基于多环QFT的高超声速飞行器鲁棒控制

阐述了定量反馈理论(QFT)的基本原理和设计方法,针对超燃冲压发动机不同工作状态时高超声速飞行器不确定性模型,应用多环QFT设计了高超声速飞行器纵向飞行控制系统;仿真结果表明,运用QFT方法设计的控制系统不仅具有良好的跟踪性能和抗干扰性能,而且能够很好地解决飞行控制系统由于模型参数具有不确定性而造成的控制系统鲁棒性设计问题,并从工程应用角度为高超飞行器纵向飞行控制系统提供了一种鲁棒控制设计方案。     

高超声速飞行器输入受限反演鲁棒控制

针对执行机构受限条件下高超声速飞行器的控制问题,提出一种鲁棒反演控制设计 方法.设计一种新的辅助系统对跟踪误差和控制律进行补偿,保证执行器受限时跟踪误差的 有界性.为了避免传统反演方法中虚拟导数计算量膨胀问题,引入滑模微分器对虚拟 导数进行求解.为了增强系统的鲁棒性,基于改进反正切跟踪微分器(MATD)设计 一种新型干扰观测器,对系统的不确定项进行估计和补偿.最后,通过实例仿真验证了所提出控制器的有效性.     

基于INA—QFT的高超声速飞行器鲁棒控制器设计

针对高超声速飞行器数学模型的不确定性,提出基于逆奈氏阵列法设计预补偿器和定量反馈理论设计控制器相结合的方法。该方法首先对相互关联的飞行器三通道进行预补偿,使开环前向通道的逆传递函数矩阵成为对角优势阵。然后根据某型号飞行器俯仰通道多个模型参数变化范围,利用定量反馈理论进行鲁棒控制器设计。线性和非线性仿真结果表明,该方法跟踪效果良好,具有较强的工程应用价值。     

基于QFT+DI的高超声速飞行器控制研究

在高超声速飞行器控制研究中,大空域大马赫数飞行造成的强耦合、高度非线性,影响控制系统的稳定性.为解决上述问题,在传统定量反馈控制理论的基础上,提出定量反馈和动态逆相结合的鲁棒控制方法,对高超声速飞行器纵向模态进行控制器设计.利用动态逆对系统非线性模型进行反馈线性化,将得到的线性模型作为控制的内环和定量反馈设计模板,设计外环系统的控制器和前置滤波器.通过计算机对设计的控制器进行仿真验证,结果表明,控制设计方法具有较好的控制效果,且比传统的设计方法在高频段具有更好的噪声抑制能力.     

高超声速飞行器基于Back-stepping的离散控制器设计

根据高超声速飞行器纵向模型的特点,提出了基于Back-stepping的离散控制器设计方法.首先通过合理的简化,将飞行器的模型转化为连续非线性系统的严格反馈形式;然后采用欧拉法得到其近似的离散模型,根据近似离散模型并结合Back-stepping和反馈线性化方法,设计了高超声速飞行器的离散控制器.利用高超声速飞行器的纵向模型对算法进行仿真验证,得到了较为满意的控制效果.     

弹性体高超声速飞行器自适应控制器设计

研究控制器优化设计问题,为能使飞行控制系统精确跟踪控制指令,并抑制住机体的结构弹性振动,研究了一种带自适应结构滤波器的LQR积分控制器.其中,LQR积分状态反馈控制器用来跟踪飞行速度与航迹倾角指令,结构滤波器用来抑制弹性模态.由于在高超声速飞行过程中结构的振动频率与阻尼比是随时间变化的,造成弹性振动偏差大.为此设计了一种鲁棒估计器来在线辨识弹性模态,并将辨识的结构自然频率作为结构滤波器的中心频率.通过在吸气式高超声速飞行器纵向非线性模型上进行仿真验证,结果显示控制方法能很好地满足跟踪指令与结构弹性抑制的要求.     

