Linux下无人机软件故障注入系统研究与设计

基于linux系统的软件故障注入方法,设计了一个软件故障注入系统UAVFI_L,采用硬件覆盖和故障模型的方法,模拟无人机系统的硬件故障,并着重讨论了在总线上注入故障的试验策略。最后用一台工控机和飞控计算机通讯,注入故障。故障注入试验结果表明了这种方案的正确性和可行性。     

故障注入器功能设计

对于容错计算机的验证 ,必须模拟在系统运行出现故障的情况下 ,容错计算机对故障的检测、隔离和定位能力。所以 ,需要研究故障注入技术。故障注入是通过一定的方法 ,按照一定的控制 ,改变计算机内部硬件或软件的状态 ,使其出现预先定义的故障状态 ,由此触发容错计算机的故障逻辑 ,验证故障逻辑的功能和性能。     

基于小脑模型关节控制器的无人机集群快速终端滑模容错控制

针对受执行器故障和外界干扰影响的集群无人机（UAV）协同编队控制问题，提出了一种自适应快速非奇异积分滑模（FNISM）容错控制（FTC）方法。为使集群无人机在执行任务时具有良好的协同跟踪性能，通过对无人机实际飞行情况的分析，考虑了无人机编队飞行时的执行器故障和尾涡扰动等对跟踪性能的不利影响。采用小脑模型关节控制器神经网络（CMANN）来估计并消除外部干扰的影响，同时运用CMANN逼近补偿执行器故障。研究表明：所提出的容错控制方案可以保证无人机编队闭环系统在故障情况下的最终一致有界稳定，并且可以通过减小滑模设计参数提高收敛速度，通过增大虚拟和实际控制器参数提高控制精度。4架无人机的集群编队在该方法、基于径向基神经网络（RBFNN）的鲁棒动态面容错控制、比例微分（PD）滑模容错控制3种方法下的对比仿真结果表明该方法在无人机集群编队出现故障时具有更优异的协同控制性能。     

作动器故障下的无人机容错控制方法

在执行任务过程中,无人机的传感器、作动器等均可能出现故障。文章针对常规布局无人机的作动器故障,提出了 1种反步法和控制分配相结合的容错控制方法。首先,建立无人机数学模型,并对作动器故障进行分类和建模;然后,根据模型设计反步最优控制器和基于控制分配的容错控制器;最后,通过仿真验证表明,所设计的容错控制方法能够实现作动器故障下的姿态快速稳定控制,且稳定性好,基本无侧滑角,各操纵面均在约束范围内,达到容错控制要求。     

临近空间艇载计算机余度管理策略研究

平流层飞艇是可靠性要求很高的系统,需要由具有容错能力的艇载计算机来进行控制和管理。针对艇载计算机采用的余度结构进行了软件管理策略的研究和设计,提出了基于异构总线的握手机制节点故障检测方法、基于“看门狗”与“心跳”相结合的 CPU 故障检测方法、基于节点健康矩阵的互援式总线重构方法及基于有限状态机的多 CPU 并行处理系统自适应重构方法。故障注入试验表明,艇载计算机在遇到故障时能实时检测出故障,诊断故障类型,并对故障进行处理,实现系统重构,保证了平流层飞艇长期驻空时的安全飞行。     

无人机动态飞行参数处理及应用策略

飞行参数处理能够有效地评价无人机在飞行过程中的行为,将其与故障注入技术相集成能够合成测试无人机系统可靠性的完整技术。文中结合无人机的特点提出了一种面向飞行参数时序数据流的飞行参数处理方案,利用飞行参数处理技术实时判读无人机的行为,监测机载设备故障在无人机系统中的传播过程。首先在分析无人机飞行参数数据特征的基础上,着重研究了飞行参数实时数据采集和数据处理方法;然后构造了一个实际的飞行参数处理系统UAVFDD_01,并分析了动态飞行参数处理过程。系统可靠性测试试验结果表明设计的系统能够满足无人机可靠性测试的要求。     

多相开路故障下的双三相PMSM统一容错控制策略

多相电机在定子开路故障下具有良好的容错性能,与此相关的设备和控制策略改进方面的研究理论也不断被提出。然而,却少有基于统一模型的适用于多相开路故障的容错控制策略。提出了一种应用于双三相永磁同步电机(PMSM)系统三相或三相以下开路故障的容错控制策略,并获得了良好的电机电力和动态性能。针对发生单相到三相开路故障的PMSM提出了统一数学模型,提取出每种故障下对应电机不对称性的矩阵。通过电压方程,推导出每种故障对应的解耦变换矩阵。为了对相电流中的每种谐波进行无差别抑制,建立了谐波子空间。考虑开路故障相数的增加,提出了用于三相开路的有中性点电流的容错控制策略,达到了降低相电流幅值和提升系统冗余度的目的。最后通过试验和仿真结果,验证了理论分析的正确性。     

