Trajectory Tracking Strategy for Gliding Hypersonic Vehicle with Aileron Stuck at an Unknown Angle

A nonlinear robust trajectory tracking strategy for a gliding hypersonic vehicle with an aileron stuck at an unknown position is presented in this paper. First, the components of translational motion dynamics perpendicular to the velocity are derived, and then a guidance law based on a time-varying sliding mode method is used to realize trajectory tracking. Furthermore, the rotational equations of motion are separated into an actuated subsystem and an unactuated subsystem. And an adaptive time-varying sliding mode attitude controller is proposed based on the actuated subsystem to track the command attitude and the tracking performance and robustness are therefore enhanced. The proposed guidance law and attitude controller make the hypersonic vehicle fly along the reference trajectory even when the aileron is stuck at an unknown angle. Finally, a hypersonic benchmark platform is used to demonstrate the effectiveness of the proposed strategy.

Numerical Simulation Research on Static Aeroelastic Effect of the Transonic Aileron of a High Aspect Ratio Aircraf

The static aeroelastic effect of aircraft ailerons with high aspect ratio at transonic velocity is investigated in this paper by the CFD/CSD fluid-structure coupling numerical simulation.The influences of wing static aeroelasticity and the‘scissor opening’gap width between aileron control surface and the main wing surface on aileron efficiency are mainly explored.The main purpose of this paper is to provide technical support for the wind tunnel experimental model of aileron static aeroelasticity.The results indicate that the flight dynamic pressure has a great influence on the static aeroelastic effect of ailerons,and the greater the dynamic pressure,the lower the aileron efficiency.Aileron deflection causes asymmetric elastic deformation of the main wing surfaces of the left and right wings.The torque difference caused by the load distribution on the main wing surface offsets the rolling torque generated by the aileron.This results in a significant reduction in aileron efficiency,and it is noticeable that it is not the elastic deformation of the aileron itself or the reduction in effective deflection that leads to the reduction in rolling control efficiency.Under typical transonic conditions,the rolling control torque of the aileron can be reduced by more than 25%,in the range of 2.5–10 mm,and the‘scissor opening’gap width of the aileron has almost no influence on its static aeroelastic effect.

Aeroelastic Optimization of the High Aspect Ratio Wing with Aileron

In aircraft wings,aileron mass parameter presents a tremendous effect on the velocity and frequency of the flutter problem.For that purpose,we present the optimization of a composite design wing with an aileron,using machine-learning approach.Mass properties and its distribution have a great influence on the multi-variate optimization procedure,based on speed and frequency of flutter.First,flutter speed was obtained to estimate aileron impact.Additionally mass-equilibrated and other features were investigated.It can deduced that changing the position and mass properties of the aileron are tangible following the speed and frequency of the wing flutter.Based on the proposed optimization method,the best position of the aileron is determined for the composite wing to postpone flutter instability and decrease the existed stress.The represented coupled aero-structural model is emerged from subsonic aerodynamics model,which has been developed using the panel method in multidimensional space.The structural modeling has been conducted by finite element method,using the p-k method.The fluid-structure equations are solved and the results are extracted.

基于飞行实测载荷的副翼操纵导数识别

某型飞机横向操纵时副翼和扰流板会耦合偏转实现飞机的滚转运动,现有气动力参数辨识方法无法单独识别出副翼和扰流板的操纵导数。基于飞机控制律设计逻辑和滚转运动时结构的受载特点,提出一种基于飞行实测载荷的副翼操纵导数识别方法。通过实测机动飞行中机翼各测载剖面的结构载荷并结合剖面外结构质量与加速度分布,提出了机动飞行中机翼气动载荷的测量方法;结合飞机横向操纵瞬时滚转力矩平衡方程和操纵面偏转逻辑,推导了滚转改出时副翼操纵导数识别过程,提出了基于机翼实测载荷的副翼操纵导数识别方法;基于前述方法开展了副翼操纵导数识别,并分析了不同马赫数对副翼操纵导数的影响。研究表明,基于飞行实测载荷能够进行副翼操纵导数识别,而且同一马赫数下副翼操纵导数识别结果集中度较好,随着马赫数的增加,副翼操纵效能将会降低。飞行载荷实测结果可用于气动参数辨识工作中。

Evaluation of aileron actuator reliability with censored data

For the purpose of enhancing reliability of aileron of Airbus new-generation A350 XWB,an evaluation of aileron reliability on the basis of maintenance data is presented in this paper.Practical maintenance data contains large number of censoring samples, information uncertainty of which makes it hard to evaluate reliability of aileron actuator.Considering that true lifetime of censoring sample has identical distribution with complete sample, if censoring sample is transformed into complete sample, conversion frequency of censoring sample can be estimated according to frequency of complete sample.On the one hand, standard life table estimation and product limit method are improved on the basis of such conversion frequency, enabling accurate estimation of various censoring samples.On the other hand, by taking such frequency as one of the weight factors and integrating variance of order statistics under standard distribution, weighted least square estimation is formed for accurately estimating various censoring samples.Large amounts of experiments and simulations show that reliabilities of improved life table and improved product limit method are closer to the true value and more conservative; moreover, weighted least square estimate（WLSE）, with conversion frequency of censoring sample and variances of order statistics as the weights, can still estimate accurately with high proportion of censored data in samples.Algorithm in this paper has good effect and can accurately estimate the reliability of aileron actuator even with small sample and high censoring rate.This research has certain significance in theory and engineering practice.

