Non-fragile switched control for morphing aircraft with asynchronous switching

This paper deals with the problem of non-fragile linear parameter-varying (LPV) H∞ control for morphing aircraft with asynchronous switching.The switched LPV model of morphing aircraft is established by Jacobian linearization approach according to the nonlinear model.The data missing is taken into account in the link from sensors to controllers and the link from controllers to actuators,which satisfies Bernoulli distribution.The non-fragile switched LPV controllers are con structed with consideration of the uncertainties of controllers and asynchronous switching phenomenon.The parameter-dependent Lyapunov functional method and mode-dependent average dwell time (MDADT) method are combined to guarantee the stability and prescribed performance of the system.The sufficient conditions on the solvability of the problem are derived in the form of linear matrix inequalities (LMI).In order to achieve higher efficiency of the designing process,an algo rithm is applied to divide the whole set into subsets automatically.Simulation results are provided to verify the effectiveness and superiority of the method in the paper.     

基于模型预测的弹性飞机阵风减缓技术研究

弹性飞机受阵风影响显著,需要设计阵风减缓系统来降低阵风的不利影响.然而,阵风减缓系统受系统约束的影响会降低减缓率,严重时甚至导致系统失稳.为解决该问题,提出了基于模型预测控制的阵风减缓系统设计方法.以某弹性飞机为例,对常见的系统约束开展仿真研究.结果 表明,所提方法在系统存在约束时具有更好的控制性能.     

变形飞机动态气动特性数值模拟研究

根据近年来国内外提出的折叠翼变形飞机方案,设计了一种折叠翼变形飞机的3D数模,利用作者发展的动态混合网格技术和非定常计算方法,对该折叠翼变形飞机机翼折叠和展开过程中的动态气动特性进行了数值模拟,并与准定常计算结果进行了对比分析.计算结果表明:机翼在展开/折叠的过程中,飞机的气动特性会发生剧烈变化,在变形飞行控制率设计时需要引起高度的重视.     

基于隐模型跟踪的倾转旋翼机飞行控制

针对倾转旋翼机过渡阶段的强耦合性和快时变性,基于隐模型跟踪法设计了过渡阶段的自主飞行控制律。首先,考虑短舱和旋翼相对机身运动带来的额外惯性力,建立了倾转旋翼机的多体动力学模型;然后,通过飞行动力学特性分析发现倾转旋翼机过渡阶段具有强耦合性和快时变性;最后,针对强耦合性使用隐模型跟踪法实现了固定倾转角时的解耦控制,针对快时变性使用插值调用控制参数的方法实现了倾转旋翼机在整个过渡阶段的连续控制。仿真结果表明,隐模型跟踪控制系统能够达到良好的速度和轨迹跟踪效果,可以实现倾转旋翼机在过渡阶段的自主飞行仿真。     

A novel three-inflection-point sliding mode control framework for forward-tilting morphing aerospace vehicle with performance constraints and actuator faults

A prescribed performance control scheme based on the three-inflection-point hyperbolic function and predefined time performance function is proposed to solve the trajectory tracking problem of the forward-tilting morphing aerospace vehicle with time-varying actuator faults.To accurately estimate the loss degree of actuator faults,an immersion and invariance observer based on the predefined time dynamic scale factor is designed to estimate and compensate it.A composite dynamic sliding mode surface is designed using a three-inflection-point hyperbolic function,and a novel three-inflection-point sliding mode control framework is proposed.The convergent domain of the sliding manifold is adjusted by parameters,and the system error convergence is controllable.A transfer function is designed to eliminate the sensitivity of the three-inflection-point hyperbolic slid-ing mode to the unknown initial state,and combined with the barrier Lyapunov function,and the performance constraint of the system is realized.The global asymptotic stability of the system is demonstrated using a strict mathematical proof.The effectiveness and superiority of the proposed control scheme are proven by simulation experiments.     

