• Title/Summary/Keyword: Equilibrium Position

Search Result 79, Processing Time 0.217 seconds

Control of a Rotary Double Inverted Pendulum using LQR Control Algorithm (LQR 제어 알고리즘을 이용한 원운동형 2축 도립 진자의 제어)

  • Hwang, Eon-Du;Park, Min-Ho;Lee, Sang-Hyuk
    • Proceedings of the KIEE Conference
    • /
    • /
    • pp.2240-2242
    • /
    • 2001
  • A rotary double inverted pendulum, the nonlinear system has a regulation problem. In this paper, we linearize the nonlinear system at the upright equilibrium position. The linearized system can be expressed in state space. To maintain the upright position, we design a feedback controller using LQR(Linear Quadratic Regulator) algorithm. Then we simulate the system with third-order Adams Bashforth Moulton Method. The simulated result shows that the applied algorithm is effective for the regulation problem.

  • PDF

3D Modeling and Balancing Control of Two-link Underactuated Robots using Matlab/Simulink

  • Yoo, Dong Sang
    • Journal of information and communication convergence engineering
    • /
    • v.17 no.4
    • /
    • pp.255-260
    • /
    • 2019
  • A pendubot is a representative example of an underactuated system that has fewer actuators than the degree of freedom of the system. In this study, the characteristics of the pendubot are first reviewed; each part is then designed using Solidworks by dividing the pendubot into three parts: the base frame, first link frame, and second link frame. These three parts are then imported into the Simulink environment via a STEP file format, which is the standard protocol used in data exchange between CAD applications. A 3D model of the pendubot is then constructed using Simscape, and the usefulness of the 3D model is validated by a comparison with a dynamic equation derived using the Lagrangian formulation. A linearized model around an upright equilibrium position is finally obtained, and a sliding mode controller is designed based on the linear quadratic regulator. Simulation results showed that the designed controller effectively maintained upright balance of the pendubot in the presence of disturbance.

Linearization Method and Vibration Analysis of a Constrained Multibody System Driven by Constant Generalized Speeds (일정 일반속력으로 구동되는 구속 다물체계의 선형화기법 및 진동해석)

  • 최동환;박정훈;유홍희
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • /
    • pp.725-730
    • /
    • 2001
  • This paper presents a vibration analysis method for constrained mechanical systems driven by constant generalized speeds. Equilibrium positions are obtained first and vibration analysis are performed around the positions. The method developed in this paper employs partial velocity matrix to obtain a minimum number of differential equations. To verify the accuracy of the proposed algorithm, linear vibration analyses of two numerical examples are performed and the results are compared with results from a commercial program or previous literature.

  • PDF

Vibration Reduction of an Optical Disk Drive Using an Automatic Ball Balancer (자동 볼 평형장치를 이용한 광 디스크 드라이브의 진동 저감)

  • 이동진;정진태;노대성
    • Journal of KSNVE
    • /
    • v.9 no.2
    • /
    • pp.355-362
    • /
    • 1999
  • Vibration reduction of an optical disk drive is achieved by an automatic ball balancer and dynamic behaviors of the drive are studied by theoretical approaches. Using Lagrange's equation, we derive nonlinear equations of motion for a non-autonomous system with respect to the rectangular coordinate. To investigate the dynamic stability of the system in the neighborhood of equilibrium positions, the Floquet theory is applied to the perturbed equations. On the other hand, time responses are computed by an explicit time integration method. We also investigate the effects of mass center and the position of the ABB on the dynamic behaviors of the system.

  • PDF

The influence of the pre-sag of a railway contact wire to the current collection performance (200km/h급 전차선로에서 사전이도가 미치는 집전성능 영향 분석연구)

  • Cho, Yong-Hyeon;Lee, Ki-Won;Park, Chan-Bae
    • Proceedings of the KSR Conference
    • /
    • /
    • pp.227-235
    • /
    • 2007
  • The railway catenary is softer in the middle of a span than at the end. This stiffness variation induce the vertical motion of a moving pantograph, which results in the large variation of contact forces. To reduce the vertical motion of a pantograph, we can introduce a pre-sag of the contact wire. The pre-sag changes merely equilibrium position of the contact wire. Because the pantograph must follow the sag added to the motion of the contact wire, the sag gives downward forces to the pantograph. If the pre-sag is proper, the variation of the vertical motion of the pantograph is reduced. However, excessive sag worses the current collection performance because the pantograph receives too large downward forces by the contact wire. The objective of the paper is to establish the theoretical basis to understand how the pre-sag affect the contact force variation and to propose the proper sag for the railway catenary for the train speed up to 200 km/h.

