• Title/Summary/Keyword: disturbance systems

Search Result 1,158, Processing Time 0.027 seconds

Combined Optimal Design of Structure-Control Systems by Sliding Mode Control (슬라이딩모드 제어 기법을 이용한 구조-제어 시스템의 통합 최적 설계)

  • Park, Jung-Hyeon
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.19 no.10
    • /
    • pp.45-51
    • /
    • 2002
  • To achieve the lightweight and robust design of a structure, it is requested to design a structure and its control system simultaneously, which is called as the combined optimal design. A constant-cross-sectional area cantilever beam was chosen as an example for the applying the optimum design method. An initial load and a time varying disturbance were applied at the free end of the beam. Sliding mode control was selected due to its insensitiveness to the disturbance compared with other modes. It is known that the sliding mode control is robust to the disturbance and the uncertainty only if a matching condition is met, after giving a switching hyper plane. In this study, the optimum method was used for the design of the switching hyper plane and the objective function of the optimum switching hyper plane was assumed to be the objective one of the control system. The total weight of the structure was treated as a constraint and the cross sectional areas of the beam were considered as design variables, which means a nonlinear programming problem. The sequential linear programming method was applied to solve it. As a result of the optimum design, the effect of attenuating vibrations has been improved obviously. Moreover, lightweight design of the structure became possible from the relationship of the weight of the structure and the control objective function.

A Study on Performance Reduction Characteristics of Digital Wireless Communication by APD (APD 통계 모델에 의한 디지털 무선 통신 성능 저감 특성 연구)

  • Lim, Sung-Jin;Hur, Min-Ho;Kwon, Se-Woong;Yoon, Young-Joon
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
    • /
    • 2003.11a
    • /
    • pp.8-12
    • /
    • 2003
  • To protect digital communications and broadcasting that are expected to be increasingly used at frequencies above 1GHz, there is a need to determine permissible disturbance limits for frequency bands above 1GHz according to indicates that better correlates with interference level in digital systems. The quality of digital communications is expressed in terms of bit error rate(BER) or throughput. In this regard, it has been reported that degradation of BER or throughput can be estimated from the amplitude probability distribution (APD) of disturbance amplitude. Therefore, if the APD can simply be measured with a high accuracy, APD will be an optimal index for the assessment of interference in digital communications. In this paper, we show that a measurement method using statistic model of APD has compatibility about performance reduction estimation of WLAN. And through approach of this inspection, we propose numeral models about interference effects of peak value and time rate of spurious.

  • PDF

Performance Enhancement of RMRAC Controller for Permanent Magnent Synchronous Motor using Disturbance compensator (외란보상기를 이용한 영구자석 동기전동기에 대한 참조모델 견실적응제어기의 성능개선)

  • Jin, Hong-Zhe;Lim, Hoon;Lee, Jang-Myung
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.57 no.5
    • /
    • pp.845-851
    • /
    • 2008
  • A simple RMRAC (Robust Model Reference Adaptive Control) scheme for the PMSM (Permanent Magnent Synchronous Motor) is proposed in the synchronous frame. A current control of PMSM is the most inner loop of electro-mechanical driving systems and it requires a fast and simple control law to play a foundation role in the control hierarchy. In the proposed synchronous current model, the input signal is composed of a calculated voltage by proposed adaptive laws and real system disturbance. The gains of feed-forward and feedback controllers are estimated by the proposed modified Gradient method respectively, where the system disturbances are assumed as filtered current tracking errors. After the estimation of the system disturbances from the tracking errors, the corresponding voltage is fed forward to control input voltage to compensate for the disturbances. The proposed method is robust against high frequency disturbance and has a fast dynamic response. It also shows a good real-time performance due to it's simplicity of control structure. Through the simulations and real experiments, efficiency of the proposed method is verified.

Performance comparison study of current control methods for grid connected inverters (계통연계형 인버터의 전류제어기법 성능 비교)

  • Jeong, Horyeong;Lee, Jae Suk
    • Journal of IKEEE
    • /
    • v.24 no.3
    • /
    • pp.877-882
    • /
    • 2020
  • This paper presents performance comparison study of current control methods for grid connected inverter (GCI) system. Different current control methods have been developed for GCI systems and each controller has its own advantages and limitations. Steady state and transient dynamic performance of the GCI current controllers are compared in this paper. The performance of the proposed command feedforward control (CFFC) and disturbance rejection control (DRC) is analyzed before and after application to all GCI current controllers. The proposed CFFC and DRC control algorithms is analyzed in a frequency domain and the simulation and experiment models of each GCI current control methods are developed for verification of the performance.

