• Title/Summary/Keyword: Multi Step Loop

Search Result 32, Processing Time 0.025 seconds

A Study on Improvement of Dynamic Characteristics and Stability of PM Stepping Motor (PM 스텝 모우터의 동특성 개선 및 안정화에 관한 연구)

  • Kim, Do-Hyung
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.23 no.6
    • /
    • pp.888-894
    • /
    • 1986
  • In this paper, a phase locked loop control system is designed to have high performance and stability in a 2-phase bifilar winding PM step motor. The BODE diagram analysis method is used to improve the stability and dynamic characteristic of the closed loop control system. Also, a PLL servo is used to accomplish high-precision speed and to attain smooth ness. In applying the PLL control to the step motor, a new design method is suggested to solve the control problem which occurs as a result of the limited maximum acceleration of the step motor. A simple design method is suggested without using the complicated multi-step characteirstic of the step motor in constant voltage driving. Computer simulation results agree clorelg with experiments, indicating that the PLL servo system of the step motor designed is very useful.

  • PDF

Modeling for Twin Rotor System Using CLID (폐로식별기법에 의한 TRMS 모델링)

  • Lee, Jung-Kyung;Kwon, Oh-Kyu
    • Proceedings of the KIEE Conference
    • /
    • 2004.11c
    • /
    • pp.644-646
    • /
    • 2004
  • The closed loop identification(CLID) is a very useful method for on-line applications since it can identify the plant in the closed-loop system composed of the plant and the controller. There are some literatures on CLID, but they and mainly focused on SISO(Single-Input/Single-Output) problem. In this paper, a CLID method is proposed for MIMO(Multi-Input/Multi-Output) systems. The CLID method is applied to a MIMO benchmark plant, TRMS(Twin-Rotor MIMO System). To illustrate the performance of the closed-loop system identification., unit step responses in the TRMS are represented and compared with the open-loop identification via some simulation.

  • PDF

Predictive Closed-Loop Power Control for CDMA Systems in Time-Varying Fading Channels (시변 페이딩 채널하에 CDMA 시스템을 위한 예측 폐루프 전력제어)

  • Choe, Sang-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.30 no.11A
    • /
    • pp.1021-1026
    • /
    • 2005
  • In this paper, we present a novel predictive CDMA closed-loop power control (CLPC) method with a multi-step least squares (LS) linear predictor for time-varying fading channels. The proposed method effectively compensates multiple power control group delays and provides significant performance gains over nonpredictive CLPCs as well as conventional predictive CLPCs with one-step linear predictor.

ROBUST CONTROL OF POSITIONING SYSTEMS WITH A BANG-BANG ACTUATOR (뱅-뱅 액츄에이터를 가진 위치 제어계의 강인제어)

  • 최진태;김종식
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1996.04a
    • /
    • pp.456-460
    • /
    • 1996
  • A nonlinear control scheme for preventing limit cycle due to the nonlinearity of themulti-step bang-bang actuator in mechanical position control systems is proposed. A linearized model, SIDF, fora multi-step bang-bang actuator is introduced to compensate the nonlinearity of the multi-step bang-bang actuator. Using that model, a $H_{\infty}$robust controller for position control systms with a bang-bang actuator is proposed by loop shaping tecniques with normalized coprime factorization stabilization to address the robustness. The proposed scheme needs a smaller deadband as a result of compensating the nonlinearity of the bang-bang actuator. A single-axis servo system is served in order to verify the proposed control scheme experimentally. Experimental results show that the controller can satisfy the special intersts, silent contact switching of the actuator.r.

  • PDF

A Study on DC-DC Power Supply for Magnetically Levitated Vehicle (자기부상열차용 DC-DC 전원장치에 관한 연구)

  • Chun, Choon-Byeon;Jeon, Kee-Young;Lee, Hoon-Goo;Han, Kyung-Hee
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.18 no.6
    • /
    • pp.128-135
    • /
    • 2004
  • The author present a modified multi-loop algorithm including feedforward for controlling a 55kW step down chopper in the power supply of Maglev. The control law for the duty cycle consists of three terms. The first is the feedforward term. which compensates for variations in the input voltaga. The second term consists of the difference between the slowly moving inductor current and output current. The third term consists of proportional and integral terms involving the perturbation in the output voltage. This perturvation is derived by subtracting the desired output voltage from the actual output voltage. The proportional and integral action stabilizes the system and minimizes output voltage error. In order to verify the validity of the proposed multi-loop controller, simulation study was tried using Matlab simulink