飞机操纵面数字化互换性设计

随着数字化装配技术的逐渐成熟和推广应用,适应数字量传递的互换性设计对于提升飞机操纵面设计效率、稳定装配质量和降低维护成本具有现实意义。以飞机操纵面的互换性设计为研究对象,针对互换性的要求分析设计要点,建立与数字化装配相协调的互换性设计流程;从操纵面的构型特征角度分析互换性设计的结构元素;提出实现操纵面互换性的技术途径,给出相应的参考指标;以某型飞机的副翼为例,对其进行互换性分析和设计,并通过实际装配进行检验。结果表明:本文建立的操纵面互换性设计流程合理可行,能够满足互换性要求。

缝隙对飞机副翼舱声振特性的影响研究

针对飞机副翼舱缝隙可能导致舱内结构产生剧烈流致振动的问题,运用ANSYS软件分别建立副翼舱结构、声腔以及声固耦合系统有限元分析模型,进行结构模态分析、空腔声学模态分析和声载荷谐响应分析。基于亥姆霍兹共振理论,建立含缝隙副翼舱内部空腔共振频率与缝隙宽度的关系,结果表明频率变化趋势与ANSYS软件分析结果吻合。声固耦合分析表明,空腔模态频率受缝隙宽度影响明显,当空腔频率与结构频率接近时,两者的耦合系统会出现两个振动模态,副翼舱结构在声载荷作用下出现较大振动响应。研究成果为噪声环境下含缝隙航空薄壁空腔结构的分析和设计提供有效的方法。

基于均值的副翼作动筒载荷事件划分方法

副翼是民用飞机重要操纵面之一,主要功用是产生飞机滚转力矩,用于改变飞机的航向。现代中大型飞机的操纵系统大都采用伺服作动器-操纵面装置,当操纵面受到铰链力矩时作动器也相应受载。以民用飞机副翼作动筒为研究对象,基于试飞实测数据与主操纵面作动筒载荷计算模型,提出了一种基于均值的作动筒载荷事件划分方法。结果表明,该事件划分方法效果理想,较好地反映出了不同飞行事件之间载荷均值的差异。通过对14000次飞行作动筒载荷历程进行雨流处理,给出了相应的载荷谱及载荷幅值、均值分布直方图,总结出相关分布规律。该疲劳载荷谱及相应的分布规律对工程实践中的寿命计算具有重要意义。

某型飞机襟副翼根部下前缘与尾梁隔板蒙皮干涉故障分析及预防

某型飞机在新的飞行作训大纲下,襟副翼根部下前缘与尾梁3号隔板蒙皮会发生干涉裂纹故障。研究分析襟副翼工作中发生干涉故障的机理,并通过测量分析多架飞机襟副翼与尾梁隔板蒙皮之间的对接活动间隙,最终确定对接活动间隙不足是产生干涉故障的主要原因。修理中应检查控制该部位的最小间隙,以预防干涉故障再次发生。

一起飞参数据显示异常故障分析

针对某型飞机一起飞参数据(右襟副翼)显示异常故障,通过机理分析得出可能发生的原因,采用目视观察法、量线法、串件法等故障分析手段,确定了故障发生的根本原因,提出了右襟副翼数值显示异常故障的分析思路以及措施,确保了装备质量。

飞机副翼载荷实测地面标定方法

针对某运输类飞机副翼的结构及受力特点,确定了应变片粘贴位置及组桥方式,设计了标定加载试验,运用多元回归方法建立了载荷标定方程,并进行了试验验证,确保后续飞机副翼载荷飞行实测结果的准确性,为副翼结构的定寿延寿及可靠性设计提供了重要依据。

三维副翼铰链力矩计算

数值模拟了带副翼偏转构型的二维、三维亚、跨、超声速来流情况的绕流流场,采用有限体积方法和AUSM+迎风格式数值求解N-S方程,四步龙格-库塔时间推进,湍流模型为Baldwin-Lomax和Spalart-All-maras湍流模型。二维模拟压强分布与实验数据以及CFD软件模拟结果吻合较好。采用交错对接网格,数值模拟了不同副翼偏角和缝隙、来流马赫数、迎角和雷诺数的三维构型流场。通过舵面铰链力矩与实验数据的对比分析表明了该数值方法模拟此类复杂流场的可靠性和舵面铰链力矩计算的有效性。发现并研究了亚声速来流时铰链力矩随迎角的反向变化趋势,初步分析了副翼的缝隙和雷诺数效应。

