• Title/Summary/Keyword: control law design

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A Study on The Optimal Data Link Window Flow Control for ISDN (ISDN을 위한 최적 데이타 링크 흐름 제어에 관한 연구)

  • Kim, Dong-Yon;Shin, Woo-Cheol;Park, Mig-Non;Lee, Sang-Bae
    • Proceedings of the KIEE Conference
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    • 1987.07b
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    • pp.1174-1177
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    • 1987
  • The design of flow control protocols for integrared networks with complete voice traffic on the data link level is investigated. The class of admissible flow control policies analyzed maximized the average data link throughput subject to an average system time delay constraints a finite intervals (O,s). In particular, it is shown that the optimum control law is bang-bang (window flow mechanism). The window size L can be analytically derived from maximum tolerated time delay T, the input arrival C of the queueing system, the duration of the time interval S, the initial number of packets in the queue.

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Adaptive Controller Design for a Synchronous Generator with Unknown Perturbation in Mechanical Power

  • Jiao Xiaohong;Sun Yuanzhang;Shen Tielong
    • International Journal of Control, Automation, and Systems
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    • v.3 no.spc2
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    • pp.308-314
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    • 2005
  • Transient stabilization with voltage regulation is investigated for a synchronous generator when the mechanical power is perturbed to any unknown value within its physical bounds so that the operating point of the system shifts to an unknown point. An adaptive excitation controller is designed based on the backstepping method with tuning functions. It will be shown that the adaptive control law proposed can achieve the convergence of the system states to the new equilibrium point in correspondence with the real value of the unknown mechanical power and the regulation of the terminal voltage to the required value. Simulation results are given to demonstrate the effectiveness of the proposed controller for the transient stabilization and voltage regulation.

Robust Pole Assignment in a Specified Disk

  • Nguyen, Van-Giap;Nguyen, Tan-Tien;Lee, Gun-You;Kim, Sang-Bong
    • Transactions on Control, Automation and Systems Engineering
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    • v.2 no.2
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    • pp.116-120
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    • 2000
  • This paper presents a method to assign robustly the closed loop system's poles in a specified disk by a state feedback for a linear time invariant system with structured or unstructured uncertainties. THe proposed robust design procedure includes two steps. Firstly, the perturbed closed loop matrix $A_{cl p}$ = $A_{cl}$ + Δ$A_{cl}$ is rearranged such that it is a function of the nominal closed loop matrix $A_{cl}$. Hence, we can control the positions of the perturbed closed loop poles by choosing $A_{cl}$ appropriately. Secondly, the feedback control law F that assigns the closed loop poles of the perturbed system in a specified disk is determined from the equation $A_{cl}$ = A + BF. A procedure for finding F is proposed based on partitioning every matrix of the equation $A_{cl}$ = A + BF in the horizontal direction.

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A Study on Fly-By-Wire Helicopter Control Law Design using SAS Actuators (안정성증강 작동기를 이용한 Fly-By-Wire 헬리콥터 제어법칙 설계에 대한 연구)

  • Kim, Eung-Tai;Choi, In-Ho
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.23 no.1
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    • pp.67-73
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    • 2015
  • The previous limited authority system capable of implementing attitude command response type and translational command response type by operating SAS actuator has the problem of early saturation of SAS actuator since SAS actuator should compensate the mechanical linkage displacement caused by control sick movement. In this paper, a limited authority system where flight control computer receives the command from the control stick which is not connected to the mechanical linkage is described. In this system the compensation by the SAS actuator is not necessary and SAS actuator saturate later. SAS actuator saturation problem can be further relaxed by using the trim actuator. This new limited authority system is applied to BO-105 model, simulation is performed for the doublet input and pirouette maneuver is also simulated and analyzed.

Adaptive Control with Antiwindup Scheme for Relaxed Static Stability(RSS) Missiles with Saturating Actuator

  • Kim, Young-Hwan;Chwa, Dong-Kyung;Im, Ki-Hong;Choi, Jin-Young
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.54.4-54
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    • 2001
  • This paper proposes an adaptive control scheme for an autopilot design of Relaxed-Static-Stability(RSS) Missiles with saturating actuator. The feedback linearization controller eliminates nonlinear terms in RSS missile dynamics and makes the entire system linear. But modeling errors, disturbances and the nonlinear mismatch due to input constraints exert a bad influence on the performance of the feedback linearization controller Thus, first, we derive a parametric affine uncertainty model with modeling errors and disturbances. Then an adaptive control law with anti-windup scheme is developed, where the bounds of uncertainties are estimated with adaptive laws. The proposed adaptive controller can remove the bad effects of uncertainties, of disturbances, and of saturating actuator ...

