scholarly journals Disturbance observer-based L1 robust tracking control for hypersonic vehicles with T-S disturbance modeling

2016 ◽  
Vol 13 (6) ◽  
pp. 172988141667111 ◽  
Author(s):  
Yang Yi ◽  
Lubing Xu ◽  
Hong Shen ◽  
Xiangxiang Fan

This article concerns a disturbance observer-based L1 robust anti-disturbance tracking algorithm for the longitudinal models of hypersonic flight vehicles with different kinds of unknown disturbances. On one hand, by applying T-S fuzzy models to represent those modeled disturbances, a disturbance observer relying on T-S disturbance models can be constructed to track the dynamics of exogenous disturbances. On the other hand, L1 index is introduced to analyze the attenuation performance of disturbance for those unmodeled disturbances. By utilizing the existing convex optimization algorithm, a disturbance observer-based proportional-integral-controlled input is proposed such that the stability of hypersonic flight vehicles can be ensured and the tracking error for velocity and altitude in hypersonic flight vehicle models can converge to equilibrium point. Furthermore, the satisfactory disturbance rejection and attenuation with L1 index can be obtained simultaneously. Simulation results on hypersonic flight vehicle models can reflect the feasibility and effectiveness of the proposed control algorithm.

2017 ◽  
Vol 14 (2) ◽  
pp. 172988141668695 ◽  
Author(s):  
Jianxin Ren ◽  
Daipeng Yang

In this article, the disturbance observer–based control is designed for a flexible hypersonic flight vehicle with the external disturbance. The aircraft structure is easy to cause elastic vibration, thus leading to serious change in structural configuration or even disintegration. Therefore, the impact of elasticity modal for altitude subsystem is described as a system disturbance, and then, the equivalent model is established. On this basis, considering the model structure and composition of nonlinear systems, the disturbance observer is used to eliminate the information of the disturbance. Finally, the simulation results make an offer to show that the disturbance observer–based control can provide a good tracking performance.


Author(s):  
Jingxing Zuo ◽  
Yunjie Wu ◽  
Lianghua Sun

This study concerns with the attitude and velocity tracking control problem for the longitudinal model of hypersonic flight vehicles, which is nonlinear in aerodynamics with model uncertainties and external disturbances. By employing back stepping sliding mode method and the strictly-lower-convex-function-constructing nonlinear disturbance observer (SNDOB), a novel composite controller is proposed to guarantee the system tracking error to converge to a small region containing the origin. Besides, several proper adaptive laws are also introduced to make the controller avoid of the differential explosion problem and be chatter-free. Compared with other robust flight control approaches, key novelties of the developed method are that one new SNDOB is proposed and drawn into the virtual control laws at each step to compensate the disturbances and that adaptive laws are utilized to simplify the tedious and complicated differential operations. Finally, it is demonstrated by the simulation results that the new method exhibits not only an excellent robustness but also a better disturbance rejection performance than the convention approach.


2017 ◽  
Vol 14 (1) ◽  
pp. 172988141668270 ◽  
Author(s):  
Zhonghua Wu ◽  
Jingchao Lu ◽  
Jingping Shi ◽  
Qing Zhou ◽  
Xiaobo Qu

A robust adaptive neural control scheme based on a back-stepping technique is developed for the longitudinal dynamics of a flexible hypersonic flight vehicle, which is able to ensure the state tracking error being confined in the prescribed bounds, in spite of the existing model uncertainties and actuator constraints. Minimal learning parameter technique–based neural networks are used to estimate the model uncertainties; thus, the amount of online updated parameters is largely lessened, and the prior information of the aerodynamic parameters is dispensable. With the utilization of an assistant compensation system, the problem of actuator constraint is overcome. By combining the prescribed performance function and sliding mode differentiator into the neural back-stepping control design procedure, a composite state tracking error constrained adaptive neural control approach is presented, and a new type of adaptive law is constructed. As compared with other adaptive neural control designs for hypersonic flight vehicle, the proposed composite control scheme exhibits not only low-computation property but also strong robustness. Finally, two comparative simulations are performed to demonstrate the robustness of this neural prescribed performance controller.


2015 ◽  
Vol 2015 ◽  
pp. 1-26 ◽  
Author(s):  
Yunjie Wu ◽  
Jianmin Wang

A continuous recursive sliding mode controller (CRSMC) with extended disturbance observer (EDO) is proposed for the longitudinal dynamics of a generic hypersonic flight vehicle (HFV) in the presence of multiple uncertainties under control constraints. Firstly, sliding mode tracking controller based on a set of novel recursive sliding mode manifolds is presented, in which the chattering problem is reduced. The CRSMC possesses the merits of both nonsingular terminal sliding mode controller (NTSMC) and high-order sliding mode controller (HOSMC). Then antiwindup controller is designed according to the input constraints, which adds a dynamic compensation factor in the CRSMC. For the external disturbance of system, an improved disturbance observer based on extended disturbance observer (EDO) is designed. The external disturbance is estimated by the disturbance observer and the estimated value is regarded as compensation in CRSMC for disturbance. The stability of the proposed scheme is analyzed by Lyapunov function theory. Finally, numerical simulation is conducted for cruise flight dynamics of HFV, where altitude is 110000 ft, velocity is 15060 ft/s, and Mach is 15. Simulation results show the validity of the proposed approach.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Lei Zhengdong ◽  
Wang Man ◽  
Yang Jianying

This paper is concerned with a novel tracking controller design for a hypersonic flight vehicle in complex and volatile environment. The attitude control model is challengingly constructed with multivariate uncertainties and external disturbances, such as structure dynamic and stochastic wind disturbance. In order to resist the influence of uncertainties and disturbances on the flight control system, nonlinear disturbance observer is introduced to estimate them. Moreover, for the sake of high accuracy and sensitivity, fuzzy theory is adopted to improve the performance of the nonlinear disturbance observer. After the total disturbance is eliminated by dynamic inversion method, a cascade system is obtained and then stabilized by a sliding-mode controller. Finally, simulation results show that the strong robust controller achieves excellent performance when the closed-loop control system is influenced by mass uncertainties and external disturbances.


Sign in / Sign up

Export Citation Format

Share Document