基于APDL的自动武器复进簧参数化建模与优化设计

采用ANSYS参数化设计语言对某自动武器复进簧进行参数化建模和优化设计.前者先定义复进簧的设计变量,确定其结构参数.再确定其目标函数、状态变量.后者利用APDL参数技术和ANSYS命令创建参数分析文件,用于优化循环分析文件,再进入优化设计器OPT执行分析过程,最后检验优化设计序列.将ANSYS优化结果与Matlab优化结果相比较.结果表明该优化设计有效.     

多股复进簧设计分析一体化技术研究

为改进传统的多股复进簧设计流程,研究了多股复进簧设计分析一体化技术。通过对多股复进簧数学模型、参数化建模方法以及自动化仿真流程的深入研究,运用C#编程语言结合UG二次开发技术开发出多股复进簧结构参数设计与计算校核程序、参数化建模和仿真分析等基本功能模块,并对各功能模块进行集成,开发出多股复进簧设计分析一体化模板。该模板能够对不同型号的多股复进簧进行快速设计和分析,并通过具体实例对一体化技术的可行性进行了验证。结果表明,应用一体化技术能够使设计人员快速完成多股复进簧设计,可大大缩短产品研发周期,对提高其他产品的设计效率也具有一定的参考价值。     

应用ANSYS进行天线罩几何建模方法探索

为解决在天线罩强度分析过程中重复繁琐的几何建模工作，利用ANSYS／Mechanic结构分析软件提供的高级参数化编程语言，采用参数化方法创建通用的天线罩几何建模程序文件。该文件为命令形式的文本文件，尺寸小，便于携带、更改并可重复使用，可替代庞大的数据库文件，便于对天线罩强度设计进行优化分析。     

高速飞行器复合材料隔热层参数化设计

以航天飞行器的复合材料隔热层为研究对象,提出了基于遗传算法和有限元(FEA)参数化分析的优化设计方案.其中,以遗传算法为优化方式,基体材料层、隔热材料层、耐烧蚀陶瓷层的厚度为设计参数,隔热层的组合厚度及各层热应力为优化目标;优化过程中调用ANSYS软件对种群中个体进行有限元参数化分析,并将分析结果返回遗传算法程序中构造...     

基于VC和ANSYS的破片侵彻参数化有限元分析

基于ANSYS与VC实现不同类型破片侵彻参数化建模与有限元分析系统，利用VC封装ANSYS的二次开发工具APDL命令流，使分析参数化，并将APDL命令流文件自动读入ANSYS进行侵彻有限元分析。建立侵彻分析的有限元模型，替代ANSYS人机交互的GUI方式，避免重复性的建模和参数设定，提高建模的工作效率和有限元分析的可靠性。     

简控火箭弹的稳健性设计

介绍了一种新型的优化设计方法－稳健性设计，其基本思想是将设计过程分为系统设计，参数设计和容差设计三个阶段。以性能稳定，波动最小为目标，用特种正交表排列设计参数，用方差分析方法分析质量特性值，以确定系统的最优设计参数。本文以某简易控制火箭弹的角稳定系统参数优化为例，概略说明了这种稳健性优化设计计算的基本过程。     

基于改进粒子群优化算法的末修子母弹总体参数优化设计

将末修子母弹对跑道封锁能力的评价指标作为优化设计的目标函数,确定了需要优化的总体参数,并利用改进的粒子群优化算法建立了总体参数的优化模型.在优化设计中,通过对总体参数的离散化提高了优化计算的效率,分析了跑道长度对最优总体参数的影响,获得了针对不同长度的跑道均具有较强封锁能力的总体参数最优搭配.研究成果对于末修子母弹总体方案设计以及子弹外弹道设计具有重要的参考价值.     

基于有限元方法的液体火箭发动机机架优化设计

采用ANSYS有限元分析软件提供的优化方法对液体火箭发动机机架的优化问题进行了分析,提出了机架优化设计的一般流程,使用ANSYS的APDL语言编写了机架优化设计分析程序,通过对优化程序的研究,获得了某型号发动机机架的最优化结果,优化后的质量比初始设计质量大大的减轻.     