  • PDF

Steady-State Equilibrium Analysis of a Multibody System Driven by Constant Generalized Speeds

  • Park, Dong-Hwan;Park, Jung-Hun;Yoo, Hong-Hee
    • Journal of Mechanical Science and Technology
    • /
    • v.16 no.10
    • /
    • pp.1239-1245
    • /
    • 2002
  • A formulation which seeks steady-state equilibrium positions of constrained multibody systems driven by constant generalized speeds is presented in this paper. Since the relative coordinates are employed, constraint equations at cut joints are incorporated into the formulation. To obtain the steady-state equilibrium position of a multibody system, nonlinear equations are derived and solved iteratively. The nonlinear equations consist of the force equilibrium equations and the kinematic constraint equations. To verify the effectiveness of the proposed formulation, two numerical examples are solved and the results are compared with those of a commercial program.

Development of Roller Wheel Mobile Robot (롤러형 바퀴를 갖는 이동로봇 개발)

  • Kim, Soon-Cheol;Yi, Soo-Yeong;Choi, Jae-Suk
    • The Journal of Korea Robotics Society
    • /
    • v.9 no.4
    • /
    • pp.250-257
    • /
    • 2014
  • In this paper, a new mobile robot, so called a rollerbot, is presented, which has single body and rugby-ball shaped roller wheel. A rollerbot has single point contact on ground and low energy consumption in motion because of the reduced friction. By changing center of mass using a balancing weight, a rollerbot is able to get steering force. The vertical position of mass center of the rollerbot in this paper is designed to lie inside radius of the roller wheel, so that to have stable equilibrium position. Thus, the posture and the steering control of the rollerbot can be easily done by changing the center of mass. Kinematics of the rollerbot is derived by transformation of differential motion in this paper.

Fuzzy Expert PID Control of Magnetic Bearing System (자기베어링 시스템의 퍼지 전문가 PID 제어)

  • Gyeong, Jin-Ho;Kim, Yu-Il;Kim, Jong-Seon;Lee, Hae
    • 연구논문집
    • /
    • /
    • pp.73-80
    • /
    • 1993
  • This study presents an intelligent PID control method based on the fuzzy logic and this method is applied to the active magnetic bearing system. By using an appropriate fuzzy matrix, some changes of values of the three coefficients of the controller are determined during system operation and these lead to the improvement of the transient and steady state behavior of the closed loop system. The presented method is actually a combination of the principles of PID control and fuzzy logic. Since the fuzzy logic using linguistic variables in place of numeric variables has many points of likeness to the human logic, the improvement in performance is notable especially in case of large nonlinearity and uncertainty such as the controller start and the excessive mass unbalance. A set of simulation and experimental results illustrate and considerable improvement in the control performance including small overshoot and small transient currents in magnet coils, while maintaining the overal static and dynamic characteristics near the equilibrium position.

  • PDF

Design of a Swing Up Controller for Inverted Pendulum System (도립진자의 스윙업 제어기 설계)

  • Kwon, Yo-Han;Choi, Won-Ho;Kim, Beom-Soo;Lim, Myo-Taeg
    • Proceedings of the KIEE Conference
    • /
    • /
    • pp.643-645
    • /
    • 1999
  • In experiment, a real inverted pendulum system has state constraints and limited amplitude of input. These problems make it difficult to design a swing-up controller. To overcome these problems, we design a sliding mode controller considering physical behaviour of the inverted pendulum system. This sliding mode controller uses a switching control action to converge along a specified path derived from energy equation from a state around the path to desired states(standing position). And optimal control method is used to guarantee stability at unstable equilibrium position. The designed controller can be applied to all inverted pendulum systems regardless of the values of their parameters. Compared with previous existing controllers, it is simple and easy to tune. Experimental results are given to show the effectiveness of this controller.

  • PDF

Design and Operation Characteristics of a Two-Stage Compressor (이단 압축기의 동력학적 설계 및 운전 특성에 관한 연구)

  • Lee, Yong-Bok;Kim, Tae-Ho;Kim, Chang-Ho;Lee, Nam-Soo;Choi, Dong-Hoon
    • The KSFM Journal of Fluid Machinery
    • /
    • v.5 no.1
    • /
    • pp.55-61
    • /
    • 2002
  • The feasibility of an oil-free, motor-driven, two-stage centrifugal compressor supported by air bump bearings is investigated. This centrifugal compressor is driven by a 75 kW motor at an operating speed of 39,000 RPM, and a pressure ratio of the compressor is set up to 4. The analysis is performed by using bearing equilibrium position, heaving stillness, Campbell diagram, unbalance response, and stability. It is demonstrated in this paper that air bump bearings can be adopted well to an oil-free, motor-driven, centrifugal compressor. Specially, Cu-coated bump bearings have enough damping force to reduce a synchronous unbalance for rigid modes of the two-stage compressor. Futhermore, this concept may be applied to the flexible rotor system such as high speed turbomachinery with a super critical speed.