scholarly journals Design of Four-DoF Compliant Parallel Manipulators Considering Maximum Kinematic Decoupling for Fast Steering Mirrors

Actuators ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 292
Author(s):  
Guangbo Hao ◽  
Haiyang Li ◽  
Yu-Hao Chang ◽  
Chien-Sheng Liu
Keyword(s):  
Degrees Of Freedom ◽  
Compliant Mechanism ◽  
Parallel Manipulators ◽  
Laser Beams ◽  
Element Analysis ◽  
Compliance Matrix ◽  
Precision Control ◽  
Motion System ◽  
Matrix Modelling

Laser beams can fluctuate in four directions, which requires active compensation by a fast steering mirror (FSM) motion system. This paper deals with the design of four-degrees-of-freedom (DoF) compliant parallel manipulators, for responding to the requirements of the FSM. In order to simplify high-precision control in parallel manipulators, maximum kinematic decoupling is always desired. A constraint map method is used to propose the four required DoF with the consideration of maximum kinematic decoupling. A specific compliant mechanism is presented based on the constraint map, and its kinematics is estimated analytically. Finite element analysis demonstrates the desired qualitative motion and provides some initial quantitative analysis. A normalization-based compliance matrix is finally derived to verify and demonstrate the mobility of the system clearly. In a case study, the results of normalization-based compliance matrix modelling show that the diagonal entries corresponding to the four DoF directions are about 10 times larger than those corresponding to the two-constraint directions, validating the desired mobility.

Performance Decomposition and Integration of a Five-Degrees-of-Freedom Compliant Hybrid Parallel Micromanipulator

2014 ◽  
Author(s):  
Zhen Gao ◽  
Dan Zhang
Keyword(s):  
Degrees Of Freedom ◽  
Parallel Manipulators ◽  
Cell Manipulation ◽  
Parallel Mechanisms ◽  
Element Analysis ◽  
Performance Visualization ◽  
Performance Decomposition ◽  
Open Issues ◽  
Dimensional Optimization

The research and development of parallel manipulators generally has two major streams, i.e. the macro/meso stream and the micro/nano stream, in which the former one has been thoroughly investigated in recent decades, while the latter one still remains many performance related open issues that significantly affect their application potentials in critical situations such as high-precision automated cell manipulation. This research is to develop a novel methodology called performance decomposition and integration for governing the design optimization process of complicated micromanipulator. A new five degrees-of-freedom (DOF) compliant hybrid parallel micromanipulator which is configured with five identical PSS limbs and one constraining UPU limb is proposed as a case study. The performance visualization, finite element analysis, and dimensional optimization are implemented. The proposed methodology is generic and feasible for the design improvement of different kinds of compliant/parallel mechanisms.

A Method to Evaluate and Calculate the Mobility of a General Compliant Parallel Manipulator

2004 ◽  
Author(s):  
Jingjun Yu ◽  
Shusheng Bi ◽  
Guanghua Zong
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Compliant Mechanism ◽  
Parallel Manipulators ◽  
Kinematic Characteristic ◽  
Parallel Kinematic Machine ◽  
Compliance Matrix ◽  
Multiple Degrees Of Freedom ◽  
Parallel Kinematic

A compliant parallel manipulator (CPM), is a kind of compliant mechanism characterizes a complicate topological structure and multiple degrees of freedom. As one of the kinematic characteristics of a CPM, the mobility of a CPM become complicate compared to its rigid-counterpart. In order to describe such a complicate kinematic characteristic of a CPM, “primary mobility of a compliant parallel manipulator” concept is proposed. By means of the screw theory, a method of quantifying the primary mobility of the CPM is investigated under the ground that the compliance matrix of the manipulator should be calculated primarily. By using this method, the primary mobility of two typical compliant parallel manipulators, one is a planar 3-RRR CPM and the other a spatial 3-RRPR CPM, is addressed respectively. This proposed method is also instructive for analyzing the instantaneous mobility of a general degenerate-DOF parallel manipulator or a Parallel Kinematic Machine (PKM).