多操纵面飞机交叉耦合控制分配方法

针对操纵面交叉耦合效应下指令分配不精准的问题,基于序列二次规划提出了一种多操纵面非线性控制分配方法.在舵效线性条件下,引入虚拟控制指令建立了线性控制分配模型;考虑操纵面舵效交叉耦合非线性特征,以最小操纵面偏量为优化目标设计了交叉耦合控制分配器;采用修正BFGS算法改进序列二次规划,有效地求解了交叉耦合控制分配指令.仿真结果表明,所提出的方法能够合理利用所有操纵面并实现精确分配.     

风切变作用下的民用飞机阵风减缓控制研究

风切变会对飞机起飞和进场着陆阶段的飞行造成较大影响.在分析现有阵风减缓控制方案的基础上,设计了符合某型民用飞机的风切变阵风减缓控制方案.通过在机翼两端和飞机重心处安装的加速度计,采用主动控制技术,使用对称副翼、扰流板和升降舵来实现阵风减缓控制.建立了阵风-飞机综合线性数学模型,并以法向过载为性能指标,针对风切变采用LQR方法设计了最优状态调节器使性能指标达到最小.仿真结果表明,所设计的控制律具有良好的控制效果.     

Composite control method for stabilizing spacecraft attitude in terms of Rodrigues parameters

In this paper, the attitude stabilization problem of a rigid spacecraft described by Rodrigues parameters is investigated via a composite control strategy, which combines a feedback control law designed by a finite time control technique with a feedforward compensator based on a linear disturbance observer (DOB) method. By choosing a suitable coordinate transformation, the spacecraft dynamics can be divided into three second-order subsystems. Each subsystem includes a certain part and an uncertain part. By using the finite time control technique, a continuous finite time controller is designed for the certain part. The uncertain part is considered to be a lumped disturbance, which is estimated by a DOB, and a corresponding feedforward design is then implemented to compensate the disturbance. Simulation results are employed to confirm the effectiveness of the proposed approach.     

舰载机自动着舰引导与控制研究进展

舰载机自动着舰是一项复杂的系统工程。本文概述与总结了舰载机自动着舰系统及着舰引导与控制关键技术的发展现状;阐述了自动着舰系统的发展历程、设计规范,详细描述了自动着舰系统的基本架构和工作原理。在总结舰载机自动着舰引导与控制关键问题的基础上,详细概述和分析了舰载机数学建模、着舰引导、着舰飞行控制、动力补偿/自动油门控制、甲板运动建模、预估和补偿控制、舰尾气流建模与抑制、雷达噪声抑制与误差标校、复飞/逃逸决策与控制等关键技术的研究进展。最后,对舰载机自动着舰引导与控制的研究成果作了总结,并对未来发展方向进行了展望。本文旨在促进舰载机自动着舰技术的发展。     

基于鲁棒伺服LQR的结冰飞机纵向控制律重构方法

由于防/除冰系统总会出现故障或者除冰不彻底,因此仅依靠防/除冰系统实现结冰条件下的安全飞行并非完全可靠,研究结冰后飞机控制律重构对飞机操纵安全和飞行安全极其重要。针对飞机的纵向运动建立了结冰影响模型和纵向动力学模型,采用鲁棒伺服线性二次型调节器(LQR)最优控制设计了飞机结冰后空中飞行纵向控制律,模拟了飞机在俯仰姿态保持模式下遭遇不同严重程度结冰后的动态响应特性,并与常规PID控制进行对比。结果表明,所设计的控制律能够有效改善结冰飞机的飞行性能和飞行品质,准确跟踪给定的俯仰角指令,且抗干扰能力、动态性能以及鲁棒性均优于常规PID控制。为飞机结冰后的重构控制问题和自动飞行控制,提供了新的思路。     

