• Title/Summary/Keyword: Gyroscopic

Search Result 123, Processing Time 0.021 seconds

Analysis of Relationship between Body and Gimbal Motion Through Experiment of a Single-wheel Robot Based on an Inverse Gyroscopic Effect (외바퀴 로봇의 역자이로 효과에 의한 바디 모션과 김벌 모션의 실험을 통한 관계 분석)

  • Lee, Sang-Deok;Jung, Seul
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.21 no.11
    • /
    • pp.1064-1069
    • /
    • 2015
  • Control Moment Gyro (CMG) has been used as an indirect actuator of a single-wheel robot system GYROBO, developed at Chungnam National University. The flip motion of the gimbal system produces the gyroscopic motion onto the body system while the body motion also produces the gyroscopic motion onto the gimbal system inversely. In this paper, the intuitive equation of the inverse gyroscopic effect is derived as the direct relation between the rate of the body system and the rate of the gimbal system. Experiments on the inverse gyroscopic effect under the chaotically generated disturbance are conducted. Experimental data are approximated by a linear equation using the least square method.

Milling Chatter Stability Analysis in Consideration of Gyroscopic Effect (자이로 스코프 효과를 고려한 밀링 채터 안정성 해석)

  • 박재현;홍성욱;김현수;박중윤
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.17 no.2
    • /
    • pp.58-63
    • /
    • 2000
  • The dynamics of spindle-bearing-workpiece system significantly affects the cutting condition and stability in milling process. The present paper investigates the chatter stability of milling process due to the change in the dynamics of spindle-bearing-workpiece systems. In particular, the present paper focuses on chatter stability due to the presence of gyroscopic effect. An eigenvalue problem approach to the stability of milling process is extensively used in this paper. To incorporate the rotational speed dependent gyroscopic effect, an iterative algorithm is proposed. A numerical example is provided for examining the chatter stability problem in the presence of gyroscopic effects.

  • PDF

Analytical Theory of Ball Bearing Considering Waviness of Rolling Elements (구름요소의 Waviness 를 고려한 볼베어링 해석 이론)

  • 정성원;장건희
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.11 no.7
    • /
    • pp.275-286
    • /
    • 2001
  • The research presents an analytical theory to calculate the characteristics of the bal bearing with waviness in its rolling elements considering the centrifugal force and gyroscopic moment of bal. The effects of centrifugal force and gyroscopic moment are introduced to the kinematic constraints and force equilibrium equations. and the waviness of rolling elements is modeled by sinusoidal function to calculate the contact force at each ball. The numerical solutions of governing equation of berating due to waviness are calculated by using the Newton-Raphson method. The accuracy of the research is validated by comparing the contact force. contact angle in case of considering the centrifugal force and gyroscopic moment of bal and the contact force and vibration frequencies in cases of considering waviness with the prior researches respectively. It investigates the stiffness, contact force. displacement and vibration frequencies of the ball bearing considering not only the centrifugal force and gyroscopic moment of ball but also the waviness of the rolling elements.

  • PDF

Model-Based Rolling Motion Control of an One-wheeled Robot Considering the Pitching Motion of a Gyroscopic Effect (자이로 효과의 피칭 모션을 고려한 한 바퀴 로봇의 모델 기반 롤링 모션 제어)

  • Lee, Sang-Deok;Jung, Seul
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.65 no.2
    • /
    • pp.335-341
    • /
    • 2016
  • In general, a yawing motion concept is used for the lateral control of one wheel robot where the gimbal system is located horizontally. In this paper, another concept of the vertically located gimbal system is presented for the same purpose. Although the vertical concept undergoes an instability more easily than the horizontal one, the pitching motion of the gyroscopic effect is considered. Firstly, the trade-off relation between two balancing concepts are investigated by comparing the gyroscopic mechanism. Secondly, the dynamic model for the problem of the proposed concept is derived using the oscillatory inverted stick model. Thirdly, the stability of the model is analyzed using the phase trajectory method. Finally, the control performance of the system by a vibration controller is simulated.

Seismic Anslysis of Rotating Machine-Foundation System (회전기계-기초의 상호작용을 고려한 지진해석)

    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.2 no.2
    • /
    • pp.1-12
    • /
    • 1998
  • The seismic behaviour of rotating machine-foundation systems subjected to six-component nonstationary earthquake ground accelerations is analyzed. The rotating machine-foundation system is idealized by using discs, rotating shaft, fluid-film journal bearings, pedestals, and space frame foundation. Thus, governing equations of motion for the rotating machine-foundation system are obtained by considering Gyroscopic effect, Coriolis effect, dynamic characteristics of fluid-film journal bearings, and translational and rotational motions of seismic rigid base. The influences due to Gyroscopic effects, Coriolis effects, and rotational motions of seismic base on the overall structural response are demonstrated by a numerical example. The results show that the inclusion of base rotations and Gyroscopic effects contributes significantly to the system response.

