scholarly journals Robust Adaptive Attitude Control for Airbreathing Hypersonic Vehicle with Attitude Constraints and Propulsive Disturbance

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Jian Fu ◽  
Liangming Wang ◽  
Mou Chen ◽  
Sijiang Chang

A robust adaptive backstepping attitude control scheme, combined with invariant-set-based sliding mode control and fast-nonlinear disturbance observer, is proposed for the airbreathing hypersonic vehicle with attitude constraints and propulsive disturbance. Based on the positive invariant set and backstepping method, an innovative sliding surface is firstly developed for the attitude constraints. And the propulsive disturbance of airbreathing hypersonic vehicle is described as a differential equation which is motivated by attitude angles in this paper. Then, an adaptive fast-nonlinear disturbance observer for the proposed sliding surface is designed to estimate this kind of disturbance. The convergence of all closed-loop signals is rigorously proved via Lyapunov analysis method under the developed robust attitude control scheme. Finally, simulation results are given to illustrate the effectiveness of the proposed attitude control scheme.

Author(s):  
Xiaoqian Yang ◽  
Jian Li ◽  
Yi Dong

A new control scheme for flexible air-breathing hypersonic vehicle is designed in this paper based on non-singular fast terminal sliding mode control and nonlinear disturbance observer. The proposed control scheme is derived from basic back-stepping method, which is capable of handling the higher-order nonlinear system, and a novel terminal sliding mode control method is designed for the last step to promise the finite time convergence and improve the steady-state precision. Meanwhile, a command filter is used to avoid the “explosion of complexity” in traditional back-stepping method. To overcome inevitable uncertainties as well as cross couplings between flexible and rigid modes, NDO is introduced to estimate diverse uncertainties. Thus flexible modes and uncertainties can be suppressed simultaneously. The convergence of overall closed-loop system states is proved via Lyapunov analysis. Numerical simulations show the effectiveness and advantages of the proposed control strategy.


Author(s):  
Vahid Razmavar ◽  
Heidar Ali Talebi ◽  
Farzaneh Abdollahi

<span>In this article a novel composite control technique is introduced. We added a nonlinear disturbance observer to a nonlinear H_∞ control to form this composite controller. The quadrotor kinematics and dynamics is formulated using euler angles and parameters. After that, this nonlinear robust controller is developed for this flying robot attitude control for the outdoor conditions. Because under these conditions the flying robot, experiences both external disturbance and parametric uncertainty. Stability analysis is also presented to show the global asymptotical stability using a Lyapunov function. The simulation results showed that the suggested composite controller had a better performance in comparison with a nonlinear H_∞ control scheme.</span>


Author(s):  
Jianguo Guo ◽  
Guoqing Wang ◽  
Zongyi Guo ◽  
Jun Zhou

The work presented here is concerned with the robust flight control problem for the longitudinal dynamics of a generic hypersonic vehicle under mismatched disturbances using adaptive sliding mode control with a nonlinear disturbance observer. A simplified control-oriented dynamic model is built with curve-fitted approximations. Based on the mismatched disturbance estimated by a nonlinear disturbance observer, a novel adaptive sliding mode control is proposed to stably track the velocity and altitude reference trajectory with back-stepping technique. The stability analysis of the closed-loop system and convergence of the system are verified based on Lyapunov stability theory. Finally, simulation results from the nonlinear model of hypersonic vehicle indicate that the proposed method can obtain promising robustness and disturbance rejection performance.


2016 ◽  
Vol 13 (6) ◽  
pp. 172988141667769 ◽  
Author(s):  
Dianwei Qian ◽  
Chengdong Li ◽  
Shiwen Tong ◽  
Lu Yu

This article proposes a control scheme for formation of maneuvers of a team of mobile robots. The control scheme integrates the integral sliding mode control method with the nonlinear disturbance observer technique. The leader–follower formation dynamics suffer from uncertainties originated from the individual robots. The uncertainties challenge the formation control of such robots. Assuming that the uncertainties are unknown but bounded, an nonlinear disturbance observer-based observer is utilized to approximate them. The observer outputs feed on an integral sliding mode control-based controller. The controller and observer are integrated into the control scheme to realize formation maneuvers despite uncertainties. The formation stability is analyzed by means of the Lyapunov’s theorem. In the sense of Lyapunov, not only the convergence of the approximation errors is guaranteed but also such a control scheme can asymptotically stabilize the formation system. Compared to the results by the sole integral sliding mode control, some simulations are presented to demonstrate the feasibility and performance of the control scheme.


2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Rongrong Qian ◽  
Minzhou Luo ◽  
Yao Zhao ◽  
Jianghai Zhao

This paper presents a novel adaptive sliding mode control based on nonlinear sliding surface with disturbance observer (ANSMC-DOB) for precision trajectory tracking control of a surface mount technology (SMT) assembly machine. A two-degree-of-freedom model with time-varying parameter uncertainties and disturbances is built to describe the first axial mode of the pick-place actuation axis of the machine. According to the principle of variable damping ratio coefficient which makes the system have a nonovershoot transient response and a short settling time in the second-order system, the nonlinear sliding surface is designed for the sliding mode control (SMC). Since the upper bound value of the disturbances is unknown, the adaptive gain estimation is applied to replace the switching gain in the SMC. In order to settle the problem of SMC unrobust to the mismatched parameter uncertainties and disturbances, the nonlinear disturbance observer is introduced to estimate the mismatched disturbances and form the novel controller of ANSMC-DOB. The stability of sliding surfaces and control laws are verified by the Lyapunov functions. The simulation research and comparative experiments are conducted to verify the improvement of positioning accuracy and robustness by the proposed ANSMC-DOB in the SMT assembly machine.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Wei Yuan ◽  
Guoqin Gao ◽  
Jianzhen Li

An adaptive backstepping sliding mode controller combined with a nonlinear disturbance observer is designed for trajectory tracking of the electrically driven hybrid conveying mechanism with mismatched disturbances. A nonlinear disturbance observer is constructed for estimation and compensation of the mismatched and matched disturbances. Then, a hybrid control scheme is designed by combining the adaptive backstepping sliding mode controller and the mentioned observer. The Lyapunov candidate functions are utilized to derive the control and adaptive law. According to the simulation and experimental results, superior tracking performance could be obtained through the presented control scheme compared with conventional backstepping sliding mode control. Meanwhile, the presented control scheme can effectively reduce the chattering problem and improve tracking precision.


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