• 제목/요약/키워드: 2-mass system

검색결과 3,170건 처리시간 0.037초

신경 회로망과 관측기에 기반한 2-mass 시스템에서의 속도 제어기 설계 (Design of a Speed Controller for 2-Mass System Based on Neural Network and Observer)

  • 현대성;박정일
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
    • /
    • pp.361-361
    • /
    • 2000
  • In the 2-mass system with flexible shaft, a torsional vibration is often generated because of the elastic elements in torque transmission as the newly required speed response which is very close to the primary resonant frequency. This vibration makes it difficult to achieve quick responses of speed and disturbance rejection. In this paper, 2-mass system is designed by using pole placement based on optimal control theory fur fast speed response and torsional vibration elimination and using neural network for disturbance rejection in particular. The simulation results show that the proposed controller based on neural network and full state feedback controller has better performance than 려ll state feedback controller, especially fur disturbance rejection.

  • PDF

Estimation of a Mass Unbalance Under the Crack on the Rotating Shaft

  • Park, Rai-Wung
    • Transactions on Control, Automation and Systems Engineering
    • /
    • 제2권4호
    • /
    • pp.228-234
    • /
    • 2000
  • The aim of the work is to present a new method of estimating the existence of a mass unbalance and mass unbalance under a crack on a rotating shaft. This is an advanced new method for the detection of a mass unbalance and a new way to estimate the position of it under crack influence. As the first step, the shaft is physically modelled with a finite element method and the dynamic mathematical model is derived by using the Hamilton principle; thus, the system is represented by various subsystems. The equation of motion of the shaft with a mass unbalance and a crack are established by adapting the local mass unbalance and the stiffness change. this is a reference system for the given system. Based on a model for transient behavior induced from vabrations measured at the bearings, an elementary Estimator is designed to detect mass unblance on the shaft. Using the Estimator, a bank of the Estimator is established to estimate the estimate the position of the mass unbalance and arranged at a certain location on the shaft. The informations for the given system are the measurements of bearing displacements and velocity.

  • PDF

최적 극배치 기법을 이용한 2관성 공진계의 2자유도 속도제어 (Two-Degree-of-Freedom Speed Control of Two-Mass System using Optimal Pole Assignment Method)

  • 전돈수;김동화
    • 대한전기학회논문지:시스템및제어부문D
    • /
    • 제49권1호
    • /
    • pp.18-25
    • /
    • 2000
  • In the two-mass servo system driving a load through a flexible shaft, a shaft torsional vibration is often generated. PI controller has been generally used is speed control of such system because of the simplicity of structure and related theory. This paper presents the inertia ratio of the PI servo control system which can be designed by using optimal pole assignment method is fixed. Therefore, it's difficult to obtain the desired control characteristics for different systems only by PI control algorithm. To solve this problems the two-mass speed control system with PID controller is designed by using pole assignment method and an optimum PID parameters are derived by evaluating ITAE(Integral of time multiplied by the absolute error) performance index. But this design method has some problems due to a trade-off between the fast command following property and the attenuation of disturbances and vibrations. In this paper, 2-DOF PID control method which satisfies the command following property, the reduction of overshoot and the property of disturbance rejection at the same time is proposed. This is a practical speed controller using the desired value filter and the feedforward gain. From several simulations, it's clarified that the proposed 2-DOF PID controller is useful for the two-mass system, in comparison with the conventional PID controller.

  • PDF

Coupled hydroelastic vibrations of a liquid on flexible space structures under zero-gravity - Part I. Mechanical model

  • Chiba, Masakatsu;Chiba, Shinya;Takemura, Kousuke
    • Coupled systems mechanics
    • /
    • 제2권4호
    • /
    • pp.303-327
    • /
    • 2013
  • The coupled free vibration of flexible structures and on-board liquid in zero gravity space was analyzed, considering the spacecraft main body as a rigid mass, the flexible appendages as two elastic beams, and the on-board liquid as a "spring-mass" system. Using the Lagrangians of a rigid mass (spacecraft main body), "spring-mass" (liquid), and two beams (flexible appendages), as well as assuming symmetric motion of the system, we obtained the frequency equations of the coupled system by applying Rayleigh-Ritz method. Solving these frequency equations, which are governed by three system parameters, as an eigenvalue problem, we obtained the coupled natural frequencies and vibration modes. We define the parameter for evaluating the magnitudes of coupled motions of the added mass (liquid) and beam (appendages). It was found that when varying one system parameter, the frequency curves veer, vibration modes exchange, and the significant coupling occurs not in the region closest to the two frequency curves but in the two regions separate from that region.

2관성 공진계에 대한 반복 학습 제어의 응용에 관한 연구 (Study on Application of Iterative Learning Control to 2-Mass Resonant System)

  • 이학성;문승빈;홍성경
    • 제어로봇시스템학회논문지
    • /
    • 제10권1호
    • /
    • pp.42-46
    • /
    • 2004
  • A 2-mass resonant system is one that has a flexible coupling between a load and a driving motor. Due to this flexibility, the system often suffers vibration especially when the motor is controlled for higher speed command. In order to suppress such a vibration, an iterative learning control is applied to the 2-mass resonant system in this paper. The motor speed is controlled according to the relation with the load speed. The desired speed trajectories are derived under the condition for no vibration. The simulation result suggests that the proposed method effectively suppresses the vibration even when there exist model uncertainties.