A Method for Compliance Modeling of Five Degree-of-Freedom Overconstrained Parallel Robotic Mechanisms With 3T2R Output Motion

2016 ◽  
Vol 9 (1) ◽  
Author(s):  
Wen-ao Cao ◽  
Huafeng Ding ◽  
Donghao Yang
Keyword(s):  
Screw Theory ◽  
Parallel Manipulators ◽  
Static Equilibrium ◽  
Equilibrium Equations ◽  
Element Analysis ◽  
Compliance Matrix ◽  
Fea Model ◽  
Stiffness Model ◽  
Compliance Modeling ◽  
The One

This paper presents an approach to compliance modeling of three-translation and two-rotation (3T2R) overconstrained parallel manipulators, especially for those with multilink and multijoint limbs. The expressions of applied wrenches (forces/torques) exerted on joints are solved with few static equilibrium equations based on screw theory. A systematic method is proposed for deriving the stiffness model of a limb with considering the couplings between the stiffness along the constrained wrench and the one along the actuated wrench based on strain energy analysis. The compliance model of a 3T2R overconstrained parallel mechanism is established based on stiffness models of limbs and the static equilibrium equation of the moving platform. Comparisons show that the compliance matrix obtained from the method is close to the one obtained from a finite-element analysis (FEA) model. The proposed method has the characteristics of involving low computational efforts and considering stiffness couplings of each limb.

Performance Optimization for a 3-DOF Micro-Motion Device

2011 ◽  
Vol 291-294 ◽  
pp. 3108-3111 ◽  
Author(s):  
Dan Zhang ◽  
Irene Fassi ◽  
Pei Gang Jiang
Keyword(s):  
Fiber Optics ◽  
Performance Optimization ◽  
Degrees Of Freedom ◽  
Compliant Mechanism ◽  
Parallel Manipulators ◽  
Mechanical Joints ◽  
Micro Motion ◽  
Optics Industry ◽  
And Behavior ◽  
Three Degrees Of Freedom

Traditional parallel manipulators suffer from errors due to backlash, hysteresis, and vibration in the mechanical joints. In this paper, a new 3SPS+RPR spatial compliant mechanism which has three degrees of freedom (DOF) and can generate motions in a microscopic scale is proposed. It can be utilized for biomedical engineering and fiber optics industry. The detailed design of the structure is introduced, followed by the performance evaluation. Then, the genetic algorithms and radial basis function networks are implemented to search for the optimal architecture and behavior parameters in terms of global stiffness/compliance, dexterity and manipulability.

Flexible Cellular Structures of a Non-Pneumatic Tire

2016 ◽  
Author(s):  
Fanhao Meng ◽  
Dengfeng Lu ◽  
Jingjun Yu
Keyword(s):  
Degrees Of Freedom ◽  
Compliant Mechanism ◽  
Design Method ◽  
Cellular Structures ◽  
Geometrical Parameters ◽  
Analysis Tool ◽  
Element Analysis ◽  
Rectangular Cell ◽  
Cellular Solid ◽  
Vertical Loading

Taking the tire of the lunar rover as the research background, this paper provides two design concepts of non-pneumatic tires (NPTs) with a compliant cellular solid spoke component. In this study, a series of degrees of freedom (DOFs) and stiffness analysis of NPTs with cellular structures are investigated with the same vertical loading conditions using a commercial finite element analysis tool, ANSYS. The research found that the tread relative to the hub only has in-plane translational degree of freedom in the radial direction, without other DOFs. According to this finding, using the improved design method based on the existing cellular structures and the synthetic design method based on the principle of compliant mechanism, two cases of cellular structures are designed: (i) cross arcs cell and (ii) rectangular cell. Analysis of the influence of geometric parameters of the cell on the performance of NPTs is critical to further improve the performance of the NPTs. Finally, by optimizing the geometrical parameters of the cellular structure, the performance of the NPTs with the cross arcs cell and rectangular cell can be enhanced.

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.

Compact design of a novel linear compliant positioning stage with high out-of-plane stiffness and large travel

2017 ◽  
Vol 232 (12) ◽  
pp. 2265-2279
Author(s):  
Hua Liu ◽  
Xin Xie ◽  
Ruoyu Tan ◽  
Dapeng Fan
Keyword(s):  
Degrees Of Freedom ◽  
Compliant Mechanism ◽  
Area Ratio ◽  
Leaf Spring ◽  
Static Stiffness ◽  
Element Analysis ◽  
Compact Size ◽  
Positioning Stage ◽  
Out Of Plane ◽  
Compact Design

Since most of the XY positioning stages with large travel range proposed in previous studies suffer from low out-of-plane stiffness and loose structure, this paper presents a novel two degrees-of-freedom large travel linear compliant positioning stage with high out-of-plane stiffness and compact size. The linear guide compliant mechanism of the stage takes spatial leaf spring parallelograms as the basic units, which are serially connected to obtain large travel, high out-of-plane stiffness, and compact size simultaneously. The theoretical static stiffness and dynamic resonant frequency are obtained by matrix structural analysis. Finite element analysis is carried out to investigate the characteristics of the developed stage. The analytical model is confirmed by experiments. It is noted that the developed stage has a workspace of 4.4 × 7.0 mm2, and the area ratio of workspace to the outer dimension of the stage is 0.16%, which is greater than that of any existing stage reported in the literature. The results of out-of-plane payload tests indicate that the stage can sustain at least 20 kg out-of-plane payload without changing the travel range. And the positioning experiments show that the developed stage is capable of tracking a circle of radius 1.5 mm with 10 µm error and the resolution is less than 2 µm.

