A droplet deformation and breakup model based on virtual work principle

2015 ◽  
Vol 27 (3) ◽  
pp. 032103 ◽  
Author(s):  
Arash B. Sichani ◽  
Mohsen D. Emami
Keyword(s):  
Virtual Work ◽  
Droplet Deformation ◽  
Virtual Work Principle ◽  
Model Based ◽  
Breakup Model

scholarly journals Dynamic modelling of a 3-CPU parallel robot via screw theory

2013 ◽  
Vol 4 (1) ◽  
pp. 185-197 ◽  
Author(s):  
L. Carbonari ◽  
M. Battistelli ◽  
M. Callegari ◽  
M.-C. Palpacelli
Keyword(s):  
Dynamic Analysis ◽  
Research Group ◽  
Screw Theory ◽  
Virtual Work ◽  
Dynamic Modelling ◽  
Parallel Robot ◽  
Computationally Efficient ◽  
Virtual Work Principle ◽  
Model Based ◽  
Advanced Model

Abstract. The article describes the dynamic modelling of I.Ca.Ro., a novel Cartesian parallel robot recently designed and prototyped by the robotics research group of the Polytechnic University of Marche. By means of screw theory and virtual work principle, a computationally efficient model has been built, with the final aim of realising advanced model based controllers. Then a dynamic analysis has been performed in order to point out possible model simplifications that could lead to a more efficient run time implementation.

A PD Computed Torque Control Method with Online Self-gain Tuning for a 3UPS-PS Parallel Robot

Robotica ◽  
2021 ◽  
pp. 1-13
Author(s):  
Xiaogang Song ◽  
Yongjie Zhao ◽  
Chengwei Chen ◽  
Liang’an Zhang ◽  
Xinjian Lu
Keyword(s):  
Feedback Loop ◽  
Control Method ◽  
Virtual Work ◽  
Parallel Robot ◽  
Torque Control ◽  
Virtual Work Principle ◽  
Tuning Method ◽  
Computed Torque Control ◽  
Control Feedback ◽  
Computed Torque

SUMMARY In this paper, an online self-gain tuning method of a PD computed torque control (CTC) is used for a 3UPS-PS parallel robot. The CTC is applied to the 3UPS-PS parallel robot based on the robot dynamic model which is established via a virtual work principle. The control system of the robot comprises a nonlinear feed-forward loop and a PD control feedback loop. To implement real-time online self-gain tuning, an adjustment method based on the genetic algorithm (GA) is proposed. Compared with the traditional CTC, the simulation results indicate that the control algorithm proposed in this study can not only enhance the anti-interference ability of the system but also improve the trajectory tracking speed and the accuracy of the 3UPS-PS parallel robot.

scholarly journals Application of the virtual work principle to compute magnetic forces with a volume integral method

2013 ◽  
Vol 27 (3) ◽  
pp. 418-432 ◽  
Author(s):  
Anthony Carpentier ◽  
Nicolas Galopin ◽  
Olivier Chadebec ◽  
Gérard Meunier ◽  
Christophe Guérin
Keyword(s):  
Integral Method ◽  
Virtual Work ◽  
Volume Integral ◽  
Virtual Work Principle ◽  
Magnetic Forces

Study on Drive Characteristic of Multi–Rope Friction Winder Using Functional Virtual Prototyping

2009 ◽  
Vol 628-629 ◽  
pp. 305-310
Author(s):  
Yi Liu ◽  
Guo Ding Chen ◽  
J.S. Li ◽  
Y.J. Xue
Keyword(s):  
Software Package ◽  
3D Model ◽  
Virtual Work ◽  
Virtual Prototyping ◽  
Research Work ◽  
Three Dimensional ◽  
Virtual Work Principle ◽  
Nodal Method ◽  
Hoisting System ◽  
Dynamics Characteristic

The main objective of this study was to model and simulate a reduced three-dimensional (3D) model for researching the hoisting system of a Multi – rope Friction Winder. By introducing the relative nodal method, the simplified dynamic equations have been derived via the virtual work principle and validated on a virtual prototype with the RecurDyn software package. Kinematics and dynamics characteristic date are obtained by computer-aided dynamic simulation of virtual Multi – rope friction winder. The result is in accord with theoretical analysis. The research work will provide a powerful tool and useful method for the design of economic and credible elevator system. The approach can be generalized to analysis other flexible drive fields.

scholarly journals Design of a Monolithic Double-Slider Based Compliant Gripper with Large Displacement and Anti-Buckling Ability

Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 665 ◽  
Author(s):  
Hao ◽  
Zhu
Keyword(s):  
Virtual Work ◽  
Large Displacement ◽  
Amplification Coefficient ◽  
Element Analysis ◽  
Virtual Work Principle ◽  
Manipulation System ◽  
The Finite Element Analysis ◽  
Rigid Body Model ◽  
Analytical Relations ◽  
Kinematic Mechanism

In a micro-manipulation system, the compliant gripper is used for gripping, handling and assembling of objects. Large displacement and anti-buckling characteristics are desired in the design of the gripper. In this paper, a compliant gripper with these two characteristics is proposed, modelled and verified. The large displacement is enabled by using distributed compliance in a double-slider kinematic mechanism. An inverted flexure arrangement enables the anti-buckling of the gripper when closing the two jaws. A pseudo-rigid-body model (PRBM) method with the help of virtual work principle is employed to obtain several desired analytical relations including the amplification coefficient and kinetostatics. The results of the finite element analysis (FEA) are shown to be consistent with the results of the derived analytical model. An experimental test was carried out through a milling machined aluminium alloy prototype, the results of which verify the good performance of the compliant gripper.

Analytical Model for the Deformation of Viscoelastic Non-Newtonian Drops Undergoing Secondary Atomization

2016 ◽  
Author(s):  
Sharon E. Snyder ◽  
Varun Kulkarni ◽  
Paul E. Sojka
Keyword(s):  
Analytical Model ◽  
Xanthan Gum ◽  
Experimental Results ◽  
Analytical Models ◽  
Drop Diameter ◽  
Droplet Deformation ◽  
Secondary Atomization ◽  
Starting Point ◽  
Breakup Model ◽  
Xanthan Gum Solution

While there is no single analytical model that accurately predicts all stages and modes of secondary atomization, many groups have developed models that predict deformation and oscillation of a single, isolated drop. The TAB (Taylor Analogy Breakup) model was chosen for this investigation, mainly due to its widespread use by Liu and Reitz [1], Hwang et al. [2], Tanner [3], and Lee and Reitz [4], among others. Since the TAB model is also the foundation for many other analytical models, it will also be used here as a starting point for the development of a viscoelastic non-Newtonian model to predict droplet deformed radii, droplet deformation time, and velocity at deformation time for viscoelastic xanthan gum - DI water solutions. Three additional improvements are made to this viscoelastic TAB model: the first is a change to a TAB coefficient; the second to the equation for the drag coefficient, and the third modification is to the breakup criterion. This model uses Carreau rheology and Zimm relaxation time. Non-dimensional drop diameter and initiation times are plotted against We; model results are compared to experimental results for a range of xanthan gum solution concentrations. Results show fair agreement between experimental results and model results for non-dimensional drop diameter, with the best match at low XG concentration and low-to-medium We (10–30). It was also noted that increased viscoelasticity seems to increase this drop diameter. Good agreement between experimental data and model results has been seen for initiation time, with increased viscoelasticity increasing this parameter as well.

Optimal Reduction Ratio Selection for the Driving System of a Novel High-Speed Parallel Manipulator

2007 ◽  
Author(s):  
Xianmin Zhang ◽  
Jianfeng Yuan
Keyword(s):  
Parallel Manipulator ◽  
High Speed ◽  
Inverse Dynamics ◽  
Virtual Work ◽  
Operation Time ◽  
Reduction Ratio ◽  
Virtual Work Principle ◽  
Driving System ◽  
S Curve ◽  
The Cost

The reduction ratio of the driving system plays a very important role in the accelerating and decelerating capacity for a parallel manipulator. In this paper, the virtual work principle was employed to develop the inverse dynamics model of a novel high-speed parallel manipulator. A new S-curve speed profile was introduced and adopted to plan the trajectory of the end-effecter of the manipulator in the operation space. Aiming at the minimal operation time, a reduction ratio optimal selection method of the driving system was presented, which can make full use of the advantages of the AC servomotor and consequently reduce the cost of the manipulator.

Dual Approach for Electromechanical Coupling in MEMS

2009 ◽  
Author(s):  
Ve´ronique Rochus ◽  
Jean-Claude Golinval ◽  
Christophe Geuzaine
Keyword(s):  
Electromechanical Coupling ◽  
Virtual Work ◽  
Scalar Potential ◽  
Test Cases ◽  
Electrostatic Problem ◽  
Dual Approach ◽  
Virtual Work Principle ◽  
Potential Formulation ◽  
Primal And Dual ◽  
Analytic Derivation

In this paper we present an approach for the computation of coupled electromechanical problems in micro-electromechanical systems based on a vector potential formulation of the electrostatic problem. This formulation is the dual of the scalar potential approach commonly used in the literature. We present an analytic derivation of the force computed using this dual method based on the virtual work principle, and compare the primal and dual approaches on the finite element solution of simple two-dimensional test-cases.

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