• Title/Summary/Keyword: Parameter Variations

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Design of a Robust Target Tracker for Parameter Variations and Unknown Inputs

  • Kim, Eung-Tai;Andrisani, D. II
    • International Journal of Aeronautical and Space Sciences
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    • v.2 no.2
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    • pp.73-81
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    • 2001
  • This paper describes the procedure to develop a robust estimator design method for a target tracker that accounts for both structured real parameter uncertainties and unknown inputs. Two robust design approaches are combined: the Mini-p-Norm. design method to consider real parameter uncertainties and the $H_{\infty}$ design technique for unknown disturbances and unknown inputs. Constant estimator gains are computed that guarantee the robust performance of the estimator in the presence of parameter variations in the target model and unknown inputs to the target. The new estimator has two design parameters. One design parameter allows the trade off between small estimator error variance and low sensitivity to unknown parameter variations. Another design parameter allows the trade off between the robustness to real parameter variations and the robustness to unknown inputs. This robust estimator design method was applied to the longitudinal motion tracking problem of a T-38 aircraft.

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Robust Controller for DC Servo Motor drive taking Disturbance and Parameter Variations into account (외란과 파라미터 변화를 고려한 직류 서어보 전공기 구동을 위한 강인성 제어기)

  • Yoon, Byung-Do;Jeong, Tak-Hee
    • Proceedings of the KIEE Conference
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    • 1988.11a
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    • pp.418-421
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    • 1988
  • A disturbance and parameter variations cause a steady and/or transient error in the conventional de servo motor drive system. In this paper robust control system for dc servo motor drive taking disturbance and parameter variations into account is proposed. The proposed control system compensates rapidly the state error caused by disturbance and parameter variations. Simulation results show that the proposed method is robust for the steady and transient response in the presence of both disturance and parameter variations.

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Dead Time Compensation Scheme Independent of Parameter Variations in an Inverter-fed PMSM Drive (파라미터 변화에 무관한 인버터 구동 PMSM의 데드타임 보상 기법)

  • Kim, Kyeong-Hwa
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.4
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    • pp.124-134
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    • 2011
  • A new dead time compensation scheme that can exactly estimate the dead time and inverter nonlinearity under parameter variations is proposed for a PWM inverter-fed PMSM drive. The proposed scheme uses the fact that the sixth harmonic component in total disturbance estimated under the presence of various uncertainties is mainly caused by the dead time and inverter nonlinearity. The total disturbance due to the parameter variations as well as the dead time and inverter nonlinearity is estimated by the adaptive scheme. The sixth harmonic component is extracted from this total disturbance through harmonic analysis. The obtained sixth harmonic is processed by the PI controller to estimate the disturbance caused by the dead time and inverter nonlinearity in the stationary reference frame. The effectiveness of the proposed scheme is verified. Without requiring an additional hardware, the proposed scheme can effectively compensate the dead time and inverter nonlinearity even under the parameter variations.

Effects of Electrical and Acoustical Variations for Loudspeaker due to Fabrication Processes (조립과정이 스피커의 전기 및 음향특성에 미치는 영향)

  • Park, Seok-Tae
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.155-159
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    • 2004
  • In this paper, it was analyzed the characteristics of electrical and acoustical variations for loudspeaker due to fabrication processes. First, mass of each components of loudspeaker was measured by electric precision scale and performed statistical analysis. Second. Thiele-Small parameters of sample loudspeakers produced by unskilled students were identified by known mass parameter identification method using electrical impedance method and investigated on the variations of each parameter. Electrical impedance tests and acoustic frequency responses were measured on sample loudspeakers and variations were examined to grasp relationship between components variation and fabrication processes. Main factors to effect the changes of electrical impedance were concluded by fabrication processes errors not by components of loudspeaker.

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Design of Adaptive Neural Networks Based Path Following Controller Under Vehicle Parameter Variations (차량 파라미터 변화에 강건한 적응형 신경회로망 기반 경로추종제어기)

  • Shin, Dong Ho
    • Journal of Drive and Control
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    • v.17 no.1
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    • pp.13-20
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    • 2020
  • Adaptive neural networks based lateral controller is presented to guarantee path following performance for vehicle lane keeping in the presence of parameter time-varying characteristics of the vehicle lateral dynamics due to the road surface condition, load distribution, tire pressure and so on. The proposed adaptive controller could compensate vehicle lateral dynamics deviated from nominal dynamics resulting from parameter variations by incorporating it with neural networks that have the ability to approximate any given nonlinear function by adjusting weighting matrices. The controller is derived by using Lyapunov-based approach, which provides adaptive update rules for weighting matrices of neural networks. To show the superiority of the presented adaptive neural networks controller, the simulation results are given while comparing with backstepping controller chosen as the baseline controller. According to the simulation results, it is shown that the proposed controller can effectively keep the vehicle tracking the pre-given trajectory in high velocity and curvature with much accuracy under parameter variations.

