monolithic configuration. This paper presents an innovative stiffness centre based approach to design a decoupled 2-legged XY compliant parallel manipulator in order to better minimise the inherent parasitic rotation and have a more compact configuration. This innovative design approach makes all of the stiffness centres, associated with the passive prismatic (P) modules, overlap at a point that all of the applied input forces can go through. A monolithic compact and decoupled XY compliant parallel manipulator with minimised parasitic rotation is then proposed using the proposed design approach based on a 2-PP kinematically decoupled translational parallel manipulator. Its load–displacement and motion range equations are derived, and geometrical parameters are determined for a specified motion range. Finite element analysis comparisons are also implemented to verify the analytical models with analysis of the performance characteristics including primary stiffness, cross-axis coupling, parasitic rotation, input and output motion difference and actuator nonisolation effect. Compared with the existing XY compliant parallel manipulators obtained using 4-legged mirror-symmetric constraint arrangement, the proposed XY compliant parallel manipulators based on stiffness centre approach mainly benefits from fewer legs resulting in reduced size, simpler modelling as well as smaller lost motion. Compared with existing 2-legged designs with the conventional arrangement, the present design has smaller parasitic rotation, which has been proved from the finite element analysis results.

Design of Large-Range XY Compliant Parallel Manipulators Based on Parasitic Motion Compensation

2013 ◽  
Author(s):  
Guangbo Hao ◽  
Qiaoling Meng ◽  
Yangmin Li
Keyword(s):  
Large Range ◽  
Coupling Effect ◽  
Parallel Manipulators ◽  
Geometrical Parameters ◽  
Element Analysis ◽  
Parasitic Motion ◽  
Prior Art ◽  
Characteristics Analysis ◽  
Optimization Function ◽  
Cross Axis

This paper presents a large-range decoupled XY compliant parallel manipulator (CPM) with good dynamics (no under-constrained/non-controllable mass). The present XY CPM is composed of novel parallelogram flexure modules (NPFMs) that are parallel four-bar mechanisms as prismatic (P) joints with four identical monolithic cross-spring flexural pivots, flexure revolute (R) joints. The parasitic translation of the NPFM is compensated via the rotational centre shift of the flexure R joint thereof based on the prior art. The optimization function and optimised geometrical parameters are investigated for the NPFM at first to achieve the largest translation. The design of a large-range XY CPM is then implemented according to the fully symmetrical 4-PP parallel kinematic mechanism (PKM) and through using the optimised NPFMs. Finally, the simplified analytical stiffness modelling and finite element analysis (FEA) are undertaken for the static and/or dynamic characteristics analysis of the 4-PP XY CPM. It is shown from FEA in the example case that the present 4-PP XY CPM has good performance characteristics such as large-range motion space (10 mm × 10 mm with the total dimension of 465 mm× 465 mm), no non-controllable mass, monolithic configuration, maximal kinematostatic decoupling (cross-axis coupling effect less than 1.2%), maximal actuator isolation (input coupling effect less than 0.13%) and well-constrained parasitic rotation (less than 0.4 urad). In addition, the stiffness-enhanced NPFM using over-constraint is proposed to produce a first/second modal frequency of about 100 Hz for the resulting XY CPM.

Design of 3-legged XYZ compliant parallel manipulators with minimised parasitic rotations

Robotica ◽  
2014 ◽  
Vol 33 (4) ◽  
pp. 787-806 ◽  
Author(s):  
Guangbo Hao ◽  
Haiyang Li
Keyword(s):  
Finite Element Analysis ◽  
Large Range ◽  
Experimental Testing ◽  
Parallel Manipulators ◽  
Analytical Models ◽  
Parallel Mechanisms ◽  
Characteristic Analysis ◽  
Electric Discharge Machining ◽  
Element Analysis ◽  
Manufacturing Technologies

