Kinematically identical manipulators derivation for the 2-RPU+UPR parallel manipulator and their constraint performance comparison

2020 ◽  
pp. 1-13 ◽  
Author(s):  
Bo Hu ◽  
DongSheng Shi ◽  
Tengfei Xie ◽  
BiBo Hu ◽  
Nijia Ye
Keyword(s):  
Optimal Design ◽  
Parallel Manipulator ◽  
Parallel Manipulators ◽  
Performance Comparison ◽  
Comparison Study ◽  
Optimal Parameters ◽  
Force Transmission ◽  
Definition Of

Abstract This paper derives the kinematically identical manipulators (KIMs) of the 2-RPU+UPR parallel manipulators (PMs) and performs a comparison study among them. Based on the principle for deriving KIMs, ten non-overconstrained and twelve overconstrained KIMs of the 2-RPU+UPR PMs are derived. The 2-RPU+UPR PM and its KIMs has identical kinematics but different constraints. On the basis of motion/force transmission indices, the optimal design of the 2-RPU+UPR PM and its KIMs is carried out and the optimal parameters are obtained. With the optimal parameters and the definition of constraint performance, their constraint performances are compared. The comparison study with the 2-RPU+UPR PM and its KIMs is helpful for obtaining the optimal architectures among them.

Optimal Design of a 2-UPR-RPU Parallel Manipulator

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Feibo Wang ◽  
Qiaohong Chen ◽  
Qinchuan Li
Keyword(s):  
Optimal Design ◽  
Parallel Manipulator ◽  
Design Space ◽  
Parameter Design ◽  
Optimal Parameters ◽  
Force Transmission ◽  
Universal Joint ◽  
Practical Applications ◽  
Optimum Region ◽  
Dimensional Optimization

This paper investigates dimensional optimization of a 2-UPR-RPU parallel manipulator (where U is a universal joint, P a prismatic pair, and R a revolute pair). First, the kinematics and screws of the mechanism are analyzed. Then, three indices developed from motion/force transmission are proposed to evaluate the performance of the 2-UPR-RPU parallel manipulator. Based on the performance atlases obtained, a set of optimal parameters are selected from the optimum region within the parameter design space. Finally, the optimized parameters are determined for practical applications.

Optimal Design of Spherical 5R Parallel Manipulators Considering the Motion/Force Transmissibility

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Chao Wu ◽  
Xin-Jun Liu ◽  
Liping Wang ◽  
Jinsong Wang
Keyword(s):  
Performance Evaluation ◽  
Optimal Design ◽  
Parallel Manipulator ◽  
Screw Theory ◽  
Parallel Manipulators ◽  
Dimensional Synthesis ◽  
Force Transmission ◽  
Minimally Invasive Surgical ◽  
Pointing Device ◽  
Force Transmissibility

The spherical 5R parallel manipulator is a typical parallel manipulator. It can be used as a pointing device or as a minimally invasive surgical robot. This study addresses the motion/force transmission analysis and optimization of the manipulator by taking into account the motion/force transmissibility. The kinematics of the manipulator is analyzed. Several transmission indices are defined by using screw theory for the performance evaluation and dimensional synthesis. The process of determining the optimal angular parameters based on performance charts is presented. The manipulator that has a large workspace and good motion/force transmissibility is identified.

Optimal design of a class of generalized symmetric Gough–Stewart parallel manipulators with dynamic isotropy and singularity-free workspace

Robotica ◽  
2011 ◽  
Vol 30 (2) ◽  
pp. 305-314 ◽  
Author(s):  
Zhizhong Tong ◽  
Jingfeng He ◽  
Hongzhou Jiang ◽  
Guangren Duan
Keyword(s):  
Particle Swarm Optimization ◽  
Optimal Design ◽  
Parallel Manipulator ◽  
Optimal Solution ◽  
Optimization Procedure ◽  
Singular Values ◽  
Parallel Manipulators ◽  
Swarm Optimization ◽  
Definition Of ◽  
Close Form