State Observer Design Considering Modelling Errors and Parameter Variations (모델링 오차와 파라미터변동을 고려한 상태 관측기 설계)

  • Kim, Chan-Ki
    • Proceedings of the KIEE Conference
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    • 1997.07f
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    • pp.2078-2081
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    • 1997
  • IP speed controller is used as a main controller and it makes the system low overshoot and easy controllability. Load torque is estimated by Kalman filter algorithm and parameter controller is used against a rotor inertia negative variations. Parameter Controller (PC) is equipped with a torque observer implemented by software of a digital signal Processor. PC is a parameter controller which selects a moment of inertia J in responding to a load torque to control the system response.

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An Adaptive Fuzzy Based Control applied to a Permanent Magnet Synchronous Motor under Parameter and Load Variations (ICCAS 2004)

  • Kwon, Chung-Jin;Kim, Sung-Joong;Won, Kyoung-Min
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1168-1172
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    • 2004
  • This paper presents a speed controller based on an adaptive fuzzy algorithm for high performance permanent magnet synchronous motor (PMSM) drives under parameter and load variations. In many speed tracking control systems PI controller has been used due to its simple structure and easy of design. PI controller, however, suffers from the electrical machine parameter variations and disturbances. In order to improve the tracking control performance under load variations, the PI controller parameters are modified during operation by adaptive fuzzy method. This method based on optimal fuzzy logic system has simple structure and computational simplicity. It needs only sample data which is obtained by optimal controller off-line. As the sample data implemented in the adaptive fuzzy system can be modified or extended, a flexible control system can be obtained. Simulation results show the usefulness of the proposed controller.

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Kinematic Tolerance Synthesis Using Generalized Configuration Spaces (컨피규레이션 공간을 이용한 기구학적 공차 설계)

  • Kyung M.-H.
    • Korean Journal of Computational Design and Engineering
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    • v.10 no.4
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    • pp.284-292
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    • 2005
  • This paper presents a new framework of kinematic tolerance synthesis and describes the implemented algorithm for planar mechanical systems comprised of higher kinematic pairs. Input to the synthesis algorithm is a parametric model of the mechanical system with allowed parameter ranges (tolerance ranges). The model is specified as the part profiles consisting of line and arc segments and the motion axes along which each part moves. The algorithm analyzes tolerance in generalized configuration space, called contact zones bounding the worst-case variations, and identifies bad system variations. The bad system variations then are removed out of the parameter ranges by adjusting the nominal parameter values if possible and then shrinking the ranges otherwise. This cycle is repeated until no more bad variations we found. I show the effectiveness of the algorithm by case studies on several mechanisms.

Speed Control of BLDC Motor Drive Using an Adaptive Fuzzy P+ID Controller (적응 퍼지 P+ID 제어기를 이용한 BLDC 전동기의 속도제어)

  • Kwon, Chung-Jin;Han, Woo-Yang;Sin, Dong-Yang;Kim, Sung-Joong
    • Proceedings of the KIEE Conference
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    • 2002.07b
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    • pp.1172-1174
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    • 2002
  • An adaptive fuzzy P + ID controller for variable speed operation of BLDC motor drives is presented in this paper. Generally, a conventional PID controller is most widely used in industry due to its simple control structure and ease of design. However, the PID controller suffers from the electrical machine parameter variations and disturbances. To improve the tracking performance for parameter and load variations, the controller proposed in this paper is constructed by using an adaptive fuzzy logic controller in place of the proportional term in a conventional PID controller. For implementing this controller, only one additional parameter has to be adjusted in comparison with the PID controller. An adaptive fuzzy controller applied to proportional term to achieve robustness against parameter variations has simple structure and computational simplicity. The controller based on optimal fuzzy logic controller has an self-tuning characteristics with clustering. Computer simulation results show the usefulness of the proposed controller.

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A Simple and Robust Digital Current Control for a PM Synchronous Motor under the Parameter Variations

  • Kim, Kyeong-Hwa;Baik, In-Cheol;Young, Myung-Joong
    • Journal of Electrical Engineering and information Science
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    • v.3 no.2
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    • pp.174-183
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    • 1998
  • A simple and robust digital current control technique for a permanent magnet (PM) synchronous motor under the parameter variations is presented. Among the various current control schemes for an inverter-fed PM synchronous motor drive, the predictive control is known to give a superior performance. This scheme, however, requires the full knowledge of machine parameters and operating conditions, and cannot give a satisfactory response under the parameter mismatch. To overcome such a limitation, the disturbances caused by the parameter variations will be estimated by using a disturbance observer theory and used for the computation of the reference voltages by a feedforward control. Thus, the steady-state control performance can be significantly improved with a relatively simple control algorithm, while retaining the good characteristics of the predictive control. The proposed control scheme is implemented on a PM synchronous motor using the software of DSP TMS320C30 and the effectiveness is verified through the comparative simulations and experiments.

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