• 제목/요약/키워드: Linear quadratic tracking controller

검색결과 27건 처리시간 0.027초

Optimal Control for Proximity Operations and Docking

  • Lee, Dae-Ro;Pernicka, Henry
    • International Journal of Aeronautical and Space Sciences
    • /
    • 제11권3호
    • /
    • pp.206-220
    • /
    • 2010
  • This paper proposes optimal control techniques for determining translational and rotational maneuvers that facilitate proximity operations and docking. Two candidate controllers that provide translational motion are compared. A state-dependent Riccati equation controller is formulated from nonlinear relative motion dynamics, and a linear quadratic tracking controller is formulated from linearized relative motion. A linear quadratic Gaussian controller using star trackers to provide quaternion measurements is designed for precision attitude maneuvering. The attitude maneuvers are evaluated for different final axis alignment geometries that depend on the approach distance. A six degrees-of-freedom simulation demonstrates that the controllers successfully perform proximity operations that meet the conditions for docking.

Target Tracking Control of a Quadrotor UAV using Vision Sensor (비전 센서를 이용한 쿼드로터형 무인비행체의 목표 추적 제어)

  • Yoo, Min-Goo;Hong, Sung-Kyung
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • 제40권2호
    • /
    • pp.118-128
    • /
    • 2012
  • The goal of this paper is to design the target tracking controller for a quadrotor micro UAV using a vision sensor. First of all, the mathematical model of the quadrotor was estimated through the Prediction Error Method(PEM) using experimental input/output flight data, and then the estimated model was validated via the comparison with new experimental flight data. Next, the target tracking controller was designed using LQR(Linear Quadratic Regulator) method based on the estimated model. The relative distance between an object and the quadrotor was obtained by a vision sensor, and the altitude was obtained by a ultra sonic sensor. Finally, the performance of the designed target tracking controller was evaluated through flight tests.

Design of tracking controller Using Artificial Neural Network & comparison with an Optimal Track ing Controller (인공 신경회로망을 이용한 추적 제어기의 구성 및 최적 추적 제어기와의 비교 연구)

  • Park, Young-Moon;Lee, Gue-Won;Choi, Myoen-Song
    • Proceedings of the KIEE Conference
    • /
    • 대한전기학회 1993년도 하계학술대회 논문집 A
    • /
    • pp.51-53
    • /
    • 1993
  • This paper proposes a design of the tracking controller using artificial neural network and the compare the result with a result of optimal controller. In practical use, conventional Optimal controller has some limits. First, optimal controller can be designed only for linear system. Second, for many systems state observation is difficult or sometimes impossible. But the controller using artificial neural network does not need mathmatical model of the system including state observation, so it can be used for both linear and nonlinear system with no additional cost for nonlinearity. Designed multi layer neural network controller is composed of two parts, feedforward controller gives a steady state input & feedback controller gives transient input via minimizing the quadratic cost function. From the comparison of the results of the simulation of linear & nonlinear plant, the plant controlled by using neural network controller shows the trajectory similar to that of the plant controlled by an optimal controller.

  • PDF

Design of Linear Pitch Controller in Wind Turbine under the condition of Varying Operating Points (동작점 변화 조건에서의 풍력터빈 선형 피치제어기 설계)

  • Cheon, Jongmin;Kim, Choonkyoung;Lee, Joohoon;Hong, Jitae;Kwon, Soonman
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 한국신재생에너지학회 2011년도 추계학술대회 초록집
    • /
    • pp.40.1-40.1
    • /
    • 2011
  • This paper presents a pitch controller which can hold output power constant at the rated value. Although wind turbine contains complicated nonlinearities, its behaviour within a certain operating range of a point can be approximated by that of a linear model. By doing so, we can apply rather simple and systematic linear control techniques such as PID and LQR(Linear Quadratic Regulator) to design a linear pitch controller. Because these linear controllers are valid only in a sufficiently small range around an operating point, linearized wind turbine model under the condition of varying wind speed needs a linear pitch controller can achieve the aims of tracking the rated rotor rotational speed. We propose an improved linear pitch controller taking each merit of LQR and PI controller under the condition of varying operating points in this paper.

  • PDF

Fuzzy Modeling and Control of Wheeled Mobile Robot

  • Kang, Jin-Shik
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • 제3권1호
    • /
    • pp.58-65
    • /
    • 2003
  • In this paper, a new model, which is a Takagi-Sugeno fuzzy model, for mobile robot is presented. A controller, consisting of two loops the one of which is the inner state feedback loop designed for stability and the outer loop is a PI controller designed for tracking the reference input, is suggested. Because the robot dynamics is nonlinear, it requires the controller to be insensitive to the nonlinear term. To achieve this objective, the model is developed by well known T-S fuzzy model. The design algorithm of inner state-feedback loop is regional pole-placement. In this paper, regions, for which poles of the inner state feedback loop are lie in, are formulated by LMI's. By solving these LMI's, we can obtain the state feedback gains for T-S fuzzy system. And this paper shows that the PI controller is equivalent to the state feedback and the cost function for reference tracking is equivalent to the LQ(linear quadratic) cost. By using these properties, it is also shown in this paper that the PI controller can be obtained by solving the LQ problem.

