空空导弹控制系统一体化设计方法研究

综述了空空导弹控制系统非线性设计的主要理论和方法,重点介绍了非线性动态逆和反馈线性化方法及其在导弹控制系统设计中的应用,对大攻角空空导弹控制系统一体化设计方法进行了分析和展望。     

舰载光电跟踪的船摇扰动复合补偿控制

针对船摇扰动引起的机械谐振和视轴不稳定的问题,舰载条件下通过安装多个陀螺来实现船摇扰动的复合补偿,在原有等效闭环系统中串入高通滤波器,消除谐振环节带来的影响。从仿真结果看,复合补偿控制具有良好船摇隔离效果,有利于高精度跟踪系统的实现。     

紫外光语音通信系统参数补偿技术及Matlab仿真

利用线谱对参数建立了针对紫外光通信的语音参数补偿模型,采用基于LSF参数奇偶采样插值方法和丢失能量线性补偿法,对样本的丢包补偿前后相关系数和音质进行了对比.仿真结果表明,前后帧的中值补偿替代丢失帧的参数效果最好;该方法简单有效,对语音质量有较大改善.     

Theoretical and numerical investigations on the headspace of cartridge cases considering axial deformation and movement

The cartridge case headspace is the axial clearance between the cartridge and bolt of an automatic weapon, and influences the reliability and security of the weapon. Accordingly, theoretical and numerical studies were conducted to analyze the dynamic response of cartridge cases during internal impact considering the initial radial clearances between the cartridge case and chamber. A theoretical model was proposed to predict the cartridge case headspace considering both the deformation and movement of the cartridge case and confirmed by the results of nonlinear finite element simulations. The differences between the results of the conventional static model and the dynamic model were then comprehensively evaluated. The effects of the angle between the cartridge and chamber, the cartridge case material, and the internal impact pressure on the predicted headspace value were also analyzed. The dynamic response of the cartridge case predicted by the dynamic model was more accurate than that predicted by the conventional static model. The internal impact pressure, pressure change rate, and cartridge material were all found to affect the predicted headspace.     

A review of dual-spin projectile stability

This paper gives a succinct review of dual-spinprojectile stability and some technologies relating to them. It describes how the traditional stability factors from linear projectile theory are modified to better describe a controlled dual-spin projectile. Finally, it reviews works which have investigated how different aspects of a controlled dual-spin design can affect flight stability, primarily airframe structure and canard properties. A conclusion is given, highlighting important guidelines from the enclosed discussions.     

基于Lambert算法的脉冲精确变轨策略

Lambert问题的求解多以二体假设为基础,从而对精确轨道控制带来不利影响.提出了一种脉冲修正策略,建立了考虑摄动影响的航天器轨道动力学计算模型,在Iambert算法基础上,通过拟牛顿法对变轨脉冲进行修正,消除终端状态误差,从而获得精确的变轨脉冲.将该修正策略用于固定时间精确变轨问题,建立了两层规划模型,并通过算例验证了算法的有效性.     

基于神经网络的导弹系统辨识

详细地讨论了神经网络在导弹动态特性中的应用 ,利用神经网络的万能拟合能力进行了神经网络的训练和仿真 ,为导弹离散控制系统的设计提供了有效的工程数据 ,给导弹系统的系统辨识提供了一条新的方法和思路     

Physical and damping properties of kenaf fibre filled natural rubber/thermoplastic polyurethane composites

The paper presents the investigation of the effect of alkaline treatment of sodium hydroxide (NaOH) on physical and dynamic mechanical analysis (DMA) viscoelastic properties of kenaf fibre filled natural rubber (NR)/thermoplastic polyurethane (TPU) composites. The treated kenaf fiber, NR and TPU were weighed and proportioned according to the required compositions and were blended using hot mixed Brabender machine. The polymer composites were then fabricated using the hot press to form a sample board. The sample was cut and prepared and water absorption, density, thickness swelling and DMA tests were performed. As far as physical properties are concerned, composites with the highest NR amount of shows the best results, which indicates good fiber bonding adhesion. The polymer composites with the highest amount of TPU shows the highest damping properties at high temperature.     

一类流行病动力学模型的稳定性研究

本文建立了一类流行病动力学的S-I-D-S模型，讨论了该模型的无病平衡点的全局稳定性及有病平衡点的局部稳定性。     

基于调频傅里叶变换的高速目标ISAR距离像算法

在大时宽带宽线性调频(LFM)体制高分辨逆合成孔径(ISAR)雷达中,目标高速运动将引起严重的回波多普勒色散,如果不消除该影响则不能正确成像。针对该问题,设计了一种通过调频傅里叶变换对目标脉内运动参数进行估计,补偿回波脉内走动得到目标距离像的方法。该方法首先估计脉内运动参数,初步补偿脉内走动,然后估计运动轨迹进一步精确补偿脉内走动,补偿脉内走动后通过包络对齐消除脉间走动,得到目标距离像。算法的主要过程在脉冲重复周期内进行,可以满足实时成像和参数估计的需求。