某型飞机机载设备寿命控制方法

某型飞机的机载设备数量庞大以及寿命的不统一给维修保障工作带来了极大的不便。在研究航空机载设备的定延寿的途径和方法的基础上,分析寿命控制过程。实例显示能够简化维修保障工作,节约经费开支。     

《企业员工工作绩效问卷》的编制

绩效评估是测量和开发组织中个人的绩效的过程。它是一种重要的管理工具,与计划、组织、指挥和控制等四种主要管理职能有关,是组织决定奖惩、晋升、培训及解雇的重要依据,更是人事选拔效度研究中的效标,因而一直备受心理学家的关注。本文在文献分析与开放式问卷的基础上,编制了《企业员工工作绩效问卷》,通过对问卷探索性因素分析后,形成正式问卷。分析表明,该量表具有较好的信度和效度。     

滚控式变质心飞行器动力学特性分析与控制

为明确滚控式变质心飞行器的控制机理,为其工程实践提供相应的理论参考,建立包含滑块运动的滚控式变质心飞行器七自由度完整动力学模型,并分析讨论其运动特性以及动力学系统的特点。其次结合频域分析法对滑块运动与载体姿态运动之间的耦合影响以及动态响应过程进行分析研究,揭示了滚控式飞行器的控制机理。同时针对其通道间的耦合效应以及执行机构参数设置对控制能力的影响分析提出了对飞行器结构设计和控制系统设计的相关要求,为滚控式变质心飞行器的工程实践提供一些理论参考。     

大气层外多拦截器协同跟踪与制导算法

针对大气层外多弹头多诱饵的进攻场景,采用多拦截器全拦截策略,提出了带故障诊断的协同跟踪算法、时间协同中制导律以及消除脱靶量的末制导律。首先,基于最小二乘算法以及误差传播理论,实现了局部信息融合以及测量方程的线性化,简化了非线性跟踪滤波算法的设计;并依托滤波算法,设计了传感器故障诊断算法,以排除其对跟踪效果的影响。然后,基于对拦截器和目标受力的合理简化,给出了相对运动解析解,设计了有限推力下的多拦截器时间协同中制导律以及末制导律,实现对多个目标的同时击毁。仿真结果显示,本文设计的协同跟踪与制导算法,可以有效估计目标的状态并排除故障传感器的干扰,实施对多个目标的时间协同拦截。     

突片形状对气膜冷却效率的影响

气膜冷却广泛应用于航空发动机热端部件的热防护,为了提高气膜冷却效果,设计了3种突片型式,采用实验的方法对其冷却效果进行了对比研究,结果表明：突片的存在强化了气膜冷却效率,使得气膜冷却效率远高于无突片的气膜冷却效率。吹风比对不同突片作用有所不同,存在一最佳吹风比,但该值随着突片的型式变化。突片的堵塞比对气膜冷却效率有很大的影响,3种突片作用下的气膜冷却效率均随堵塞比的增加而增大。梯形突片的冷却效率明显优于三角形突片和椭圆突片。但突片亦增大了气膜孔的流动阻力,降低了流量系数。     

Proportional fuzzy feed-forward architecture control validation by wind tunnel tests of a morphing wing

In aircraft wing design, engineers aim to provide the best possible aerodynamic performance under cruise flight conditions in terms of lift-to-drag ratio. Conventional control sur-faces such as flaps, ailerons, variable wing sweep and spoilers are used to trim the aircraft for other flight conditions. The appearance of the morphing wing concept launched a new challenge in the area of overall wing and aircraft performance improvement during different flight segments by locally altering the flow over the aircraft's wings. This paper describes the development and appli-cation of a control system for an actuation mechanism integrated in a new morphing wing structure. The controlled actuation system includes four similar miniature electromechanical actuators dis-posed in two parallel actuation lines. The experimental model of the morphing wing is based on a full-scale portion of an aircraft wing, which is equipped with an aileron. The upper surface of the wing is a flexible one, being closed to the wing tip; the flexible skin is made of light composite materials. The four actuators are controlled in unison to change the flexible upper surface to improve the flow quality on the upper surface by delaying or advancing the transition point from laminar to turbulent regime. The actuators transform the torque into vertical forces. Their bases are fixed on the wing ribs and their top link arms are attached to supporting plates fixed onto the flex-ible skin with screws. The actuators push or pull the flexible skin using the necessary torque until the desired vertical displacement of each actuator is achieved. The four vertical displacements of the actuators, correlated with the new shape of the wing, are provided by a database obtained through a preliminary aerodynamic optimization for specific flight conditions. The control system is designed to control the positions of the actuators in real time in order to obtain and to maintain the desired shape of the wing for a specified flight condition. The feasibility and effectiveness of the developed control system by use of a proportional fuzzy feed-forward methodology are demon-strated experimentally through bench and wind tunnel tests of the morphing wing model.     

A high-order SPH method by introducing inverse kernels

The smoothed particle hydrodynamics (SPH) method is usually expected to be an effi-cient numerical tool for calculating the fluid-structure interactions in compressors; however, an endogenetic restriction is the problem of low-order consistency. A high-order SPH method by intro-ducing inverse kernels, which is quite easy to be implemented but efficient, is proposed for solving this restriction. The basic inverse method and the special treatment near boundary are introduced with also the discussion of the combination of the Least-Square (LS) and Moving-Least-Square (MLS) methods. Then detailed analysis in spectral space is presented for people to better under-stand this method. Finally we show three test examples to verify the method behavior.     

基于径向基神经网络的不确定非线性系统的鲁棒自适应控制

 针对能够采用仿射非线性表示的含有不确定动态的非线性系统 ,提出了一种鲁棒自适应控制方法 ,该方法根据离线辨识出的受控对象的已知部分 ,采用神经网络在线辨识其未知部分 ,并针对辨识得到神经网络模型采用反馈线性化方法设计出自适应控制器 ,同时引入滑模控制方法以增强控制系统的鲁棒性 ,从而实现鲁棒自适应控制。通过对具有未建模动态的非线性直升机空气动力学模型 ,设计了总距通道系统。仿真表明该方法是有效的。     

水悬浮法制备GF／PVC复合材料的界面形态和形成机理

应用扫描电镜、红外光谱、电子探针等方法研究了水悬浮法制备GF/PVC复合材料的界面形态和形成机理 ,研究结果表明 :由含有I,II,III ,V号悬浮液制备的复合材料 ,其纤维与机体的界面粘结和界面相互作用主要是纤维表面与这些高分子添加剂之间的物理作用 ,由Ⅳ号悬浮液制备的复合材料 ,其两相间的界面粘接很好 ,界面相互作用以化学相互作用为主。纤维经KH5 5 0或KH5 6 0及LCB或LCM复合涂层处理 ,材料纤维与基体间的界面相互作用主要归结为偶联剂的活性基团与聚合物涂层及PVC的化学作用     

电磁轴承及其应用第一部分 电磁轴承的发展及其应用前景

第一部分简述了电磁轴承及电传动技术在国内外的发展及其在航空领域中的应用前景.第二部分介绍了在燃气涡轮发动机中电磁轴承的设计要求、主要设计问题及其解决方法.