SUMMARYThis paper deals with the design of 3-legged distributed-compliance XYZ compliant parallel manipulators (CPMs) with minimised parasitic rotations, based on the kinematically decoupled 3-PPPRR (P: prismatic joint, and R: revolute joint) and 3-PPPR translational parallel mechanisms (TPMs). The designs are firstly proposed using the kinematic substitution approach, with the help of the stiffness center (SC) overlapping based approach. This is done by an appropriate embedded arrangement so that all of the SCs associated with the passive compliant modules overlap at the point where all of the input forces applied at the input stages intersect. Kinematostatic modelling and characteristic analysis are then carried out for the proposed large-range 3-PPPRR XYZ CPM with overlapping SCs. The results from finite element analysis (FEA) are compared to the characteristics found for the developed analytical models, as are experimental testing results (primary motion) from the prototyped 3-PPPRR XYZ CPM with overlapping SCs. Finally, issues on large-range motion and dynamics of such designs are discussed, as are possible improvements of the actuated compliant P joint. It is shown that the potential merits of the designs presented here include a) minimised parasitic rotations by only using three identical compliant legs; b) compact configurations and small size due to the use of embedded designs; c) approximately kinematostatically decoupled designs capable of easy controls; and d) monolithic fabrication for each leg using existing planar manufacturing technologies such as electric discharge machining (EDM).

Novel XY Compliant Parallel Manipulators for Large Displacement Translation With Enhanced Stiffness

2010 ◽  
Author(s):  
Guangbo Hao ◽  
Xianwen Kong
Keyword(s):  
Range Of Motion ◽  
Building Block ◽  
Parallel Manipulator ◽  
Large Range ◽  
Parallel Manipulators ◽  
Large Displacement ◽  
Analytical Models ◽  
The Novel ◽  
Out Of Plane ◽  
Error Motion

A novel XY compliant parallel manipulator (CPM) and a spatial double three-beam module both with distributed compliance are first proposed for large range of translation. Then, an improved XY CPM is proposed by combining the above XY CPM and a spatial double three-beam module in parallel. The normalized analytical models are further presented for the novel XY CPM, double three-beam module and improved XY CPM. It is shown that the improved XY CPM has the following merits: (1) large range of motion, constrained parasitic error motion, output-decoupling, maximal actuation isolation and minimal lost motion; and (2) large out-of-plane stiffness and no friction with base. The improved XY CPM may also be used as a building block to construct new spatial CPMs.

A 3-DOF Translational Compliant Parallel Manipulator Based on Flexure Motion

2009 ◽  
Author(s):  
Guangbo Hao ◽  
Xianwen Kong
Keyword(s):  
Range Of Motion ◽  
Parallel Manipulator ◽  
Large Range ◽  
Parallel Manipulators ◽  
Mathematic Modeling ◽  
Ultra Precision ◽  
Cross Axis ◽  
Force Displacement

This paper presents a novel class of 3-DOF translational compliant parallel manipulators (CPMs) based on flexure motion. The analytic mathematic modeling of CPMs is first developed. The analysis of CPMs is then implemented. It is shown that the proposed CPMs have many characteristics such as large range of motion, negligible cross-axis coupling, actuator complete isolation, and no loss motion and no rotational yaw. The inverse relationships of force-displacement of the 3-DOF CPM are further derived to calculate the input forces required for generating a specified path. In addition, the 3-DOF CPM can also be turned into a 2-DOF CPM. This work lays the foundation for the development of new spatial CPMs based on flexure motions for applications such as ultra precision manipulation.

scholarly journals Kinematic Analysis Of Tricept Parallel Manipulator

2012 ◽  
Vol 12 (5) ◽  
Author(s):  
Mir Amin Hosseini ◽  
Hamid-Reza Mohammadi Daniali
Keyword(s):  
Kinematic Analysis ◽  
Parallel Manipulator ◽  
Parallel Manipulators ◽  
Degree Of Freedom ◽  
Geometric Constraints ◽  
Design Parameters ◽  
Forward Kinematics ◽  
Jacobian Matrices ◽  
Moving Platforms ◽  
Workspace Optimization