故障注入在无人机飞行仿真中的应用

首先引入故障注入的一般概念、各种分类方法以及目前国内外的应用情况。其次研究了用于飞行控制仿真试验的故障注入系统的组成、设计、测试和试验方法，分析了相应故障注入技术的特点。最后介绍了一种在飞行控制系统的研制、试验过程中进行故障注入试验的专用装置——故障注入与分析装置的设计、实现及应用。     

无人机航向测量的罗差修正研究

 针对数字式磁航向测量系统在无人机上的应用,系统地研究了任意姿态下的罗差修正问题。通过分析罗差形成的原因,提出一种更为简单的罗差修正方法和确定罗差系数的工程方法。为了减少试验工作量和试验数据的错误,用计算机检验罗差系数的正确性,并提出试验数据正确性的检验方法。实验结果表明,该方法是很有效的。这种方法不仅可用于无人机,也可用于车辆、轮船等其它运载工具。     

蜂群对抗决策故障下的容错博弈控制

针对大规模分簇蜂群无人机的任务分配问题,考虑对抗场景下某些无人机由于受到敌方攻击或操控,决策规则遭到篡改,进而导致群决策行为与期望的均衡点产生偏差的决策故障。在演化矩阵博弈的框架下,运用多群体复制子动态方程对蜂群无人机和故障建模,基于李雅普诺夫函数对故障发生前后均衡点的局部渐近稳定性及其吸引域进行了分析,从而建立了自容错条件,并设计了基于激励的簇间协同容错博弈控制方法,对群决策行为偏差进行补偿,使得蜂群任务分配状态在故障下仍能达到期望的均衡点,获得理想的分工收益。     

活塞式发动机排气喷管断裂故障分析

对某型无人机活塞式发动机发生断裂故障的排气喷管进行了现场检查、断口分析及静力学分析,表明焊接质量不合格是导致故障发生的主要原因;提出了增加焊接点数、加大熔核尺寸、加强无损检测等排故措施。     

Numerical simulation of a UAV impacting engine fan blades

A 3D digital model of a small Unmanned Aerial Vehicle (UAV) is obtained by using the method of scanning reverse modeling and joint mapping. A numerical simulation of a small UAV strikes on rotary engine blades, presented in this paper, was performed with a Transient Nonlinear Finite Element code PAM-CRASH software. A test of motor strike on plate was developed and the dynamic response of the plate were obtained to validate the numerical simulation method of a UAV strike on blades. Based on this, dynamic damage response caused by UAV on the engine blades were studied. It is indicated that the impact process between the UAV and a single blade can be divided into two typical stages: cutting and impact. Cutting mainly leads to the failure of the leading edge material, and impact mainly leads to the plastic deformation of the blade. At the same time, it is compared with the damage impacted by bird with the same mass. For the same mass of bird and UAV, the damage caused by UAV striking fan blade is more serious, and 1.345 kg UAV striking fan blade of typical civil aviation engine is enough to cause damage to flight safety.     

Longitudinal parameter identification of a small unmanned aerial vehicle based on modified particle swarm optimization

This paper describes a longitudinal parameter identification procedure for a small unmanned aerial vehicle(UAV)through modified particle swam optimization(PSO).The procedure is demonstrated using a small UAV equipped with only an micro-electro-mechanical systems(MEMS)inertial measuring element and a global positioning system(GPS)receiver to provide test information.A small UAV longitudinal parameter mathematical model is derived and the modified method is proposed based on PSO with selective particle regeneration(SRPSO).Once modified PSO is applied to the mathematical model,the simulation results show that the mathematical model is correct,and aerodynamic parameters and coefficients of the propeller can be identified accurately.Results are compared with those of PSO and SRPSO and the comparison shows that the proposed method is more robust and faster than the other methods for the longitudinal parameter identification of the small UAV.Some parameter identification results are affected slightly by noise,but the identification results are very good overall.Eventually,experimental validation is employed to test the proposed method,which demonstrates the usefulness of this method.     