Motion Analysis of a Translating Flexible Beam Carrying a Moving Mass

  • Park, Sangdeok;Youngil Youm
    • International Journal of Precision Engineering and Manufacturing
    • /
    • 제2권4호
    • /
    • pp.30-39
    • /
    • 2001
  • This paper investigates vibrational motion of a flexible beam fixed on a moving cart and carrying a moving mass. The equations of motion of the beam-mass-cart system are analysed through the unconstrained modal analysis. The exact normal mode solution used in modal analysis correspond to the eigenfrequencies for each position of the moving mass and to the ratios of the weight of the beam-mass-car system. Time solutions of normal modes are also transformed properly according to the position of the moving mass. Numerical simulations are carried out to obtain open-loop responses of the system in tracking pre-designed paths of the moving mass. The simulation results show that the model predicts the dynamic behavior of the beam-mass-cart system well. Experiments are carried out to show the validity of the proposed analytical method.

  • PDF

A Review of Heat and Mass Transfer Analysis for Absorption Process

  • Kim, Jin-Kyeong;Kang, Yong-Tae
    • International Journal of Air-Conditioning and Refrigeration
    • /
    • 제14권4호
    • /
    • pp.131-137
    • /
    • 2006
  • The absorber in which heat and mass transfer phenomena occur simultaneously is one of the most critical components in the absorption system. It has the most significant influence on the performance and the size of the absorption system. During the absorption process, heat and mass transfer resistances exist in both liquid and vapor regions, so that the heat transfer mode should be carefully selected to reduce them. The objective of this paper is to review the previous papers analysing mathematical models of simultaneous heat and mass transfer phenomena during the absorption process. The most conventional working fluids ($H_2O$LiBr and $NH_3/H_2O$) are considered and the most common absorption modes (falling film and bubble mode) are dealt with in this review.

바이오매스용 해조류 대량 양식을 위한 자동화 시스템 개발 (Development of The Automation System for Seaweed Biomass Mass Production)

  • 최국진
    • 한국산업융합학회 논문집
    • /
    • 제23권2_2호
    • /
    • pp.351-359
    • /
    • 2020
  • The algae biomass is considered as one of the potential sources of ocean renewable energy because it can be easily mass-produced with abundant sunshine in the vast ocean space. However, the practical use of the biomass has been hindered by the lack of efficient and cost-effective harvesting and maintenance system so far. The algae biomass aquaculture systems are installed in far offshore locations in much larger scales compared to the conventional aquaculture systems so that the automatic seaweed planting and harvesting system needs to operate in heavy sea conditions in far offshore location. In this research, we develop a concept design of a mega-scaled aquaculture system and an automatic seaweed planting and harvesting system, which can operate in heavy seas and mass-produce the algae biomass.

2단 증기 압축식 냉동시스템을 적용한 해상용 제빙장치의 냉매에 따른 성능 분석 (Performance Analysis of a Seawater Ice Machine Applied Two-stage vapor compression refrigeration system for Various Refrigerants)

  • 윤정인;손창효;허성관;전민주;전태영
    • 동력기계공학회지
    • /
    • 제20권2호
    • /
    • pp.85-90
    • /
    • 2016
  • Coefficient of performance (COP) for two-stage compression system is investigated in this paper to develop seawater ice machine. The system performance is analyzed with respect to degrees of superheating and subcooling, condensing and evaporating temperatures, compression and mechanical efficiencies and mass flow ratio in an inter-cooler. The main results are summarized as follows : The COP of the system grows when the mass flow ratio, subcooling degree and evaporating temperature edge up. Contrariwise, the system performance descends in case that superheating degree and condensing temperature increase. The most effective factor for the COP is the mass flow rate ratio. Each refrigerant has different limitation for a value of the mass flow ratio in the inter-cooler because of difference in material property.

다목적실용위성2호 질량특성 데이터베이스 관리

  • 문홍열;김규선
    • 항공우주기술
    • /
    • 제3권2호
    • /
    • pp.1-6
    • /
    • 2004
  • 위성을 설계함에 있어 질량제어 계획을 작성하고 질량자료를 유지하며 시스템의 질량특성을 계산하고 제어하는 것은 기계 시스템 담당자가 수행하는 임무 중에 하나이다. 위성의 질량특성은 자료수집, 특성예측 그리고 실제 측정의 순서로 설계 및 제작이 진행됨에 따라 수행된다. 질량특성 데이터베이스는 설계과정을 통하여 작성하게 되며 질량특성 측정 시험을 수행하여 데이터베이스의 신뢰성을 확인할 수 있어야 한다. 본 논문에서는 위성에서의 질량 제어계획의 일반적인 내용과 시스템 수준의 질량중심 및 관성 모멘트 계산과 관련된 여러 가지 구체적인 사항을 고려한 이론적 질량 특성 데이터베이스를 개발하고, 다목적 실용위성 2호 개발을 수행하면서 얻게 된 실제적인 자료/경험을 토대로 본 연구에서 개발된 데이터베이스의 신뢰성을 확인하였다.

  • PDF