基于LQG/LTR的飞翼飞机阵风减缓系统研究

根据我国《运输类飞机适航标准》的要求,采用有理谱逼近的方法建立了Von Karman大气紊流的数值仿真模型;详细推导了多变量系统鲁棒性的衡量方法,给出了开环系统奇异值曲线形状与闭环系统鲁棒性的关系;针对飞翼飞机多操纵面的特点,将控制分配技术与LQG/LTR控制器结合在一起,同时兼顾了对飞机过载和翼根弯矩的减缓。仿真结果表明,所设计的控制系统在对飞机过载减缓的同时,也对机翼的翼根弯矩进行了有效的减缓。     

Closed-loop dynamic control allocation for aircraft with multiple actuators

A closed-loop control allocation method is proposed for a class of aircraft with multiple actuators. Nonlinear dynamic inversion is used to design the baseline attitude controller and derive the desired moment increment. And a feedback loop for the moment increment produced by the deflections of actuators is added to the angular rate loop, then the error between the desired and actual moment increment is the input of the dynamic control allocation. Subsequently, the stability of the closed-loop dynamic control allocation system is analyzed in detail. Especially, the closedloop system stability is also analyzed in the presence of two types of actuator failures: loss of effectiveness and lock-in-place actuator failures, where a fault detection subsystem to identify the actuator failures is absent. Finally, the proposed method is applied to a canard rotor/wing (CRW) aircraft model in fixed-wing mode, which has multiple actuators for flight control. The nonlinear simulation demonstrates that this method can guarantee the stability and tracking performance whether the actuators are healthy or fail.     

An asymmetrically variable wingtip anhedral angles morphing aircraft based on incremental sliding mode control: Improving lateral maneuver capability

This paper presents the design of an asymmetrically variable wingtip anhedral angles morphing aircraft,inspired by biomimetic mechanisms,to enhance lateral maneuver capability.Firstly,we establish a lateral dynamic model considering additional forces and moments resulting during the morphing process,and convert it into a Multiple Input Multiple Output (MIMO) virtual control system by importing virtual inputs.Secondly,a classical dynamics inversion controller is designed for the outer-loop system.A new Global Fast Terminal Incremental Sliding Mode Controller (NDO-GFTISMC) is proposed for the inner-loop system,in which an adaptive law is implemented to weaken control surface chattering,and a Nonlinear Disturbance Observer (NDO) is integrated to compensate for unknown disturbances.The whole control system is proven semiglobally uniformly ultimately bounded based on the multi-Lyapunov function method.Furthermore,we consider tracking errors and self-characteristics of actuators,a quadratic programmingbased dynamic control allocation law is designed,which allocates virtual control inputs to the asymmetrically deformed wingtip and rudder.Actuator dynamic models are incorporated to ensure physical realizability of designed allocation law.Finally,comparative experimental results validate the effectiveness of the designed control system and control allocation law.The NDO-GFTISMC features faster convergence,stronger robustness,and 81.25%and 75.0%reduction in maximum state tracking error under uncertainty compared to the Incremental Nonlinear Dynamic Inversion Controller based on NDO (NDO-INDI) and Incremental Sliding Mode Controller based on NDO(NDO-ISMC),respectively.The design of the morphing aircraft significantly enhances lateral maneuver capability,maintaining a substantial control margin during lateral maneuvering,reducing the burden of the rudder surface,and effectively solving the actuator saturation problem of traditional aircraft during lateral maneuvering.     