Parallel manipulators consist of fixed and moving platforms connected to each other with some actuated links. They have some significant advantages over their serial counterparts. While, they suffer from relatively small workspaces, complex kinematics relations and highly singular points within their workspaces. In this paper, forward kinematics of Tricept parallel manipulator is solved analytically and its workspace optimization is performed. This parallel manipulator has a complex degree of freedom, therefore leads to dimensional in-homogeneous Jacobian matrices. Thus, we divide some entries of the Jacobian by units of length, thereby producing a new Jacobian that is dimensionally homogeneous. Moreover, its workspace is parameterized using some design parameters. Then, using GA method, the workspace is optimized subjects to some geometric constraints. Finally, dexterity of the design is evaluated. Keywords- Kinematic, Workspace, Singularity, TriceptABSTRAK - Manipulator selari terdiri daripada platform tetap dan bergerak yang bersambung antara satu sama lain dengan beberapa pautan bergerak. Manipulator selari mempunyai beberapa kebaikan tertentu dibandingkan dengan yang bersamaan dengannya. Walaupun ia mempunyai ruang kerja yang sempit, hubungan kinematik kompleks dan titik tunggal tinggi dalam linkungan ruang kerjanya. Dalam kajian ini, kinematik ke hadapan manipulator selari Tricept diselesaikan secara analisa dan pengoptimuman ruang kerja dijalankan. Manipulator selari ini mempunyai darjah kebebasan yang kompleks, yang menyebabkan ia mendorong kepada kehomogenan dimensi matriks Jacobian. Catatan Jacobian dibahagikan kepada unit panjang, dimana ia menghasilkan Jacobian baru yang homogen dimensinya. Tambahan, ruang kerjanya diparameterkan dengan menggunakan beberapa parameter reka bentuk. Kemudian, dengan kaedah GA, ruang kerja mengoptimakan subjek kepada beberapa kekangan geometrik. Akhirnya, kecakatan reka bentuk dinilaikan.Keywords- Kinematic, Workspace, Singularity, Tricept

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.

Optimal Dimensioning for Parallel Manipulators: Workspace, Dexterity, and Energy

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Oscar Altuzarra ◽  
C. Pinto ◽  
B. Sandru ◽  
A. Hernandez
Keyword(s):  
Parallel Manipulator ◽  
Optimization Problems ◽  
Parallel Manipulators ◽  
Design Parameters ◽  
Frobenius Norm ◽  
Pareto Optimal ◽  
Pareto Optimal Solutions ◽  
Optimal Solutions ◽  
Motion Generation ◽  
Schönflies Motion

In mechanism design and in the particular case of the parallel manipulator, most optimization problems involve simultaneously optimizing more than one objective function. In this paper, a method to identify Pareto-optimal solutions for the design of low-mobility parallel manipulators is presented. A 4-degree-of-freedom symmetric parallel manipulator for Schönflies-motion generation is taken as a case study. The design goals used are workspace volume and manipulator dexterity based on a dispersion weighted Frobenius norm. In addition, an expression for energy per cycle has been defined for different types of trajectory to evaluate the power drive. Finally, the set of Pareto-optimal solutions of the design parameters are represented in the design parameter space.

scholarly journals Performance Analysis and Optimum Design of a Redundant Planar Parallel Manipulator

Symmetry ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 908 ◽  
Author(s):  
Xiaoyong Wu
Keyword(s):  
Optimum Design ◽  
Parallel Manipulator ◽  
Optical Design ◽  
Kinematic Model ◽  
Parallel Manipulators ◽  
Performance Comparison ◽  
Design Parameters ◽  
Redundant Manipulator ◽  
Symmetrical Structure ◽  
Planar Parallel Manipulator

This work presents a comprehensive performance evaluation and optimum design of a novel symmetrical 4-PPR (P indicates the prismatic joint, R denotes the revolute joint, and the letter with underline represents an active joint) redundant planar parallel manipulator. The kinematic model is established, upon which the inverse position and singularity are analyzed. Based on the evaluation of dexterity, velocity, and stiffness performance, the optimum region is achieved. With the optical design parameters, a case study for the analysis of dynamic behavior is conducted. Performance comparison between the redundant manipulator and another two non-redundant 3-PPR planar parallel manipulators, one with a Δ-shape symmetrical structure and the other with U-shape symmetrical structure, is presented. Simulation results reveal that the U-shape manipulator has the greatest velocity performance. Moreover, the redundant manipulator possesses the best dexterity, stiffness, and dynamic performance.

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