高超声速飞行器最优PI-Hinf控制器设计

研究高超音速控制器优化问题,由于控制系统存在较强鲁棒性和非线性,用传统方法寻优计算量大,影响实时控制.为解决上述问题,采用最优比例积分H无穷(PI-Hinf)二环控制方法对高速飞行器构型的输入/输出线性化模型进行了控制器设计.控制方法能有效地抑制模型参数不确定性带来的扰动并使系统达到很好的静态性能.对模型进行仿真,结果表明,所设计的控制器具有较强的鲁棒性,可以满足飞行器在复杂条件下飞行的控制要求,达到0误差的跟踪精度,为设计提供了依据.     

高超声速飞行器神经网络动态逆姿态控制器设计

以一类通用高超声速飞行器纵向模型为研究对象,推导了飞行器纵向姿态运动方程。考虑受到飞行器附加攻角扰动以及气动参数不确定性的影响,对运动方程中速率变化快慢不同的攻角和俯仰速率分别引入精确线性化动态逆反馈,并利用神经网络对系统逆反馈误差进行补偿,有效地抑制了模型参数摄动,实现了对攻角指令的精确跟踪。将设计的控制器对高超声速非线性模型进行系统闭环仿真,仿真结果说明所设计的姿态控制器具有抗参数摄动的性能,能够满足高超声速飞行器复杂飞行条件下的姿态控制要求,具有较强的鲁棒性。     

高超声速飞行器及其飞行状态控制

概述了高超声速飞行技术研究的意义及发展现状,从气动外形、推进手段及气动热效应等方面探讨了高超声速飞行器飞行状态控制面临的挑战;从空气动力学理论、仿真手段、工作环境及流场特性方面指出飞行器飞行状态描述的复杂性,在回顾并评价目前高超声速飞行器飞行状态控制策略的基础上,提出了以工作环境及飞行速率为变量的多模型建模方法描述飞行器的飞行状态,以机理建模和伪动力学建模综合应用的方法建立飞行器高超声速飞行状态模型的思路,并针对其高超声速飞行特点探讨了可能的控制策略。     

考虑迟滞非线性的高超声速飞行器颤振分析

为给飞行器颤振控制及结构设计等提供支持,利用适合复杂结构建模的动态子结构方法中的自由界面模态综合法,考虑飞行器在超声速飞行状态下高超声速流和飞行器自身结构的特点,将整个飞行器分成多个子结构;考虑飞行器机身与机翼之间相互连接构件的实际工作状况和制造工艺情况,带有间隙非线性与立方非线性相互作用所产生的迟滞非线性特性,以及阻尼因子对非线性的影响,用有限元计算软件计算各子结构的动力学特性参数和气动力分布情况,建立飞行器整机的振动微分方程以分析颤振特性．对得到的飞行器在所设工况下的振动和颤振特性及颤振临界状态进行分析,实现全机气动弹性问题的仿真计算．分析结果表明,该方法拓展高超声速飞行器颤振的计算,可为动态子结构方法应用于颤振研究提供参考．     

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...     

Multi-objective robust control based on fuzzy singularly perturbed models for hypersonic vehicles

In this paper, we propose a multi-objective robust controller based on fuzzy singularly perturbed models (FSPM) for the longitudinal motion of an air-breathing hypersonic vehicle. The control objective is to provide velocity and altitude tracking in the presence of the uncertainties and unknown nonlinearities in the model caused by variations in flight conditions. By approximating the multi-time-scale model with FSPM, ill-posed matrix calculations are circumvented. Under this framework, a fuzzy multi-object...     

Nonlinear robust state feedback control system design for nonlinear uncertain systems

This paper presents a systematic approach to the design of a nonlinear robust dynamic state feedback controller for nonlinear uncertain systems using copies of the plant nonlinearities. The technique is based on the use of integral quadratic constraints and minimax linear quadratic regulator control, and uses a structured uncertainty representation. The approach combines a linear state feedback guaranteed cost controller and copies of the plant nonlinearities to form a robust nonlinear controller with a novel control architecture. A nonlinear state feedback controller is designed for a synchronous machine using the proposed method. The design provides improved stability and transient response in the presence of uncertainty and nonlinearity in the system and also provides a guaranteed bound on the cost function. An automatic voltage regulator to track reference terminal voltage is also provided by a state feedback equivalent robust nonlinear proportional integral controller. Copyright © 2016 John Wiley & Sons, Ltd.     

