scholarly journals Morphological Synthesis and workspace design for a parallel manipulator with linear actuators

DYNA ◽  
2020 ◽  
Vol 87 (213) ◽  
pp. 129-139
Author(s):  
Carlos Andrés Mesa Montoya ◽  
Hector Fabio Quintero Riaza ◽  
Federico Gutiérrez Madrid
Keyword(s):  
Computer Aided Design ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Cylindrical Shape ◽  
Dimensional Synthesis ◽  
Workspace Analysis ◽  
Transmission Index ◽  
Linear Actuators ◽  
Condition Indices ◽  
Aided Design

This paper addresses the kinematic structure and workspace analysis of a parallel manipulator with linear actuators considering two studies.The first one was based on a morphological synthesis in which a kinematic connections approach was implemented. The set of combinations of joints and links for the desired system and their linkage are illustrated. Finally, the development regarding the conceivable morphologyis detailed, providing three linear degrees of freedom between the mobile and fixed platforms. The second study presented the dimensional synthesis of the manipulator, considering a workspace required and an input transmission index. The geometrical design was based on the maximum inscribed workspace volume; the cylindrical shape radius inscribed on a workspace intersection is also exemplified. The geometric determination of the workspace for the manipulator was demonstrated using computer-aided design. A design result of the Delta as checked with the stiffness and condition indices.

Determination of the Workspace of a Three-Degrees-of-Freedom Parallel Manipulator Using a Three-Dimensional Computer-Aided-Design Software Package and the Concept of Virtual Chains1

2015 ◽  
Vol 8 (2) ◽  
Author(s):  
Andrew Johnson ◽  
Xianwen Kong ◽  
James Ritchie
Keyword(s):  
Computer Aided Design ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Graphical Representation ◽  
Three Dimensional ◽  
Parallel Manipulators ◽  
Workspace Analysis ◽  
Computer Aided ◽  
Aided Design

The determination of workspace is an essential step in the development of parallel manipulators. By extending the virtual-chain (VC) approach to the type synthesis of parallel manipulators, this technical brief proposes a VC approach to the workspace analysis of parallel manipulators. This method is first outlined before being illustrated by the production of a three-dimensional (3D) computer-aided-design (CAD) model of a 3-RPS parallel manipulator and evaluating it for the workspace of the manipulator. Here, R, P and S denote revolute, prismatic and spherical joints respectively. The VC represents the motion capability of moving platform of a manipulator and is shown to be very useful in the production of a graphical representation of the workspace. Using this approach, the link interferences and certain transmission indices can be easily taken into consideration in determining the workspace of a parallel manipulator.

Workspace, dexterity and dimensional optimization of microhexapod

2015 ◽  
Vol 35 (4) ◽  
pp. 341-347 ◽  
Author(s):  
E. Rouhani ◽  
M. J. Nategh
Keyword(s):  
Degrees Of Freedom ◽  
Optimization Problem ◽  
Screw Theory ◽  
Design Parameters ◽  
Dimensional Synthesis ◽  
Content Type ◽  
Workspace Analysis ◽  
The Difference ◽  
Flexure Joints ◽  
6 Degrees Of Freedom

Purpose – The purpose of this paper is to study the workspace and dexterity of a microhexapod which is a 6-degrees of freedom (DOF) parallel compliant manipulator, and also to investigate its dimensional synthesis to maximize the workspace and the global dexterity index at the same time. Microassembly is so essential in the current industry for manufacturing complicated structures. Most of the micromanipulators suffer from their restricted workspace because of using flexure joints compared to the conventional ones. In addition, the controllability of micromanipulators inside the whole workspace is very vital. Thus, it is very important to select the design parameters in a way that not only maximize the workspace but also its global dexterity index. Design/methodology/approach – Microassembly is so essential in the current industry for manufacturing complicated structures. Most of the micromanipulators suffer from their restricted workspace because of using flexure joints compared to the conventional ones. In addition, the controllability of micromanipulators inside the whole workspace is very vital. Thus, it is very important to select the design parameters in a way that not only maximize the workspace but also its global dexterity index. Findings – It has been shown that the proposed procedure for the workspace calculation can considerably speed the required calculations. The optimization results show that a converged-diverged configuration of pods and an increase in the difference between the moving and the stationary platforms’ radii cause the global dexterity index to increase and the workspace to decrease. Originality/value – The proposed algorithm for the workspace analysis is very important, especially when it is an objective function of an optimization problem based on the search method. In addition, using screw theory can simply construct the homogeneous Jacobian matrix. The proposed methodology can be used for any other micromanipulator.

