基于MATLAB的航空用同步发电机故障暂态模型仿真

提出在MATLAB环境中对航空用同步发电机故障暂态进行仿真的方法。用SIMULINK建立起同步发电机模型，并将其与PSB模块联合使用，能方便灵活地建立起发电机故障暂态模型。该模型不仅可以对发电机故障的瞬态和稳态过程进行仿真，而且能够揭示发电机故障瞬态的运行特征及瞬态过程中各个故障量的变化规律。运行结果表明该模型切实可行。     

基于MATLAB的航空用同步发电机故障暂态模型仿真

提出在MATLAB环境中对航空用同步发电机故障暂态进行仿真的方法。用SIMULINK建立起同步发电机模型,并将其与PSB模块联合使用,能方便灵活地建立起发电机故障暂态模型。该模型不仅可以对发电机故障的瞬态和稳态过程进行仿真,而且能够揭示发电机故障瞬态的运行特征及瞬态过程中各个故障量的变化规律。运行结果表明该模型切实可行。     

基于相关向量机的SAR图像飞机目标分类方法研究

随着合成孔径雷达(SAR)成像技术的发展,SAR图像的数据处理和图像分类工作近年来成为研究热点.在本文中,将相关向量机(RVM)应用于SAR图像目标分类识别,对3类飞机仿真目标进行分类,从分类正确率、分类时间、泛化能力和鲁棒性方面全面考察其性能.与支持向量机(SVM)相比,相关向量机没有多余的参数调整,核函数不需要满足Mercer条件,可以获得更多的稀疏模型.仿真结果表明,在对3种类型的飞机仿真目标进行分类的情况下,使用RVM方法总体分类性能略高于SVM.     

基于Simulink的飞机电源系统建模与仿真

分析了某型号飞机的电源系统，讨论了发电机模型和负载模型及其相互关系，以发电部分为例，采用微增量和分段线性化的方法，建立了以发电机为核心的电源系统发电部分数学模型。最后利用Matlab软件中的Simulink工具箱，根据系统各部分模型间的关系建立了整个电源系统仿真模型，并对其进行了仿真研究。仿真结果表明，所建立模型简单、方便、仿真精度高。     

CJ1奖状飞行训练设备维护仿真建模与实现技术研究

奖状飞行模拟机系统繁多,与真飞机相比,维护手册章程简单,维护技术要求高。按照现有的维护手册很难精准判断故障组件,并对故障组件快速完成拆装更换工作。针对此问题通过分析奖状飞行模拟机的系统结构,提出并建立了维修仿真管理模型MSM,构建了MSM模型框架,定义了MSM模型的3个要素:状态、迁移和约束条件。基于状态定义维修组件的各种状态情况,基于迁移定义维修实现的触发条件,基于约束条件建立状态与触发条件的制约关系。并阐述了MSM模型的虚拟场景的渲染驱动和切换。最后以仿真维修平台中声音控制组件拆装仿真为例,验证了维修仿真管理模型的有效性。     

电力现货市场技术支持系统关键技术探讨

中国新一轮电力体制改革已逐步进入深水区,各试点地区结合自身特点设计电力现货市场交易产品和运行规则,并在不同阶段根据运营情况不断进行调整完善,具有复杂多变的特点,对技术支持系统提出高要求。提出了分区部署的系统总体架构及分层应用功能框架,重点在技术支撑平台、核心算法、模型数据管理、评估分析、模拟推演等关键技术进行探讨,并取得初步应用。     

Microsimulation of Freeway Ramp Merging Processes Under Congested Traffic Conditions

This paper describes a microsimulation program developed to study freeway ramp merging phenomena under congested traffic conditions. The results of extensive macroscopic and microscopic studies are used to establish a model for the behavior of merging drivers. A theoretical framework for modeling the ramp and freeway lag driver acceleration-deceleration behavior guided the model development. This methodology uses the stimuli-response psychophysical concept as a fundamental rule and is formulated as a modified form of the conventional car-following models. Data collected at the two merging points are used to calibrate the hypothesized ramp and freeway lag vehicle acceleration models. Drawing on this behavioral model, the freeway merging capacity simulation program (FMCSP) is developed to simulate actual traffic conditions. This model evaluates the capacity of a merging section for a given geometric design and flow condition. Validation of FMCSP is performed using the observed flow, vehicle trajectories, and lane-changing maneuvers. The simulation model is applied to investigate a variety of merging strategies. The results indicated that the FMCSP is capable of simulating the actual traffic conditions of congested freeway ramp merging sections and will aid in the development of traffic management strategies for complex freeway ramp merging areas.     

