Symbolic Graph Techniques Applied to Mechanical System Analysis and Featuring

2005 ◽  
Author(s):  
Mourad Fakhfakh ◽  
Tahar Fakhfakh ◽  
Mourad Loulou ◽  
Mohammed Haddar ◽  
Nouri Masmoudi
Keyword(s):  
Transfer Function ◽  
Mechanical System ◽  
Directed Graph ◽  
Dynamic Systems ◽  
System Analysis ◽  
Symbolic Analysis ◽  
Analysis Tool ◽  
Automatic Modeling ◽  
Input And Output

In this paper we present a symbolic analysis tool. It uses the directed graph techniques for the automatic modeling, featuring and analysis of dynamic systems. We use the proposed tool to model mechanical system. With the help of the electromechanical analogies, this tool automatically generates symbolic and semi-symbolic transfer function between specified input and output nodes. The performances of the symbolic tool are exemplified for some dynamic systems.

The Motion of the Human Center of Mass and its Relationship to Mechanical Impedance

1966 ◽  
Vol 8 (5) ◽  
pp. 399-405 ◽  
Author(s):  
Edmund B. Weis ◽  
Frank P. Primiano
Keyword(s):  
Transfer Function ◽  
Mechanical System ◽  
Degrees Of Freedom ◽  
Center Of Mass ◽  
Mechanical Impedance ◽  
Second Order ◽  
Analysis Tool ◽  
Isotropic Theory ◽  
Spatial Degrees Of Freedom

This report concerns the development of a relationship between the human mechanical impedance and the coupling of the human center of mass to the environment. The mechanical impedance is a common analysis tool in biomechanics while the analysis of the coupling of the center of mass to the environment is technically more difficult, if not impossible. The development is based on linear, passive, isotropic theory and shows that the transfer function which expresses the relation between the motion of the center of mass and the motion of the source is similar to a linear second order mechanical system in each of the translational spatial degrees of freedom.

scholarly journals Studying State Convergence of Input-to-State Stable Systems with Applications to Power System Analysis

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 92 ◽  
Author(s):  
Antonio T. Alexandridis
Keyword(s):  
Nonlinear Systems ◽  
Power Systems ◽  
Power System ◽  
System Analysis ◽  
Nonlinear Models ◽  
Sufficient Conditions ◽  
Stability And Convergence ◽  
Convergence To Equilibrium ◽  
Analysis Tool ◽  
Wide Range

In stability studies, the response of a system enforced by external, known or unknown, inputs is of great importance. Although such an analysis is quite easy for linear systems, it becomes a cumbersome task when nonlinearities exist in the system model. Nevertheless, most of the real-world systems are externally enforced nonlinear systems with nonzero equilibriums. Representative examples in this category include power systems, where studies on stability and convergence to equilibrium constitute crucial objectives. Driven by this need, the aim of the present work is twofold: First, to substantially complete the theoretical infrastructure by establishing globally valid sufficient conditions for externally enforced nonlinear systems that converge to nonzero equilibriums and, second, to deploy an efficient method easily applicable on practical problems as it is analyzed in detail on a typical power system example. To that end, in the theoretical first part of the paper, a rigorous nonlinear analysis is developed. Particularly, starting from the well-established nonlinear systems theory based on Lyapunov techniques and on the input-to-state stability (ISS) notion, it is proven after a systematic and lengthy analysis that ISS can also guarantee convergence to nonzero equilibrium. Two theorems and two corollaries are established to provide the sufficient conditions. As shown in the paper, the main stability and convergence objectives for externally enforced systems are fulfilled if simple exponential or asymptotic converging conditions can be proven for the unforced system. Then, global or local convergence is established, respectively, while for the latter case, a novel method based on a distance-like measure for determining the region of attraction (RoA) is proposed. The theoretical results are examined on classic power system generation nonlinear models. The power system examples are suitably selected in order to effectively demonstrate the proposed method as a stability analysis tool and to validate all the particular steps, especially that of evaluating the RoA. The examined system results clearly verify the theoretical part, indicating a rather wide range of applications in power systems.

Dynamic System Identification Using a Step Input

2005 ◽  
Vol 24 (2) ◽  
pp. 125-134
Author(s):  
Manabu Kosaka ◽  
Hiroshi Uda ◽  
Eiichi Bamba ◽  
Hiroshi Shibata
Keyword(s):  
Steady State ◽  
System Identification ◽  
Transfer Function ◽  
Step Response ◽  
Output Data ◽  
Mass System ◽  
Input And Output ◽  
Rational Transfer ◽  
Line Identification ◽  
The Moment

In this paper, we propose a deterministic off-line identification method performed by using input and output data with a constant steady state output response such as a step response that causes noise or vibration from a mechanical system at the moment when it is applied but they are attenuated asymptotically. The method can directly acquire any order of reduced model without knowing the real order of a plant, in such a way that the intermediate parameters are uniquely determined so as to be orthogonal with respect to 0 ∼ N-tuple integral values of output error and irrelevant to the unmodelled dynamics. From the intermediate parameters, the coefficients of a rational transfer function are calculated. In consequence, the method can be executed for any plant without knowing or estimating its order at the beginning. The effectiveness of the method is illustrated by numerical simulations and also by applying it to a 2-mass system.

Improving Cylindrical Pin Cage Bearing Performance in Mill Applications Using Dynamic Modeling and Space Filling Design

2007 ◽  
Author(s):  
Bradley M. Pederson ◽  
Jerry Rhodes
Keyword(s):  
Transfer Function ◽  
Dynamic Modeling ◽  
Space Filling ◽  
Input And Output ◽  
Performance Response ◽  
Response Optimization ◽  
Space Filling Design

A dynamic cylindrical bearing model was modified to analyze large bore cylindrical mill bearings with pin cages. A factor-response methodology was coupled to the dynamic modeling input and output variables in order to generate a suitable transfer function for predicting bearing performance. Response optimization of the transfer function indicated that a traction-based parameter was determined to have the greatest effect on reducing roller slip and improving bearing performance.

SATORC: A system analysis tool for reengineering complex systems

1997 ◽  
Vol 33 (1-2) ◽  
pp. 179-183 ◽  
Author(s):  
Sharon D. Ramsey ◽  
Celestine A. Ntuen
Keyword(s):  
Complex Systems ◽  
System Analysis ◽  
Analysis Tool
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