scholarly journals Analog Circuit Design Automation Tool Using Genetic Algorithms

1970 ◽  
Vol 1 (1) ◽  
Author(s):  
Y. M. A. Khalifa ◽  
D. H. Horrocks
Keyword(s):  
Genetic Algorithms ◽  
Circuit Design ◽  
Analog Circuits ◽  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Analog Circuit ◽  
Search Space ◽  
Design Stage ◽  
Specific Frequency ◽  
Aided Design

An investigation into the application of Genetic Algorithms (GA) for the design of electronic analog circuits is presented in this paper. In this paper an investigation of the use of genetic algorithms into the problem of analog circuits design is presented. In a single design stage, circuits are produced that satisfy specific frequency response specifications using circuit structures that are unrestricted and with component values that are chosen from a set of preferred values. The extra degrees of freedom resulting from unbounded circuit structures create a huge search space. It is shown in this paper that Genetic Algorithms can be successfully used to search this space. The application chosen is a LC all pass ladder filter circuit design.Key Words: Computer-Aided Design, Analog Circuits, Artificial Intelligence.

Vision-force guided precise robotic assembly for 2.5D components in a semistructured environment

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Boyoung Kim ◽  
Minyong Choi ◽  
Seung-Woo Son ◽  
Deokwon Yun ◽  
Sukjune Yoon
Keyword(s):  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Printed Circuit Board ◽  
Force Sensor ◽  
Circuit Board ◽  
Robotic Assembly ◽  
Ccd Cameras ◽  
Content Type ◽  
3 Dimensional ◽  
Aided Design

Purpose Many manufacturing sites require precision assembly. Particularly, similar to cell phones, assembly at the sub-mm scale is not easy, even for humans. In addition, the system should assemble each part with adequate force and avoid breaking the circuits with excessive force. The purpose of this study is to assemble high precision components with relatively reasonable vision devices compared to previous studies. Design/methodology/approach This paper presents a vision-force guided precise assembly system using a force sensor and two charge coupled device (CCD) cameras without an expensive 3-dimensional (3D) sensor or computer-aided design model. The system accurately estimates 6 degrees-of-freedom (DOF) poses from a 2D image in real time and assembles parts with the proper force. Findings In this experiment, three connectors are assembled on a printed circuit board. This system obtains high accuracy under 1 mm and 1 degree error, which shows that this system is effective. Originality/value This is a new method for sub-mm assembly using only two CCD cameras and one force sensor.

Analyses of kinematics, statics, and workspace of a 3-RRPRR parallel manipulator and its three isomeric mechanisms

2008 ◽  
Vol 222 (9) ◽  
pp. 1829-1837 ◽  
Author(s):  
B Hu ◽  
Y Lu
Keyword(s):  
Computer Aided Design ◽  
Parallel Manipulator ◽  
Analytical Approach ◽  
Displacement Velocity ◽  
Active Force ◽  
Kinematic Characteristics ◽  
Computer Aided ◽  
Analytical Formulae ◽  
The Common ◽  
Aided Design

A novel 3-RRPRR parallel manipulator with three pure translational movements and a relative larger workspace is proposed. Its three isomeric mechanisms 3-RR PU, 3-R PRU, and 3-U PU with three pure translational movements are constructed by varying dimensions of some links. Their common kinematic characteristics, workspace, and singularity are analysed, the active force and the constrained torque are solved. First, a simulation mechanism of the 3-RR PRR manipulator is created, and its kinematics, singularity, and workspace are analysed by using an analytical approach and a computer-aided design (CAD) variation geometry approach. Second, the common analytical formulae for solving the displacement, velocity, and acceleration of the four manipulators are derived. Third, the formulae for solving the active forces and constrained torques of the 3-RR PRR manipulator are derived. The analytic-solved results are verified by their simulation mechanisms.

