Dynamic Modeling of Underway Ship-to-Ship Operations

2011 ◽  
Author(s):  
Carlos Eduardo Silva de Souza ◽  
Helio Mitio Morishita
Keyword(s):  
Dynamic Model ◽  
Dynamic Modeling ◽  
Hydrodynamic Interaction ◽  
Equations Of Motion ◽  
Wave Interaction ◽  
Memory Effects ◽  
The Other ◽  
Transfer Phase ◽  
Mooring Lines

A dynamic model for underway ship-to-ship operations with surge velocity is developed. It is admitted that one ship develops power ahead, towing the other vessel together. Models for all relevant loads involved in such operation are present, like environment, mooring, fenders and hydrodynamic interaction loads. The equations of motion take fluid memory effects and wave interaction into account. The model was implemented and simulations were carried out, focusing in the transfer phase of a STS operation. The results are used to analyze mooring lines loads, which is a useful tool for mooring schemes design.

Dynamic modeling and simulation of two cooperating structurally-flexible robotic manipulators

Robotica ◽  
1995 ◽  
Vol 13 (4) ◽  
pp. 375-384 ◽  
Author(s):  
K. Krishnamurthy ◽  
L. Yang
Keyword(s):  
Modeling And Simulation ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Equations Of Motion ◽  
Robotic Manipulators ◽  
Geometric Constraints ◽  
Flexible Manipulators ◽  
Order Model ◽  
Closed Chain ◽  
Extended Hamilton’S Principle

SummaryA dynamic model for two three-link cooperating structurally-flexible robotic manipulators is presented in this study. The equations of motion are derived using the extended Hamilton's principle and Galerkin's method, and must satisfy certain geometric constraints due to the closed chain formed by the two manipulators and the object. The dynamic model presented here is for the purpose of designing controllers. Therefore, a low-order model which captures all the major effects is of interest. Computer simulated results are presented for the case of moving an object along an elliptical path using the two cooperating flexible manipulators.

scholarly journals Kinematic and dynamic modeling of a 3gdl robot for educational purposes

2020 ◽  
pp. 1-7
Author(s):  
Aleyda Irene Reyes-González ◽  
José Luis Ortiz-Simón ◽  
Martha Isabel Aguilera-Hernández ◽  
Gustavo Emilio Rojo-Velázquez
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
The Other ◽  
Final Position ◽  
Specific Point ◽  
Simulink Model

The following article presents the process to obtain the kinematic and dynamic model of a Cartesian robot with 3 degrees of freedom. The robot that is used was designed for educational purposes, it allows two linear movements and one angular. The kinematic model has two forms, direct and inverse, the first provides the final position of the robot if desired values are given to each of the robot's joints, the second provides the values of the joints if there are desired values for the effector final. On the other hand, the obtaining of the dynamic model is presented in detail, which obtains the torques and forces necessary for the robot to be able to move to a specific point. The procedure includes kinematic analysis using Denavit-Hartenberg parameters and dynamic analysis using Jacobeans. As a result, responses obtained from a Simulink model are presented that show the behavior of the developed models.

Dynamic Modeling and Vibration Control of Electrorheological Mounts

2004 ◽  
Vol 126 (4) ◽  
pp. 537-541 ◽  
Author(s):  
Seung-Bok Choi ◽  
Sung-Ryong Hong
Keyword(s):  
Vibration Control ◽  
Frequency Domain ◽  
Dynamic Modeling ◽  
Static Load ◽  
Equations Of Motion ◽  
The Other ◽  
Flow Mode ◽  
Governing Equations ◽  
Field Dependent ◽  
Different Types

This paper presents two different types of electrorheological (ER) mounts that can support a static load of 200 kg. One is a flow mode type, and the other is a squeeze mode type. After analyzing the governing equations of motion, two ER mounts are designed and manufactured. The field-dependent displacement transmissibilities are evaluated in the frequency domain. In addition, vibration control responses of two ER mounts are experimentally investigated by implementing a skyhook controller.

scholarly journals Dynamic Modeling of a Front-Loading Type Washing Machine and Model Reliability Investigation

