• Title/Summary/Keyword: Full order state observer

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A ROBUST VECTOR CONTROL FOR PARAMETER VARIATIONS OF INDUCTION MOTOR

  • Park, Jee-ho;Cho, Yong-Kil;Woo, Jung-In;Ahn, In-Mo
    • Proceedings of the KIPE Conference
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    • 1998.10a
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    • pp.330-335
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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 estimations of the stator current and the rotor flux are obtained by the full order state observer with corrective prediction error feedback. and the adaptive scheme is constructed to estimate the rotor speed with the error signal between real and estimation value of the stator current. Adaptive sliding observer based on the variable structure control is applied to parameter identification. Consequently predictive current control and speed sensorless vector control can be obtained simultaneously regardless of the parameter variations.

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H filter design for offshore platforms via sampled-data measurements

  • Kazemy, Ali
    • Smart Structures and Systems
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    • v.21 no.2
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    • pp.187-194
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    • 2018
  • This paper focuses on the $H_{\infty}$ filter design problem for offshore steel jacket platforms. Its objective is to design a full-order state observer for offshore platforms in presence of unknown disturbances. To make the method more practical, it is assumed that the measured variables are available at discrete-time instants with time-varying sampling time intervals. By modelling the sampling intervals as a bounded time-varying delay, the estimation error system is expressed as a time-delay system. As a result, the addressed problem can be transformed to the problem of stability of dynamic error between the system and the state estimator. Then, based on the Lyapunov-Krasovskii Functional (LKF), a stability criterion is obtained in the form of Linear Matrix Inequalities (LMIs). According to the stability criterion, a sufficient condition on designing the state estimator gain is obtained. In the end, the proposed method is applied to an offshore platform to show its effectiveness.

Design of Deadbeat Controller for DC Motor Driving a Rotational Mechanical System (회전기계 계통을 가동시키는 직류전동기를 위한 데드비트저어기 설계)

  • Lee, Heung-Jae;Song, Ja-Youn
    • Proceedings of the KIEE Conference
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    • 1999.07b
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    • pp.579-582
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    • 1999
  • This paper presents a design method of deadbeat controller for DC motor driving a rotational system with gear. The results of sampling a continuous-data process does not guarantee that no ripples occur between the sampling instants in the continuous-data output, but the proposed deadbeat control system that consists of the integral controller and the full state observer, and zero order hold using in continuous systems, has many advantages of such as an output response without the ripple and reaching the steady state without error after a given sampling period and faster settling time than the optimal control system in the short sampling period. The results of case study through matlab simulation shown that the efficiency of the proposed controller for DC motor driving a rotational system with gear, is verified by comparing with optimal controller etc.

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Robust Tracking Control of Smart Flexible Structures Featuring Piezofilm Actuators (압전필름 작동기로 구성된 스마트 유연 구조물의 강건추적제어)

  • Lee, Chul-Hee;Choei-Seung-Bok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.5
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    • pp.1498-1507
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    • 1996
  • This paper presents a robust control of a smart flexible structure featured by a piezofilm actuator characterizing its light weght and quick response time. A mathematical governing equation for the proposed structure is derived by employing Hamilton's principle and a state space control model is subsequentrly obtained through modal analysis. Uncertain system parameters such as frequency variation are included in the control model. A sliding mode control theroy thich has inherent robustness to systme uncertainties is adopted to design a tracking controller for the peizofilm actuator. Using the output informaiton from the tip deflection sensor, a full-order observer is constructed ot estimate state variables for the system. Tracking performances for desired trajectories of sinusoidal amd step functions are evaluated by undertaking both simulation and experimental works.

Speed Control Of The Magnet Gear-Based Speed Reducer For Non-contact Power Transmission (비접촉 동력 전달을 위한 마그네트 기어 기반 감속기의 속도 제어에 관한 연구)

  • Jung, Kwang Suk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.7
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    • pp.380-388
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    • 2016
  • Using the magnet gear, it is possible to transmit power without mechanical contact. As the drive shaft in a magnet gear-based speed reducer system is isolated from the drive shaft, the system is a two-inertia resonance system that should cope with an external load with the limited air-gap stiffness. On the other hand, the drive shaft or low-speed side is controlled only by the torque of the drive shaft through an air-gap, and the excessive oscillation or the slip can then be generated because of an abrupt disturbance that is different from the general mechanical gear system. Therefore, the disturbance loaded at the low speed side should be measured or estimated, and considered in the control of the driving shaft. This paper proposes a novel full-state feedback controller with a reduced-order observer for the speed reducer system using a magnet gear with a unified harmonic modulator. The control method was verified by simulation and experiment. To estimate the load at the low speed side, a novel observer was designed, in which the new state variable is introduced and the new state equation is formulated. Using a full-state feedback controller including the observer, the test result against disturbance was compared with two D.O.F PI speed controllers. The pole slip was compensated within relatively a short time, and the simulation result about the estimated variable shows a similar tendency to the test result. The test results showed that the magnet gear-based reducer can be applied to an accurate servo system.