适用于飞机电网的并联型有源电力滤波器功率电路及其控制策略

针对飞机电网频率较高、电源内阻抗较大的特点,采用并联型有源电力滤波器实现对电网谐波的集中抑制。采用改进的交叉矢量算法实现对基准补偿电流的检测和计算,采用滞环电流控制实现对较高频率电源系统瞬时电流的补偿,同时对直流侧电压进行稳压调节,并推导其传递函数。仿真和实验结果验证了将APF应用于飞机电网的正确性和可行性,表明采用本文的有源滤波器可集中抑制电网谐波电流,具有较好的补偿效果。     

四旋翼飞行器姿态控制建模与仿真

四旋翼飞行器是典型的欠驱动、非线性、强耦合系统。其姿态控制精度和抗干扰问题一直是研究热点之一。为了实现小型低成本四旋翼飞行器姿态准确控制,详细分析了四旋翼飞行器受力情况,利用牛顿-欧拉方程建立了四旋翼飞行器非线性动力学模型,针对四旋翼飞行器在实际飞行过程中经常会遇到阵风、气流等不确定外界干扰,设计了基于小扰动的PID控制器,并通过对俯仰通道、横滚通道、偏航通道MATLAB/Simulink仿真模型进行仿真测试和结果分析。结果表明:所设计控制算法能够满足四旋翼飞行器姿态控制要求,并具有较好的抗干扰性能。     

基于奇异值分解的风电场杂波微动特征提取

风电场作为一种特殊的大型建筑物,会影响航管监视雷达对飞机目标的准确探测。同时,由于风电场通常分布在某一大面积区域,风轮机之间具有多径传输特性,进而会影响航管监视雷达对飞机目标的定位和测速。因而,分析风电场杂波的微动特征有助于检测和识别风电场杂波信号,提高雷达探测目标的准确性。基于航管监视雷达风电场回波信号模型,利用奇异值分解技术分析了风电场回波信号的微动特征,并构造相应的特征量实现其微动特征的提取。同时,在飞机目标存在背景下,提取了风电场回波的微动特征,并将其与飞机目标的多普勒特征进行对比分析,仿真结果证明了所提方法的有效性。     

基于行为模型的飞机电源系统建模仿真技术研究

针对新型飞机电源系统部件种类多、控制复杂以及电路级仿真运算量大、速度慢的特点,提出了基于行为模型的飞机电源系统电能部件的建模方法。从电能部件的输入输出出发,依据功率平衡关系,并且结合受控源,来描述部件功能特征。利用Simulink软件,建立了系统中的关键部件的行为模型,并且构建了整个电源系统仿真模型。通过该模型,开展了飞机电源系统的特性仿真研究。仿真结果表明,所建立模型简单、方便、可以反映部件和系统的行为特性,仿真速度比电路模型更快。     

A study of aircraft taxi performance for enhancing airport surfacetraffic control

In view of the ever-increasing air traffic, much attention in air traffic management research has been given to improving arrival and departure efficiency. As air traffic begins and ends at the airport, the issues of taxi delays and ground incursions are becoming more evident. The paper considers the surface-traffic problem at major airports and envisions a collaborative traffic and aircraft control environment where a surface traffic automation system will help coordinate surface traffic movements. Specifically, the paper studies the performance potential of high-precision taxi toward the realization of such an environment. A state-of-the-art nonlinear control system based on feedback linearization is designed for a detailed B-737 aircraft taxi model. The simulation model with the nonlinear control system is evaluated extensively in a scenario representing the demanding situation of an arrival aircraft crossing an adjacent active runway immediately following its own landing. The evaluation establishes the potential of an automated system to achieve high-precision taxi control, including the ability to comply with taxi clearances with tight time margins. Such a high-precision taxi capability reduces the time margin required for clearing taxiing aircraft to cross active runways, thus increasing the opportunity for issuing such clearances, which in turn reduces the need for aircraft to hold short at the runways to wait for the opportunity for crossing. The results from the analyses provide insight into future aircraft operational capabilities toward the design of the envisioned surface traffic automation system. Moreover, the nonlinear control design serves as a preliminary study for future auto-taxi functional development     

突风气象条件下电动飞机电推进系统 PI控制参数的设定方法

电动飞机电推进系统采用高效永磁同步电机作为主驱动,配备矢量控制器。飞机在巡航过程中不可避免地会遭遇突风,影响飞机的稳定飞行。通过建立电动飞机在巡航阶段遭遇突风时的空气动力学模型和电推进系统的动态响应数学模型,并对模型进行求解,给出了突风气象条件下电推进系统速度PI控制参数的设定方法。以某双座电动飞机的电推进系统为研究对象,采用MATLAB仿真和样机地面试验对速度PI控制进行了仿真分析和试验测试,对比了未考虑和考虑突风气象条件下的速度PI控制器的动态特性。仿真和样机试验结果表明:当飞机遭遇突风时,采用考虑突风气象条件的速度PI控制参数可以有效地降低螺旋桨的转速波动范围。     

Synchronic modal equivalencing (SME) for structure-preservingdynamic equivalents

A novel framework for dynamic equivalencing of interconnected power systems that the authors recently introduced in the context of classical swing-equation models is extended in this paper to detailed models in structure-preserving, differential/algebraic-equation form. The system is partitioned into a study area and one or more external areas on the basis of synchrony, a generalization of slow-coherency that forms one leg of their framework. Retaining a detailed model for a single reference generator from each external area, the dynamics of the remaining external generators are then modally equivalenced in the style of selective modal analysis; this modal equivalencing is the other leg of their framework. The equivalenced external generators are thereby collectively replaced by a linear multi-port “admittance”, which is easily represented using controlled current injectors at the buses of the replaced generators. The rest of the system model can be retained in its original nonlinear dynamic form. The approach is tested-with encouraging results-on the familiar third-order, 10-machine, 39-bus New England model, using an implementation in the EUROSTAG simulation package     

