• Title/Summary/Keyword: Dynamic numerical modeling

Search Result 473, Processing Time 0.024 seconds

An analysis scheme for protocols specified in SDL using reachability graph (도달성 그래프를 이용한 SDL 표현 프로토콜 분석 기법)

  • 김환철
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.21 no.12
    • /
    • pp.3109-3120
    • /
    • 1996
  • SDL has been standardized to specify behavioral aspects of communication systems based on the formal description technique, and it is powerful and user friendly in the sense of supporting human communication and understanding, formal analysis andcomparison of behaviors, alternative implementations and design optimization, and its structural decomposition. However, SDL is not sufficient for an efficient handing of entrire system descriptions because the communication systems are generally very complex, and composed from the various interactions among sub-systems. Also, it is very difficult to explicitly verify dynamic views such as liveness and reachability. it leads the demands on analysis scheme to verify dynamic behaviros of specified systems. This paper presents modeling concepts of Petri Nets from SDL and transformation rules to Numerical Petri Nets to provide efficient technqiques for verification of dynamic behaviors, and proposes the reachability garaph that is able to trace all reachable states of a modeled system and reduce an information loss on the reachability tree.

  • PDF

Dynamic Analysis of an Impulsively Forced Rotating Cantilever Beam (충격력을 받는 회전하는 외팔 보의 동적 해석)

  • Lim, Hong-Seok;Yoo, Hong-Hee
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.16 no.3 s.108
    • /
    • pp.226-232
    • /
    • 2006
  • This paper presents the dynamic analysis of an impulsively forced rotating cantilever beam with rigid body motion. The transient response induced by the impulsive force and the rigid body motion of the beam are calculated using hybrid deformation variable modeling with the Rayleigh-Ritz assumed mode methods. The stiffness variation effect due to the rigid body motion of the beam is considered in this study Also, the effects of the impulsive force position and the angular velocity on the transient responses of the beam are investigated through numerical works.

Sliding Mode Control for a High-Load Wheeled Mobile Robot (중하중을 받는 이동로붓의 슬라이딩모드 제어)

  • 홍대희;정재훈
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.17 no.5
    • /
    • pp.145-153
    • /
    • 2000
  • This paper discusses the dynamic modeling and robust control development for a differentially steered mobile robot subject to wheel slip according to high load. Consideration of wheel slip is crucial for high load applications such as construction automation tasks because wheel slip acts as a severe disturbance to the system. It is shown that the uncertainty terms due to the wheel slip satisfy the matching condition for the sliding mode control design. From the full dynamic model of the mobile robot, a reduced ideal model is extracted to facilitate the control design. The sliding mode control method ensures the dynamic tracking performance for such a mobile robot. Numerical simulation shows the promise of the developed algorithm.

  • PDF

The grain size prediction of Al-5wt%Mg alloy by FEM (유한요소법을 이용한 Al-5%Mg 합금의 미세조직 크기예측)

  • 조종래
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 1999.03b
    • /
    • pp.249-252
    • /
    • 1999
  • A numerical analysis was perfomed to predict flow curves and dynamic recrystallization behaviors of Al-5%Mg alloy on the basis of results of hot compression tests. The hot compression tests were carried out in the ranges of 350-50$0^{\circ}C$ and 5$\times${{{{ {10 }^{-3 } }}}}~3$\times${{{{ {10 }^{0 } }}}}/sec to obtain the Zener-Hollmon parameter. In the modelling equation the effects os strain hardening and dynamic recrystallization were taken into consideration. A model for predicting the evolution of microstructure in Al-5%Mg alloy during thermomechanical processing was developed in terms of dynamic recrystallization phenomena, The microstructure model was combined with finite element modeling(FEM) to predict microstructure development Model predictions showed good agreement with microstructures obtained in compression tests.

  • PDF

Identification and Control of Nonlinear System Using Dynamic Neural Model with State Parameter Representation (상태변수 표현을 가진 동적 신경망을 이용한 비선형 시스템의 식별과 제어)

  • Park, Seong-Wook;Seo, Bo-Hyeok
    • Proceedings of the KIEE Conference
    • /
    • 1995.11a
    • /
    • pp.157-160
    • /
    • 1995
  • Neural networks potentially offer a general framework for modeling and control of nonlinear systems. The conventional neural network models are a parody of biological neural structures, and have very slow learning. In order to emulate some, dynamic functions, such as learning and adaption, and to better reflect the dynamics of biological neurons, M.M.Gupta and D.H.Rao have developed a 'dynamic neural model'(DNU). Proposed neural unit model is to introduce some dynamics to the neuron transfer function, such that the neuron activity depends on internal states. Numerical examples are presented for a model system. Those case studies showed that the proposed DNU is so useful in practical sense.