Kinematic Synthesis of a Spatial 3-RPS Parallel Manipulator

2003 ◽  
Vol 125 (1) ◽  
pp. 92-97 ◽  
Author(s):  
Han Sung Kim ◽  
Lung-Wen Tsai
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Parallel Manipulators ◽  
Point Of View ◽  
Dimensional Synthesis ◽  
Kinematic Synthesis ◽  
End Effector ◽  
Solution Methods ◽  
Moving Platform ◽  
At Will

This paper presents the design of spatial 3-RPS parallel manipulators from dimensional synthesis point of view. Since a spatial 3-RPS manipulator has only 3 degrees of freedom, its end effector cannot be positioned arbitrarily in space. It is shown that at most six positions and orientations of the moving platform can be prescribed at will and, given six prescribed positions, there are at most ten RPS chains that can be used to construct up to 120 manipulators. Further, solution methods for fewer than six prescribed positions are also described.

Orientation Workspace Analysis of a Novel 3SPS+1PS Symmetrical Parallel Manipulator Based on Unit Quaternion

2011 ◽  
Vol 201-203 ◽  
pp. 1849-1853
Author(s):  
Jing Li Yu ◽  
Gang Cheng ◽  
Shuai Zhang ◽  
De Kun Zhang
Keyword(s):  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Unit Quaternion ◽  
Structure Characteristics ◽  
Workspace Analysis ◽  
Moving Platform ◽  
Position And Orientation ◽  
4 Degrees Of Freedom ◽  
Orientation Workspace

For a novel 3SPS+1PS parallel manipulator with 4 degrees of freedom including three rotations and one translation, the formulae for solving the inverse kinematics equations are derived based on quaternion method. Unit quaternion is used to represent the position and orientation of moving platform, and the singularities caused by Euler angles are avoided. Combining the topological structure characteristics of the parallel manipulator, it only has three rotations when its moving platform is at a given translation position. Based on the inverse position/pose equations and the all the constraints of the parallel manipulator, the discrete algorithm for the orientation workspaces of 3SPS+1PS parallel manipulator where the moving platform is at some different given translation positions are designed. The research builds the theoretical basis for optimizing the orientation workspace with given position.

A Toolbox for Tripod Design, Simulation, and Monitoring

2005 ◽  
Author(s):  
Z. M. Bi ◽  
S. Y. T. Lang ◽  
Peter E. Orban ◽  
Marcel Verner
Keyword(s):  
Computer Aided Design ◽  
Design System ◽  
Forward Kinematics ◽  
Design Tools ◽  
Actual Application ◽  
Workspace Analysis ◽  
Purity Analysis ◽  
On Line ◽  
Aided Design ◽  
User Friendly

The paper presents a concept and implementation of a toolbox for the design and application of the tripod-based parallel kinematic machines (PKMs). The toolbox is a suite of design tools to support the users from the conceptual design to the actual application of the tripod-based PKMs. These design tools have been individually developed in different languages and they are integrated seamlessly using a Java-based platform. Users can access all of the design tools through a user-friendly graphical interface. It is the first computer-aided design system specially developed for tripod-based PKMs. The toolbox includes some implementations of our innovative methodologies, such as a forward kinematics solver, the concept of joint workspace analysis, on-line monitoring based on forward kinematics, and the concept of motion purity analysis. The paper gives an overview on the toolbox architecture, GUI, and some key technologies.

A NUMERICAL SIMULATION INVESTIGATION OF THE HYDRODYNAMIC MOTIONS OF A SHIP ADVANCING IN WAVES

2021 ◽  
Vol 156 (A4) ◽  
Author(s):  
D C Lo ◽  
D T Su ◽  
J T Lin
Keyword(s):  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Fluid Dynamic ◽  
Wave Interaction ◽  
Six Degrees Of Freedom ◽  
Ship Model ◽  
Computer Aided ◽  
Cad Tool ◽  
Aided Design ◽  
Wave Incidence

This study establishes a relationship diagram of the ship-wave interaction under a ship advancing in waves. A finite difference method based on volume of fluid (VOF) principles was used to simulate the hydrodynamic motions of a ship advancing in waves. A ship model was constructed using a computer aided design (CAD) tool. The computational fluid dynamic (CFD) technique was used to calculate the hydrodynamic motions effect of a ship sailing in waves at varying angles of incidence. This study investigates a number of significant related parameters, such as the speed of the ship model, the various wave incidence angles, the wave height, and the navigation time. A chart is also used to show the flow field, and changes in the six degrees of freedom motion and continually compare changes in the drag force.

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