• Title/Summary/Keyword: state dependent Riccati equation

Search Result 26, Processing Time 0.03 seconds

Nonlinear Observer Design for Satellite Angular Rate Estimation by SDRE Method (SDRE 기법을 이용한 위성 각속도 추정용 비선형 관측기 설계)

  • Jin, Jaehyun
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.42 no.10
    • /
    • pp.816-822
    • /
    • 2014
  • The estimation of the angular rate of a satellite has been discussed. A nonlinear observer has been proposed based on the state-dependent Riccati equation method. A sufficient stability condition for the convergence of estimation error has been presented. This condition is related to a state-dependent algebraic Riccati equation. It has been derived by transforming nonlinear error dynamics into a Lipschitz nonlinearity. An observer gain is obtained from this condition. Numerical simulations are presented to verify the proposed method.

Research on the Design of Helicopter Nonlinear Optimal Controller using SDRE Technique (SDRE 기법을 이용한 헬리콥터 비선형 최적제어기 설계 연구)

  • Yang, Chang-Deok;Kim, Min-Jae;Lee, Jung-Hwan;Hong, Ji-Seung;Kim, Chang-Joo
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.36 no.12
    • /
    • pp.1152-1162
    • /
    • 2008
  • This paper deals with the State-Dependent Riccati Equation (SDRE) technique for the design of helicopter nonlinear flight controllers. Since the SDRE controller requires a linear system-like structure for nonlinear motion equations, a state-dependent coefficient (SDC) factorization technique is developed in order to derive the conforming structure from a general nonlinear helicopter dynamic model. Also on-line numerical methods of solving the algebraic Riccati equation are investigated to improve the numerical efficiency in designing the SDRE controllers. The proposed method is applied to trajectory tracking problems of the helicopter and computational tips for a real time application are proposed using a high fidelity rotorcraft mathematical model.

SDRE-Based Near Optimal Traffic Controller Design (SDRE 기반 준최적 교통 혼잡 제어기 설계)

  • Choi, Han Ho
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.18 no.12
    • /
    • pp.1086-1089
    • /
    • 2012
  • We propose a near optimal controller design method for ramp metering based on SDRE (State Dependent Riccati Equation) approach. We parameterize the optimal nonlinear controller in terms of the solution matrices of an SDRE. We also give a simple algorithm to obtain the controller gain. Finally we give numerical results to show the effectiveness of the proposed near optimal traffic controller design method.

SDRE Based Optimal Nonlinear Observer-Controller Design for Ramp Metering System (진입로 신호등 시스템을 위한 SDRE 기반 최적 비선형 관측기 제어기 설계)

  • Lee, Kiho;Choi, Han Ho
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.20 no.5
    • /
    • pp.533-536
    • /
    • 2014
  • In this paper, a near optimal decentralized observer-controller design method is proposed for ramp metering systems based on SDRE (State Dependent Riccati Equation) approach. The optimal nonlinear observer gain is parameterized in terms of the solution matrix of an SDRE. This paper gives a simple algorithm to compute the near optimal observer gain. The optimal control design problem is also considered. Finally, numerical simulation results are given to illuminate the effectiveness and practicality of the proposed design method.

Optimal Control for Proximity Operations and Docking

  • Lee, Dae-Ro;Pernicka, Henry
    • International Journal of Aeronautical and Space Sciences
    • /
    • v.11 no.3
    • /
    • 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.

SDRE Based Near Optimal Controller Design of Permanent Magnet Synchronous Generator for Variable-Speed Wind Turbine System (가변속 풍력 발전용 영구자석형 동기발전기의 SDRE 기반 준최적 비선형 제어기 설계)

  • Park, Hyung-Moo;Choi, Han Ho
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.21 no.1
    • /
    • pp.28-33
    • /
    • 2015
  • In this paper, we propose a near optimal controller design method for permanent magnet synchronous generators (PMSGs) of MW-class direct-driven wind turbine systems based on SDRE (State Dependent Riccati Equation) approach. Using the solution matrix of an SDRE, we parameterize the optimal controller gain. We present a simple algorithm to compute the near optimal controller gain. The proposed optimal controller can enable PMSGs to precisely track the reference speed determined by the MPPT algorithm. Finally, numerical simulation results are given to verify the effectiveness of the proposed optimal controller.

Seismic response control of buildings with force saturation constraints

  • Ubertini, Filippo;Materazzi, A. Luigi
    • Smart Structures and Systems
    • /
    • v.12 no.2
    • /
    • pp.157-179
    • /
    • 2013
  • We present an approach, based on the state dependent Riccati equation, for designing non-collocated seismic response control strategies for buildings accounting for physical constraints, with particular attention to force saturation. We consider both cases of active control using general actuators and semi-active control using magnetorheological dampers. The formulation includes multi control devices, acceleration feedback and time delay compensation. In the active case, the proposed approach is a generalization of the classic linear quadratic regulator, while, in the semi-active case, it represents a novel generalization of the well-established modified clipped optimal approach. As discussed in the paper, the main advantage of the proposed approach with respect to existing strategies is that it allows to naturally handle a broad class of non-linearities as well as different types of control constraints, not limited to force saturation but also including, for instance, displacement limitations. Numerical results on a typical building benchmark problem demonstrate that these additional features are achieved with essentially the same control effectiveness of existing saturation control strategies.

Preliminary Test of Adaptive Neuro-Fuzzy Inference System Controller for Spacecraft Attitude Control

  • Kim, Sung-Woo;Park, Sang-Young;Park, Chan-Deok
    • Journal of Astronomy and Space Sciences
    • /
    • v.29 no.4
    • /
    • pp.389-395
    • /
    • 2012
  • The problem of spacecraft attitude control is solved using an adaptive neuro-fuzzy inference system (ANFIS). An ANFIS produces a control signal for one of the three axes of a spacecraft's body frame, so in total three ANFISs are constructed for 3-axis attitude control. The fuzzy inference system of the ANFIS is initialized using a subtractive clustering method. The ANFIS is trained by a hybrid learning algorithm using the data obtained from attitude control simulations using state-dependent Riccati equation controller. The training data set for each axis is composed of state errors for 3 axes (roll, pitch, and yaw) and a control signal for one of the 3 axes. The stability region of the ANFIS controller is estimated numerically based on Lyapunov stability theory using a numerical method to calculate Jacobian matrix. To measure the performance of the ANFIS controller, root mean square error and correlation factor are used as performance indicators. The performance is tested on two ANFIS controllers trained in different conditions. The test results show that the performance indicators are proper in the sense that the ANFIS controller with the larger stability region provides better performance according to the performance indicators.

Robust $H_{\infty}$ Control for Bilinear Systems with Parameter Uncertainties via output Feedback

  • Kim, Young-Joong;Lee, Su-Gu;Chang, Sae-Kwon;Kim, Beom-Soo;Lim, Myo-Taeg
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2003.10a
    • /
    • pp.386-391
    • /
    • 2003
  • This paper focuses on robust $H_{\infty}$ control for bilinear systems with time-varying parameter uncertainties and exogenous disturbance via output feedback. $H_{\infty}$ control is achieved via separation into a $H_{\infty}$ state feedback control problem and a $H_{\infty}$ state estimation problem. The suitable robust stabilizing output feedback control law can be constructed in term of approximated solution to x-dependent Riccati equation using successive approximation technique. Also, the $H_{\infty}$ filter gain can be constructed in term of solution to algebraic Riccati equation. The output feedback control robustly stabilizes the plant and guarantees a robust $H_{\infty}$ performance for the closed-loop systems in the face of parameter uncertainties and exogenous disturbance.

  • PDF