Optimal Control Design-based Gain Selection of an LCL-filtered Grid-connected Inverter in State-Space under Distorted Grid Environment

  • Tran, Vi-Thuy;Yoon, Seung-Jin;Kim, Kyeong-Hwa
    • Proceedings of the KIPE Conference
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    • 2018.07a
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    • pp.344-345
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    • 2018
  • In order to alleviate the negative impacts of harmonically distorted grid condition on grid-connect inverters, an optimal control design-based gain selection scheme of an LCL-filtered grid-connected inverter and its ability to compensate selective harmonics are presented in this paper. By incorporating resonant terms into the control structure in the state-space to provide infinity gain at selected frequencies, the proposed control offers an excellent steady-state response even under distorted grid voltage. The proposed control scheme is achieved by using a state feedback controller for stabilization purpose and by augmenting the resonant terms as well as intergral term into a control structure for reference tracking and harmonic compensation. Furthermore, the optimal linear quadratic control approach is adopted for choosing an optimal feedback gain to ensure an asymptotic stability of the whole system. A discrete-time full state observer is also introduced into the proposed control scheme for the purpose of reducing a total number of sensors used in the inverter system. The simulation results are given to prove the effectiveness and validity of the proposed control scheme.

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A Study on Improvement of Low Speed Control Characteristics in PMSM (영구자석형 동기전동기의 저속도 제어 특성 개선에 관한 연구)

  • Jun B.S.;Yu J.S.;Kim L.H.;Won C.Y.;Kim G.S.;Choi S.W.
    • Proceedings of the KIPE Conference
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    • 2003.07a
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    • pp.485-489
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    • 2003
  • This paper presents the method of speed measurement for permanent magnet synchronous motor(PMSM) with the full-order observer using reduced-order state equation. This Is able to improve the operating performance at low speed. Therefore, by the proposed technique, a low resolution encoder can be used. Because it make the system improve the performance of speed response. The proposed method is verified to simulation and experiments.

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Design of Deadbeat Controller for DC Motor Driving a Rotational Mechanical System (회전기계 계통을 가동시키는 직류전동기를 위한 데드비트제어기 설계)

  • 이흥재;송자윤
    • Journal of Korea Society of Industrial Information Systems
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    • v.5 no.1
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    • pp.31-36
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    • 2000
  • This paper presents a design method of deadbeat controller for DC motor driving a rotational system with gear. The deadbeat-response design developed for control system of a sampled continuous-data process does not guarantee zero intersampling ripples, but the proposed deadbeat control system that consists of the integral controller and the full-order state observer, and zero-order hold using in continuous systems, has many advantages such as an output response without the ripples and reaching the steady state without error after a given sampling period and faster settling time than the optimal control system in the same sampling period. The results of a case study through matlab simulation are shown that the efficiency of the proposed controller for DC motor driving a rotational system with gear is verified by comparing with optimal controller etc.

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Force Tracking Control of a Smart Flexible Gripper Featuring Piezoceramic Actuators (압전 세라믹 작동기로 구성된 스마트 유연 그리퍼의 힘 추적 제어)

  • Choi, Seung-Bok;Cheong, Chae-Cheon;Lee, Chul-Hee
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.1
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    • pp.174-184
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    • 1997
  • This paper presents a robust force tracking control of a smart flexible gripper featured by a piezoceramic actuator characterizing its durability and quick response time. A mathematical governing equation for the proposed gripper structure is derived by employing Hamilton's principle and a state space control model is subsequently obtained through model analysis. Uncertain system parameters such as frequency variation are included in the control model. A sliding mode control theory which has inherent robustness to the sys- tem uncertainties is adopted to design a force tracking controller for the piezoceramic actuator. Using out- put information from the tip force sensor, a full-order observer is constructed to estimate state variables of the system. Force tracking performances for desired trajectories represented by sinusoidal and step func- tions are evaluated by undertaking both simulation and experimental works. In addition, in order to illustrate practical feasibility of the proposed method, a two-fingered gripper is constructed and its performance is demonstrated by showing a capability of holding an object.

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Speed Sensorless of Induction Motor using 2 layer Neural Networks (2단 신경회로망을 이용한 유도전동기의 센서리스제어)

  • Lee, Chang-Min;Choi, Chul;Park, Sung-Joon;Kim, Chul-Woo
    • Proceedings of the KIPE Conference
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    • 2000.07a
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    • pp.409-412
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    • 2000
  • This paper investigates a novel speed identification of induction motor using 2 layer neural networks. The proposed control strategy is based on neural networks using model of full order state observer. in the proposed neural networks system the error between the desired variable and the adaptive variable is back-propagated to adjust the rotor speed, So that the adaptive variable will coincide with the desired variable. The proposed control algorithm is verified through simulation and experiment using th digital signal processor of TMS320C31

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