Vibration Adaptive Algorithm for Vision Systems (비전 시스템의 성능개선을 위한 진동 적응 방법)

  • Seo, Kap-Ho;Yun, Sung-Jo;Park, Jeong Woo;Park, Sungho;Kim, Dae-Hee;Sohn, Dong-Seop;Suh, Jin-Ho
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.25 no.6
    • /
    • pp.486-491
    • /
    • 2016
  • Disturbance/vibration reduction is critical in many applications using machine vision. The off-focusing or blurring error caused by vibration degrades the machine performance. In line with this, real-time disturbance estimation and avoidance are proposed in this study instead of going with a more familiar approach, such as the vibration absorber. The instantaneous motion caused by the disturbance is sensed by an attitude heading reference system module. A periodic vibration modeling is conducted to provide a better performance. The algorithm for vibration avoidance is described according to the vibration modeling. The vibration occurrence function is also proposed, and its parameters are determined using the genetic algorithm. The proposed algorithm is experimentally tested for its effectiveness in the vision inspection system.

Experimental Results of Adaptive Load Torque Observer and Robust Precision Position Control of PMSM (PMSM의 정밀 Robust 위치 제어 및 적응형 외란 관측기 적용 연구)

  • Go, Jong-Seon;Yun, Seong-Gu
    • The Transactions of the Korean Institute of Electrical Engineers D
    • /
    • v.49 no.3
    • /
    • pp.117-123
    • /
    • 2000
  • A new control method for precision robust position control of a PMSM (Permanent Magnet Synchronous Motor) using asymptotically stable adaptive load torque observer is presented in the paper. Precision position control is obtained for the PMSM system approximately linearized using the field-orientation method. Recently, many of these drive systems use the PMSM to avoid backlashes. However, the disadvantages of the motor are high cost and complex control because of nonlinear characteristics. Also, the load torque disturbance directly affects the motor shaft. The application of the load torque observer is published in [1] using fixed gain. However, the motor flux linkage is not exactly known for a load torque observer. There is the problem of uncertainty to obtain very high precision position control. Therefore, a model reference adaptive observer is considered to overcome the problem of unknown parameter and torque disturbance in this paper. The system stability analysis is carried out using Lyapunov stability theorem. As a result, asymptotically stable observer gain can be obtained without affecting the overall system response. The load disturbance detected by the asymptotically stable adaptive observer is compensated by feedforwarding the equivalent current which gives fast response. The experimental results are presented in the paper using DSP TMS320c31.

  • PDF

Genetic algorithm-based design of a nonlinear PID controller for the temperature control of load-following coolant systems (부하추종 냉각수 시스템의 온도 제어를 위한 유전알고리즘 기반 비선형 PID 제어기 설계)

  • Yu-Soo, LEE;Soon-Kyu, HWANG;Jong-Kap, AHN
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.58 no.4
    • /
    • pp.359-366
    • /
    • 2022
  • In this study, the load fluctuation of the main engine is considered to be a disturbance for the jacket coolant temperature control system of the low-speed two-stroke main diesel engine on the ships. A nonlinear PID temperature control system with satisfactory disturbance rejection performance was designed by rapidly transmitting the load change value to the controller for following the reference set value. The feed-forwarded load fluctuation is considered the set points of the dual loop control system to be changed. Real-coded genetic algorithms were used as an optimization tool to tune the gains for the nonlinear PID controller. ITAE was used as an evaluation function for optimization. For the evaluation function, the engine jacket coolant outlet temperature was considered. As a result of simulating the proposed cascade nonlinear PID control system, it was confirmed that the disturbance caused by the load fluctuation was eliminated with satisfactory performance and that the changed set value was followed.

[ $H_{\infty}$ ] Filtering for Descriptor Systems

  • Chen, Yue-Peng;Zhou, Zu-De;Zeng, Chun-Nian;Zhang, Qing-Ling
    • International Journal of Control, Automation, and Systems
    • /
    • v.4 no.6
    • /
    • pp.697-704
    • /
    • 2006
  • The paper is concerned with $H_{\infty}$ filtering for descriptor systems. A necessary and sufficient condition is established in terms of linear matrix inequalities(LMIs) for the existence of normal filters such that the error systems are admissible and the transfer function from the disturbance to the filtering error output satisfies a prescribed $H_{\infty}$-norm bound constraint. When these LMIs are feasible, an explicit parameterization expression of all desired normal filter is given. All these results are yielded without decomposing the original descriptor systems, which makes the filter design procedure simple and direct. Finally, a numerical example is derived to demonstrate the applicability of the proposed approach.

Intelligent tuning of 2-DOG controller (2-자유도 제어기의 지능형 튜우닝 연구)

  • 김동화;조일인;이원규
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1997.10a
    • /
    • pp.135-138
    • /
    • 1997
  • In this paper, Tuning method of the parameter P.I.D of the 2DOG-PID controller for having a required response to the disturbance and the setpoint is studied by the neural network. This algorithms is simulated in the level control of the steam generator and the flow control system, and resulting represents than the conventional PID controller.

  • PDF