遗传算法在柴油机喷油系统参数优化设计中的应用研究

为了获得理想的燃油喷雾特性，需要对柴油机喷油系统参数进行优化设计，但由于所涉及的设计参数多、设计目标多，采用传统的优化设计方法，难以获得令人满意的结果。本文应用遗传算法，根据柴油机燃油喷雾特性的计算公式和6V150柴油机的具体情况，对其喷油系统的参数进行了优化设计；对基于遗传算法的参数优化过程进行了全面、简要的介绍。结果表明：遗传算法可适用于多设计变量、多设计目标的柴油机喷油系统参数优化设计。     

轨姿控舱体的优化设计研究

采用ANSYS有限元软件对轨姿控舱体进行了结构强度分析和优化设计．用十节点四面体单元对轨姿控舱体几何模型离散化；在最苛刻的加载方式下分析了舱体的结构强度；在最大应力约束下，以减少舱体的总质量为目标，对舱体的壁厚尺寸和安装脉冲发动机孔的直径尺寸等设计变量进行了优化，并对设计变量的敏感度进行了分析．计算结果表明，在最苛刻的加载方式下，轨姿控舱体的强度可以满足设计要求；壁厚尺寸是关键的优化设计变量．优化后舱体的总质量约减轻6‰，说明现有舱体的设计是紧凑合理的．理论分析与试验结果相吻合．     

Stability of the Third Generation Intensifier under Illumination

The stability under illumination of transmission-mode GaAs photocathode sealed in the third generation intensifier is investigated by use of spectral response testing instruments. The variations of spectral response with the illumination times under weak and intense illumination are compared. The variations of photoemission performance parameters are also characterized. The results show that during initial several weak illuminations photocathode behaves no evident decay and a maximum sensitivity is achieved, while under intense illumination the sensitivity of photocathode begin to decrease largely at the first illumination. The calculated performance parameters show that the variation of surface escape probability with illumination times is a direct cause of instability of photocathode. It is also found that under intense illumination peak wavelength is moved towards short-wave and peak response is decreased, which shows that the ability of long-wave response of photocathode is decreased.     

Passive Acoustic Radar for Detecting Supersonic Cruise Missile

A Passive Acoustic Radar is presented as a necessary complement to electromagnetic wave radar, which will be expected to be an effective means for detecting cruise missiles. Acoustic characteristics of supersonic flying projectiles with diverse shapes are expounded via experiment. It is pointed out that simulation experiment could be implemented using bullet or shell instead of cruise missile. Based on theoretical analysis and experiment, the ““acoustic fingerprint““ character of cruise missile is illustrated to identify it in a strong noise environment. After establishing a locating mathematical model, the technique of acoustic embattling is utilized to resolve a problem of confirming the time of early-warning, considering the fact that velocity of sound is much slower than that of light. Thereby, a whole system of passive acoustic radar for detecting supersonic cruise missile is formed.     

Super-resolution Restoration of Remote-sensing Images

A novel image restoration scheme, which is super-resolution image restoration algorithm Poisson-maximum-afterword-probability based on Markvo constraint （MPMAP） combined with evaluating image detail parameter D, has been proposed. The advantage of super-resolution algorithm MPMAP incorporated with parameter D lies in the fact that superresolution algorithm MPMAP model is discrete, which is in accordance with remote-sensing imaging model, and the algorithm MPMAP is proved applicable to linear and non-linear imaging models with a unique solution when noise is not severe. According to simulation experiments for practical images, super-resolution algorithm MPMAP can retain image details better than most of traditional restoration methods; at the same time, the proposed parameter D can help to identify real point spread function （PSF） value of degradation process. Processing result of practical remote-sensing images by MPMAP combined with parameter D are given, it illustrates that MPMAP restoration scheme combined PSF estimation has a better restoration result than that of Photoshop processing, based on the same original images. It is proved that the proposed scheme is helpful to offset the lack of resolution of the original remote-sensing images and has its extensive application foreground.     

Design and Simulation of TF and TA Controller for Missile

A nonlinear terrain following(TF) and terrain avoidance(TA) controller is proposed for missile control systems. Based on classical TF algorithm (adaptive angle method), a new method for TF controller is proposed by using angle of attack. A method of obtaining terrain outline data from digital elevation map (DEM) for TF control is discussed in order to save store space. A TA algorithm is proposed by using bank-to-turn technique. The block control model, which is suitable for backstepping design, is given for nonlinear model of missile. Making full use of the characteristics of the system and combining block control principle and backstepping technique, a robust controller design method is proposed. Uncertainties in every sub-block are allowed, and can be canceled by using the idea of nonlinear damping. It is proved that the state tracking errors are converged to a neighborhood of the origin exponentially. Finally, nonlinear six-degree-of-freedom simulation results for the missile model are presented to demonstrate the effectiveness of the proposed control law.     