  • PDF

Dynamic Response Analysis of Rotating Functionally Graded Thin-Walled Blades Exposed to Steady High Temperature and External Excitation (고온에서 외부 가진력을 받는 회전하는 경사기능 박간 블레이드의 동적응답 해석)

  • Na Sunsoo;Oh Byungyoung
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.29 no.7 s.238
    • /
    • pp.976-982
    • /
    • 2005
  • This paper is dedicated to the thermoelastic modeling and dynamic response of the rotating blades made of functionally graded ceramic-metal based materials. The blades are modeled as non-uniform thin walled beams fixed at the hub with various selected values of setting angles and pre-twisted angles. In this study, the blade is rotating with a constant angular velocity and exposed to a steady temperature field as well as external excitation. Moreover, the effect of the temperature gradient through the blade thickness is considered. Material properties are graded in the thickness direction of the blade according to the volume fraction power law distribution. The numerical results highlight the effects of the volume fraction, temperature gradient, taper ratio, setting angle and pre-twisted angle on the dynamic response of bending-bending coupled beam characteristics and pertinent conclusions are outlined.

Fuzzy control for geometrically nonlinear vibration of piezoelectric flexible plates

  • Xu, Yalan;Chen, Jianjun
    • Structural Engineering and Mechanics
    • /
    • v.43 no.2
    • /
    • pp.163-177
    • /
    • 2012
  • This paper presents a LMI(linear matrix inequality)-based fuzzy approach of modeling and active vibration control of geometrically nonlinear flexible plates with piezoelectric materials as actuators and sensors. The large-amplitude vibration characteristics and dynamic partial differential equation of a piezoelectric flexible rectangular thin plate structure are obtained by using generalized Fourier series and numerical integral. Takagi-Sugeno (T-S) fuzzy model is employed to approximate the nonlinear structural system, which combines the fuzzy inference rule with the local linear state space model. A robust fuzzy dynamic output feedback control law based on the T-S fuzzy model is designed by the parallel distributed compensation (PDC) technique, and stability analysis and disturbance rejection problems are guaranteed by LMI method. The simulation result shows that the fuzzy dynamic output feedback controller based on a two-rule T-S fuzzy model performs well, and the vibration of plate structure with geometrical nonlinearity is suppressed, which is less complex in computation and can be practically implemented.

Dynamic Walking Analysis for Biped Robot (이족 로봇을 위한 동적 보행 해석)

  • Park, In-Gyu;Kim, Jin-Geol
    • Proceedings of the KIEE Conference
    • /
    • 2000.07d
    • /
    • pp.2804-2807
    • /
    • 2000
  • This paper suggests a method of the forward dynamic analysis for the computer simulation on the analysis of the dynamic behavior for biped walking robot. The equations f motion of the system or the simulation are constructed by using the Method of the multibody dynamics which is powerful method for modeling of the complex biped system. For the simplicity of simulation, we consider that the sole of the contacting foot is affected by the reaction forces for tree structure system topology instead of the addition or deletion of the kinematic constraints. The ground reaction forces can be modeled using the simple spring and damper model at the three contacting points on the sole of the foot. For minimizing the errors of numerical integration, the number of equations of motion is minimized by adding the driving constraints or a controller instead of the direct driving torques.

  • PDF

3D Transient Analysis of Linear Induction Motor Using the New Equivalent Magnetic Circuit Network Method

  • Jin Hur;Kang, Gyu-Hong;Hong, Jung-Pyo
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
    • /
    • v.3B no.3
    • /
    • pp.122-127
    • /
    • 2003
  • This paper presents a new time-stepping 3-D analysis method coupled with an external circuit with motion equation for dynamic transient analysis of induction machines. In this method, the magneto-motive force (MMF) generated by induced current is modeled as a passive source in the magnetic equivalent network. So, by using only scalar potential at each node, the method is able to analyze induction machines with faster computation time and less memory requirement than conventional numerical methods. Also, this method is capable of modeling the movement of the mover without the need for re-meshing and analyzing the time harmonics for dynamic characteristics. From comparisons between the results of the analysis and the experiments, it is verified that the proposed method is capable of estimating the torque, harmonic field, etc. as a function of time with superior accuracy.

A Study on the Frequency Response Characteristics of High Response Flow Control Servo Valve

  • Seo Jong Soo;Shin You Sik;Chun Young Heung;Jeong Hyo Min;Chung Han Shik
    • International Journal of Air-Conditioning and Refrigeration
    • /
    • v.12 no.3
    • /
    • pp.131-140
    • /
    • 2004
  • The purpose of this research is to derive the principal design parameters governing the dynamic characteristics of the high response flow control servo valve. For this purpose, a numerical modeling of the servo valve system and a parameter sensitivity analysis to a frequency response characteristics were performed. As a result of these analysis, a basis for improvement of a dynamic characteristics of servo valve was arranged.