Improved DMC for the integrating process (적분 공정 제어를 위한 향상된 DMC)

  • 강병삼;한종훈;장근수
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1996.10b
    • /
    • pp.1120-1123
    • /
    • 1996
  • DMC(Dynamic Matrix Control) algorithm has been successfully used in industries for more than a decade. It can handle constraints and easily extended to MIMO case. The application of DMC, however, is limited to the open loop stable process because it uses the FIR(Finite Impulse Response) or FSR(Finite Step Response) model. Integrating process widely used in chemical process industry, is the representative open loop unstable process. The disturbance rejection of DMC is relatively poor due to the assumption that the current disturbance is equivalent to the future disturbance. We propose the IDMC(Improved Dynamic Matrix Control) for the integrating process, as well as non-integrating process. IDMC has shown better disturbance rejection using multi-step ahead predictor for the disturbance.

  • PDF

Design of Lateral Controller for Automatic Valet Parking and Its Performance Analysis with Respect to Vehicle Types (자동 발렛 파킹을 위한 횡방향 제어기 설계 및 차종변화에 대한 제어 성능 분석)

  • Choi, Heejae;Song, Bongsob
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.18 no.11
    • /
    • pp.1051-1058
    • /
    • 2012
  • The unified lateral control algorithm for automatic valet parking for various types of vehicles is presented and its feasibility is shown experimentally via field tests for the given parking scenario. First, a trajectory generation algorithm for forward driving and backward multi-step parking maneuvers is developed. Then, with consideration of different types of vehicles and operating conditions, a kinematic vehicle model is used and validated using field test data. Using the nonlinear vehicle model, the lateral controller is designed based on dynamic surface control. Finally the proposed lateral control law is validated via hardware-in-the-loop simulations for different types of vehicles and experimentally using a test vehicle through field tests.

A Research for Improvement of WIM System by Abnormal Driving Patterns Analysis (비정상 주행패턴 분석을 통한 WIM 시스템 개선 연구)

  • Park, Je-U;Kim, Young-Back;Chung, Kyung-Ho;Ahn, Kwang-Seon
    • Journal of Internet Computing and Services
    • /
    • v.11 no.4
    • /
    • pp.59-72
    • /
    • 2010
  • WIM(Weigh-In-Motion) is the system measuring the weight of the vehicle with a high-speed. In the existing WIM system, vehicle weight is measured based on the constant speed and the error ratio has 10%. However, because of measuring the driving pattern, that is abnormal driving pattern which is like the acceleration and down-shift of the drivers, it has the error ratio which is bigger than the real. In order to it reduces the error ratio of WIM system, the improved WIM system needs to find the abnormal driving pattern. In order to reducing the error ratio of these WIM systems, the improved WIM system can find abnormal driving patterns. In this paper, the improved WIM system which analyzes the abnormality driving pattern influencing on the error ratio of WIM system of an existing and minimizes the error span is designed. The improved WIM system has the multi step loop structure of adding the loop sensor to an existing system. In addition, the measure function defined as an intrinsic is improved and the weight measured by the abnormal driving pattern is amended. The analysis of experiment result improved WIM system can know the fact that the error span reduces by 8% less than in the existing the maximum average sampling error 22.98%.

Structural Design Optimization of a High Speed Machining Center by Using a Simple Genetic Algorithm (유전 알고리즘을 이용한 고속 금형센터의 구조설계 최적화)

  • 최영휴;박선균;배병태;이재윤;김태형;박보선
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2000.11a
    • /
    • pp.1006-1009
    • /
    • 2000
  • In this study, a multi-step optimization technique combined with a simple genetic algorithm is introduced in order to minimize the static compliance, the dynamic compliance, and the weight of a high speed machining center simultaneously. Dimensional thicknesses of the eight structural members on the static force loop are adopted as design variables. The first optimization step is a static design optimization, in which the static compliance and the weight are minimized under some dimensional and safety constraints. The second step is a dynamic design optimization, where the dynamic compliance and the weight are minimized under the same constraints. After optimization, the weight of the moving body only was reduced to 57.75% and the weight of the whole machining center was reduced to 46.2% of the initial design respectively. Both static and dynamic compliances of the optimum design are also in the feasible range even though they were slightly increased than before.

  • PDF