• Title/Summary/Keyword: Full-order observer

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Digital Optimal Contorl of Servomotor System Considering Torsional Vibration Characteristics (비틀림 진동특성을 고려한 서어보모터계의 디지털 최적제어)

  • Jo, Seung-Ho
    • Journal of the Korean Society for Precision Engineering
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    • v.6 no.4
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    • pp.52-60
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    • 1989
  • In order to control the transient torsional vibration of rotational shaft system, the torsional stiffness of it has been taken into account in modelling the plant. In this paper the observer and controller has been designed in two ways. One is to consider the torsional stiffness and the other is to idealize the rotational shaft as rigid body. The third order observer considering torsional stiffness shows stable response on computer simulation. When the observer is designed on assumption of the rotational shaft being rigid body, the reduced order observer shows stable response whereas the full order observer shows unstable response.

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A Nonlinear Reduced Order Observer Design and Its Application to Ball and Beam System (비선형 저차화 관측기의 설계기법 및 구보시스템에의 적용)

  • 조남훈
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.53 no.9
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    • pp.630-637
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    • 2004
  • In this paper, we present a local reduced-order observer for a class of nonlinear systems that have full robust relative degree. The proposed observer utilizes the coordinate change which transforms a nonlinear system into an approximate normal form. The proposed reduce order observer is applied to a ball and beam system, and simulation results show that substantial improvement in the performance was achieved compared with the jacobian linearization observers.

Reduced-Order Observer Design for Nonlinear Systems Using Input Output Linearization Transformation (입출력선형화 상태변환을 이용한 비선형 시스템의 저차 관측기 설계)

  • 조남훈
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.10
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    • pp.907-914
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    • 2004
  • In this paper, we present a reduced-order observer for a class of nonlinear systems based on the input output linearization. While the most results in the literature presented full-order nonlinear observer, we proposed a procedure for the design of reduced-order observer far nonlinear systems that are not necessarily observable. Assuming that there exists a global observer fer internal dynamics and that certain functions are globally Lipschitz, we can design a global reduced-order observer An illustrative example is included that demonstrate the design procedure of the proposed reduced-order observer.

Nonlinear Feedback Linearization-Full Order Observer/Sliding Mode Controller Design for Improving Transient Stability in a Power System

  • Lee, Sang-Seung;Park, Jong-Keun
    • Journal of Electrical Engineering and information Science
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    • v.3 no.2
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    • pp.184-192
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    • 1998
  • In this paper, we present a nonlinear feedback linearization-full order observer/sliding mode controller (NFL-FOO/SMC), to obtain smmoth control as a linearized controller in a linear system (or to cancel the nonlinearity in a nonlinear system), and to solve the problem of the unmeasurable state variables as in the conventional SMC. The proposed controller is obtained by combining the nonlinear feedback linearization-sliding mode control (NFL-SMC) with the full order observer (FOO)and eliminates the need to measure all the state variables in the traditional SMC. The proposed controller is applied to the nonlinear power system stabilizer (PSS) for damping oscillations in a power system. The effectiveness of the proposed controller is verified by the nonlinear time-domain simulations in case of a 3-cycle line-to-ground fault and in case of the parameter variation for the AVR gain K\ulcorner and for the inertia moment M.

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Reduced Order Luenberger State Observer Design for the Jackknifing Phenomenon Prevention of Articulated Vehicles using GPS (위성항법시스템을 이용한 연결식 차량의 잭나이핑 현상 예방을 위한 축소차수 상태관측기 설계)

  • Lee, Byung-Seok;Heo, Moon-Beom
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.7
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    • pp.688-698
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    • 2012
  • This paper deals with ROLSO (Reduced Order Luenberger State Observer) design to prevent jackknifing phenomenon of articulated vehicles consisting of the tractor and semi-trailer by using GPS. In addition, by applying the regulator system using ROLSO feedback system, simulation's result presents that articulated vehicle's states are stabilized than the human's PR time (Preception Response time) rapidly. This simulation verifies that the automatic control of articulated vehicle's can be applied for the accident prevention for the time that the driver is unable to manage with the sudden accident. For this simulation, by using the equation of planar motion, the modeling of the articulated vehicle was performed. This modeling was expressed in the state space model. And FOLSO (Full Order Luenberger State Observer), ROLSO were designed by using the state space model of an articulated vehicle's dynamics.

