Identification of Nonlinear Manoeuvring Models for Marine Vessels Using Planar Motion Mechanism Tests

2015 ◽  
Author(s):  
Andrew Ross ◽  
Vahid Hassani ◽  
Ørjan Selvik ◽  
Edvard Ringen ◽  
Dariusz Fathi
Keyword(s):  
Degrees Of Freedom ◽  
Experimental Methods ◽  
Numerical Determination ◽  
Motion Mechanism ◽  
Planar Motion Mechanism ◽  
Numerical Tools ◽  
Marine Vessels ◽  
Advanced Model ◽  
Three Degrees Of Freedom

A nonlinear manoeuvring model in three degrees of freedom is presented. MARINTEK’s approach to the numerical determination of this manoeuvering model’s parameters is then shown. Finally the process of taking advanced experimental methods, and utilising MARINTEK’s numerical tools to generate an advanced model available for use in VeSim, MARINTEK’s in-house simulator tool, is shown as a demonstration that the model combined with numerical tools is of great use in making manoeuvring predictions.

Contributions to the Determination of the Equations of Motion for Multidegree of Freedom Systems

1971 ◽  
Vol 93 (1) ◽  
pp. 191-195 ◽  
Author(s):  
Desideriu Maros ◽  
Nicolae Orlandea
Keyword(s):  
Differential Equations ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
System Of Differential Equations ◽  
Original Contribution ◽  
Deductive Method ◽  
Method Of Solution ◽  
Further Development ◽  
Three Degrees Of Freedom

This paper is a further development of the kinematic problem presented in our 1967 paper [1] in which we have obtained the transmission functions for different orders of plane systems with many degrees of freedom. This paper establishes the corresponding system of differential equations of motion beginning with these functions. The purpose of this paper is to facilitate computer programming. Our study is based on the work of R. Beyer [2, 3] and is the first original addition to his papers. A second original contribution to Beyer’s theories is the deductive method of solution, from general to particular, which we have, incorporated in our work. Beyer concluded that the cases having two or three degrees of freedom can be considered as particular solutions to the results obtained.

Determination of Hydrodynamic Parameters for Remotely Operated Vehicles

2016 ◽  
Author(s):  
Ole A. Eidsvik ◽  
Ingrid Schjølberg
Keyword(s):  
Numerical Simulations ◽  
Degrees Of Freedom ◽  
Analytical Data ◽  
Relative Difference ◽  
Accurate Estimate ◽  
Six Degrees Of Freedom ◽  
Hydrodynamic Parameters ◽  
Planar Motion Mechanism ◽  
Rotational Degrees Of Freedom

In this paper the hydrodynamic parameters that characterize the behavior of a typical unmanned underwater vehicle are evaluated. A complete method for identifying these parameters is described. The method is developed to give a brief and accurate estimate of these parameters in all six degrees of freedom using basic properties of the vehicle such as dimensions, mass and shape. The method is based on both empirical and analytical results for typical reference geometries (ellipsoids, cubes, etc.). The method is developed to be applicable for a wide variety of UUV designs as these typically varies substantially. The method is then applied to a small observation class ROV. The results are first verified using an experimental method in which the full scale ROV is towed using a planar motion mechanism. An additional verification is performed with numerical simulations using Computational Fluid Dynamics and a radiation/diffraction program. The method shows promising results for both damping and added mass for the tested case. The translational degrees of freedom are more accurate than the rotational degrees of freedom which are expected as most empirical and analytical data are for translational degrees of freedom. The case study also reveals that the relative difference between the numerical simulations and the experimental results are similar to the relative difference between the proposed method and the experiment.

SHIP MANOEUVRING PREDICTION BASED ON NUMERICAL TOWING TANK TECHNIQUE

2021 ◽  
Vol 160 (A3) ◽  
Author(s):  
J Yao ◽  
X Cheng ◽  
Z Liu
Keyword(s):  
Degrees Of Freedom ◽  
Measured Data ◽  
Type Model ◽  
Empirical Formulas ◽  
Practical Procedure ◽  
Group Type ◽  
Hydrodynamic Derivatives ◽  
Planar Motion Mechanism ◽  
The Us ◽  
Three Degrees Of Freedom

A practical procedure is proposed in this paper to predict ship manoeuvrability. A three degrees of freedom MMG (Japanese Manoeuvring Mathematical Modelling Group)-type model is established to simulate rudder manoeuver. Propeller thrust and rudder loads are calculated by empirical formulas, whereas the hull forces as well as moment are determined with hydrodynamic derivatives which are derived from CFD (Computational Fluid Dynamics) computations. An own developed RANS (Reynolds-Averaged Naiver-Stokes) solver on the base of OpenFOAM is applied to simulate a range of PMM (Planar Motion Mechanism) tests and Fourier analyses of the computed results are carried out to obtain the required derivatives. In order to demonstrate the effectivity of the whole procedure and the RANS computations, the US (United States) combatant DTMB 5415 is taken as a sample for an application. Forced motions of surge, sway, yaw and yaw with drift for the bare hull with bilge keels are simulated. Thereafter, simulations of standard rudder manoeuvers, i.e. turning and zigzag, are performed by applying the computed derivatives. The results are compared with available measured data. It has been shown that the present procedure together with the RANS method can be used to evaluate the manoeuvrability of a ship since general good agreements between the simulated results and measured data are achieved.