Adaptive control for a class of uncertain linear parameter‐varying flight aircraft systems

The concept of linear parameter‐varying (LPV) model has been developed as a convenient framework to describe a special class of uncertain LPV flight aircraft systems. In this paper, an adaptive control method for a class of uncertain LPV systems whose state‐space matrix elements are unknown affine functions of a set of measurable scalar parameters is presented. Firstly, the scalar parameters are separated from the state matrices such that the LPV model is rewritten as general unknown parameter model, then state feedback adaptive control laws, in both cases: the matched uncertainty and the unmatched uncertainty, are designed with the aim of controlling the system state to follow a desired trajectory. The sufficient condition of stability is derived using a Lyapunov equation, not a parameterized Lyapunov equation. Simulation tests based on a simple example and a nonlinear model of a transport aircraft are given to illustrate the effectiveness of the control algorithm and to demonstrate that the adaptive controller satisfies the performance requirement for an aircraft control system. Copyright © 2016 John Wiley & Sons, Ltd.     

基于改进的快速趋近律的四旋翼姿态控制

为了提高四旋翼控制系统的稳定性以及快速性,设计了基于改进的趋近律的控制器,以解决扰动下的四旋翼姿态控制问题。对四旋翼飞行器建模。根据系统的特征,将系统分成了全驱动和欠驱动两个子系统。分别利用改进的快速趋近律设计了控制器。仿真结果表明,控制器具有较好的控制效果,并且在动态性能方面能够快速地跟踪信号,抖振现象也得到了削弱。     

基于HLA的反潜巡逻机浮标搜潜模型仿真框架结构设计

进行反潜巡逻机的仿真需要考虑的因素很多，普通针对单一武器平台的仿真无法满足现代化战场的需要。在对反潜巡逻机浮标搜潜战术执行过程的研究基础之上，设计并建立了反潜巡逻机浮标搜潜系统的模型结构体系以及系统框架结构，给出联邦成员之间的接口与功能，并通过HLA/RTI分布式交互仿真系统的仿真引擎将不同的联邦成员加入其中，构成反潜巡逻机浮标搜潜战术运用符合实际的环境空间，从而使得仿真效果更加贴近实际。     

基于有限元的破损屏蔽层转移阻抗仿真分析

针对飞机电缆屏蔽层破损会影响其屏蔽性能的问题,研究了薄壁管状屏蔽层和编织网状屏蔽层破损时的转移阻抗。首先,提出了低频并联等效模型,并根据不同的屏蔽层结构应用电磁耦合理论推导出破损屏蔽层的转移阻抗数学模型;然后,基于有限元方法将破损屏蔽层的三维几何模型在ANSYS HFSS中进行电磁场分析;最后,应用算例对比破损屏蔽层转移阻抗的仿真结果和理论计算结果,并分析不同破损因素影响转移阻抗的变化规律。文中结果表明,破损屏蔽层的转移阻抗与屏蔽层的结构、所处频率、破损半径等因素相关,具有一定的工程应用价值。     

基于模糊反步自适应算法的飞机发电控制研究

随着多电化和全电化趋势的发展,飞机电气与电子设备大量增加,恒频系统已不能满足飞机用电需求。飞机供电体制需要由恒频系统向变频系统转变,而变频发电机是变频系统中尤为重要的设备。传统的PID控制采用固定参数,无法很好地在宽变频发电系统中工作,因此提出了基于模糊反步自适应控制算法的控制参数修正方法以提高调压系统适应性。结合三级式发电系统数学模型,设计了调压系统中不确定参数的自适应律分析方法,并建立了基于该算法的调压系统仿真模型。通过仿真验证了模糊反步自适应控制可以有效抑制工作条件变化对调压系统造成的影响,增强调压系统的稳定性和调节性能,为飞机发电机控制器的设计提供理论支持。     

Mathematical modeling and analysis of brushless doubly fed reluctance generator under unbalanced grid voltage condition

The brushless doubly fed reluctance generator (BDFRG) can be an attractive choice for wind power application where mostly located at remote areas with unbalanced grid voltages, however there is not any study on the BDFRG under this condition up to now. In this paper, a mathematical model for the BDFRG under unbalanced grid voltage condition has been developed. Its equivalent circuit in dq reference frames has been extracted, and the torque and power equations have been derived, all based on the positive and negative sequence components. Also, a real-time separation method has been proposed to separate the BDFRG positive and negative sequences. The developed model and equations express the basis of the BDFRG operation under unbalanced grid voltage condition. The proposed model is simulated in MATLAB/Simulink software and the accuracy of the proposed model and equations has been validated by comparison with simulation results of an existing BDFRG model under balanced condition, which has already been experimentally verified in the literature.