A new scheme for discrete implicit adaptive observer and controller (이산형 적응관측자 및 제어기의 새로운 구성)

  • 고명삼;허욱열
    • 전기의세계
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    • v.30 no.12
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    • pp.822-831
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    • 1981
  • Many different schemes of the adaptive observer and controller have been developed for both continuous and discrete systems. In this paper we have presented a new scheme of the reduced order adaptive observer for the single input discrete linear time invariant plant. The output equation of the plant, is transformed into the bilinear form in terms of system parameters and the states of the state variable filters. Using the plant output equation the discrete implicit adaptive observer based on the similar philosophy to Nuyan and Carroll is derived and the parameter adaptation algorithm is derived based on the exponentially weighted least square method. The adaptive model following control system is also constructed according to the proposed observer scheme. The proposed observer and controller are rather than simple structure and have a fast adaptive algorithm, so it may be expected that the scheme is suitable to the practical application of control system design. The effectiveness of the algorithm and structure is illustrated by the computer simulation of a third order system. The simulation results show that the convergence speed is proportinal to the increasing of weighting factor alpha, and that the full order and reduced order observer have similar convergence characteristics.

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An Improved High-Resolution Rotor Position Estimation Using Gain Scheduled Speed Observer in PMSM Drives with Hall-Effect Position Sensors (홀-이펙트 위치센서를 갖는 PMSM 드라이브에서 이득 스케줄 속도관측기에 의한 향상된 고 해상도 회전자 위치추정)

  • Kim, Sam-Young;Byun, Hang-Gil;Ko, Bong-Jin;Park, Seung-Yub
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.10
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    • pp.1809-1815
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    • 2010
  • This paper presents an improved method for high-resolution rotor position estimation in the permanent magnet synchronous motor (PMSM) drives with low-resolution Hall-effect sensors. The proposed method adopts a gain-scheduled full-order speed observer. Since the quantized position signal, which is obtained from Hall-effect sensors, is basically used as the input of the observer, the sixth-order harmonics are essentially included in the estimated position. To eliminate the harmonic components, the quantized position is linearized by a linear extrapolation based on the estimated average speed and futhermore the speed-depentent observer gain scheduling strategy is developed. The observer gain is also scheduled by considering the motor acceleration to improve the dynamic performance according to the changes of the motor speed and load. Several experiments are performed for 800W PMSM drive and the results demonstrate the effectiveness of the proposed method.

Accurate Voltage Parameter Estimation for Grid Synchronization in Single-Phase Power Systems

  • Dai, Zhiyong;Lin, Hui;Tian, Yanjun;Yao, Wenli;Yin, Hang
    • Journal of Power Electronics
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    • v.16 no.3
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    • pp.1067-1075
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    • 2016
  • This paper presents an adaptive observer-based approach to estimate voltage parameters, including frequency, amplitude, and phase angle, for single-phase power systems. In contrast to most existing estimation methods of grid voltage parameters, in this study, grid voltage is treated as a dynamic system related to an unknown grid frequency. Based on adaptive observer theory, a full-order adaptive observer is proposed to estimate voltage parameters. A Lyapunov function-based argument is employed to ensure that the proposed estimation method of voltage parameters has zero steady-state error, even when frequency varies or phase angle jumps significantly. Meanwhile, a reduced-order adaptive observer is designed as the simplified version of the proposed full-order observer. Compared with the frequency-adaptive virtual flux estimation, the proposed adaptive observers exhibit better dynamic response to track the actual grid voltage frequency, amplitude, and phase angle. Simulations and experiments have been conducted to validate the effectiveness of the proposed observers.

Sensorless Vector Control of Induction Motor using Sliding Observer (슬라이딩 관측기를 이용한 유도전동기의 센서리스 벡터제어)

  • Park, J.H.;Kim, G.H.;Cho, Y.K.;Kim, C.S.;Woo, J.I.
    • Proceedings of the KIEE Conference
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    • 1998.07f
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    • pp.1922-1924
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    • 1998
  • In this paper, the robust vector control method of Induction Motor for the purpose of improving the system performance deterioration caused by parameter variations is proposed. The full order state observer estimates the stator current and the rotor flux by using the state prediction of state variables. And, the motor speed is estimated without speed sensor using the full order state observer. Also, the parameter variation is compensate by the Sliding Observer. By using this method, speed sensorless control and current contol with no affection of the parameter variation can be obtained simultaneously.

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A Simple Strategy for Sensorless Speed Control for an IPMSM During Startup and Over Wide Speed Range

  • Sim, Hyun-Woo;Lee, June-Seok;Lee, Kyo-Beum
    • Journal of Electrical Engineering and Technology
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    • v.9 no.5
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    • pp.1582-1591
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    • 2014
  • This paper presents a hybrid sensorless control for an interior permanent magnet synchronous motor (IPMSM) for zero-, low-, and high-speed regions. Many sensorless control methods such as an observer-based estimator have been introduced. However, most of the observer-based estimators have a disadvantage at start-up and in the low-speed region. To solve this problem, a simple strategy of using a hybrid system is proposed by integrating a high-frequency (HF) signal injection method and a full-order flux observer. In addition, an HF signal injection method with only a low pass filter (LPF) is proposed to simplify the hybrid system. The hybrid system achieves high-performance drive throughout the entire speed range. The effectiveness of the proposed hybrid technique is verified by experiments using an 11-kW IPMSM drive system.