Four Dimensional Holospectrum—A New Method for Analyzing Force Distributions

1997 ◽  
Vol 119 (1) ◽  
pp. 95-104 ◽  
Author(s):  
R. Du ◽  
Yue-Dong Chen ◽  
Yubao Chen
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Major Axis ◽  
Minor Axis ◽  
New Method ◽  
Normal Vector ◽  
Force Analysis ◽  
On Line ◽  
Three Dimensional Space

In this paper, a new method, called four dimensional (4D) holospectrum, is introduced for analyzing force distributions. First, it is shown that the dynamics of a three dimensional force can be represented by the holospectrum, which consists of a series of ellipses in a three dimensional space with each ellipse representing the frequency characteristics of the force at a concerned frequency. An ellipse can be described by its normal vector, major axis, minor axis, eccentric ratio, area, and inclination angle. The formula of calculating these quantities are derived next. 4D holospectrum reveals the dynamic characteristics of a three dimensional force such as phase and spatial correlation that cannot be accessed otherwise. As demonstrated by the experimental tests on a spindle, 4D holospectrum adds a new dimension for force analysis and is very valuable for on-line monitoring and diagnosis as well as design.

Research on Mass Partition Coefficient for a Whole Car under Vertical and Lateral Road Excitations

2010 ◽  
Vol 29-32 ◽  
pp. 177-182 ◽  
Author(s):  
Long Wu
Keyword(s):  
Partition Coefficient ◽  
Physical Model ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Force Analysis ◽  
Analytical Results ◽  
Dynamical Coupling ◽  
And Control ◽  
Three Dimensional Space

Consider the imperfectness of mass partition coefficient for a whole car in automotive theories, a vehicle physical model with fourteen degree of freedoms under vertical and lateral road excitations is adopted as research background in this paper. With the help of force analysis of sprung mass in three dimensional space and investigations on vertical, lateral, pitch, roll and yaw motions, the ration relations of dynamical coupling between a whole suspension and four quarter suspensions are deduced and achieved. The analytical results obtained in this paper develop the theoretical content of mass partition coefficient. It will be utilized to analyze, test and control among different car suspensions in the fields of vibration, handling and steering systems in future.

Neural Networks Based Attitude Decoupling Control for AUV with X-Shaped Fins

2013 ◽  
Vol 819 ◽  
pp. 222-228 ◽  
Author(s):  
Xiu Jun Sun ◽  
Jian Shi ◽  
Yan Yang
Keyword(s):  
Neural Networks ◽  
Attitude Control ◽  
Autonomous Underwater Vehicle ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Mathematic Model ◽  
On Line ◽  
The Neural Networks ◽  
Vehicle Motion ◽  
Three Dimensional Space

Attitude control in three-dimensional space for AUV (autonomous underwater vehicle) with x-shaped fins is complicated but advantageous. Yaw, pitch and roll angles of the vehicle are all associated with deflection angle of each fin while navigating underwater. In this paper, a spatial motion mathematic model of the vehicle is built by using theorem of momentum and angular momentum, and the hydrodynamic forces acting on x-shaped fins and three-blade propeller are investigated to clarify complex principle of the vehicle motion. In addition, the nonlinear dynamics equation which indicates the coupling relationship between attitude angles of vehicle and rotation angles of x-shaped fins is derived by detailed deduction. Moreover, a decoupling controller based on artificial neural networks is developed to address the coupling issue exposed in attitude control. The neural networks based controller periodically calculates and outputs deflection angles of fins according to the attitude angles measured with magnetic compass, thus the vehicles orientation can be maintained. By on-line training, twenty four weights in this controller converged according to index function.

scholarly journals Application of SN-EMD in Mode Feature Extraction of Ship Radiated Noise

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Fang Niu ◽  
Juan Hui ◽  
Anbang Zhao ◽  
Yue Cheng ◽  
Yang Chen
Keyword(s):  
High Frequency ◽  
Dimensional Space ◽  
Three Dimensional ◽  
New Method ◽  
Center Frequency ◽  
Radiated Noise ◽  
Mode Decomposition ◽  
Mixing Problem ◽  
Original Information ◽  
Three Dimensional Space

Due to the randomness of added noise, noise-assisted versions based on EMD (empirical mode decomposition) usually cause new “mode mixing” problem. In addition, these algorithms also have problems such as high time-consuming and large recovering error. For the reasons, a new method SN-EMD (Selective Noise-assisted EMD) is put forward in this paper. It determines whether to add noise as assistance by judging whether there is high frequency intermittent component contained in the signal or not. The new method was proved to have the optimal performance by comparing the performance parameters for evaluating the decomposition. In this paper, SN-EMD was used to decompose ship radiated noise. On account of the differences in the original information contained in each mode of radiated noise signals from different ship, we selected the first three modes for processing. Average instantaneous frequency, center frequency, energy density, and energy distribution ratio were extracted as mode feature of ship targets for classification and recognition. Spatial distribution of the feature quantities in three-dimensional space verified similarity of the same target and separability of different targets.

