• Title/Summary/Keyword: Limit Cycle

Search Result 188, Processing Time 0.231 seconds

Limit Cycle Analysis Of Attitude Control System Using Thruster Under Time Delay Effect (시간지연을 갖는 추력기 자세제어시스템의 Limit Cycle 분석)

  • 안재명;노웅래;정호락;최형돈
    • 제어로봇시스템학회:학술대회논문집
    • /
    • /
    • pp.3-3
    • /
    • 2000
  • Limit cycle analysis of attitude control system using gas jet thrusters is performed. Schmitt-Trigger and PD control laws are applied and solenoid valve time delay is considered. Phase plane method is used for calculation of characteristics of limit cycle. Important characteristics of resultant limit cycle such as frequency, amplitude, maximum rate, and duty ratio could be expressed analytically by proposed method.

  • PDF

Analysis of Dynamic Stability of Limit-cycle Navigation Method (Limit-cycle 항법의 동역학적 안정성 분석)

  • Kim, Dong-Han;Kang, Soo-Hyeok;Lee, Eun-Jin;Ko, Kuk-Won;Nam, Sang-Yep
    • 전자공학회논문지 IE
    • /
    • v.46 no.3
    • /
    • pp.33-41
    • /
    • 2009
  • Because the stability of obstacle avoidance ability is important for the safe operation of mobile robots, this paper deals with the analysis of dynamic stability of Limit-cycle navigation method that was proposed by authors. Limit-cycle navigation method is fast and easy to implement for fast moving mobile robots using limit-cycle characteristics of the 2nd-order nonlinear function. It can be applied to robots in dynamically changing environment such as the robot soccer. By adjusting the radius of the motion circle and the direction of the obstacle avoidance, the mobile robot can avoid the collision with obstacles and move to the destination point. The stability of Limit-cycle navigation method is analyzed with a linear model. To demonstrate the effectiveness and applicability, it is applied to the robot soccer Simulations and real experiments ascertain the merits of the proposed method.

A Real-Time Obstacle Avoidance of Mobile Robot Using Nearness Diagram, Limit-Cycle and Vector Field Method (Nearness Diagram, Limit-Cycle 및 벡터장법을 이용한 이동로봇의 실시간 장애물 회피)

  • Kim, Pil-Gyeom;Jung, Yoon-Ho;Yoon, Jae-Ho;Jie, Min-Seok;Lee, Kang-Woong
    • Journal of Advanced Navigation Technology
    • /
    • v.10 no.2
    • /
    • pp.145-151
    • /
    • 2006
  • In this paper, we propose a novel navigation method combined Nearness Diagram, Limit-Cycle method and the Vector Field Method for avoidance of unexpected obstacles in the dynamic environment. The Limit-Cycle method is used to obstacle avoidance in front of the robot and the Vector Field Method is used to obstacle avoidance in the side of robot. And the Nearness Diagram Navigation is used to obstacle avoidance in the nearness area of the robot. The performance of the proposed method is demonstrate by simulations.

  • PDF

On the limit cycles of aeroelastic systems with quadratic nonlinearities

  • Chen, Y.M.;Liu, J.K.
    • Structural Engineering and Mechanics
    • /
    • v.30 no.1
    • /
    • pp.67-76
    • /
    • 2008
  • Limit cycle oscillations of a two-dimensional airfoil with quadratic and cubic pitching nonlinearities are investigated. The equivalent stiffness of the pitching stiffness is obtained by combining the linearization and harmonic balance method. With the equivalent stiffness, the equivalent linearization method for nonlinear flutter analysis is generalized to address aeroelastic system with quadratic nonlinearity. Numerical example shows that good approximation of the limit cycle can be obtained by the generalized method. Furthermore, the proposed method is capable of revealing the unsymmetry of the limit cycle; however the ordinary equivalent linearization method fails to do so.

Stabilization Control for Limit Cycle of an Inverted Pendulum System

  • Tajima, Takeshi;Ishii, Chiharu
    • 제어로봇시스템학회:학술대회논문집
    • /
    • /
    • pp.507-507
    • /
    • 2000
  • In this paper, a kind of limit cycle of an inverted pendulum system is discussed. We propose a stabilization control law for such a limit cycle of an inverted pendulum system that the pendulum rotates periodically. Besides, the stabilization control law is extended so as to ensure not only stability of the limit cycle but also an L$_2$-gain disturbance attenuation in the presence of modeling error and viscosity friction.

