• Title/Summary/Keyword: control parameter

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Reconfigurable Flight Control Law based on Model Following Scheme and Parameter Estimation (매개변수 추정 및 모델추종 적응제어기법을 이용한재형상 비행제어시스템 연구)

  • Mun, Gwan-Yeong;Kim, Yu-Dan;Lee, Han-Min
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.3
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    • pp.67-73
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    • 2006
  • In this paper, a reconfigurable model following flight control method is proposed based on direct adaptive scheme using parameter estimation. Adaptive control scheme updates the control gains to make the system output follow the reference output even when fault occurs. By adopting the frequency domain parameter estimation method, system changes by the fault can be estimated. Recursive Fourier transformation is used for system identification. Using recursive Fourier transform, the proposed adaptive control algorithm guarantees the system stability and improves the system characteristics. To evaluate the performance of proposed control method, numerical simulations are performed.

On-line Parameter Estimation of IPMSM Drive using Neural Network (신경회로망을 이용한 IPMSM 드라이브의 온라인 파라미터 추정)

  • Park, Ki-Tae;Choi, Jung-Sik;Ko, Jae-Sub;Lee, Jung-Ho;Kim, Jong-Kwan;Park, Byung-Sang;Chung, Dong-Hwa
    • Proceedings of the KIEE Conference
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    • 2006.07b
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    • pp.761-762
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    • 2006
  • A number of techniques have been developed for estimation of speed or position in motor drives. The accuracy of these techniques is affected by the variation of motor parameters such as the stator resistance, stator inductance or torque constant. This paper is proposed a neural network based estimator for torque and stator resistance in IPMSM Drives. The neural weights are initially chosen randomly and a model reference algorithm adjusts those weights to give the optimum estimations. The neural network estimator is able to track the varying parameters quite accurately at different speeds with consistent performance. The neural network parameter estimator has been applied to slot and flux linkage torque ripple minimization of the IPMSM. The validity of the proposed parameter estimator is confirmed by the operating characteristics controlled by neural networks control.

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A Simulation Method of PID Tuning with Process Modeling in Operating Nuclear Power Plants (가동원전에서 공정모델링을 통한 PID 튜닝 시뮬레이션 방법)

  • Min, Moon-Gi;Jung, Chang-Gyu;Lee, Kwang-Hyun;Lee, Jae-Ki;Kim, Hee-Je
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.63 no.4
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    • pp.290-294
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    • 2014
  • PID(Proportional, Integral, Derivative) controller is the most popular process controllers in nuclear power plants. The optimized parameter setting of the process controller contributes to the stable operation and the efficiency of the operating nuclear power plants. PID parameter setting is tuned when new process control systems are installed or current process control systems are changed. When the nuclear plant is shut down, a lot of PID tuning methods such as the Trial and Error method, Ultimate Oscillation method operation, Ziegler-Nichols method, frequency method are used to tune the PID values. But inadequate PID parameter setting can be the cause of the unstable process of the operating nuclear power plant. Therefore the results of PID parameter setting should be simulated, optimized and finally verified. This paper introduces the simulation method of PID tuning to optimize the PID parameter setting and confirms them of the actual PID controller in the operating nuclear power plants. The simulation method provides the accurate process modeling and optimized PID parameter setting of the multi-loop control process in particular.

A Method of Tuning Optimization for PID Controller in Nuclear Power Plants (원자력발전소 PID 공정제어기에 대한 튜닝 최적화 방법)

  • Sung, Chan Ho;Min, Moon Gi
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.10 no.1
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    • pp.1-6
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    • 2014
  • PID(Proportional, Integral, Derivative) controller is one of the most used process controllers in nuclear power plants. The optimized parameter setting of process controller contributes to the stable operation and efficiency in the operating nuclear power plants. PID parameter setting is tuned when new process control system is established or process control system is changed. It is a burdensome work for I&C(Instrument and Control) engineers to tune the PID controller because it requires a lot of experience and knowledge. When the plant is in operation, inadequate PID parameter setting can be the cause of the unstable process of the plant. Therefore the results of PID parameter setting should be compared, simulated, verified and finally optimized. The practical PID tuning methods used in process controller are tuning operation calculation(Ziegler-Nicholes, Minimum TIAE, Lambda, IMC), exclusive tuning program based on computer and Matlab application. This paper introduces the various tuning methods and suggests an optimized PID tuning process in the operating nuclear power plants.

Parameter Study for Optimal Design of Smart TMD (스마트 TMD의 최적설계를 위한 파라메터 연구)

  • Kim, Hyun-Su;Kang, Joo-Won
    • Journal of Korean Association for Spatial Structures
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    • v.17 no.4
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    • pp.123-132
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    • 2017
  • A smart tuned mass damper (TMD) was developed to provide better control performance than a passive TMD for reduction of earthquake induced-responses. Because a passive TMD was developed decades ago, optimal design methods for structural parameters of a TMD, such as damping constant and stiffness, have been developed already. However, studies of optimal design method for structural parameters of a smart TMD were little performed to date. Therefore, parameter studies of structural properties of a smart TMD were conducted in this paper to develop optimal design method of a smart TMD under seismic excitation. A retractable-roof spatial structure was used as an example structure. Because dynamic characteristics of a retractable-roof spatial structure is changed based on opened or closed roof condition, control performance of smart TMD under off-tuning was investigated. Because mass ratio of TMD and smart TMD mainly affect control performance, variation of control performance due to mass ratio was investigated. Parameter studies of structural properties of a smart TMD was performed to find optimal damping constant and stiffness and it was compared with the results of optimal passive TMD design method. The design process developed in this study is expected to be used for preliminary design of a smart TMD for a retractable-roof spatial structure.

