Fuzzy dynamic characteristic model based attitude control of hypersonic vehicle in gliding phase

The intelligent autonomous control of hypersonic vehicles has aroused great interest from the field of spacecraft. To solve the problem of longitudinal attitude control of hypersonic vehicle in gliding phase, a new intelligent controller is proposed in this paper. This new controller is based on the fuzzy dynamic characteristic modeling method. The fuzzy logic is introduced into the characteristic modeling by dividing the whole restriction range into several subspaces. Simulations show that this modificatio...     

基于动态面的高超声速飞行器模糊自适应非线性控制

针对高超声速飞行器模型非线性、多变量和参数不确定特性, 并考虑控制增益变化可能导致控制奇异值问 题, 提出一种基于动态面的模糊自适应非线性控制方法. 根据动态面和动态逆策略, 分别设计了高度和速度跟踪控制 器. 利用模糊自适应方法在线逼近不确定函数项, 并采用Nussbaum 增益技术抑制虚拟控制增益不确定影响, 以减少 在线学习量, 保证系统的半全局一致最终有界性. 仿真结果表明, 所提出的方法可实现飞行器对高度和速度的准确跟 踪控制.

     

A new approach to fuzzy modeling and control for nonlinear dynamic systems: Neuro-fuzzy dynamic characteristic modeling and adaptive control mechanism

The study on nonlinear control system has received great interest from the international research field of automatic engineering. There are currently some alternative and complementary methods used to predict the behavior of nonlinear systems and design nonlinear control systems. Among them, characteristic modeling (CM) and fuzzy dynamic modeling are two effective methods. However, there are also some deficiencies in dealing with complex nonlinear system. In order to overcome the deficiencies, a novel intelligent modeling method is proposed by combining fuzzy dynamic modeling and characteristic modeling methods. Meanwhile, the proposed method also introduces the low-level learning power of neural network into the fuzzy logic system to implement parameters identification. This novel method is called neuro-fuzzy dynamic characteristic modeling (NFDCM). The neuro-fuzzy dynamic characteristic model based overall fuzzy control law is also discussed. Meanwhile the local adaptive controller is designed through the golden section adaptive control law and feedforward control law. In addition, the stability condition for the proposed closed-loop control system is briefly analyzed. The proposed approach has been shown to be effective via an example. Recommended by Editor Young-Hoon Joo. This work was jointly supported by National Natural Science Foundation of China under Grant 60604010, 90716021, and 90405017 and Foundation of National Laboratory of Space Intelligent Control of China under Grant SIC07010202. Xiong Luo received the Ph.D. degree from Central South University, Changsha, China, in 2004. From 2005 to 2006, he was a Postdoctoral Fellow in the Department of Computer Science and Technology at Tsinghua University. He currently works as an Associate Professor in the Department of Computer Science and Technology, University of Science and Technology Beijing. His research interests include intelligent control for spacecraft, intelligent optimization algorithms, and intelligent robot system. Zengqi Sun received the bachelor degree from Tsinghua University, Beijing, China, in 1966, and the Ph.D. degree from Chalmers University of the Technology, Gothenburg, Sweden, in 1981. He currently works as a Professor in the Department of Computer Science and Technology, Tsinghua University. His research interests include intelligent control of robotics, fuzzy neural networks, and intelligent flight control. Fuchun Sun received the Ph.D. degree from Tsinghua University, Beijing, China, in 1998. From 1998 to 2000, he was a Postdoctoral Fellow in the Department of Automation at Tsinghua University, where he is currently a Professor in the Department of Computer Science and Technology. His research interests include neural-fuzzy systems, variable structure control, networked control systems, and robotics.     

Fuzzy tracking control design for hypersonic vehicles via T-S model

The main focus of this paper is on designing a T-S fuzzy controller for the hypersonic vehicle. The longitudinal dynamics of the vehicle are studied using time-scale decomposition to reduce the complexity of T-S modeling. The dynamic inversion with PI control technique is applied for the slow dynamics to derive the flight path angle command and throttle setting by taking the pilot altitude and velocity command as its inputs. The T-S fuzzy controller is designed for the fast dynamics to derive the elevator d...     