  • PDF

A Real-time Obstacle Avoidance of Mobile Robots using Limit-cycle and Vector Field Method (Limit-cycle과 벡터장법을 이용한 이동로봇의 실시간 장애물 회피)

  • Yun, Jae-Ho;Jie, Min-Seok;Lee, Kang-Woong
    • Proceedings of the KIEE Conference
    • /
    • /
    • pp.243-246
    • /
    • 2003
  • In this paper, we propose a novel navigation method combined limit-cycle method and the vector field method for avoidance of unexpected obstacles in the dynamic environment. The limit-cycle method is used to obstacle avoidance in front of the robot and the vector field method is used to obstacle avoidance in the side of robot. The proposed method is tested on pioneer 2-DX mobile robot. The simulations and experiments demonstrate in the effectiveness of the proposed method for navigation of a mobile robot in the complicated and dynamic environments.

  • PDF

An Evaluation on the Limit cycle Analysis Methods using the Hardware in the Loop Simulation (실시간 모의시험을 통한 리밋 사이클 해석 결과 분석)

  • Jeon, Sang-Woon
    • Aerospace Engineering and Technology
    • /
    • v.11 no.1
    • /
    • pp.145-157
    • /
    • 2012
  • The novel limit cycle analysis of the attitude control system using jet thrusters was presented based on a phase plane method by paper. It was shown in the software simulation results that the analysed results of the limit cycle was more accurate than those of the Haloulakos' method. But it was not verified in the real system. The proposed method is verified in the reaction control system for KSLV-I via an real time hardware in the loop simulation. It can be shown in this test that analyzed result of the limit cycle is very accurate.

The Effects of Damping on the Limit Cycle of a 2-dof Friction Induced Self-oscillation System (마찰 기인 2자유도계 시스템의 자려진동에 대한 댐핑의 영향)

  • 조용구;신기홍;이유엽;오재응
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.12 no.7
    • /
    • pp.502-509
    • /
    • 2002
  • A two-degree of freedom model Is suggested to understand the basic dynamical behaviors of the interaction between two masses of the friction induced vibration system. The two masses may be considered as the pad and the dusk of the brake. The phase space analysis is performed to understand complicated dynamics of the non-linear model. Attractors in the phase space are examined for various conditions of the parameters of the model especially by emphasizing on the damping parameters. In certain conditions, the attractor becomes a limit cycle showing the stick-slip phenomena. In this Paper, not only titre existence of the limit cycle but also the sloe of the limit cycle is examined to demonstrate the non-linear dynamics that leads the unstable state. For the two different cases of the system frequency[(1) Two masses with same natural frequencies, (2) with different natural frequencies] . the propensity of limit cycle Is discussed In detail. The results show an important fact that it may make the system worse when too much damping Is present in the only one part of the masses.

The effects of damping on the limit cycle of a 2-dof friction induced self-oscillation system (마찰 기인 2 자유도계 시스템의 자려진동에 대한 댐핑의 영향)

  • 조용구;신기흥;오재웅
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • /
    • pp.89-96
    • /
    • 2002
  • A two-degree of freedom model is suggested to understand the basic dynamical behaviors of the interaction between two masses of the friction induced vibration system. The two masses may be considered as the pad and the disk of the brake, The phase space analysis is performed to understand complicated dynamics of the non-linear model. Attractors in the phase space are examined for various conditions of the parameters of the model especially by emphasizing on the damping parameters. In certain conditions, the attractor becomes a limit cycle showing the stick-slip phenomena. In this paper, not only the existence of the limit cycle but also the size of the limit cycle is examined to demonstrate the non-linear dynamics that leads the unstable state. For the two different cases of the system frequency ((1)two masses with same natural frequencies, (2) with different natural frequencies), the propensity of limit cycle is discussed in detail. The results show an important fact that it may make the system worse when too much damping is present in the only one part of the masses.

  • PDF

Warning Signal for Limit Cycle Flutter of 2D Airfoil with Pitch Nonlinearity by Critical Slowing Down (비틀림 비선형성을 갖는 2차원 익형의 Critical Slowing Down 을 이용한 Limit Cycle Flutter 예측 인자)

  • Lim, Joosup;Lee, Sang-Wook;Kim, Tae-Uk
    • Journal of the Korean Society for Aviation and Aeronautics
    • /
    • v.21 no.4
    • /
    • pp.47-52
    • /
    • 2013
  • In this paper, limit cycle flutter induced by Hopf bifurcation is studied with nonlinear system analysis approach and observed for the critical slowing down phenomenon. Considering an attractor of the dynamics of a system, when a small perturbation is applied to the system, the dynamics converge toward the attractor at some rate. The critical slowing down means that this recovery rate approaches zero as a parameter of the system varies and the size of the basin of attraction shrinks to nil. Consequently, in the pre-bifurcation regime, the recovery rates decrease as the system approaches the bifurcation. This phenomenon is one of the features used to forecast bifurcation before they actually occur. Therefore, studying the critical slowing down for limit cycle flutter behavior would have potential applicability for forecasting those types of flutter. Herein, modeling and nonlinear system analysis of the 2D airfoil with torsional nonlinearity have been discussed, followed by observation of the critical slowing down phenomenon.