Design and Assessment of a Flexure-Based 2-DOF Micromanipulator for Automatic Cell Micro-Injection

2012 ◽  
Vol 457-458 ◽  
pp. 445-448 ◽  
Author(s):  
Hui Tang ◽  
Yang Min Li ◽  
Ji Ming Huang ◽  
Qin Min Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Theoretical Analysis ◽  
Degrees Of Freedom ◽  
Lagrange Equation ◽  
Element Analysis ◽  
Compliance Matrix ◽  
Cell Injection ◽  
Modeling And Analysis ◽  
Compliance Matrix Method

The design and assessment of a flexure-based parallel micromanipulator with two-degrees-of-freedom (2-DOF) for automatic cell injection is presented in this paper. The design and modeling of the micromanipulator are conducted by employing compliance matrix method. The dynamic modeling and analysis via Lagrange equation are conducted to improve the bandwidth of the mechanism. Both theoretical analysis and finite element analysis (FEA) results well validate the good performance of the micromanipulator which will be applied to practical cell manipulations.

Design of Nonperiodic Microarchitectured Materials That Achieve Graded Thermal Expansions

2016 ◽  
Vol 8 (5) ◽  
Author(s):  
Jonathan B. Hopkins ◽  
Lucas A. Shaw ◽  
Todd H. Weisgraber ◽  
George R. Farquar ◽  
Chris D. Harvey ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Compliant Mechanism ◽  
System Level ◽  
Element Analysis ◽  
Ambient Temperatures ◽  
Thermal Expansion Coefficients ◽  
Layered Coatings ◽  
Unit Cells ◽  
Expansion Coefficients

The aim of this paper is to introduce an approach for optimally organizing a variety of nonrepeating compliant-mechanism-like unit cells within a large deformable lattice such that the bulk behavior of the lattice exhibits a desired graded change in thermal expansion while achieving a desired uniform stiffness over its geometry. Such lattices with nonrepeating unit cells, called nonperiodic microarchitectured materials, could be sandwiched between two materials with different thermal expansion coefficients to accommodate their different expansions and/or contractions induced by changing ambient temperatures. This capability would reduce system-level failures within robots, mechanisms, electronic modules, or other layered coatings or structures made of different materials with mismatched thermal expansion coefficients. The closed-form analytical equations are provided, which are necessary to rapidly calculate the bulk thermal expansion coefficient and Young's modulus of general multimaterial lattices that consist first of repeating unit cells of the same design (i.e., periodic microarchitectured materials). Then, these equations are utilized in an iterative way to generate different rows of repeating unit cells of the same design that are layered together to achieve nonperiodic microarchitectured material lattices such that their top and bottom rows achieve the same desired thermal expansion coefficients as the two materials between which the lattice is sandwiched. A matlab tool is used to generate images of the undeformed and deformed lattices to verify their behavior and an example is provided as a case study. The theory provided is also verified and validated using finite-element analysis (FEA) and experimentation.

scholarly journals Compliant Mechanism Road Bicycle Brake: A Rigid-Body Replacement Case Study

2011 ◽  
Author(s):  
Brian M. Olsen ◽  
Larry L. Howell ◽  
Spencer P. Magleby
Keyword(s):  
Rigid Body ◽  
High Performance ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Element Analysis ◽  
Low Weight ◽  
Rigid Body Model ◽  
Compliant Mechanism Design

This paper demonstrates rigid-body replacement synthesis in the design a mechanism with known design objectives. The design of high-performance bicycle brakes is complicated by a variety of competing design objectives, including increased performance and low weight. But this challenge also provides a good case study to demonstrate the design of compliant mechanisms to replace traditional rigid-link mechanisms. This paper briefly reviews current road brake designs, demonstrates the use of rigid-body replacement synthesis to design a compliant mechanism, and illustrates the combination of compliant mechanism design tools. The resulting concept was generated from the modified dual-pivot brake design and is a partially compliant mechanism where one pin has the dual role of a joint and a mounting pin. The pseudo-rigid-body model, finite element analysis, and optimization algorithms are used to generate design dimensions, and designs are considered for both titanium and E-glass flexures. The resulting design has the potential of reducing the part count and overall weight while maintaining a performance similar to the benchmark.

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