Robust Coupling-Observer-Based Linear Quadratic Regulator for Air-Breathing Hypersonic Vehicles with Flexible Dynamics and Parameter Uncertainties

Aiming at the longitudinal motion model of the air-breathing hypersonic vehicles (AHVs) with parameter uncertainties, a new prescribed performance-based active disturbance rejection control (PP-ADRC) method was proposed. First, the AHV model was divided into a velocity subsystem and altitude system. To guarantee the reliability of the control law, the design process was based on the nonaffine form of the AHV model. Unlike the traditional prescribed performance control (PPC), which requires accurate initial tracking errors, by designing a new performance function that does not depend on the initial tracking error and can ensure the small overshoot convergence of the tracking error, the error convergence process can meet the desired dynamic and steady-state performance. Moreover, the designed controller combined with an active disturbance rejection control (ADRC) and extended state observer (ESO) further enhanced the disturbance rejection capability and robustness of the method. To avoid the differential expansion problem and effectively filter out the effects of input noise in the differential signals, a new tracking differentiator was proposed. Finally, the effectiveness of the proposed method was verified by comparative simulations.

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H∞-Based LQR Control for Flexible Air-Breathing Hypersonic Vehicles with Pole Placement

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.787.938 ◽

2013 ◽

Vol 787 ◽

pp. 938-943

Author(s):

Xue Zhang ◽

Xiao Geng Liang

Keyword(s):

Linear Quadratic Regulator ◽

Pole Placement ◽

Control Law ◽

Linear Quadratic ◽

External Disturbances ◽

Air Breathing ◽

Lqr Control ◽

Flight Vehicles ◽

Quadratic Performance ◽

Linearized Model

Focusing on a nonlinear longitudinal dynamical model for air-breathing hypersonic flight vehicles (AHFV), we propose a state feedback linearized model on a nominal trim condition. To stabilize the flight of an AHFV in the presence of external disturbances, a newHbased Linear Quadratic Regulator (LQR) control law with pole placement is designed. Indexes forHperformance, quadratic performance and pole placement are considered together. As a result, the robustness of system is improved and the AHFV system is effectively stabilized. Numerical simulation shows that the controller can effectively stabilize the AHFV system with some disturbances and assign the poles into a desired region.

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Hovering stability of a model helicopter

Aircraft Engineering and Aerospace Technology ◽

10.1108/aeat-01-2015-0004 ◽

2016 ◽

Vol 88 (6) ◽

pp. 810-817 ◽

Cited By ~ 2

Author(s):

Ilker Murat Koc ◽

Semuel Franko ◽

Can Ozsoy

Keyword(s):

Initial Conditions ◽

Linear Quadratic Regulator ◽

Open Loop ◽

Small Scale ◽

Linear Quadratic ◽

Parameter Uncertainties ◽

Control Effort ◽

Content Type ◽

Modeling Uncertainties ◽

Angular Displacements

Purpose The purpose of this paper is to investigate the stability of a small scale six-degree-of-freedom nonlinear helicopter model at translator velocities and angular displacements while it is transiting to hover with different initial conditions. Design/methodology/approach In this study, model predictive controller and linear quadratic regulator are designed and compared within each other for the stabilization of the open loop unstable nonlinear helicopter model. Findings This study shows that the helicopter is able to reach to the desired target with good robustness, low control effort and small steady-state error under disturbances such as parameter uncertainties, mistuned controller. Originality/value The purpose of using model predictive control for three axes of the autopilot is to decrease the control effort and to make the close-loop system insensitive against modeling uncertainties.

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Robust Compensator Control of a Non-Resonant MEMS Gyroscope With Linear Quadratic Regulator

Volume 10: Micro and Nano Systems ◽

10.1115/imece2010-38871 ◽

2010 ◽

Author(s):

Wei Cui ◽

Xiaolin Chen ◽

Wei Xue

Keyword(s):

Closed Loop ◽

Linear Quadratic Regulator ◽

Open Loop ◽

High Order ◽

Behavior Modeling ◽

Linear Quadratic ◽

Parameter Uncertainties ◽

Control Effort ◽

Wide Range ◽

Sinusoidal Input

This paper presents a controller design for a four degrees-of-freedom (4-DOF) non-resonant gyroscope via the linear quadratic regulator (LQR) technique. Compared to conventional MEMS gyroscopes, non-resonant gyroscopes are less vulnerable to fabrication perturbations. However, closed-loop performance of non-resonant gyroscopes has not been investigated previously. The control of non-resonant gyroscopes involves consideration of high order systems. LQR, which achieves balances between a fast response and a low control effort, has proven to be effective for high order systems. Our simulation results show that the closed-loop 4-DOF non-resonant gyroscope presented in this paper is able to achieve faster response and higher robustness to parameter uncertainties than the open-loop device. Under the sinusoidal input, compared to an error of 11.06% for the open-loop system, the closed-loop scale factor uniformity error is reduced to 0.014% under ±10% parameter perturbations. The device performance is analyzed by the behavior modeling approach in CoventorWare. The results show that the closed-loop non-resonant gyroscope achieves better performance through the LQR. The method reported here is proven to be effective and can be used in a wide range of applications.

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Nonlinear Disturbance-Observer-Based Sliding Mode Control for Flexible Air-Breathing Hypersonic Vehicles

Mathematical Problems in Engineering ◽

10.1155/2015/675659 ◽

2015 ◽

Vol 2015 ◽

pp. 1-15 ◽

Cited By ~ 3

Author(s):

Na Wang ◽

Xiu-Ming Yao ◽

Wen-Shuo Li

Keyword(s):

Disturbance Observer ◽

Sliding Mode ◽

Lyapunov Theory ◽

Hypersonic Vehicles ◽

Sliding Mode Controller ◽

Parameter Uncertainties ◽

Nonlinear Disturbance Observer ◽

Air Breathing ◽

Nonlinear Disturbance ◽

Uniformly Ultimate Boundedness

This paper investigates a tracking problem for flexible air-breathing hypersonic vehicles (FAHVs) with composite disturbance. The composite disturbance produced by flexible effects, parameter uncertainties, and external interferences is modeled as a kind of unknown derivative-bounded disturbance in this paper. Then a novel composite control strategy is presented for the nonlinear FAHV model with the composite disturbance, which combines a nonlinear disturbance-observer-based compensator (NDOBC) and a dynamic-inversion-based sliding mode controller (DIBSMC). Specifically, the NDOBC is constructed to estimate and compensate for the composite disturbance, and the DIBSMC is designed to track desired trajectories of velocity and flight path angle. Moreover, the uniformly ultimate boundedness of the composite system can be guaranteed by using Lyapunov theory. Finally, simulation results on a full nonlinear model of FAHVs demonstrate that the proposed nonlinear disturbance-observer-based sliding mode controller is more effective than the traditional DIBSMC. Specifically, it is shown that the chattering of traditional DIBSMC in presence of composite disturbances can be attenuated with the NDOBC.

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