SUMMARYIn this paper, the definition of generalized symmetric Gough–Stewart parallel manipulators is presented. The concept of dynamic isotropy is proposed and the singular values of the bandwidth matrix are introduced to evaluate dynamic isotropy and solved analytically. Considering the payload's mass-geometry characteristics, the formulations for completely dynamic isotropy are derived in close form. It is proven that a generalized symmetric Gough–Stewart parallel manipulator is easer to achieve dynamic isotropy and applicable in engineering applications. An optimization procedure based on particle swarm optimization is proposed to obtain better dexterity and large singularity-free workspace, which guarantees the optimal solution and gives mechanically feasible realization.

Pareto-Optimal Solutions Using Kinematic and Dynamic Functions for a Scho¨nflies Parallel Manipulator

2009 ◽  
Author(s):  
Oscar Altuzarra ◽  
Charles Pinto ◽  
Bogdan Sandru ◽  
Enrique Amezua
Keyword(s):  
Optimal Design ◽  
Parallel Manipulator ◽  
Parallel Manipulators ◽  
Frobenius Norm ◽  
Pareto Optimal ◽  
Pareto Optimal Solutions ◽  
Optimal Solutions ◽  
Objective Functions ◽  
Motion Generation ◽  
Dimensional Parameters

The search of Pareto-optimal solutions for the optimal design of Low-Mobility Parallel Manipulators with Scho¨nflies motion is the subject of this paper. As a working example, a four-degree-of-freedom symmetric parallel manipulator for Scho¨nflies-motion generation is taken. In previous work, analytically found objective functions for the optimal design were used. As a consequence, some limitations were detected and new functions are required. First, a manipulator description is made, and kinematic and dynamic problems are solved. Next, an operational and dexterous workspace along with its volume is found making use of a discretization. Further, the variation of this volume with dimensional parameters is shown for purpose of optimal design. Similarly, the manipulator’s dexterity based on the Frobenius norm is found and weighted with the measure of dispersion. Then, upon a type of testing trajectory over this workspace, kinematic and dynamic results in the actuators are proposed as objective functions in multiobjective optimization.

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.

An Approach for Acceleration Analysis of Lower Mobility Parallel Manipulator

2010 ◽  
Author(s):  
Haitao Liu ◽  
Tian Huang ◽  
Derek G. Chetwynd
Keyword(s):  
Parallel Manipulator ◽  
Hessian Matrix ◽  
Parallel Manipulators ◽  
Unified Framework ◽  
Generalized Jacobian ◽  
Kinematic Chains ◽  
Lie Bracket ◽  
Lower Mobility ◽  
Acceleration Analysis ◽  
Definition Of

This paper presents an approach for velocity and acceleration analyses of lower mobility parallel manipulators. Based on the definition of the acceleration motor, the forward/inverse velocity and acceleration equations are formulated with the goal to integrate the relevant analyses under a unified framework based on the generalized Jacobian. A new Hessian matrix of serial kinematic chains (or limb) is developed in an explicit and compact form using Lie bracket. This idea is then extended to cover parallel manipulators by considering the loop closure constraints. A 3-PRS parallel manipulator with coupled translational and rotational moving capabilities is taken as example to illustrate the generality and effectiveness of this approach.

Extension of Motion/Force Transmission Index to Parallel Manipulators With Double Platforms: Case Study on the Par4 Manipulator

2018 ◽  
Author(s):  
Qizhi Meng ◽  
Fugui Xie ◽  
Xin-Jun Liu ◽  
Yukio Takeda
Keyword(s):  
Parallel Manipulators ◽  
Parallel Mechanisms ◽  
Force Transmission ◽  
Traditional Concept ◽  
Extended Approach ◽  
Transmission Index ◽  
Kinematic Performance ◽  
Definition Of ◽  
Unified Index