基于特征模型的高超声速飞行器自适应控制研究进展

钱学森先生1945年在论文《论高超声速相似律》中,首次提出了高超声速(hypersonic)的术语.高超声速飞行器具有的强大的军事和民事应用前景,20世纪80年代初,在世界上掀起了研究和发展高超声速飞行器的热潮,其中高超声速飞行器控制是其关键科学和技术问题之一.高超声速飞行器的研究取得了大量理论成果,与其形成鲜明对比的是,高超声速飞行器在试飞实验中却遇到了很大困难,例如X–51A,HTV–2.这种现象不得不引发我们进行深入思考.由于高超声速空气动力学研究的局限性,导致目前所建立的高超声速飞行器的动力学模型,与真实系统相比,其结构和参数不确定性非常大,它从根本上限制了控制理论和方法的研究.并且由于高超声速飞行器动力学模型的复杂性,导致目前工程应用中的控制方法复杂化.因此,针对高超声速飞行器控制问题,需要深入开展气动、控制交叉学科的研究,以及适于工程应用的自适应控制的研究.针对上述问题,我们开展了一定的研究.我们建立了三轴耦合的高超声速飞行器被控对象类X–20及其气动模型,并结合工程应用,直接针对表格形式的气动模型开展控制研究.针对强耦合和无解析动力学的控制问题,特征模型理论有其独特优势.近年来,我们系统研究了基于特征模型的高超声速飞行器的爬升、滑翔和再入控制问题.本文首先介绍特征模型理论和方法,进而综述和分析基于特征模型的高超声速飞行器自适应控制的研究进展,并提出进一步需要研究的问题.     

模糊自适应的高超飞行器控制与干扰

针对具有超大飞行马赫数、超宽飞行包络、飞行环境复杂等特点的高超声速飞行器,提出了基于模糊自适应的高超飞行器高度控制方法,分别设计了高度和速度控制器.针对所设计的控制器,分析了气动干扰力矩、测量噪声、舵机干扰、气动参数不确定性和飞行器模型参数不确定性对飞行器高度控制和速度控制效果的影响,然后又分析了综合考虑以上干扰和不确定性对飞行器高度控制和速度控制效果的影响.仿真结果表明,对各种干扰和不确定性,所设计的控制器速度和高度控制有较好的跟踪性和鲁棒性,达到了满意的效果.     

Phugoid dynamic characteristic of hypersonic gliding vehicles

This paper focuses on the phugoid dynamic characteristic of hypersonic gliding vehicle. By regarding equilibrium glide as the fixed state of reentry trajectory, the dynamic equations are simplified and a hyper-geometric equation with a forcing function is deduced. Linearization theory is applied to analyze the characteristic of the motion, and the phugoid mode is found to be stable. An analytical solution of flight path angle as a function of speed is derived based on General Multiple Scale theory. The dyna...     

高超飞行器的再入非线性鲁棒控制

针对再入段高超飞行器非线性动力学模型存在不确定性和干扰,基于奇异摄动理论提出了鲁棒变结构+动态逆内外环解耦控制方法.为避免在线实时求逆,控制系统的外环基于简化的模型设计自适应滑模变结构控制律,通过反馈干扰观测器在线估计广义干扰量,实现角度的跟踪和闭环系统的稳定,抑止外来干扰.强耦合的姿态动力学内环采用动态逆跟踪角速度指...     

动态不确定非线性系统直接自适应模糊backstepping控制

对一类单输入单输出动态不确定非线性系统,提出一种直接自适应模糊backstepping和小增益相结合的控制方法.设计中,首先用模糊逻辑系统逼近虚拟控制器:其次把自适应模糊控制和backstepping控制设计技术相结合.给出了直接自适应模糊控制设计方法.最后基于Lyapunov函数和小增益方法证明了整个闭环系统的稳定性.仿真实例进一步验证了所提方法的有效性.     