Parameter estimation of permanent magnet synchronous motor and adaptive control by MRAS (MRAS를 이용한 매입형 영구자석 동기전동기의 상수 추정 및 적응제어기법)

  • Yang, Hyunsuk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.2
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    • pp.697-702
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    • 2016
  • To control permanent magnet synchronous motors smoothly, it is important to know the exact parameter values of the stator resistance, various inductances, and the flux linkage of the permanent magnet. In practice, these parameters vary due to a variable operating point, temperature change, or a fault. This paper proposes a MRAS (Model Reference Adaptive System) based parameter estimator and adaptive control scheme. Owing to the non-linearity of the system equation with respect to these parameters, although many schemes proposed previously assumed that some parameters are known, all the parameters were assumed to be unknown. The simulation results revealed the effectiveness of the proposed algorithm.

Robot Control Method in Parameter Space Adopting Biomimetics (생체모방기술을 접목한 파라미터 공간에서의 로봇제어 기법)

  • Kim, Heejoong
    • Journal of Aerospace System Engineering
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    • v.12 no.5
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    • pp.16-23
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    • 2018
  • In the paper, a robot control technique by employing Biomimetics is described. Rhythmic movements of the diving beetle's leg were analyzed and the formulated equations on the motion were drawn by applying Fourier least mean square fitting method. Simple control parameters were defined by comparing the observed locomotion through a motion capture system and reproduced motions according to changes in the values in the equation. Subsequently, the correlation of each parameter was discovered and expressed in a parameter space. Apparently, it was confirmed that various bio-mimicking motions can simply be generated for controlling the robot. Additionally, robot designing based on adopting structural advantages which the living organism possess have been briefly introduced. The proposed bio-mimicking motion generating technique was observed to be applicable to robot system developments under various environmental conditions.

Effective Strategy for Precise Orbital and Geodetic Parameter Estimation Using SLR Observations for ILRS AAC

  • Kim, Young-Rok;Oh, Jay;Park, Sang-Young;Park, Chandeok;Park, Eun-Seo;Lim, Hyung-Chul
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.159.2-159.2
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    • 2012
  • In this study, we propose an effective strategy for precise orbital and geodetic parameter estimation using SLR (Satellite Laser Ranging) observations for ILRS AAC (Associate Analysis Center). The NASA/GSFC GEODYN II software and SLR normal point observations of LAGEOS-1, LAGEOS-2, ETALON-1, and ETALON-2 are utilized for precise orbital and geodetic parameter estimation. Weekly-based precise orbit determination strategy is applied to process SLR observations, and Precise Orbit Ephemeris (POE), TRF (Terrestrial Reference Frame), and EOPs (Earth Orientation Parameters) are obtained as products of ILRS AAC. For improved estimation results, selection strategies of dynamic and measurement models are experimently figured out and configurations of various estimation parameters are also carefully chosen. The results of orbit accuracy assessment of POE and precision analysis of TRF/EOPs for each case are compared with those of existing results. Finally, we find an appropriate strategy for precise orbital and geodetic parameter estimation using SLR observations for ILRS AAC.

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A Survey of Robust Control in Both Frequency Domain and Time Domain (주파수와 시간영역에서의 강인제어에 관한 연구동향조사)

  • Jeung, Eun Tae;Park, Hong Bae
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.3
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    • pp.270-276
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    • 2014
  • This survey paper reviews robust control problems in both frequency domain and time domain. Robust control is focused on model uncertainties such as modeling error, system parameter variations, and disturbances. Robust control design problems are discussed according to parameter uncertainty, polytopic uncertainty, and norm-bounded uncertainty. Nowadays, robust control theory is combined with various control theory such as model predictive control, adaptive control, intelligent control, and time delay control.

Pareto Optimized EDCA Parameter Control for Wireless Local Area Networks

  • Kim, Minseok;Oh, Wui Hwan;Chung, Jong-Moon;Lee, Bong Gyou;Seo, Myunghwan;Kim, Jung-Sik;Cho, Hyung-Weon
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.10
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    • pp.3458-3474
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    • 2014
  • The performance of IEEE 802.11e enhanced distributed channel access (EDCA) is influenced by several interactive parameters that make quality of service (QoS) control complex and difficult. In EDCA, the most critical performance influencing parameters are the arbitration interframe space (AIFS) and contention window size (CW) of each access category (AC). The objective of this paper is to provide a scheme for parameter control such that the throughput per station as well as the overall system throughput of the network is maximized and controllable. For this purpose, a simple and accurate analytical model describing the throughput behavior of EDCA networks is presented in this paper. Based on this model, the paper further provides a scheme in which a Pareto optimal system configuration is obtained via an appropriate CW control for a given AIFS value, which is a different approach compared to relevant papers in the literature that deal with CW control only. The simulation results confirm the effectiveness of the proposed method which shows significant performance improvements compared to other existing algorithms.