Three-Dimensional Simulation of Virtual Plants Branch Structure Based on Quasi Binary-Tree and L System

2014 ◽  
Vol 1049-1050 ◽  
pp. 1650-1653
Author(s):  
Ying Ying Yin
Keyword(s):  
Binary Tree ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Tree Structure ◽  
New Method ◽  
L System ◽  
Dimensional Simulation ◽  
Binary Tree Structure ◽  
Three Dimensional Space

In order to simulate the plant branch structure in three-dimensional space, and extract the growth more efficiently, this paper presented a new method to simulate the structure of plant branch based on quasi binary-tree structure and three-dimensional L system. The results of the actual trees simulation shows that this method can describe the plants branch structure efficiently and provide a new way for the simulation of plants.

A New Method to Solving the Internal Mass of Rigid Body Based on the Principle of Inertia Parameters

2013 ◽  
Vol 344 ◽  
pp. 37-40
Author(s):  
Ning Sun ◽  
Huan Yu Li ◽  
Jing Jing Gong
Keyword(s):  
Rigid Body ◽  
Coordinate Transformation ◽  
Dimensional Space ◽  
Three Dimensional ◽  
New Method ◽  
Internal Mass ◽  
System A ◽  
Coordinate Origin ◽  
Inertia Parameters ◽  
Three Dimensional Space

On the basis of Coordinate transformation analysis of the inertia parameters in three-dimensional space, according to the characteristic that the coordinate direction is existed and unique which the product of inertia is 0 when rotating the coordinate system, a new method to judge and calculate the particle information by searching for the intersection of the two lines that lead from two different coordinate origin is proposed. The processes and procedures to calculate the internal mass of rigid body are deduced theoretically. A special numerical example is given to verify the correctness of the theory. The error factors are analyzed qualitatively as well.

The principles of a new method, MNF-3D, for concentration of magnetic particles in three-dimensional space

Measurement ◽  
2017 ◽  
Vol 112 ◽  
pp. 137-140 ◽  
Author(s):  
Ryszard Krzyminiewski ◽  
Bernadeta Dobosz ◽  
Grzegorz Schroeder ◽  
Joanna Kurczewska
Keyword(s):  
Magnetic Particles ◽  
Dimensional Space ◽  
Three Dimensional ◽  
New Method ◽  
Three Dimensional Space

A Discrete Model of an Extensible String in Three-Dimensional Space

1999 ◽  
Vol 66 (3) ◽  
pp. 695-701 ◽  
Author(s):  
K. Nishinari
Keyword(s):  
Exact Solutions ◽  
Numerical Simulations ◽  
Discrete Model ◽  
Dimensional Space ◽  
Three Dimensional ◽  
New Method ◽  
Continuous Limit ◽  
Soliton Theory ◽  
Basic Equations ◽  
Three Dimensional Space

In this paper, a discrete model of an extensible string in three-dimensional space is presented. The model contains the bending and twisting of a string, and becomes the special Cosserat string in the continuous limit. We also present a new method of analyzing a string in space by the soliton theory, which can reduce the basic equations to a simpler tractable form. Some exact solutions are obtained by the soliton theory. The discrete basic equations are also shown to be suitable for numerical simulations of string dynamics.

Stereokinesis with Moving Visual Phantoms

Perception ◽  
1987 ◽  
Vol 16 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Paola Bressan ◽  
Giorgio Vallortigara
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Major Axis ◽  
Circular Ring ◽  
Frontoparallel Plane ◽  
Flat Pattern ◽  
Three Dimensional Space

When a flat pattern composed of a solid ellipse with two symmetrical semirings (corresponding to the visible parts of a contour ellipse whose major axis is perpendicular to that of the solid ellipse) is slowly rotated in the frontoparallel plane, a compelling three-dimensional impression occurs. Subjects report seeing an egg-shaped object that is inserted into a circular ring: the two objects move solidly into three-dimensional space and a moving visual phantom is generated so that the ring appears completed by an illusory curved bar in the region closest to the observer during rotation. A number of variations of this illusion are presented. It is shown that stereokinetic phantoms (i) maintain the shape of the inducing elements; (ii) appear only after the stereokinetic transformation has taken place; and (iii) depend on the organization of the three-dimensional percept as a whole. Relations between stereokinetic phantoms and other completion phenomena are presented and discussed.

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