双框架飞机蒙皮检测机器人切换运动控制方法

针对一种双框架飞机蒙皮检测机器人,通过分析该机器人在飞机表面上的受力情况,在飞机表面该机器人受到了非完整约束,基于牛顿-欧拉法建立了机器人非完整约束动力学模型。根据机器人机械结构和运动步态分析,将该非完整机器人系统分为子系统A和子系统B。为了实现机器人在飞机表面运动,采用反演技术和快速Terminal滑模控制相结合的思想对系统设计了控制器,提出了一种反演-滑模控制方法;对于非完整机器人子系统A和子系统B,设计了一种基于事件驱动的切换策略,实现了机器人对期望轨迹的全局渐近跟踪,并利用Lyapunov稳定性证明系统的跟踪误差收敛。仿真和试验表明,采用该切换策略和反演-滑模控制方法,双框架飞机蒙皮检测机器人可以在飞机表面自由运动并进行损伤检测,具有良好的可靠性和稳定性。     

Aeroservoelastic stability analysis for flexible aircraft based on a nonlinear coupled dynamic model

A unified theoretical aeroservoelastic stability analysis framework for flexible aircraft is established in this paper. This linearized state space model for stability analysis is based on nonlinear coupled dynamic equations, in which rigid and elastic motions of aircraft are both considered. The common body coordinate system is utilized as the reference frame in the deduction of dynamic equations, and significant deformations of flexible aircraft are also fully concerned without any excessive assumptions. Therefore, the obtained nonlinear coupled dynamic models can well reflect the special dynamic coupling mechanics of flexible aircraft. For aeroservoelastic stability analysis, the coupled dynamic equations are linearized around the nonlinear equilibrium state and together with a control system model to establish a state space model in the time domain. The methodology in this paper can be easily integrated into the industrial design process and complex structures. Numerical results for a complex flexible aircraft indicate the necessity to consider the nonlinear coupled dynamics and large deformation when dealing with aeroservoelastic stability for flexible aircraft.     

基于非线性动态逆的舰载机直接升力航迹控制

针对舰载机人工进场着舰精确轨迹控制中飞行员操纵负担重、着舰环境复杂的问题,提出采用非线性动态逆(NDI)先进控制方法设计基于直接升力的舰载机精确着舰轨迹控制律。首先,综合分析了"魔毯"技术的控制策略,从航迹调整和姿态保持的直接升力解耦控制角度出发,设计了两层NDI回路;然后,采用合理的控制分配方法实现直接升力的舵面分配。仿真结果表明,所提出的精确着舰控制方法能够有效实现"魔毯"式航迹操纵。     

基于Reason模型的航空器事故调查分析软件设计

通过对航空器事故进行分析与研究,从而提出相应的改进措施,对于减少飞行事故、保障飞行安全具有重要意义.在现有航空器事故分析的基础上,提出了基于Reason模型的航空器事故调查分析软件设计.在分析Reason模型基本概念的基础上,详细介绍了该软件的系统结构、软件的界面和相应的操作步骤与方法,并结合实际的案例介绍了该软件在分析航空器事故调查方面的优势.该软件对于调查分析民航业不安全事件中的人为因素具有一定的借鉴作用.     

基于隐身的三维航迹规划研究

为提高飞行器对地攻击效能,必须对其三维航迹规划技术进行研究。考虑到威胁并非不可穿越,建立了间歇式暴露模型;通过考虑飞行器姿态变化对暴露范围的影响,建立了飞行器战术隐身模型;对传统稀疏A*算法进行了改进,有效提高了规划速度,在此基础上提出了具有实时规划能力的分步规划算法,并给出了解决在线重规划的方法;最后,在真实地形下进行了仿真验证,仿真结果证明了所建模型及算法的有效性和实用性。     

基于动态RCS的隐身飞机探测概率研究

动态RCS是影响战斗机突防概率的重要因素。围绕动态RCS这一关键要素,建立了空空动态RCS求解模型,得到了典型机动下战斗机的动态RCS变化规律,并分析了基于动态RCS的典型机动下的雷达探测概率。基于仿真的静态RCS数据库,耦合飞机抖动模型,研究了拉升机动、空间机动以及空空对抗下某型隐身飞机的动态RCS。通过仿真发现:战斗机的机腹、垂尾及尾喷管部位RCS较大,从而导致了较高的探测概率;对于拉升机动,保持较大的航路捷径更有利于隐蔽突防。