Robust Adaptive Control of Hydraulic Positioning System Considering Frequency Domain Performance (주파수역 성능을 고려한 유압 위치시스템의 강인 적응 제어)

  • Kim, Ki-Bum;Kim, In-Soo
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • 제23권2호
    • /
    • pp.157-163
    • /
    • 2014
  • In this paper, a robust MRAC (model reference adaptive control) scheme is applied to control an electrohydraulic positioning system under various loads. The inverse dead-zone compensator in the control system cancels out the dead-zone response, and an integrator added to the controller provides good position-tracking ability. LQG/LTR (linear quadratic Gaussian control with loop transfer recovery) closed-loop model is used as the reference model for learning the MRAC system. LQG/LTR provides a systematic technique to design the linear controller that optimizes the objective function using some compromise between the control effort and the system performance in the frequency domain. Different external load tests are performed to investigate the effectiveness of the designed MRAC system in real time. The experimental results show that the tracking performance of the proposed system is highly accurate, which offers considerable robustness even with a large change in the load.

Constrained multivariable model based predictive control application to nonlinear boiler system (제약조건을 갖는 다변수 모델 예측 제어기의 비선형 보일러 시스템에 대한 적용)

  • 손원기;이명의;권오규
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
    • /
    • pp.160-163
    • /
    • 1996
  • This paper deals with MCMBPC(Multivariable Constrained Model Based Predictive Controller) for nonlinear boiler system with noise and disturbance. MCMBPC is designed by linear state space model obtained from some operating point of nonlinear boiler system and Kalman filter is used to estimate the state with noise and disturbance. The solution of optimization of the cost function constrained on input and/or output variables is achieved using quadratic programming, viz. singular value decomposition (SVD). The controller designed is shown to have excellent tracking performance via simulation applied to nonlinear dynamic drum boiler turbine model for 16OMW unit.

  • PDF

LQG/LTR Control of Hydraulic Positioning System with Dead-zone (사역대가 포함된 유압 위치 시스템의 LQG/LTR 제어)

  • Kim, In-Soo;Kim, Yeung-Shik;Kim, Ki-Bum
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • 제22권8호
    • /
    • pp.729-735
    • /
    • 2012
  • A LQG/LTR(linear quadratic Gaussian/loop transfer recovery) controller with an integrator is designed to control the electro-hydraulic positioning system. Without considering the nonlinearity in the dead-zone, computer simulations are performed and show good performances and tracking abilities with the feedback controller based on the linear system model. However, the performance of the closed loop hydraulic positioning system shows big steady-state error in real system because of the dead-zone. In this paper, the feedback controller with a nonlinear compensator is introduced to overcome the dead-zone phenomenon in hydraulic systems. The inverse dead-zone as a nonlinear compensator is used to cancel out the dead-zone phenomenon. Experimental tests are performed to verify the performance of the controller.

LQG/LTR Control of Hydraulic Positioning System with Dead-zone (사역대가 포함된 유압 위치 시스템의 LQG/LTR 제어)

  • Kim, Ki-Bum;Kim, Yeung-Shik;Kim, In-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 한국소음진동공학회 2012년도 춘계학술대회 논문집
    • /
    • pp.614-619
    • /
    • 2012
  • A LQG/LTR(Linear Quadratic Gaussian/Loop Transfer Recovery) controller with an integrator is designed to control the electro-hydraulic positioning system. Without considering the nonlinearity in the dead-zone, computer simulations are performed and show good performances and tracking abilities with the feedback controller based on the linear system model. However, the performance of the closed loop hydraulic positioning system shows big steady-state error in real system because of the dead-zone. In this paper, the feedback controller with a nonlinear compensator is introduced to overcome the dead-zone phenomenon in hydraulic systems. The inverse dead-zone as a nonlinear compensator is used to cancel out the dead-zone phenomenon. Experimental tests are performed to verify the performance of the controller.

  • PDF

Robust Optimal Nonlinear Control with Observer for Position Tracking of Permanent Magnet Synchronous Motors

  • Ha, Dong-Hyun;Lim, Chang-Soon;Hyun, Dong-Seok
    • Journal of Power Electronics
    • /
    • 제13권6호
    • /
    • pp.975-984
    • /
    • 2013
  • This paper proposes a robust optimal nonlinear control with an observer to reject the offset errors of position tracking for surface mounted permanent magnet synchronous motors. We provide the control method to reject offset errors and load torque for designing field oriented control (FOC) based the alternating current (AC) frame. The proposed method consists of a torque generator, a commutation scheme, an electrical controller, and a load torque observer. The mechanical controller is designed to compensate for load torque and the offset error and generate the desired torque. The commutation scheme is proposed to create the desired currents for the desired torque. The electrical controller is developed to guarantee the desired currents. The observer is designed to estimate both the velocity and the load torque. In order to obtain the robustness to parameter uncertainties and a gain tuning guide, the linear quadratic regulator method is applied to the proposed method. The closed-loop stability is proven. A detailed process for the FOC design and an analysis of the control methods based on the AC frame are presented. The performance of the proposed method was validated via experiments. The proposed method obtains the FOC based on the AC frame. Furthermore, the position tracking performance of the proposed method is superior to that of the conventional method.