  • PDF

Observer-based Controller Design of a Magnetic Bearing System (외란관측기에 기초한 자기베어링시스템의 제어기 설계)

  • 송상호;박영진;정성종
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1995.10a
    • /
    • pp.470-473
    • /
    • 1995
  • There exist two critical in application of the magnetic bearing system. One is the control axis interference caused by gyroscopic effect and the other is the vibration caused by the unbalance on the rotor. To solve both problems at the same time, first, a centralized full-state feedback controller based on the LQR control theory was designed to compensate for the gyroscopic effect. Second, disturbance rejection control input based on the observer was designed to avoid the vibration causer by the unbalanced rotor. Balancing input computer accroding to LQR and output of the observer were derived in term of rotational speed. Effectiveness of the on-line balancing was verified through numerical simulation. The developed observer-based controller was also applied to the linear and nonlinear magnetic bearing systems.

  • PDF

Research on a Single Wheeled Robot : GYROBO (한 바퀴로 구동하는 로봇 GYROBO에 대한 연구)

  • Kim, Pil-Kyo;Kim, Yeon-Seop;Jung, Seul
    • Proceedings of the KIEE Conference
    • /
    • 2007.04a
    • /
    • pp.255-257
    • /
    • 2007
  • In this paper, we develop a single wheeled robot that has one wheel to move. The single wheel robot is similar to a rolling disk relying on gyroscopic motions to balance. The Gyrobo consists of three actuators: a spin motor, a tilt motor and a drive motor. The spin motor spins a flywheel at high rate so that it provides the balancing stability to upright the robot. The tilt motor controls steering of the robot by gyroscopic effect. The drive motor make forward accelerated motion to the robot. We have built and tested the Gyrobo to turn and move forward.

  • PDF

Design of a Fuzzy Compensator for Balancing Control of a One-wheel Robot

  • Lee, Sangdeok;Jung, Seul
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • v.16 no.3
    • /
    • pp.188-196
    • /
    • 2016
  • For the balancing control of a one-wheel mobile robot, CMG (Control Moment Gyro) can be used as a gyroscopic actuator. Balancing control has to be done in the roll angle direction by an induced gyroscopic motion. Since the dedicated CMG cannot produce the rolling motion of the body directly, the yawing motion with the help of the frictional reaction can be used. The dynamic uncertainties including the chattering of the control input, disturbances, and vibration during the flipping control of the high rotating flywheel, however, cause ill effect on the balancing performance and even lead to the instability of the system. Fuzzy compensation is introduced as an auxiliary control method to prevent the robot from the failure due to leaning aside of the flywheel. Simulation studies are conducted to see the feasibility of the proposed control method. In addition, experimental studies are conducted for the verification of the proposed control.

Vibration Analysis of 5-DOF Rotor System Supported by Two or More Ball Bearings Considering Centrifugal Force and Gyroscopic Moment of Ball (Waviness가 존재하며 볼의 원심력과 자이로스코픽 모멘트가 작용하는 볼베어링으로 지지된 5 자유도 회전계의 진동해석)

  • 정성원;장건희
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2001.11a
    • /
    • pp.297-303
    • /
    • 2001
  • This research presents an analytical model to characterize the ball bearing vibration due to the waviness in a rigid rotor supported by multi-row ball bearings considering centrifugal force and gyroscopic moment of ball. The effects of centrifugal force and gyroscopic moment are introduced to the kinematic constraints and force equilibrium equations. The waviness of ball and races is modeled by the superposition of sinusoidal function and it is introduced to position vectors of race curvature center to use the Hertzian contact theory in order to calculate the elastic deflection and nonlinear contact force resulting from the waviness while the rotor has translational and angular motion. They can be determined by solving the nonlinear equations of motion with five degrees of freedom by using the Runge-Kutta-Fehlberg algorithm. The accuracy of this research is validated by comparing with the results of the prior researches. It characterizes the vibration frequencies resulting from the various kinds of waviness in rolling elements, the harmonic frequencies resulting from the nonlinear load-deflection characteristics of ball bearing resulting from the waviness interaction.

  • PDF