Robust controller design for uncertain delayed systems and its applications to hypersonic vehicles

The longitudinal dynamics of hypersonic flight vehicles involves strong nonlinearity and coupling, uncertainties including parametric uncertainties, unmodeled uncertainties, external disturbances, and time‐varying input and state time delays. In this paper, a robust controller design method is proposed for the longitudinal stabilization of these vehicles by the signal‐compensation‐based control idea. Theoretical analysis is given to prove the robustness properties of the designed closed‐loop control system subject to multiple time‐varying uncertainties and time‐varying input and state delays. Simulation results are performed to show the validness and advantages of the proposed robust control approach.     

高超声速飞行器基于特征模型的自适应姿控系统稳定性分析

文中研究了高超声速飞行器基于特征模型的全系数自适应姿态控制系统的稳定性问题,提出了一种通过计算有限个矩阵导出1范数或无穷范数来分析系统稳定性的方法,克服了特征模型时变和参数辨识给稳定性分析造成的困难.首先利用泰勒展开,获得高超飞行器姿态动力学输入输出描述的离散化方程.该组方程具有二阶特征模型的形式,可以分析出系统处于一个工作点附近时特征模型参数的取值范围.当使用线性反馈控制器,并引入一定保守性的情况下,可以将闭环系统看作一类由区间时变参数决定的时变对象.对于这样的一类对象,文中给出了其指数稳定的充要条件.最后利用前述结果,给出了判断高超声速飞行器基于特征模型的自适应控制系统稳定的充分条件,并通过一个算例来说明该方法的应用.     

Fault-tolerant control of flexible air-breathing hypersonic vehicles in linear ODE-beam systems

ABSTRACT

This paper addresses the fault-tolerant control issue for a class of flexible air-breathing hypersonic vehicles. Firstly, a longitudinal dynamic model with process faults is established, which contains an ordinary differential equation (ODE) for rigid body, an Euler–Bernoulli beam equation for flexible modes, and a new boundary connection between them; Secondly, a novel fault-tolerant control scheme is proposed to accommodate process faults and suppress vibrations, which relies on the direct Lyapunov method and the bilinear matrix inequalities (BMIs) technique; Thirdly, in order to compute the gain matrices of the fault-tolerant control law, a two-step algorithm is provided to solve the BMI feasibility problem in terms of linear matrix inequality optimisation technique. Finally, the simulation results are provided to illustrate the effectiveness of the theoretical results.     

Robust adaptive tracking control for a class of switched time-delay systems with application of vehicle roll dynamic control

The problems of stability and robust tracking control for a class of switched nonlinear systems with uncertain input and state delays are investigated in this study. In the presence of unknown functions and external disturbances, an adaptive fuzzy technique based on nonlinear disturbance observer is used to counteract the effects of external disturbances and approximate unknown functions. For this purpose, it is first assumed that a common Lyapunov function exists for the switched system, and then a new common Lyapunov–Krasovskii functional is built using the terms of the hypothetical common Lyapunov function. By employing this new function, the delay-dependent input-to-state stability (ISS) under an arbitrary switching signal is provided. The robust tracking control problem for this system is investigated next. Finally, to assure ISS and robust tracking performance, an adaptive control law is developed that ensures conditions of the aforementioned hypothetical common Lyapunov function. In addition, to demonstrate the efficiency of the proposed strategy, the aforesaid method is applied to a vehicle roll dynamic as well as a mass-spring system.     

Adaptive recurrent-functional-link-network control for hypersonic vehicles with atmospheric disturbances

The controller design for a near-space hypersonic vehicle (NHV) is challenging due to its plant uncertainties and sensitivity to atmospheric disturbances such as gusts and turbulence. This paper first derives 12 states equations of NHVs subjected to variable wind field, and presents a novel recurrent neural network (RNN) control method for restraining atmospheric disturbances. The method devises a new B-spline recurrent functional link network (BRFLN) and combines it with the nonlinear generalized predictiv...