Design and Analysis of Test Schemes of Static Postponing Time on Shrapnels Used to Riot Control

The test scheme of static postponing time given in our actual national military test standard on shrapnels used to control riot is a nine-point test scheme on the combined action of three kinds of temperatures and three kinds of pressures,the consumed ammunitions are more excessive. Statistic analysis and tentative checkout about a lot of test data are done,feasibility gists are put forward for optimizing of the test design scheme. The optimizing design and data analysis of test scheme of the item are done by managing uniformity design theory, two scientific and reasonable six-point test schemes are confirmed. The feasibility and reliability of the optimizing design schemes put forward above are proved ulteriorly by test validating. The gained schemes not only have good design uniformity and little ammunition wastage and meet the test demand, but also have better forecast ability for the result data of other points using the mathematic models from the actual test points.     

Design of Non-fragile Satisfactory Estimator for Linear Continuous Perturbed Stochastic Systems

The design problem of non-fragile estimator is addressed for a class of perturbed linear continuous systems. The perturbations occur on the plant and estimator parameters. The estimator designed should force the error system to achieve the desired decay rate and force the steady error variance less than the specified upper bound irrdevancy of the admissible plant perturbations and estimator perturbations. Consistency problem of the decay rate with the variance upper bound is first considered via linear matrix inequality （LMI） approach. The solution of the estimator parameter under specifications to be consistent is then discussed. The consistency condition of specifications and estimator parameter solution are transformed to feasible or minimum problems subject to a set of LMI respectively. The method is illustrated by a numerical example.     

An Improved Scene-based Nonuniformity Correction Algorithm for Infrared Focal Plane Arrays Using Neural Networks

The improved scene-based adaptive nonuniformity correction （NUC） algorithms using a neural network （NNT） approach for infrared image sequences are presented and analyzed. The retlna-like neural networks using steepest descent model was the first proposed infrared focal plane arrays （IRFPA） nonuniformity compensation method, which can perform parameter estimation of the sensors over time on a frame by frame basis. To increase the strength and the robustness of the NNT algorithm and to avoid the presence of ghosting artifacts, some optimization techniques, including momentum term, regularization factor and adaptive learning rate, were executed in the parameter learning process. In this paper, the local median filtering result of Xij （ n ） is proposed as an alternative value of desired network output of neuron Xij （ n ）, denoted as Tij （ n ）, which is the local spatial average of Xij （ n ） in traditional NNT methods. Noticeably, the NUC algorithm is inter-frame adaptive in nature and does not rely on any statistical assumptions on the scene data in the image sequence. Applications of this algorithm to the simulated video sequences and real infrared data taken with PV320 show that the correction results of image sequence are better than that of using original NNT approach, especially for the short-time image sequences （several hundred frames） subjected to the dense impulse noises with a number of dead or saturated pixels.     

Piecewise Filter of Infrared Image Based on Moment Theory

The disadvantages of IR images mostly include high noise, blurry edge and so on. The characteristics make the existent smoothing methods ineffective in preserving edge, To solve this problem, a piecewise moment filter （PMF） is put forward. By using moment and piecewise linear theory, the filter can preserve edge. Based on the statistical model of random noise, a related-coefficient method is presented to estimate the variance of noise. The edge region and model are then detected by the estimated variance. The expectation of first-order derivatives is used in getting the reliable offset of edge. At last, a fast moment filter of double-stair edge model is used to gain the piecewise smoothing results and reduce the calculation. The experimental result shows that the new method has a better capability than other methods in suppressing noise and preserving edge.     

Bistatic Sonar Localization Based on Best Linear Unbiased Estimation

A best linear unbiased estimation （BLUE） algorithm for bistatic sonar localization is proposed. The Cramer-Rao bound for bistatic Sonar and the geometrical dilution of precision （GDOP） in different conditions are given. The simulation results show that the location accuracy of BLUE algorithm is higher than the weighted least square method.     

Research on Gear-broken Fault Diagnosis in a Tank Gearbox

A fault diagnosis method of working position gear in a tank gearbox is put forward based on simulating the fault of working position gear in an actual tank, extracting the envelope of vibration signal by Hilbert transformation amplitude demodulation method, and zooming the low-frequency band to envelope signal.