scholarly journals Some aspects of topology and kinematics of a 3DOF translational parallel mechanism

2014 ◽  
Vol 19 (1) ◽  
pp. 5-15 ◽  
Author(s):  
J. Bałchanowski
Keyword(s):  
Kinematic Analysis ◽  
Inverse Kinematics ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Analytical Procedure ◽  
Method Of Determination ◽  
Fixed Orientation ◽  
Three Degrees Of Freedom ◽  
Selection Of

Abstract The paper presents elements of the topology, geometry and the kinematic analysis of a translational parallel mechanism with three degrees of freedom. In such mechanisms the selection of a proper structure and geometry ensures that the driven link maintains a fixed orientation relative to the base. The method of determination of the configuration of mechanisms using contour vector notation was elaborated in the paper. The equations for the analysis of the direct and inverse kinematics task are determined. An analytical procedure for determining the system’s singular positions is presented and illustrated with examples

scholarly journals An Application of a Special Method for Designating the Control Forces for the Homing of an Anti-Aircraft Missile on an Aerial Target by Use of a Method of Proportional Navigation

2018 ◽  
Vol 9 (4) ◽  
pp. 149-162
Author(s):  
Konrad STEFAŃSKI
Keyword(s):  
Degrees Of Freedom ◽  
Control Method ◽  
Special Method ◽  
Proportional Navigation ◽  
Switching Algorithm ◽  
Airborne Target ◽  
Control Forces ◽  
Positive Results ◽  
Three Degrees Of Freedom

An analysis of application feasibility of a special method for surface-to-air missile (SAM) control during homing on an airborne target was carried out in this paper. A prior implementation of the method was motion control for a gyroscope axis with three degrees of freedom [1, 2] at the stages of spatial seeking and tracking of a detected target. The positive results obtained during that research led to a conclusion that the proposed control method would be appropriate for the determination of the control forces for missile guidance. This method consists of the application of the phase trajectories of control errors. Switching over of the control forces at suitable phase plane points reduced the control errors to zero and facilitated a proper flight path of the SAM. This paper presents a switching algorithm, equations of the kinematics and dynamics of SAM flight, and a number of examples of numerical simulations of the problem contemplated herein. The simulation results were represented in a graphic format.

Structural and Kinematic Analysis of the Isomorphic Mechanism of a Parallel Structure for Translational Movements of the Output Link

2021 ◽  
pp. 35-40
Author(s):  
T.V. Edakina ◽  
A.I. Edakin ◽  
V.V. Samoilova ◽  
V.S. Ramzhaev
Keyword(s):  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Kinematic Chain ◽  
Parallel Structure ◽  
Dimensional Model ◽  
Output Link ◽  
Three Dimensional Model ◽  
Industrial Enterprises ◽  
Three Degrees Of Freedom

The article considers the mechanism of a parallel structure with three degrees of freedom, having the property of isomorphism. The ratio between the movements in the drive and the movements of the output link is constant. This is due to the fact that all linear drivers are located parallel to the corresponding axes of the fixed coordinate system, and in each kinematic chain there are two rotational kinematic pairs, the which axes are parallel to the axes of the corresponding linear drivers. In addition, each kinematic chain has two dyads that provide linear motion of the linear driver rod. On the basis of the developed three-dimensional model, a structural analysis of the mechanism with determination of the number of degrees of freedom and solving the problem of its positions was carried out. The proposed mechanism can be applied in many areas of activity of industrial enterprises, including additive technologies due to the growth of automation, robotization and the development of artificial intelligence.

Ship Manoeuvring Prediction Based on Numerical Towing Tank Technique

2018 ◽  
Vol Vol 160 (A3) ◽  
Author(s):  
J Yao ◽  
X Cheng ◽  
Z Liu
Keyword(s):  
Degrees Of Freedom ◽  
Measured Data ◽  
Type Model ◽  
Empirical Formulas ◽  
Practical Procedure ◽  
Group Type ◽  
Hydrodynamic Derivatives ◽  
Planar Motion Mechanism ◽  
The Us ◽  
Three Degrees Of Freedom

A practical procedure is proposed in this paper to predict ship manoeuvrability. A three degrees of freedom MMG (Japanese Manoeuvring Mathematical Modelling Group)-type model is established to simulate rudder manoeuver. Propeller thrust and rudder loads are calculated by empirical formulas, whereas the hull forces as well as moment are determined with hydrodynamic derivatives which are derived from CFD (Computational Fluid Dynamics) computations. An own developed RANS (Reynolds-Averaged Naiver-Stokes) solver on the base of OpenFOAM is applied to simulate a range of PMM (Planar Motion Mechanism) tests and Fourier analyses of the computed results are carried out to obtain the required derivatives. In order to demonstrate the effectivity of the whole procedure and the RANS computations, the US (United States) combatant DTMB 5415 is taken as a sample for an application. Forced motions of surge, sway, yaw and yaw with drift for the bare hull with bilge keels are simulated. Thereafter, simulations of standard rudder manoeuvers, i.e. turning and zigzag, are performed by applying the computed derivatives. The results are compared with available measured data. It has been shown that the present procedure together with the RANS method can be used to evaluate the manoeuvrability of a ship since general good agreements between the simulated results and measured data are achieved.

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