Machines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 289
Author(s):  
Jungjoon Park ◽  
Sinwoo Jeong ◽  
Honghee Yoo
Keyword(s):  
Dynamic Model ◽  
Dynamic Modeling ◽  
Equations Of Motion ◽  
Rigid Bodies ◽  
Washing Machine ◽  
System Parameters ◽  
Linear Dynamic ◽  
Revolute Joints ◽  
Model Reliability ◽  
Loading Type

A linear dynamic model of a front-loading type washing machine was developed in this study. The machine was conceptualized with three moving rigid bodies, revolute joints, springs, and dampers along with prescribed rotational drum motion. Kane’s method was employed for deriving the equations of motion of the idealized washing machine. Since the modal and transient characteristics can be conveniently investigated with a linear dynamic model, the linear model can be effectively used for the design of an FL type washing machine. Despite the convenience, however, the reliability of the linear dynamic model is often restricted to a certain range of system parameters. Parameters relevant to the reliability of the linear dynamic model were identified and the parameters’ ranges that could guarantee the reliability of the proposed linear dynamic model were numerically investigated in this study.

Study on the Dynamics on the Brake of Vehicle after the Effects of Deicing Salt

2010 ◽  
Vol 26-28 ◽  
pp. 862-869
Author(s):  
Tao Peng ◽  
Zhi Peng Li ◽  
Chang Shu Zhan ◽  
Xiang Luo ◽  
Qian Wang
Keyword(s):  
Simulation Model ◽  
Dynamic Model ◽  
The Other ◽  
Snow Melting ◽  
Adhesion Coefficient ◽  
Deicing Salt ◽  
Other Hand ◽  
Road Condition ◽  
Braking Distance ◽  
The Relationship

Through analyzing the process of brake, a dynamic model of automobile and a model of the relationship between braking distance and adhesion coefficient were formed; also a simulation calculating model of braking distance was established with the use of Matlab. Finally, a research was done toward the braking distance of a type of a car running on a road after using snow-melting agent. On one hand, with the application of the simulation model which has been established, calculations have been done to the braking distance of Bora vehicles running on roads after using deicing salt; on the other hand, by experiments, Bora vehicles’ braking distance and maximum braking deceleration under the same road condition were measured, meanwhile, the established simulation model was verified.

An Analysis of Competitive Oscillations between Japanese Twin Cities

1989 ◽  
Vol 21 (6) ◽  
pp. 803-816 ◽  
Author(s):  
H Kohsaka
Keyword(s):  
Dynamic Model ◽  
Diffusion Of Innovation ◽  
The Other ◽  
Twin Cities ◽  
Competitive Condition ◽  
Medium Term ◽  
Competitive Position ◽  
Retail Development ◽  
Market Shares ◽  
Strong Competition

In this paper keenly-competing Japanese twin cities are examined and the competitive oscillations occurring between them is analyzed as a typical example of medium-term competitive processes. From an analysis of market shares for annual retail sales of women's and children's clothes it was found that there are certain oscillations between the twin cities. As these oscillations are derived from the strong competition between closely-located twin cities, they are called competitive oscillations. In order to analyze the generation of the competitive oscillations, an attempt to reproduce a strongly competitive condition by constructing a dynamic model of two-centre competition was made. As the twin cities share a large part of their populations, they are under strong competitive conditions in which major retail development at one city produces an absolute loss to the other city. Therefore, the twin cities seesaw through the introduction of innovations such as large shops in order to gain a more advantageous competitive position, resulting in competitive oscillations between them. This finding implies that the introduction of innovation to centres is a competitive device in the medium-term and is consistent with the view that the diffusion of innovation is closely related to the competitive process.