飞行器模型簇描述及鲁棒控制器设计

通过分析飞行器运动方程，给出了分段线性化模型簇描述．为了得到一定飞行区域的鲁棒控制器，选取负实极点并采用对角占优势的方法对状态反馈矩阵进行设计．同时，提出了全飞行区域(飞行包线内)的多个子系统划分及鲁棒镇定控制的设计方法．为了抑制飞行器的建模误差，采用了输入补偿方法．与常规鲁棒控制设计方法相比较，该方法可以降低飞行控制器设计的复杂度．飞行控制器设计结果表明，该方法对不确定系统的分析和设计是有效的。     

风力发电系统的恒功率非线性H∞鲁棒控制

风力发电系统传统控制器的缺点在于, 基于某一工况点的局部线性化方法无法实现全局范围的精确控制, 且传统的控制理论无法应对内外干扰. 本文将精确反馈线性化方法与线性H∞理论相结合设计非线性H∞控制器. 首先用微分几何精确线性化方法将非线性风电模型全局线性化, 然后运用线性H∞控制理论对此线性系统设计控制器, 将两者结合有原风电系统的非线性H∞变桨距控制器. 最后对12 m/s至24 m/s阶跃风, 12 m/至22 m/s骤变风, 18 m/s至20 m/s随机风, 以及风力机转动惯量下降10%的情况进行仿真, 能实现风机转速及输出功率的恒定. 验证了该控制器在全风速段的精确控制, 并且具有良好鲁棒性.     

一类具有L∞范数有界扰动的非线性系统鲁棒控制

首先针对不确定非线性系统,基于L∞范数定义了鲁棒稳定化和鲁棒跟踪控制问题.然后利用反馈线性化技术和Lvapunov方法,设计了相应的鲁棒控制器.仿真结果验证了控制器设计的正确性.     

Depth control of autonomous underwater vehicles using indirect robust control method

In this article, we propose a robust depth control design scheme for autonomous underwater vehicles (AUVs) in the presence of hydrodynamic parameter uncertainties and disturbances. The controller is designed via a new indirect robust control method that handles the uncertainties by formulating the uncertainty bounds into the cost functional and then transforming the robust control problem into an equivalent optimal control problem. Both robust asymptotic stability and optimality can be achieved and proved with this new formulation. The θ-D method is utilised to solve the resultant nonlinear optimal control problem such that an approximate closed-form feedback controller can be obtained and thus is easy to implement onboard without intensive computation load. Simulation results demonstrate that robust depth control is accomplished under the system parameter uncertainties and disturbances with small control fin deflection requirement.     

Adaptive fault-tolerant control for a class of flexible air-breathing hypersonic vehicles

In this paper, a novel adaptive fault-tolerant control (FTC) scheme is proposed for a class of flexible air-breathing hypersonic vehicles with unknown inertial and aerodynamic parameters and even input constraints. The fault model under consideration covers the case that all actuators suffer from unknown time-varying faults. In the controller design and stability analysis, we introduce new Lyapunov functions, some differentiable auxiliary functions, a bound estimation approach, and a Nussbaum function, which help us successfully circumvent the obstacle caused by the faults, input constraints, and flexible modes. In addition to higher reliability, the proposed scheme is able to ensure that all closed-loop signals are globally uniformly bounded and to steer the tracking errors of altitude and velocity into predefined arbitrarily small residual sets. As a result, the tracking accuracy can be designated in advance. Simulation results illustrate the effectiveness of the proposed scheme.     

LMI optimization approach to robust decentralized controller design

A new approach for design of robust decentralized controllers for continuous linear time‐invariant systems is proposed using linear matrix inequalities (LMIs). The proposed method is based on closed‐loop diagonal dominance. Sufficient conditions for closed‐loop stability and closed‐loop block‐diagonal dominance are obtained. Satisfying the obtained conditions is formulated as an optimization problem with a system of LMI constraints. By adding an extra LMI constraint to the system of LMI constraints in the optimization problem, the robust control is addressed as well. Accordingly, the decentralized robust control problem for a multivariable system is reduced to an optimization problem for a system of LMI constraints to be feasible. An example is given to show the effectiveness of the proposed method. Copyright © 2010 John Wiley & Sons, Ltd.