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An analytical expression for a dynamic optimal design of the stewart platform (스튜어트 플랫폼의 동역학적 최적설계를 위한 해석적인 표현)

  • Kwon, Byung-Hee;Son, Kwon
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.175-178
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    • 1997
  • This study was carried out to obtain an analytical expression for the specifications of the Stewart Platform that minimize the maximum force acting on the hydraulic cylinder. The position and orientation of the platform were calculated by means of the inverse kinematic analysis. The maximum force to be exerted on a cylinder was calculated using the Newton's second law for the case when the platform is moved along a horizontal axis with 0.6 g, the maximum translational acceleration possible. This paper suggests a mathematical model to minimize the maximum actuating force using radius and angle ratios as design variables. Finally, a fuzzy set for the minimum actuating force is proposed for this dynamic optimal design problem.

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Nonlinear analysis of service stresses in reinforced concrete sections-closed form solutions

  • Barros, Helena F.M.;Martins, Rogerio A.F.
    • Computers and Concrete
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    • v.10 no.5
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    • pp.541-555
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    • 2012
  • This paper presents an algorithm for the evaluation of stresses in reinforced concrete sections under service loads. The algorithm is applicable to any section defined by polygonal contours and is based on an analytical integration of the stresses. The nonlinear behaviour of concrete is represented by the parabola-rectangle law used in the Eurocode-2 for the ultimate concrete design. An integrated definition of the strains in concrete and steel is possible by the use of Heaviside functions, similarly to what is done for ultimate section design in Barros et al. (2004). Other constitutive equations for the definition of the stresses in the concrete or steel can be easily incorporated into the code. The examples presented consist in the evaluation of resulting axial load and bending moment in an irregular section and in a section in L shape. The results, for service stresses, can also be plotted in terms of design abacus; a rectangular doubly reinforced section is presented as example.

Design of a Speed Controller for the Synchronous Motor in Electric Vehicle (전기자동차용 동기기의 속도제어기 설계)

  • Hyun, Keun-Ho
    • Proceedings of the KIEE Conference
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    • 2007.10a
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    • pp.239-240
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    • 2007
  • In this paper, a robust adaptive backstepping controller will be proposed for the speed control of permanent magnet synchronous motors in using electrical vehicles. Stator resistance, damping coefficient, load torque are considered as uncertainties and noise generated at applying load torque to motor is also considered. It shows that the backstepping algorithm can be used to solve the problems of nonlinear system very well and robust controller can be designed without the variation of adaptive law. Simulation results are provided to demonstrate the effectiveness of the Proposed controller.

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Design and Control of a Quad-Rotor (쿼드로터 비행체의 설계 및 제어)

  • Shim, Sanghyun;Kim, Ji-Chul;Yang, Sungwook;Cheon, Dong-Ik;Lee, Sangchul;Oh, Hwa-Suk;Kang, Min-Young;Keum, Dong-Kyo
    • Journal of Aerospace System Engineering
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    • v.3 no.1
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    • pp.36-41
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    • 2009
  • Quad-rotor is one kind of a rotorcraft in Unmanned Aerial Vehicle (UAV), which consists of four rotors in total and fixed-pitch blades located at the four corners. This vehicle is emerging as popular platform for UAV research due to the simplicity of its construction, the ability of hovering and the vertical take-off and landing (VTOL) capability, etc. Because of those specific capabilities, this vehicle can be applied to many fields: search and rescue, mobile sensor networks, fire observation, etc. However a quad-rotor is much affected by the disturbance due to the characteristics of structure. So this vehicle needs attitude control for stabilizing. In this paper, we design the control law for automatic stabilization. The PID controller is used to control a brushless DC motor. And an accelerometer is used to measure the roll and pitch angles of a quad-rotor.

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Design of Robust Adaptive Fuzzy Controller for Uncertain Nonlinear System Using Estimation of Bounding Constans and Dynamic Fuzzy Rule Insertion (유계상수 추정과 동적인 퍼지 규칙 삽입을 이용한 비선형 계통에 대한 강인한 적응 퍼지 제어기 설계)

  • Park, Jang-Hyun;Park, Gwi-Tae
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.50 no.1
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    • pp.14-21
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    • 2001
  • This paper proposes an indirect adaptive fuzzy controller for general SISO nonlinear systems. In indirect adaptive fuzzy control, based on the proved approximation capability of fuzzy systems, they are used to capture the unknown nonlinearities of the plant. Until now, most of the papers in the field of controller design for nonlinear system considers the affine system using fuzzy systems which have fixed grid-rule structure. We proposes a dynamic fuzzy rule insertion scheme where fuzzy rule-base grows as time goes on. With this method, the dynamic order of the controller reduces dramatically and an appropriate number of fuzzy rules are found on-line. No a priori information on bounding constants of uncertainties including reconstruction errors and optimal fuzzy parameters is needed. The control law and the update laws for fuzzy rule structure and estimates of fuzzy parameters and bounding constants are determined so that the Lyapunov stability of the whole closed-loop system is guaranteed.

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