不定线性系统的鲁棒故障检测

 <正> 1.引言 Beard等提出的检测滤波器是一种基于模型的故障检测与识别(FDI)方法,然而,检测滤波器要求精确地已知系统的动力学方程 X=AX+Bu,Y=CX (1) 其中,X∈R~n,Y∈R~m,u∈R~r分别为系统状态输出和控制;A、B、C为具有相应维数已知常阵。由于系统的复杂性以及系统外界干扰的不确定性,获取系统精确的数学模型非常困难。因此要解决的基本问题即考虑下列不定系统的故障检测     

Unmanned aerial vehicle strike on a flat plate: Tests and numerical simulations

The incursion of Unmanned Aerial Vehicles (UAVs) into airports often occurs due to the popularity of drones, which may lead to a threat to aircraft flight safety. Therefore, estimating the dynamic impact load caused by drone strikes is essential. This paper proposes a test method with high precision and low cost involving launching of a UAV to impact a flat plate specimen by using an air gun. The test results of UAVs impacting flat plates at different impact velocities, such as the UAV damage deformation captured by a high-speed camera and strain vs time dynamic response curves of plates, were obtained and analysed. At the same time, a corresponding numerical simulation was carried out by using the explicit finite element software LS-DYNA. The predicted damage to the UAV and strain on the flat plate during the strike process were compared with the test results. The overall trend of the simulation results is in good agreement with the test results, at least for the first three milliseconds of the event. This shows that the numerical simulation model established in this paper is reasonable. The UAV numerical method established in the present paper can be used to carry out numerical simulations and evaluations of the collision safety of UAVs against large aircraft and high-value ground targets. The results show that the local deformation of the impacted target is uneven due to the distribution of concentrated mass components such as motors, battery, and camera. As the impact velocity of the UAV increases, all parts of the UAV are seriously damaged and basically in a fragmented state, and the battery is greatly deformed. The interaction between the UAV and the flat plate specimen is approximately 2.7 ms, and the UAV numerical simulation model established in this paper can well simulate the real UAV impact process.     

基于火箭橇的无人机碰撞民用飞机试验技术研究

无人机碰撞民用飞机关键部位损伤程度的研究是民航领域关注的新型热点问题。本文首次提出采用 火箭橇试验评估无人机碰撞民用飞机的安全性。通过对碰撞速度、碰撞位置、无人机姿态、参数测量等进行研 究,设计碰撞技术方案,论述火箭橇的设计、弹道控制设计、强度校核和测试方案,并进行试验验证和仿真计算。 结果表明:本文设计的火箭橇碰撞试验方案是可行的,实现了单一弹道上的连续多点碰撞及多视角、全覆盖、高 稳定的全过程记录;可为后续开展同类碰撞试验提供必要的技术参考,所开展的多发次碰撞试验也为无人机碰 撞民用飞机的安全性评估提供了有效的试验数据。     

某型飞机刹车失效分析及对策研究

刹车系统是飞机的重要组成部分,是保证飞机滑跑、起飞和着陆的重要装置,其工作可靠性直接影响飞行安全.本文对某型飞机因刹车失效,发生一起与地面停放飞机相擦的飞行事故征候,进行了刹车失效分析和机理研究.同时,按技术问题“五归零”要求,深入开展了多余物产生根源的排查工作,进行了改进研究和试验验证,并制定了对策.     

Efficiency optimized fuel supply strategy of aircraft engine based on air-fuel ratio control

Accurate fuel injection control of aircraft engine can optimize the energy efficiency of UAV power system while meeting the propeller speed requirement. Traditional injection control method such as open-loop calibration causes instability of fuel supply which brings the risk of power loss of UAV. Considering that the closed-loop control of AFR can ensure a stable fuel feeding, this paper proposes an AFR control based fuel supply strategy in order to improve the efficiency of fuel-powered UAV while obtaining the required engine speed. According to the optimum fuel injection results, we implement fuzzy-PID method to control the set AFR in different situations. Through simulation and experiment studies, the results indicate that, to begin with, the calibrated mathematical model of the aircraft engine is effective. Next, this fuel supply strategy based on AFR control can normally realize the engine speed regulation, and the applied control algorithm can eliminate the overshoot of AFR throughout all the working progress. What is more,the fuel supply strategy can averagely shorten the response time of the engine speed by about two seconds. In addition, compared with the open-loop calibration, in this work the power efficiency is improved by 9% to 33%. Last but not the least, the endurance can be improved by 30 min with a normal engine speed. This paper can be a reference for the optimization of UAV aircraft engine.