At present, the research of motion/force characteristics is concentrated on the single-platform parallel mechanisms (PMs). On the contrary, relatively little attention has been paid to the double-platform PMs, and there is also no unified index. What actually causes this? One of the reasons is that the complex and inaccessible wrench system of this manipulator with the double platforms. Especially the transmission wrench screws (TWSs) are no longer like its traditional concept, i.e., linear forces along the symmetric axis of the passive arms. Essentially, the TWSs in the double-platform PMs should be applied to the end effector but not to the sub-platforms from active arms. With this new idea, the concept equivalent transmission wrench screw (ETWS) of PMs with double platforms is firstly proposed and its identification process is also provided. Then, the motion/force transmission index which considers the input transmission index (ITI) and output transmission index (OTI) is extended to the area of kinematic performance evaluation of the double-platform PMs. Finally, the validity of the proposed extension is verified by the transmission index (TI) based on the concept of pressure angle. In this paper, the typical Par4 mechanism is investigated as an example. This extended approach with a new definition of the ETWS which covers the concept of the TWS in traditional mechanism actually provides a uniform kinematic performance index of both single- and double-platforms PMs.

scholarly journals Orientation Singularity Analysis of Parallel Manipulators

2016 ◽  
Vol 5 (4) ◽  
pp. 295
Author(s):  
Qimin Xu
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Parallel Manipulators ◽  
Singularity Analysis ◽  
Variable Geometry ◽  
Force Transmission ◽  
Performance Indices ◽  
Unique Form ◽  
Velocity Transmission ◽  
Variable Geometry Truss

<p>In this paper, an approach for orientation singularity analysis of parallel manipulators (PMs) is proposed by introducing several performance indices referred to the<br />unique form of screw based Jacobian in the velocity transmission as well as force transmission. Here, to prove the effectiveness of the approach, an example of 3 degrees of freedom (DOF) prismatic-revolute-spherical (PRS) parallel manipulator (PM) is first presented to illustrate the fact that the distributions of singularity boundary of the proposed approach is consistence with the result referred to nonredunant PMs by Liu et al. [22]. Further, the proposed approach is an appropriate one not only for nonredunant PMs, but also for a class of redunant PMs by providing another example of the redunant variable geometry truss (VGT) PM, since the performance index of orientation singularity for the manipulator can be<br />created only by determining the unique form of screw based Jacobian.</p>

scholarly journals Solving the dynamic equations of a 3-PRS Parallel Manipulator for efficient model-based designs

2016 ◽  
Vol 7 (1) ◽  
pp. 9-17 ◽  
Author(s):  
M. Díaz-Rodríguez ◽  
J. A. Carretero ◽  
R. Bautista-Quintero
Keyword(s):  
Optimal Design ◽  
Dynamic Model ◽  
Parallel Manipulator ◽  
Dynamic Models ◽  
Computational Cost ◽  
Parallel Manipulators ◽  
Inverse Dynamic ◽  
Inverse Dynamic Model ◽  
Kinematic Chains ◽  
Model Based

Abstract. Introduction of parallel manipulator systems for different applications areas has influenced many researchers to develop techniques for obtaining accurate and computational efficient inverse dynamic models. Some subject areas make use of these models, such as, optimal design, parameter identification, model based control and even actuation redundancy approaches. In this context, by revisiting some of the current computationally-efficient solutions for obtaining the inverse dynamic model of parallel manipulators, this paper compares three different methods for inverse dynamic modelling of a general, lower mobility, 3-PRS parallel manipulator. The first method obtains the inverse dynamic model by describing the manipulator as three open kinematic chains. Then, vector-loop closure constraints are introduced for obtaining the relationship between the dynamics of the open kinematic chains (such as a serial robot) and the closed chains (such as a parallel robot). The second method exploits certain characteristics of parallel manipulators such that the platform and the links are considered as independent subsystems. The proposed third method is similar to the second method but it uses a different Jacobian matrix formulation in order to reduce computational complexity. Analysis of these numerical formulations will provide fundamental software support for efficient model-based designs. In addition, computational cost reduction presented in this paper can also be an effective guideline for optimal design of this type of manipulator and for real-time embedded control.

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