The Anchor-Last Deployment Problem for Inextensible Mooring Lines

1975 ◽  
Vol 97 (3) ◽  
pp. 1046-1052 ◽  
Author(s):  
Robert C. Rupe ◽  
Robert W. Thresher
Keyword(s):  
Numerical Model ◽  
Equations Of Motion ◽  
Simultaneous Equations ◽  
Mooring Line ◽  
Integration Scheme ◽  
Lumped Mass ◽  
Mooring Lines ◽  
Concentrated Masses ◽  
Predictor Corrector ◽  
Lagrange’S Method

A lumped mass numerical model was developed which predicts the dynamic response of an inextensible mooring line during anchor-last deployment. The mooring line was modeled as a series of concentrated masses connected by massless inextensible links. A set of angles was used for displacement coordinates, and Lagrange’s Method was used to derive the equations of motion. The resulting formulation exhibited inertia coupling, which, for the predictor-corrector integration scheme used, required the solution of a set of linear simultaneous equations to determine the acceleration of each lumped mass. For the selected cases studied the results show that the maximum tension in the cable during deployment will not exceed twice the weight of the cable and anchor in water.

scholarly journals Planetary Gearbox Dynamic Modeling Considering Bearing Clearance and Sun Gear Tooth Crack

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2638
Author(s):  
Xianhua Chen ◽  
Xingkai Yang ◽  
Ming J. Zuo ◽  
Zhigang Tian
Keyword(s):  
Dynamic Model ◽  
Dynamic Modeling ◽  
Failure Modes ◽  
Gear Tooth ◽  
Working Environment ◽  
The Sun ◽  
Planetary Gearbox ◽  
Bearing Clearance ◽  
Vibration Responses ◽  
Planet Gear

Planetary gearbox systems are critical mechanical components in heavy machinery such as wind turbines. They may suffer from various failure modes, due to the harsh working environment. Dynamic modeling is a useful method to support early fault detection for enhancing reliability and reducing maintenance costs. However, reported studies have not considered the sun gear tooth crack and bearing clearance simultaneously to analyze their combined effect on vibration characteristics of planetary gearboxes. In this paper, a dynamic model is developed for planetary gearboxes considering the clearance of planet gear, sun gear, and carrier bearings, as well as sun gear tooth crack levels. Bearing forces are calculated considering bearing clearance, and the dynamic model equations are updated accordingly. The results reveal that the combination of bearing clearances can affect the vibration response with sun gear tooth crack by increasing the kurtosis. It is found that the effect of planet gear bearing clearance is very small, while the sun gear and carrier bearing clearance has clear impact on the vibration responses. These findings suggest that the incorporation of bearing clearance is important for planetary gearbox dynamic modeling.

Concise Equations for Rotor Dynamics Analysis

1995 ◽  
Author(s):  
W. J. Chen
Keyword(s):  
Equations Of Motion ◽  
Rotor Dynamics ◽  
Memory Storage ◽  
The Other ◽  
Dynamics Analysis ◽  
Real Domain ◽  
The Matrix ◽  
System Equations ◽  
Ordering Algorithms ◽  
Matrix Bandwidth

Abstract Concise equations for rotor dynamics analysis are presented. Two coordinate ordering methods are introduced in the element equations of motion. One is in the real domain and the other is in the complex domain. The two proposed ordering algorithms lead to more compact element matrices. A station numbering technique is also proposed for the system equations during the assembly process. This numbering technique can minimize the matrix bandwidth, the memory storage and can increase the computational efficiency.

Sensor Dynamic Modeling Based on LS-SVM and NGA

2008 ◽  
Vol 381-382 ◽  
pp. 439-442
Author(s):  
Qi Wang ◽  
Zhi Gang Feng ◽  
K. Shida
Keyword(s):  
Genetic Algorithm ◽  
Neural Networks ◽  
Support Vector Machine ◽  
Least Squares ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Support Vector ◽  
Local Minima ◽  
Highly Nonlinear ◽  
Sharing Function

Least squares support vector machine (LS-SVM) combined with niche genetic algorithm (NGA) are proposed for nonlinear sensor dynamic modeling. Compared with neural networks, the LS-SVM can overcome the shortcomings of local minima and over fitting, and has higher generalization performance. The sharing function based niche genetic algorithm is used to select the LS-SVM parameters automatically. The effectiveness and reliability of this method are demonstrated in two examples. The results show that this approach can escape from the blindness of man-made choice of LS-SVM parameters. It is still effective even if the sensor dynamic model is highly nonlinear.

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