飞机完好率预测仿真研究

利用飞机完好率时间序列特性,建立了NAR神经网络模型和基于不同核函数的3种支持向量机模型对平时状态下的飞机完好率变化趋势进行建模、训练和预测;运用Matlab仿真软件进行试验验证,结果表明:支持向量机模型具有较好的拟合效果,预测精度优于NAR神经网络模型,基于RBF核函数的支持向量机预测准确率相对较高.两种预测模型相比于部队现行的预测方法均具有更高的准确度和可靠度.     

基于多基地声纳的反潜巡逻机检查搜潜效能研究

为解决传统反潜巡逻机检查搜潜存在作用距离短、搜索盲区大、精度低和经济性差的缺点,提出基于多基地声纳的反潜巡逻机检查搜潜方法.根据反潜巡逻机先布设的多基地声纳阵得到潜艇初步定位坐标,以4种不同的方案补投被动浮标,并利用声波衰减原理和TOL算法分别通过Matlab进行多基地搜索概率和GDOP定位精度的仿真.仿真结果表明:同等条件下,反潜巡逻机进行等边三角形补投被动浮标情况下的多基地声纳检查搜潜方法具有高搜索概率和定位精度,并能使用较少的浮标形成一个有效的检查圈.该方法可应用于反潜巡逻机检查搜潜,对反潜作战具有一定的军事意义.     

基于Creo的飞行器电缆三维协同设计研究

针对飞行器电缆传统设计方法存在效率低、偏差大、电缆走向不合理、设计阶段难以估算质量特性等问题,文中在研究电缆设计原理及Creo三维电缆设计模块的基础上,给出了一种电缆三维协同设计方法,提高飞行器电缆设计效率和电缆网布局的合理性,对飞行器电缆设计有重要的推广意义.文中以某飞行器舱段电缆设计为例,验证了该方法的可行性.     

飞机腹鳍根部型材疲劳断裂强度分析

针对某型飞机腹鳍根部型材疲劳断裂问题,依据腹鳍的结构和工作特点,应用疲劳断裂理论进行定量分析,排除了因飞行中所受空气动力引起的静载和动载造成损伤的可能性,分析了其裂纹产生原因并提出使用维修建议.     

舰载机协同无源定位系统精度比较分析

针对舰载机协同对海上和空中目标进行无源定位,采用时差(TDOA)、测向、时差/频差等典型无源定位方法,对利用目标辐射源信号的舰载机协同无源定位系统进行建模仿真和精度分析.仿真结果表明:双机时差/频差定位、三机时差定位、双机测向交叉定位3种无源定位方法各有优劣.因此,明确电子侦察的作战目标以及方法,对分布在战场不同位置的舰载机实施合理分群,为建立多机协同无源定位系统提供理论支撑.     

小型无人机发动机控制系统 CAN 总线通信技术

为了提高小型无人机发动机控制系统通信的实时性和可靠性,设计一种基于CAN总线通信的小型无人机机载设备通信系统.该系统采用响应式和分时式2种发送机制,设计一种基于PIC单片机的多ID CAN总线通信程序和同步时序,详细设计了发动机控制系统CAN总线通信的实现方法,并在发动机热试车和飞行试验中进行验证.试验结果表明:该系统设计合理,提高了发动机控制系统的通信速率,增强了抗干扰能力,满足发动机控制系统与机载各设备之间实时可靠通信的要求,可广泛应用在小型无人机通信系统中.     

Impact of organic inter-layer dielectric for improvement in mechanical flexibility of self-aligned coplanar in-Ga-Zn-O thin-film transistor

A novel device structure has been suggested to introduce organic inter-layer dielectric (ILD) for improving mechanical flexibility of self-aligned (SA) coplanar In-Ga-Zn-O (IGZO) thin-film transistor (TFT). The SA coplanar TFTs fabricated on poly(ethylene naphthalate) (PEN) substrate showed a high saturation mobility of 11.4 cm²/V∙s, low threshold voltage of 0.26 V, steep subthreshold swing of 115 mV/dec, and high on/off current ratio (~10⁹) at flat state. In the proposed structure, all-oxide gate stacks were defined into an island configuration embedded in the organic ILD, and hence, the mechanical stress applied to the active region could be effectively relieved. To investigate the feasibility of a new device concept, the mechanical properties of the fabricated TFTs were characterized. When the PEN thickness was varied 25 and 50 μm, the critical radius of curvature (R_C) values were estimated to be 1 and 3 mm, respectively, which were superior to those for conventional oxide devices. In addition, the mechanical durability during the cyclic bending test at R_C of 5 mm was significantly improved from 20,000 to 70,000 cycles when the PEN film thickness was reduced from 50 to 25 μm. The effects of PEN thickness on the mechanical stability of the SA coplanar TFTs were quantitatively discussed from a view point of surface strain. As a result, robust mechanical bendability of proposed device was confirmed even under harsh deformation conditions.     

军用飞机研制风险的模糊综合评价方法

针对风险评价中信息的模糊性和不确定性,提出了军用飞机研制风险的模糊综合评价方法.首先,对风险评价的一般方法进行分析;然后,确定了军用飞机研制的风险源因素和风险后果因素.采用模糊集表示风险源因素对研制失败的影响和风险后果因素的大小,并对各个因素进行模糊评价;最后,根据各个因素的模糊评价矩阵及其权重,采用模糊综合评价方法获得研制风险的失败概率和失败后果,由失败概率和失败后果可得到研制风险的大小.算例表明,模糊综合评价方法可将风险评价中的模糊和不确定信息定量化处理,能够有效地对军用飞机的研制风险进行评价.     

基于卫星中继的无人机图像传输系统

基于卫星中继的无人机图像传输系统在遥感图像的传输中有着十分重要的作用。首先讨论了这种系统的应用意义 ,然后提出了一种具体的实现方案 ,对系统中的几个关键部分的设计进行了详细分析。目前的实验成果表明 ,这种基于卫星中继的无人机图像传输系统方案是可行的。     

Integrated structure and control design for mechatronic systems with configuration-dependent dynamics

This paper considers the optimal design of mechatronic systems with configuration-dependent dynamics. An optimal mechatronic design requires that, among the structural and control parameters, an optimal choice has to be made with respect to design specifications in the different domains. Two main challenges are treated in this paper: the non-convex nature of the optimization problem and the difficulty in modeling serial machines with flexible components and their embedded controllers. The optimization problem is treated using the direct design strategy which considers simultaneously structural and control parameters as variables and adopts non-convex optimization algorithms. Linear time-invariant and gain-scheduling PID controllers are addressed. This methodology is exploited for the multi-objective optimization of a pick-and-place assembly robot with a gripper carried by a variable-length flexible beam. The resulting design tradeoffs between system accuracy and control efforts demonstrate the advantage of an integrated design approach for mechatronic systems with configuration-dependent dynamics.