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.

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.

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 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 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).

An Investigation Into the Effects of Curved Beam Elements on the Out-of-Plane Stiffness Profile in a Compliant Large-Displacement Finger

2013 ◽  
Author(s):  
Valerie Y. Goemans ◽  
Just L. Herder ◽  
Mary I. Frecker
Keyword(s):  
Range Of Motion ◽  
Compliant Mechanisms ◽  
Large Displacement ◽  
Curved Beam ◽  
Trade Off ◽  
Beam Elements ◽  
Straight Beam ◽  
Double Beam ◽  
Out Of Plane ◽  
Stiffness Profile

Compliant mechanisms have many advantages over rigid-link mechanisms. However, one of the challenges of compliant mechanisms is the trade-off between a large range of motion and a high out-of-plane stiffness. Furthermore, the out-of-plane stiffness is shown to vary over the range of motion. Especially for large-displacement compliant mechanisms this can be by a significant amount. In this paper the use of curved beam elements in a compliant mechanism is shown to have impact on this trade-off. The influence of curved beam elements on the out-of-plane stiffness over the entire range of motion is presented for simple structures such as a single beam element and double beam elements, as well as a compliant finger. With the use of a genetic algorithm optimization, the difference in performance of a design with only straight beam elements versus one with curved beam elements is highlighted and the effect on the out-of-plane stiffness profile is presented. The optimization with curved beam elements results in solutions with a performance in terms of objective function values that cannot be found by the optimization with only straight beam elements. It is shown that for simple structures the use of curved beam elements has a large influence on the shape of the out-of-plane stiffness profile along the range of motion, while for the compliant finger the influence is mainly in the variables of the out-of-plane stiffness profile.

Forward Acceleration of Kinematic Limbs for Redundant Serial–Parallel Manipulators

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Yi Lu ◽  
Zefeng Chang ◽  
Nijia Ye
Keyword(s):  
Parallel Manipulator ◽  
Parallel Manipulators ◽  
The Novel ◽  
Jacobian Matrices ◽  
Acceleration Model ◽  
Forward Kinematic ◽  
General Velocity

Abstract A forward acceleration of the kinematic limbs for the redundant serial–parallel manipulators is studied. The relationships between the input velocity/acceleration and the output general velocity/acceleration of the kinematic limbs are discovered. The forward kinematic Jacobian matrices and the forward kinematic Hessian matrices are derived. A unified forward acceleration of the kinematic limbs is established for solving the output general acceleration of the kinematic limbs by only giving the input general velocity/acceleration of every parallel manipulator. A novel 2(RPS + SPR + UPS + SPU) type serial–parallel manipulator is constructed, several formulas are derived for solving the full forward general acceleration of the kinematic limbs in the redundant serial–parallel manipulator based on the unified forward acceleration model. The theoretical solutions are proved to be correct by the simulation solution of the novel serial–parallel manipulator.

A geometrical formulation for the workspace of parallel manipulators

Robotica ◽  
2021 ◽  
pp. 1-11
Author(s):  
Matteo Russo ◽  
Marco Ceccarelli
Keyword(s):  
Parallel Mechanism ◽  
Parallel Manipulator ◽  
Kinematic Chain ◽  
Parallel Manipulators ◽  
Analytical Models ◽  
Kinematic Chains ◽  
Motion Constraints ◽  
Geometrical Formulation ◽  
Geometric Formulation ◽  
Algebraic Formulation

Abstract In study this paper, a geometric formulation is proposed to describe the workspace of parallel manipulators by using a recursive approach as an extension of volume generation for solids of revolution. In this approach, the workspace volume and boundary for each limb of the parallel manipulator is obtained with an algebraic formulation derived from the kinematic chain of the limb and the motion constraints on its joints. Then, the overall workspace of the mechanism can be determined as the intersection of the limb workspaces. The workspace of different kinematic chains is discussed and classified according to its external shape. An algebraic formulation for the inclusion of obstacles in the computation is also proposed. Both analytical models and numerical simulations are reported with their advantages and limitations. An example on a 3-SPR parallel mechanism illustrates the feasibility of the formulation and its efficiency.

Design and Experimental Testing of an Improved Large-Range Decoupled XY Compliant Parallel Micromanipulator1

2015 ◽  
Vol 7 (4) ◽  
Author(s):  
Jingjun Yu ◽  
Yan Xie ◽  
Zhenguo Li ◽  
Guangbo Hao
Keyword(s):  
Range Of Motion ◽  
Parallel Manipulator ◽  
Large Range ◽  
Experimental Testing ◽  
Experimental Results ◽  
Topology Design ◽  
Motion Range ◽  
Large Motion ◽  
Cross Axis ◽  
Large Improvement

There is an increasing need for XY compliant parallel micromanipulators (CPMs) providing good performance characteristics such as large motion range, well-constrained cross-axis coupling, and parasitic rotation. Decoupled topology design of the CPMs can easily realize these merits without increasing the difficulty of controlling. This paper proposes an improved 4-PP model on the basis of a classical 4-PP model and both of them are selected for manufacturing and testing to verify the effectiveness of the improvement. It has shown from experimental results that there is a large improvement on the performances of improved 4-PP compliant parallel manipulator (CPM): large range of motion up to 5 mm × 5 mm in the unidirection in the dimension of 311 mm × 311 mm × 24 mm, smaller compliance fluctuation (only 36.63% of that of the initial 4-PP model), smaller cross-axis coupling (only 28.10% of that of the initial 4-PP model generated by a single-axis 5 mm actuation), smaller in-plane parasitic yaw (only 57.14% of that of the initial 4-PP model generated by double-axis 5 mm actuation).

A Large Range Spatial Linear Guide With Torsion Reinforcement Structures

2018 ◽  
Author(s):  
J. Rommers ◽  
M. Naves ◽  
D. M. Brouwer ◽  
J. L. Herder
Keyword(s):  
Range Of Motion ◽  
Large Range ◽  
Small Range ◽  
The Novel ◽  
Precision Engineering ◽  
Linear Guide ◽  
Leaf Springs

Flexure mechanisms are popular in the precision engineering field due to their highly repeatable behavior. However, implementations are limited to small range of motion applications. In this paper, a spatial linear guide with a range comparable to the size of its footprint is presented. The design is based on two novel ‘Triflex’ elements in which torsion reinforcement structures are used to decrease build volume and increase guiding stiffness. The mechanism is compared to a common linear guide consisting of six folded leaf springs, after optimizing both designs. The novel linear guide shows better guiding stiffness performance, while occupying a smaller and less obstructive build volume.

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