基于Simulink的无人机六自由度仿真

加装滑翔增程组件的炸弹气动外形和无人机类似,研究无人机的运动特性将对研究滑翔增程组件起到重要作用。利用Simulink对无人机进行六自由度建模,分析无人机在滑翔过程当中的运动姿态特性,副翼对无人机运动的影响,无人机在风干扰的环境中的运动姿态特性,通过这些分析,可以对炸弹的滑翔增程组件的设计起到至关重要的作用,可为后续的控制、制导、导航研究打下基础。

带副翼的翼身组合体的数值模拟

利用NUMECA公司的FINE软件对带副翼的翼身组合体进行数值模拟,在副翼和主翼的两个交界面分别形成结构化网格,利用FINE中的FNMB功能进行计算。通过与文献中此类工作的对比,认为FINE软件完成网格自动拼接是行之有效的。用不同网格数进行验算分别得到文献[1]和文献[2]的压力曲线,由此证明两者的区别源于网格数的不同。

无尾飞机布局方向控制特性研究

介绍了无尾飞机布局方向控制特性风洞试验研究的主要结果。在两种典型布局上研究了扰流板、开裂副翼、机头边条、活动和偏转翼梢及舵面的方向控制特性。认为机头边条、开裂副翼、活动(偏转)翼梢及其舵面组合是一种极具潜力的方向控制方案,可供无尾飞机布局参考。

某型歼击机副翼人力操纵可行性分析

为消除飞行人员对副翼人力操纵的疑虑 ,在建立副翼人力操纵可行性分析模型的基础上 ,应用飞行力学的基本原理 ,对某型歼击机因液压系统正常供压部分失效 ,副翼助力器转换为人力操纵后所需的压杆力进行了定量分析计算。结果表明 ,在应急情况下 ,只要处理得当 。

基于遗传算法的半开环单侧副翼卡死控制

无人机副翼卡死会严重影响无人机的操纵性和安全性。针对单侧副翼极限位置卡死故障,提出了一种根据侧滑配平的半开环控制方法,该方法在不引入侧滑角反馈的情况下,通过侧滑角指令与洗出网络代替偏差量,利用副翼和方向舵产生一定的侧滑角来平衡滚转力矩。首先,分析了在不同侧滑下配平卡死故障的可能性,并提出了半开环控制方案;然后,基于经典PID结构研究了侧滑角指令生成和控制的方法;最后,为了改善半开环系统的性能,通过遗传算法对参数进行优化。仿真结果表明通过遗传寻优的半开环控制方案能使无人机在单副翼极限卡死时快速稳定,恢复操纵性能,该方案具有一定的可行性和合理性。

双正交RSSR副翼差分机构运动分析与优化

以RSSR空间机构为基础构型设计了双正交RSSR副翼差分机构,建立了差分机构分析模型,采用D-H方法进行了开式运动链坐标变换,利用杆长法推导了差分机构的运动分析表达式,得到了不同杆长条件下差分机构的运动特性,确定了符合副翼控制精度要求的杆长条件,并在多体动力学软件ADAMS中建立了仿真分析模型,对理论分析进行了验证。结果表明双正交RSSR副翼差分驱动机构可实现左、右副翼在同一驱动舵机作用下反向运动、偏转角度相等的差分驱动目的,通过特定杆长配置可实现传动比近似为1的等速传递。

带控制舵钝双锥削面体的气动特性研究

提出了带控制舵的钝双锥削面体飞行器气动布局概念,计算分析了其压心特性、升阻比特性、配平特性及操纵效率问题,同时还研究了纵向稳定配平条件下的航向安定性问题及动稳定性问题,并与带配平翼的钝双锥削面体外形进行了比较。两类外形的典型空间机动动作不同,操纵方式也各不相同:控制舵削面体具有更大的配平攻角变化范围和操纵效率,较小的舵面等效攻角有利于舵面防热及结构设计,而且俯仰配平时的航向安定性及动稳定性较好;而配平翼钝双锥削面体可采用迎风及背风进行俯仰控制,结合侧翼的扩张及迎风翼的差动实现空间"Z"形机动。

大侧滑模型参考自适应飞行控制方法研究

针对飞机单侧副翼舵机卡死故障的飞行问题,研究了基于模型参考自适应控制的大侧滑角飞行控制方法。首先给出进行大侧滑角直飞的级联式飞行控制方案,并对控制信号间的关系进行分析;其次对与侧滑角指令有关的姿态内环进行模型参考自适应控制结构和算法设计,同时给出参考模型选取方法;最后分别在无故障和单侧副翼舵机卡死飞机下进行非线性仿真验证。仿真结果表明,该控制方法能够在气动数据摄动和控制器参数初值随意选取下,仅利用故障前配平点使得飞机在发生单侧副翼舵机卡死后能够跟随参考模型响应,并进一步无静差地跟踪大侧滑角指令,具有较好的鲁棒性和实用性。